TOPS-20
                               Monitor Calls
                              Reference Manual
|  
|  
|                        Electronically Distributed
|  
|  
|  
|            This manual describes all the monitor  calls  that
|            exist  in  the TOPS-20 operating system.  For easy
|            reference,  the  monitor  call  descriptions   are
|            arranged  alphabetically  and presented concisely.
|            This manual supercedes the TOPS-20  Monitor  Calls
|            Reference  Manual  published  in  June, 1988.  The
|            part  number  for  that  manual,  AA-FV52B-TM,  is
|            obsolete.

             Change bars in the margins indicate material  that
             has  been  added  or  changed  since  the previous
             printing of this manual.



             Operating System:              TOPS-20 Version 7.0










   digital equipment corporation                   maynard, massachusetts

| TOPS-20 Software Update Tape No. 04, November 1990 First Printing, September 1985 Revised, June 1988 | Revised, November 1990 The information in this document is subject to change without notice and should not be construed as a commitment by Digital Equipment Corporation. Digital Equipment Corporation assumes no responsibility for any errors that may appear in this document. The software described in this document is furnished under a license and may only be used or copied in accordance with the terms of such license. No responsibility is assumed for the use or reliability of software on equipment that is not supplied by Digital Equipment Corporation or its affiliated companies. | | | | Copyright C 1985, 1988, 1990 Digital Equipment Corporation. All Rights Reserved. The following are trademarks of Digital Equipment Corporation: CI DECtape LA50 SITGO-10 DDCMP DECUS LN01 TOPS-10 DEC DECwriter LN03 TOPS-20 DECmail DELNI MASSBUS TOPS-20AN DECnet DELUA PDP UNIBUS DECnet-VAX HSC PDP-11/24 UETP DECserver HSC-50 PrintServer VAX DECserver 100 KA10 PrintServer 40 VAX/VMS DECserver 200 KI Q-bus VT50 DECsystem-10 KL10 ReGIS DECSYSTEM-20 KS10 RSX d i g i t a l
CONTENTS PREFACE 1 REFERENCES . . . . . . . . . . . . . . . . . . . . iv 2 OBSOLETE JSYSS . . . . . . . . . . . . . . . . . . iv 3 CONVENTIONS USED IN THIS MANUAL . . . . . . . . . . v 3.1 Number Bases . . . . . . . . . . . . . . . . . . . v 3.2 Abbreviations . . . . . . . . . . . . . . . . . . v 3.3 Symbols . . . . . . . . . . . . . . . . . . . . vi 3.4 Unimplemented Features . . . . . . . . . . . . . vi CHAPTER 1 INTRODUCTION 1.1 CALLING CONVENTIONS . . . . . . . . . . . . . . . 1-2 1.2 MONITOR CALL ARGUMENTS . . . . . . . . . . . . . . 1-2 1.2.1 Addresses . . . . . . . . . . . . . . . . . . . 1-3 1.2.2 Page Numbers . . . . . . . . . . . . . . . . . . 1-4 1.2.3 Section Numbers . . . . . . . . . . . . . . . . 1-4 1.2.4 Byte Pointers . . . . . . . . . . . . . . . . . 1-4 1.2.5 File Handles and File Designators . . . . . . . 1-6 1.2.6 Source/Destination Designators . . . . . . . . . 1-6 1.2.6.1 File Designator . . . . . . . . . . . . . . . 1-8 1.2.6.2 Byte Pointers and ASCII Strings . . . . . . . 1-8 1.2.6.3 Special Designators . . . . . . . . . . . . . 1-9 1.2.6.4 Numeric Designators . . . . . . . . . . . . . 1-9 1.2.7 Device Designator . . . . . . . . . . . . . . 1-10 1.2.7.1 Restrictions for Extended Addressing . . . . 1-10 1.2.8 Process Handles . . . . . . . . . . . . . . . 1-10 1.2.8.1 Process/File Handle . . . . . . . . . . . . 1-11 1.3 SYSTEM DATE AND TIME . . . . . . . . . . . . . . 1-11 1.4 PROCESSING ERRORS . . . . . . . . . . . . . . . 1-12 CHAPTER 2 FUNCTIONAL ORGANIZATION OF MONITOR CALLS 2.1 ACCOUNTING FUNCTIONS . . . . . . . . . . . . . . . 2-1 2.2 REFERENCING FILES . . . . . . . . . . . . . . . . 2-1 2.2.1 File Specifications . . . . . . . . . . . . . . 2-1 2.2.2 Logical Names . . . . . . . . . . . . . . . . . 2-3 2.2.3 File Handles . . . . . . . . . . . . . . . . . . 2-3 2.2.4 File References . . . . . . . . . . . . . . . . 2-5 2.2.4.1 Files and Devices . . . . . . . . . . . . . . 2-6 2.2.5 Sample Program . . . . . . . . . . . . . . . . . 2-6 2.2.6 File Access . . . . . . . . . . . . . . . . . . 2-9 2.2.7 Directory Access . . . . . . . . . . . . . . . 2-10 2.2.8 File Descriptor Block . . . . . . . . . . . . 2-11 2.2.9 Primary Input and Output Files . . . . . . . . 2-22 2.2.10 Methods of Data Transfer . . . . . . . . . . . 2-22 2.2.11 File Byte Count . . . . . . . . . . . . . . . 2-22
2.2.12 EOF Limit . . . . . . . . . . . . . . . . . . 2-23 2.2.13 Input/Output Errors . . . . . . . . . . . . . 2-23 2.2.13.1 Testing for End-of-File . . . . . . . . . . 2-24 2.3 OBTAINING INFORMATION . . . . . . . . . . . . . 2-26 2.3.1 Error Mnemonics and Message Strings . . . . . 2-26 2.3.2 System Tables . . . . . . . . . . . . . . . . 2-27 2.4 COMMUNICATING WITH DEVICES . . . . . . . . . . . 2-34 2.4.1 Physical Card Reader (PCDR:) . . . . . . . . . 2-36 2.4.2 Spooled Card Reader (CDR:) . . . . . . . . . . 2-37 2.4.3 Physical Card Punch (PCDP:) . . . . . . . . . 2-37 2.4.4 Spooled Card Punch (CDP:) . . . . . . . . . . 2-38 2.4.5 Physical Line Printer (PLPT:) . . . . . . . . 2-38 2.4.5.1 PLPT: Status Bits . . . . . . . . . . . . . 2-40 2.4.6 Spooled Line Printer (LPT:) . . . . . . . . . 2-41 2.4.7 Physical Magnetic Tape (MTA:) . . . . . . . . 2-42 2.4.7.1 Buffered I/O . . . . . . . . . . . . . . . . 2-42 2.4.7.2 Unbuffered I/O . . . . . . . . . . . . . . . 2-44 2.4.7.3 Magnetic Tape Status . . . . . . . . . . . . 2-44 2.4.7.4 Reading a Tape in the Reverse Direction . . 2-45 2.4.7.5 Hardware Data Modes . . . . . . . . . . . . 2-45 2.4.8 Logical Magnetic Tape (MT:) . . . . . . . . . 2-48 2.4.9 Terminal (TTY:) . . . . . . . . . . . . . . . 2-48 2.4.9.1 JFN Mode Word . . . . . . . . . . . . . . . 2-49 2.4.9.2 Control Character Output Control . . . . . . 2-52 2.4.9.3 Character Set . . . . . . . . . . . . . . . 2-52 2.4.9.4 Terminal Characteristics Control . . . . . . 2-55 2.4.9.5 Terminal Linking . . . . . . . . . . . . . . 2-58 2.4.9.6 Terminal Advising . . . . . . . . . . . . . 2-58 2.4.10 Transmission Control Protocol (TCP:) . . . . . 2-58 2.4.10.1 GTJFN JSYS . . . . . . . . . . . . . . . . . 2-58 2.4.10.2 OPENF JSYS . . . . . . . . . . . . . . . . . 2-59 2.4.10.3 Other JSYSs . . . . . . . . . . . . . . . . 2-60 2.5 SOFTWARE DATA MODES . . . . . . . . . . . . . . 2-61 2.6 SOFTWARE INTERRUPT SYSTEM . . . . . . . . . . . 2-64 2.6.1 Software Interrupt Channels . . . . . . . . . 2-64 2.6.2 Software Interrupt Priority Levels . . . . . . 2-66 2.6.3 Software Interrupt Tables . . . . . . . . . . 2-66 2.6.4 Terminating Conditions . . . . . . . . . . . . 2-67 2.6.5 Panic Channels . . . . . . . . . . . . . . . . 2-67 2.6.6 Terminal Interrupts . . . . . . . . . . . . . 2-67 2.6.6.1 Terminal Interrupt Modes . . . . . . . . . . 2-70 2.6.7 Dismissing an Interrupt . . . . . . . . . . . 2-70 2.7 PROCESS CAPABILITIES . . . . . . . . . . . . . . 2-72 2.7.1 Assigned Capabilities . . . . . . . . . . . . 2-72 2.7.2 Access Control . . . . . . . . . . . . . . . . 2-74 2.7.3 Processes and Scheduling . . . . . . . . . . . 2-76 2.7.3.1 Process Freezing . . . . . . . . . . . . . . 2-76 2.7.3.2 Execute-Only Files and Execute-Only Processes 2-78 2.8 SAVE FILES . . . . . . . . . . . . . . . . . . . 2-80 2.8.1 Format for Nonsharable Save Files . . . . . . 2-80 2.8.2 Format of Sharable Save Files . . . . . . . . 2-81 2.8.3 Entry Vector . . . . . . . . . . . . . . . . . 2-84
2.8.4 Program Data Vector . . . . . . . . . . . . . 2-85 2.9 INPUT/OUTPUT CONVERSION . . . . . . . . . . . . 2-86 2.9.1 Floating Output Format Control . . . . . . . . 2-86 2.9.1.1 Free Format . . . . . . . . . . . . . . . . 2-86 2.9.1.2 General Format Control . . . . . . . . . . . 2-87 2.9.2 Date And Time Conversion Monitor Calls . . . . 2-89 2.10 ARCHIVE/VIRTUAL DISK SYSTEM . . . . . . . . . . 2-92 2.11 PRIVILEGED MONITOR CALLS . . . . . . . . . . . . 2-94 CHAPTER 3 TOPS-20 MONITOR CALLS 3.1 ACCES JSYS 552 . . . . . . . . . . . . . . . . 3-1 3.2 ADBRK JSYS 570 . . . . . . . . . . . . . . . . 3-3 3.3 AIC JSYS 131 . . . . . . . . . . . . . . . . . 3-7 3.4 ALLOC JSYS 520 . . . . . . . . . . . . . . . . 3-8 3.5 ARCF JSYS 247 . . . . . . . . . . . . . . . . . 3-9 3.6 ASND JSYS 70 . . . . . . . . . . . . . . . . 3-13 3.7 ASNIQ% JSYS 756 . . . . . . . . . . . . . . . 3-13 3.8 ASNSQ JSYS 752 . . . . . . . . . . . . . . . 3-14 3.9 ATACH JSYS 116 . . . . . . . . . . . . . . . 3-15 3.10 ATI JSYS 137 . . . . . . . . . . . . . . . . 3-17 3.11 ATNVT JSYS 274 . . . . . . . . . . . . . . . 3-17 3.12 BIN JSYS 50 . . . . . . . . . . . . . . . . . 3-18 3.13 BKJFN JSYS 42 . . . . . . . . . . . . . . . . 3-19 3.14 BOOT JSYS 562 . . . . . . . . . . . . . . . . 3-19 3.15 BOUT JSYS 51 . . . . . . . . . . . . . . . . 3-25 3.16 CACCT JSYS 4 . . . . . . . . . . . . . . . . 3-25 3.17 CFIBF JSYS 100 . . . . . . . . . . . . . . . 3-26 3.18 CFOBF JSYS 101 . . . . . . . . . . . . . . . 3-27 3.19 CFORK JSYS 152 . . . . . . . . . . . . . . . 3-27 3.20 CHFDB JSYS 64 . . . . . . . . . . . . . . . . 3-29 3.21 CHKAC JSYS 521 . . . . . . . . . . . . . . . 3-30 3.22 CIS JSYS 141 . . . . . . . . . . . . . . . . 3-31 3.23 CLOSF JSYS 22 . . . . . . . . . . . . . . . . 3-31 3.24 CLZFF JSYS 34 . . . . . . . . . . . . . . . . 3-33 3.25 CNFIG% JSYS 627 . . . . . . . . . . . . . . . 3-34 3.26 COMND JSYS 544 . . . . . . . . . . . . . . . 3-37 3.27 CRDIR JSYS 240 . . . . . . . . . . . . . . . 3-61 3.28 CRJOB JSYS 2 . . . . . . . . . . . . . . . . 3-68 3.29 CRLNM JSYS 502 . . . . . . . . . . . . . . . 3-75 3.30 DEBRK JSYS 136 . . . . . . . . . . . . . . . 3-76 3.31 DELDF JSYS 67 . . . . . . . . . . . . . . . . 3-76 3.32 DELF JSYS 26 . . . . . . . . . . . . . . . . 3-78 3.33 DELNF JSYS 317 . . . . . . . . . . . . . . . 3-79 3.34 DEQ JSYS 514 . . . . . . . . . . . . . . . . 3-80 3.35 DEVST JSYS 121 . . . . . . . . . . . . . . . 3-82 3.36 DFIN JSYS 234 . . . . . . . . . . . . . . . . 3-82 3.37 DFOUT JSYS 235 . . . . . . . . . . . . . . . 3-83 3.38 DIAG JSYS 530 . . . . . . . . . . . . . . . . 3-84 3.39 DIBE JSYS 212 . . . . . . . . . . . . . . . . 3-91 3.40 DIC JSYS 133 . . . . . . . . . . . . . . . . 3-92
3.41 DIR JSYS 130 . . . . . . . . . . . . . . . . 3-92 3.42 DIRST JSYS 41 . . . . . . . . . . . . . . . . 3-93 3.43 DISMS JSYS 167 . . . . . . . . . . . . . . . 3-94 3.44 DOB% JSYS 635 . . . . . . . . . . . . . . . . 3-94 3.45 DOBE JSYS 104 . . . . . . . . . . . . . . . . 3-97 3.46 DSKAS JSYS 244 . . . . . . . . . . . . . . . 3-97 3.47 DSKOP JSYS 242 . . . . . . . . . . . . . . . 3-98 3.48 DTACH JSYS 115 . . . . . . . . . . . . . . . 3-101 3.49 DTI JSYS 140 . . . . . . . . . . . . . . . . 3-101 3.50 DUMPI JSYS 65 . . . . . . . . . . . . . . . . 3-102 3.51 DUMPO JSYS 66 . . . . . . . . . . . . . . . . 3-103 3.52 DVCHR JSYS 117 . . . . . . . . . . . . . . . 3-105 3.53 EIR JSYS 126 . . . . . . . . . . . . . . . . 3-106 3.54 ENQ JSYS 513 . . . . . . . . . . . . . . . . 3-106 3.55 ENQC JSYS 515 . . . . . . . . . . . . . . . . 3-113 3.56 EPCAP JSYS 151 . . . . . . . . . . . . . . . 3-117 3.57 ERSTR JSYS 11 . . . . . . . . . . . . . . . . 3-118 3.58 ESOUT JSYS 313 . . . . . . . . . . . . . . . 3-118 3.59 FFFFP JSYS 31 . . . . . . . . . . . . . . . . 3-119 3.60 FFORK JSYS 154 . . . . . . . . . . . . . . . 3-119 3.61 FFUFP JSYS 211 . . . . . . . . . . . . . . . 3-120 3.62 FLIN JSYS 232 . . . . . . . . . . . . . . . . 3-120 3.63 FLOUT JSYS 233 . . . . . . . . . . . . . . . 3-121 3.64 GACCT JSYS 546 . . . . . . . . . . . . . . . 3-122 3.65 GACTF JSYS 37 . . . . . . . . . . . . . . . . 3-122 3.66 GCVEC JSYS 300 . . . . . . . . . . . . . . . 3-123 3.67 GDSKC JSYS 214 . . . . . . . . . . . . . . . 3-123 3.68 GDSTS JSYS 145 . . . . . . . . . . . . . . . 3-124 3.69 GDVEC JSYS 542 . . . . . . . . . . . . . . . 3-125 3.70 GET JSYS 200 . . . . . . . . . . . . . . . . 3-125 3.71 GETAB JSYS 10 . . . . . . . . . . . . . . . . 3-128 3.72 GETER JSYS 12 . . . . . . . . . . . . . . . . 3-129 3.73 GETJI JSYS 507 . . . . . . . . . . . . . . . 3-129 3.74 GETNM JSYS 177 . . . . . . . . . . . . . . . 3-131 3.75 GETOK% JSYS 574 . . . . . . . . . . . . . . . 3-132 3.76 GEVEC JSYS 205 . . . . . . . . . . . . . . . 3-142 3.77 GFRKH JSYS 164 . . . . . . . . . . . . . . . 3-142 3.78 GFRKS JSYS 166 . . . . . . . . . . . . . . . 3-143 3.79 GFUST JSYS 550 . . . . . . . . . . . . . . . 3-145 3.80 GIVOK% JSYS 576 . . . . . . . . . . . . . . . 3-146 3.81 GJINF JSYS 13 . . . . . . . . . . . . . . . . 3-146 3.82 GNJFN JSYS 17 . . . . . . . . . . . . . . . . 3-147 3.83 GPJFN JSYS 206 . . . . . . . . . . . . . . . 3-148 3.84 GTAD JSYS 227 . . . . . . . . . . . . . . . . 3-148 3.85 GTDAL JSYS 305 . . . . . . . . . . . . . . . 3-149 3.86 GTDIR JSYS 241 . . . . . . . . . . . . . . . 3-149 3.87 GTFDB JSYS 63 . . . . . . . . . . . . . . . . 3-151 3.88 GTHST% JSYS 273 . . . . . . . . . . . . . . . 3-151 3.89 GTJFN JSYS 20 (SHORT FORM) . . . . . . . . . 3-159 3.90 GTJFN JSYS 20 (LONG FORM) . . . . . . . . . 3-167 3.91 GTRPI JSYS 172 . . . . . . . . . . . . . . . 3-175 3.92 GTRPW JSYS 171 . . . . . . . . . . . . . . . 3-176
3.93 GTSTS JSYS 24 . . . . . . . . . . . . . . . . 3-177 3.94 GTTYP JSYS 303 . . . . . . . . . . . . . . . 3-178 3.95 HALTF JSYS 170 . . . . . . . . . . . . . . . 3-178 3.96 HFORK JSYS 162 . . . . . . . . . . . . . . . 3-179 3.97 HPTIM JSYS 501 . . . . . . . . . . . . . . . 3-179 3.98 HSYS JSYS 307 . . . . . . . . . . . . . . . . 3-180 3.99 IDCNV JSYS 223 . . . . . . . . . . . . . . . 3-181 3.100 IDTIM JSYS 221 . . . . . . . . . . . . . . . 3-182 3.101 IDTNC JSYS 231 . . . . . . . . . . . . . . . 3-184 3.102 IIC JSYS 132 . . . . . . . . . . . . . . . . 3-186 3.103 INFO% JSYS 633 . . . . . . . . . . . . . . . 3-186 3.104 INLNM JSYS 503 . . . . . . . . . . . . . . . 3-195 3.105 IPOPR% JSYS 760 . . . . . . . . . . . . . . . 3-196 3.106 JFNS JSYS 30 . . . . . . . . . . . . . . . . 3-197 3.107 KFORK JSYS 153 . . . . . . . . . . . . . . . 3-200 3.108 LATOP% JSYS 631 . . . . . . . . . . . . . . . 3-200 3.109 LGOUT JSYS 3 . . . . . . . . . . . . . . . . 3-215 3.110 LLMOP% JSYS 624 . . . . . . . . . . . . . . . 3-216 3.111 LNMST JSYS 504 . . . . . . . . . . . . . . . 3-224 3.112 LOGIN JSYS 1 . . . . . . . . . . . . . . . . 3-225 3.113 LPINI JSYS 547 . . . . . . . . . . . . . . . 3-226 3.114 MDDT% JSYS 777 . . . . . . . . . . . . . . . 3-227 3.115 METER% JSYS 766 . . . . . . . . . . . . . . . 3-227 3.116 MRECV JSYS 511 . . . . . . . . . . . . . . . 3-229 3.117 MSEND JSYS 510 . . . . . . . . . . . . . . . 3-231 3.118 MSFRK JSYS 312 . . . . . . . . . . . . . . . 3-235 3.119 MSTR JSYS 555 . . . . . . . . . . . . . . . . 3-236 3.120 MTALN JSYS 774 . . . . . . . . . . . . . . . 3-257 3.121 MTOPR JSYS 77 . . . . . . . . . . . . . . . . 3-257 3.122 MTU% JSYS 600 . . . . . . . . . . . . . . . . 3-293 3.123 MUTIL JSYS 512 . . . . . . . . . . . . . . . 3-295 3.124 NI% JSYS 630 . . . . . . . . . . . . . . . . 3-302 3.125 NIN JSYS 225 . . . . . . . . . . . . . . . . 3-320 3.126 NODE JSYS 567 . . . . . . . . . . . . . . . . 3-321 3.127 NOUT JSYS 224 . . . . . . . . . . . . . . . . 3-329 3.128 NTINF% JSYS 632 . . . . . . . . . . . . . . . 3-330 3.129 NTMAN% JSYS 604 . . . . . . . . . . . . . . . 3-332 3.130 ODCNV JSYS 222 . . . . . . . . . . . . . . . 3-334 3.131 ODTIM JSYS 220 . . . . . . . . . . . . . . . 3-336 3.132 ODTNC JSYS 230 . . . . . . . . . . . . . . . 3-338 3.133 OPENF JSYS 21 . . . . . . . . . . . . . . . . 3-339 3.134 PBIN JSYS 73 . . . . . . . . . . . . . . . . 3-344 3.135 PBOUT JSYS 74 . . . . . . . . . . . . . . . . 3-345 3.136 PDVOP% JSYS 603 . . . . . . . . . . . . . . . 3-345 3.137 PEEK JSYS 311 . . . . . . . . . . . . . . . . 3-348 3.138 PLOCK JSYS 561 . . . . . . . . . . . . . . . 3-349 3.139 PMAP JSYS 56 . . . . . . . . . . . . . . . . 3-350 3.140 PMCTL JSYS 560 . . . . . . . . . . . . . . . 3-355 3.141 PPNST JSYS 557 . . . . . . . . . . . . . . . 3-358 3.142 PRARG JSYS 545 . . . . . . . . . . . . . . . 3-359 3.143 PSOUT JSYS 76 . . . . . . . . . . . . . . . . 3-361 3.144 QUEUE% JSYS 615 . . . . . . . . . . . . . . . 3-361
3.145 RCDIR JSYS 553 . . . . . . . . . . . . . . . 3-368 3.146 RCM JSYS 134 . . . . . . . . . . . . . . . . 3-372 3.147 RCUSR JSYS 554 . . . . . . . . . . . . . . . 3-372 3.148 RCVIM JSYS 751 . . . . . . . . . . . . . . . 3-374 3.149 RCVIN% JSYS 755 . . . . . . . . . . . . . . . 3-375 3.150 RCVOK% JSYS 575 . . . . . . . . . . . . . . . 3-376 3.151 RDTTY JSYS 523 . . . . . . . . . . . . . . . 3-377 3.152 RELD JSYS 71 . . . . . . . . . . . . . . . . 3-380 3.153 RELIQ% JSYS 757 . . . . . . . . . . . . . . . 3-380 3.154 RELSQ JSYS 753 . . . . . . . . . . . . . . . 3-381 3.155 RESET JSYS 147 . . . . . . . . . . . . . . . 3-381 3.156 RFACS JSYS 161 . . . . . . . . . . . . . . . 3-382 3.157 RFBSZ JSYS 45 . . . . . . . . . . . . . . . . 3-383 3.158 RFCOC JSYS 112 . . . . . . . . . . . . . . . 3-383 3.159 RFMOD JSYS 107 . . . . . . . . . . . . . . . 3-384 3.160 RFORK JSYS 155 . . . . . . . . . . . . . . . 3-385 3.161 RFPOS JSYS 111 . . . . . . . . . . . . . . . 3-385 3.162 RFPTR JSYS 43 . . . . . . . . . . . . . . . . 3-386 3.163 RFRKH JSYS 165 . . . . . . . . . . . . . . . 3-386 3.164 RFSTS JSYS 156 . . . . . . . . . . . . . . . 3-387 3.165 RFTAD JSYS 533 . . . . . . . . . . . . . . . 3-390 3.166 RIN JSYS 54 . . . . . . . . . . . . . . . . . 3-391 3.167 RIR JSYS 144 . . . . . . . . . . . . . . . . 3-392 3.168 RIRCM JSYS 143 . . . . . . . . . . . . . . . 3-393 3.169 RLJFN JSYS 23 . . . . . . . . . . . . . . . . 3-393 3.170 RMAP JSYS 61 . . . . . . . . . . . . . . . . 3-394 3.171 RNAMF JSYS 35 . . . . . . . . . . . . . . . . 3-394 3.172 ROUT JSYS 55 . . . . . . . . . . . . . . . . 3-396 3.173 RPACS JSYS 57 . . . . . . . . . . . . . . . . 3-397 3.174 RPCAP JSYS 150 . . . . . . . . . . . . . . . 3-398 3.175 RSCAN JSYS 500 . . . . . . . . . . . . . . . 3-398 3.176 RSMAP% JSYS 610 . . . . . . . . . . . . . . . 3-400 3.177 RTFRK JSYS 322 . . . . . . . . . . . . . . . 3-401 3.178 RTIW JSYS 173 . . . . . . . . . . . . . . . . 3-402 3.179 RUNTM JSYS 15 . . . . . . . . . . . . . . . . 3-402 3.180 RWM JSYS 135 . . . . . . . . . . . . . . . . 3-403 3.181 RWSET JSYS 176 . . . . . . . . . . . . . . . 3-404 3.182 SACTF JSYS 62 . . . . . . . . . . . . . . . . 3-404 3.183 SAVE JSYS 202 . . . . . . . . . . . . . . . . 3-405 3.184 SCS% JSYS 622 . . . . . . . . . . . . . . . . 3-406 3.185 SCTTY JSYS 324 . . . . . . . . . . . . . . . 3-423 3.186 SCVEC JSYS 301 . . . . . . . . . . . . . . . 3-424 3.187 SDSTS JSYS 146 . . . . . . . . . . . . . . . 3-426 3.188 SDVEC JSYS 543 . . . . . . . . . . . . . . . 3-426 3.189 SETER JSYS 336 . . . . . . . . . . . . . . . 3-427 3.190 SETJB JSYS 541 . . . . . . . . . . . . . . . 3-428 3.191 SETNM JSYS 210 . . . . . . . . . . . . . . . 3-431 3.192 SETSN JSYS 506 . . . . . . . . . . . . . . . 3-431 3.193 SEVEC JSYS 204 . . . . . . . . . . . . . . . 3-431 3.194 SFACS JSYS 160 . . . . . . . . . . . . . . . 3-432 3.195 SFBSZ JSYS 46 . . . . . . . . . . . . . . . . 3-433 3.196 SFCOC JSYS 113 . . . . . . . . . . . . . . . 3-433
3.197 SFMOD JSYS 110 . . . . . . . . . . . . . . . 3-434 3.198 SFORK JSYS 157 . . . . . . . . . . . . . . . 3-435 3.199 SFPOS JSYS 526 . . . . . . . . . . . . . . . 3-436 3.200 SFPTR JSYS 27 . . . . . . . . . . . . . . . . 3-436 3.201 SFRKV JSYS 201 . . . . . . . . . . . . . . . 3-438 3.202 SFTAD JSYS 534 . . . . . . . . . . . . . . . 3-439 3.203 SFUST JSYS 551 . . . . . . . . . . . . . . . 3-441 3.204 SIBE JSYS 102 . . . . . . . . . . . . . . . . 3-442 3.205 SIN JSYS 52 . . . . . . . . . . . . . . . . . 3-443 3.206 SINR JSYS 531 . . . . . . . . . . . . . . . . 3-444 3.207 SIR JSYS 125 . . . . . . . . . . . . . . . . 3-446 3.208 SIRCM JSYS 142 . . . . . . . . . . . . . . . 3-447 3.209 SIZEF JSYS 36 . . . . . . . . . . . . . . . . 3-447 3.210 SJPRI JSYS 245 . . . . . . . . . . . . . . . 3-448 3.211 SKED% JSYS 577 . . . . . . . . . . . . . . . 3-449 3.212 SKPIR JSYS 127 . . . . . . . . . . . . . . . 3-455 3.213 SMAP% JSYS 767 . . . . . . . . . . . . . . . 3-455 3.214 SMON JSYS 6 . . . . . . . . . . . . . . . . . 3-459 3.215 SNDIM JSYS 750 . . . . . . . . . . . . . . . 3-464 3.216 SNDIN% JSYS 754 . . . . . . . . . . . . . . . 3-465 3.217 SNOOP JSYS 516 . . . . . . . . . . . . . . . 3-466 3.218 SOBE JSYS 103 . . . . . . . . . . . . . . . . 3-469 3.219 SOBF JSYS 175 . . . . . . . . . . . . . . . . 3-470 3.220 SOUT JSYS 53 . . . . . . . . . . . . . . . . 3-470 3.221 SOUTR JSYS 532 . . . . . . . . . . . . . . . 3-472 3.222 SPACS JSYS 60 . . . . . . . . . . . . . . . . 3-473 3.223 SPJFN JSYS 207 . . . . . . . . . . . . . . . 3-474 3.224 SPLFK JSYS 314 . . . . . . . . . . . . . . . 3-475 3.225 SPOOL JSYS 517 . . . . . . . . . . . . . . . 3-477 3.226 SPRIW JSYS 243 . . . . . . . . . . . . . . . 3-479 3.227 SSAVE JSYS 203 . . . . . . . . . . . . . . . 3-480 3.228 STAD JSYS 226 . . . . . . . . . . . . . . . . 3-482 3.229 STCMP JSYS 540 . . . . . . . . . . . . . . . 3-482 3.230 STDEV JSYS 120 . . . . . . . . . . . . . . . 3-483 3.231 STI JSYS 114 . . . . . . . . . . . . . . . . 3-484 3.232 STIW JSYS 174 . . . . . . . . . . . . . . . . 3-485 3.233 STO JSYS 246 . . . . . . . . . . . . . . . . 3-486 3.234 STPAR JSYS 217 . . . . . . . . . . . . . . . 3-487 3.235 STPPN JSYS 556 . . . . . . . . . . . . . . . 3-488 3.236 STSTS JSYS 25 . . . . . . . . . . . . . . . . 3-489 3.237 STTYP JSYS 302 . . . . . . . . . . . . . . . 3-490 3.238 SWJFN JSYS 47 . . . . . . . . . . . . . . . . 3-490 3.239 SWTRP% JSYS 573 . . . . . . . . . . . . . . . 3-491 3.240 SYERR JSYS 527 . . . . . . . . . . . . . . . 3-492 3.241 SYSGT JSYS 16 . . . . . . . . . . . . . . . . 3-493 3.242 TBADD JSYS 536 . . . . . . . . . . . . . . . 3-493 3.243 TBDEL JSYS 535 . . . . . . . . . . . . . . . 3-494 3.244 TBLUK JSYS 537 . . . . . . . . . . . . . . . 3-495 3.245 TCOPR% JSYS 761 . . . . . . . . . . . . . . . 3-497 3.246 TEXTI JSYS 524 . . . . . . . . . . . . . . . 3-499 3.247 TFORK JSYS 321 . . . . . . . . . . . . . . . 3-504 3.248 THIBR JSYS 770 . . . . . . . . . . . . . . . 3-507
3.249 TIME JSYS 14 . . . . . . . . . . . . . . . . 3-507 3.250 TIMER JSYS 522 . . . . . . . . . . . . . . . 3-507 3.251 TLINK JSYS 216 . . . . . . . . . . . . . . . 3-509 3.252 TMON JSYS 7 . . . . . . . . . . . . . . . . . 3-511 3.253 TTMSG JSYS 775 . . . . . . . . . . . . . . . 3-514 3.254 TWAKE JSYS 771 . . . . . . . . . . . . . . . 3-515 3.255 UFPGS JSYS 525 . . . . . . . . . . . . . . . 3-516 3.256 USAGE JSYS 564 . . . . . . . . . . . . . . . 3-516 3.257 USRIO JSYS 310 . . . . . . . . . . . . . . . 3-520 3.258 UTEST JSYS 563 . . . . . . . . . . . . . . . 3-520 3.259 UTFRK JSYS 323 . . . . . . . . . . . . . . . 3-521 3.260 VACCT JSYS 566 . . . . . . . . . . . . . . . 3-523 3.261 WAIT JSYS 306 . . . . . . . . . . . . . . . . 3-523 3.262 WFORK JSYS 163 . . . . . . . . . . . . . . . 3-524 3.263 WILD% JSYS 565 . . . . . . . . . . . . . . . 3-524 3.264 WSMGR% JSYS 623 . . . . . . . . . . . . . . . 3-526 3.265 XGSEV% JSYS 614 . . . . . . . . . . . . . . . 3-527 3.266 XGTPW% JSYS 612 . . . . . . . . . . . . . . . 3-528 3.267 XGVEC% JSYS 606 . . . . . . . . . . . . . . . 3-529 3.268 XPEEK% JSYS 626 . . . . . . . . . . . . . . . 3-529 3.269 XRIR% JSYS 601 . . . . . . . . . . . . . . . 3-531 3.270 XRMAP% JSYS 611 . . . . . . . . . . . . . . . 3-531 3.271 XSFRK% JSYS 605 . . . . . . . . . . . . . . . 3-533 3.272 XSIR% JSYS 602 . . . . . . . . . . . . . . . 3-533 3.273 XSSEV% JSYS 613 . . . . . . . . . . . . . . . 3-534 3.274 XSVEC% JSYS 607 . . . . . . . . . . . . . . . 3-535 APPENDIX A ASCII, SIXBIT, AND EBCDIC COLLATING SEQUENCES AND CONVERSIONS APPENDIX B TOPS-20 ERROR CODES AND MNEMONICS INDEX TABLES 1-1 P-Field Values for One-word Global Byte Pointers . 1-5 1-2 Source/Destination Designators . . . . . . . . . . 1-7 2-1 File Descriptor Block (FDB) . . . . . . . . . . 2-12 2-2 System Tables . . . . . . . . . . . . . . . . . 2-27 2-3 Device Types . . . . . . . . . . . . . . . . . . 2-35 2-4 PCDR: Status Bits . . . . . . . . . . . . . . . 2-36 2-5 PCDP: Status Bits . . . . . . . . . . . . . . . 2-37 2-6 PLPT: Control Characters . . . . . . . . . . . . 2-39 2-7 PLPT: Status Bits . . . . . . . . . . . . . . . 2-40 2-8 MTA: Status Bits . . . . . . . . . . . . . . . . 2-42 2-9 JFN Mode Word . . . . . . . . . . . . . . . . . 2-49 2-10 Wakeup Classes/CCOC Word Bits . . . . . . . . . 2-53
2-11 Terminal Characteristics . . . . . . . . . . . . 2-55 2-12 Software Interrupt Channels . . . . . . . . . . 2-65 2-13 Terminal Interrupt Codes . . . . . . . . . . . . 2-68 2-14 Process/Job Capabilities . . . . . . . . . . . . 2-72 2-15 Floating-Point Format Control . . . . . . . . . 2-87 2-16 Time Zones . . . . . . . . . . . . . . . . . . . 2-91 A-1 ASCII and SIXBIT Collating Sequence and Conversion to EBCDIC . . . . . . . . . . . . . . . . . . . . A-1 A-2 EBCDIC Collating Sequence and Conversion to ASCII A-4

PREFACE This manual is written for the assembly language programmer who is already familiar with TOPS-20 monitor calls. For an introductory discussion of some basic monitor calls, refer to the TOPS-20 Monitor Calls User's Guide. Chapter 1 introduces the conventions to follow when using monitor calls, and describes the types of arguments used with the monitor calls. Chapter 2 presents the calls related to particular functions and tasks, such as using the software interrupt system. Chapter 3 contains, in alphabetical order, descriptions of all the monitor calls. Appendix A contains the EBCDIC, ASCII, and SIXBIT collating sequences, and conversions between these three character set representations. Appendix B contains a numeric list of error codes with their corresponding mnemonic, and an alphabetic list of mnemonics with their corresponding code and text string. iii
1 REFERENCES The following publications are either referenced in this manual or are recommended as supplements to this manual: Referenced as Title Monitor Calls User's Guide TOPS-20 Monitor Calls User's Guide System Administrator TOPS-20 System Manager's Guide TCP/IP Handbook Internet Protocol Transition Workbook Available from: Network Information Center SRI International Menlo Park, California 94025 DECnet Manual DECnet-20 User's Guide Assembler Manual MACRO Assembler Reference Manual Link Manual TOPS-20 LINK Reference Manual Hardware Reference Manual DECsystem-10/DECSYSTEM-20 Processor Reference Manual Commands Reference Manual TOPS-20 Commands Reference Manual RMS Manual TOPS-20 RMS User's Guide SPEAR Manual TOPS-10/TOPS-20 SPEAR Manual TOPS-20 User's Guide TOPS-20 User's Guide Installation Guide TOPS-20 KL Model B Installation Guide Network Management Spec Network Management Architecture Specification 2 OBSOLETE JSYSS The following JSYSs are obsolete as of version V6.1 of TOPS-20: CVHST CVSKT iv
FLHST GTNCP 3 CONVENTIONS USED IN THIS MANUAL 3.1 Number Bases Except where otherwise noted, numbers used in this manual, including those in the definition of a monitor call description, are octal. When indicated, bits in words are numbered in decimal with the leftmost bit of the word labeled B0 and the rightmost bit of the word labeled B35. 3.2 Abbreviations The following abbreviations are used in this manual: B0, B1, ... Bit 0, bit 1, ... of the computer word nBm Field whose rightmost bit is m and whose value is n (5B2, for example). LH Left Half (B0-B17 of the word) RH Right Half (B18-B35 of the word) JFN Job File Number PSB Process Storage Block (a table containing all monitor data for the process) JSB Job Storage Block (a table containing all monitor data relevant to the job) CCOC words Control Character Output Control words (2 words containing 36 2-bit bytes that determine the way in which control characters are output. Refer to Section 2.4.9.2.) FDB File Descriptor Block (a table in a file that contains information about the file). Refer to Section 2.2.8. TCP/IP Transmission Control Protocol/Internet Protocol v
3.3 Symbols The symbols used in this manual, including the names of the monitor calls, are defined in the system file MONSYM.MAC. A program that uses a monitor call or other symbol must include the statement SEARCH MONSYM before the first occurrence of a symbol. Failure to include this statement causes errors in the compilation of the program. The system file MACSYM.MAC contains a number of useful macros for the assembly language programmer. To use MACSYM macros, the user's program must contain the statements SEARCH MACSYM .REQUIRE SYS:MACREL ;include support routines at the beginning of the program. Since most bits defined for use with the monitor have symbolic names, macros enable the programmer to use these bits without knowledge of their exact position. Refer to the Monitor Calls User's Guide for more information on MACSYM macros. 3.4 Unimplemented Features The MONSYM file contains symbol names for several monitor calls and bit positions that are not described in this manual. These features are not implemented in TOPS-20. If an unimplemented monitor call is used in a user program, it causes an illegal instruction interrupt unless followed by an ERJMP or ERCAL symbol. In this case, the ERJMP will be executed. It is recommended that unimplemented or undefined bit positions be zero to allow for future expansion. 6
CHAPTER 1 INTRODUCTION The TOPS-20 Monitor Calls Reference Manual describes every monitor call in the TOPS-20 system. Monitor calls for TCP/IP systems and DECnet systems are also described. TOPS-20 monitor calls invoke the TOPS-20 monitor by means of the JSYS instruction (op code 104). The UUO-type monitor calls (op codes 40-77) invoke the TOPS-10 compatibility package, which simulates the action of these UUO's in the TOPS-10 monitor. Programs written for TOPS-20 should use TOPS-20 monitor calls, not UUO's. For easy reference, monitor call descriptions in Chapter 3 are arranged alphabetically and presented concisely. This concise format begins with the monitor call name and numeric definition, followed by a brief description of the monitor call function. The calling sequence for the monitor call is next, indicated by statements in the format ACCEPTS IN ACn: description where n is an accumulator number. Following the list of accumulators and descriptions of their contents are statements of the form RETURNS +1: condition +2: condition These statements define where control returns, and under what conditions, after execution of the monitor call. The statement RETURNS+1: means that control returns to the memory location immediately following the calling location. The statement RETURNS+2: means that control returns to the second memory location after the calling location. Next, there is an optional description of the action taken by the monitor call. 1-1
INTRODUCTION 1.1 CALLING CONVENTIONS Arguments for the monitor call are placed in accumulators (ACs), then the monitor call is executed. The first argument is in AC1, the second in AC2, and so forth. Many calls also require an argument block. This is a group of contiguous words of memory that contain additional arguments. If an argument block is required, an AC must contain a pointer to the argument block. See the description of the GTJFN% monitor call for an example of the use of argument blocks. In addition, arguments in an argument block can point to other argument blocks. These other argument blocks can, in turn, contain other groups of arguments. For an example of this way of passing many arguments to a monitor call, see the description of the GTJFN call in Chapter 3. (There are several exceptions to this convention; refer to the individual descriptions in Chapter 3.) Data returned by the execution of a monitor call is often returned in the ACs. If a call returns more data than can be held in four ACs, it returns the data to a data block. A pointer to the data block must be passed as an argument to the monitor call. Such a pointer can be passed in either an AC or an argument block. When using a monitor call in a program, end the name of the call with a percent (%) character. This convention helps avoid conflicts between monitor call names and symbols defined by your programs. In addition, this convention is required by monitor calls defined in TOPS-20 Version 4.0 or later. Although older calls do not require a percent character at the end of their names, they will accept one. 1.2 MONITOR CALL ARGUMENTS A monitor call argument can be one of the following: o a word of data o the memory address word that contains data o a page number o a section number o a byte pointer o a file handle o a source (or destination) designator that defines where to obtain (or send) data 1-2
INTRODUCTION o a process handle o a file/process handle The following sections describe these arguments. 1.2.1 Addresses On a DECSYSTEM-20, addresses can be one of two types: an 18-bit address, or a 30-bit address. TOPS-20 supports 30-bit addressing, but currently allows access to an address space of 32 (decimal) sections, each of which contains 256K words. Therefore, although a global address is said to be a 30-bit address, only the rightmost 23 bits are meaningful: five bits of section number and 18 bits of in-section address. An 18-bit address is called a local (section-relative) address. With such an address you can specify any word in a 256K-word section of memory, but you cannot also specify a section number. With a 30-bit, or global, address you can reference any word of any section of memory. (Refer to the Hardware Reference Manual for a description of global addresses.) TOPS-20 allows you to use 18-bit or 30-bit addresses. Some monitor calls require one kind, some the other; some calls accept either kind. Some monitor calls use only 18 bits to hold an address. These calls interpret 18-bit addresses as locations in the current section, the same section as that of the code being executed (the same section as the user PC.) To form an unambiguous global address, these calls add the section number of the PC to the section-relative address. Monitor calls that use an entire word for an address can accept either 18-bit or 30-bit addresses. If the address is 30 bits (the section number is not 0), it is a global address. If the address is 18 bits (the section number is 0), the monitor call acts in one of two ways. If the call existed in Release 4 or earlier, it interprets the address as a section-relative address, as stated above. But if the call is one of the extended-addressing calls (if the call starts with an X), the call interprets the zero in the section-number field as indicating section 0. It is sometimes desireable to specify addresses in section 0 when executing a JSYS from a nonzero section. The bit PM%EPN for PMAP%, and FH%EPN for JSYSs that accept fork handles, prevent the current section (the section in which the program is running) from being the target section for the monitor call's arguments. 1-3
INTRODUCTION 1.2.2 Page Numbers A TOPS-20 page number can be 9 bits or 18 bits long. A page number can refer to either a page of memory, or a page of a disk file. The 9-bit number is called a section-relative page number. Such a page number can specify any page within a 256K-word section of memory, or any page within a 256K section of a file. (A file section is a unit of 512 pages within a file. The first page of each such section has a page number that is an integer multiple of 512.) The left half of a section-relative (18-bit) address can be considered to be a section-relative page number. If a monitor call uses only 9 bits of a word to hold a page number, the monitor considers that page to be within the current section. Most monitor calls that require page numbers as arguments use at least half of a word to contain the page number. Such calls allow you to specify an 18-bit, or global, page number. A global page number refers to both a section of memory and a page within that section. Page 23200, for example, is page 200 in section 23. 1.2.3 Section Numbers A section number is five bits long. In a global address, a section number occupies bits 13 through 17. Because TOPS-20 supports 40 (octal) sections of memory, using section numbers larger than 37 causes an error. 1.2.4 Byte Pointers Monitor calls accept two kinds of byte pointers as arguments: one-word local byte pointers, and one-word global byte pointers. One-word local byte pointers work in all sections, but one-word global byte pointers cannot be used in section 0. The Hardware Reference Manual describes one-word local byte pointers in detail. The following paragraphs discuss one-word global byte pointers. Any monitor calls that accept source/destination designators (See Section 1.2.6.) also accept byte pointers, and the bytes can be from 1 to 36 bits long. SIN and SOUT are examples of such monitor calls. If a call cannot accept a source/destination designator, however, that call only accepts byte pointers that point to 7-bit bytes. Examples of such calls are CACCT and PSOUT. Note, however, that for historical reasons some monitor calls accept one-word global byte pointers that point to bytes of other lengths. 1-4
INTRODUCTION TOPS-20 monitor calls do not accept the two-word local byte pointers or the two-word global byte pointers described in the Hardware Reference Manual. Local byte pointers can only point to a byte in the current section. This is because they use 18 bits to hold the address of the byte. You can use indexing with local byte pointers, however, to point to a byte in another section of memory. If, for example, AC5 contains a 30-bit address, the following instruction generates an indexed local byte pointer in AC2. The pointer points to a byte in another section, the section of the address in AC5. MOVE 2,[POINT 7,0(5)] Use of indirect addressing with local byte pointers is discouraged. Global byte pointers use 30 bits to hold the address of the byte, thus they can point to a byte in any section of memory. One-word global byte pointers have the following format: ------------------------------------------------ | P | address | ------------------------------------------------ Table 1-1 shows how the KL-10 processor interprets the P field. Table 1-1: P-Field Values for One-word Global Byte Pointers ______________________________________________________________________ P (octal) Byte Size Position of the Right-Most Bit (count, in octal, of the number of bits to the right of the current pointer position) ______________________________________________________________________ Less than 45 a local byte pointer. 45 6 44 46 6 36 47 6 30 50 6 22 51 6 14 52 6 6 53 6 0 54 8 44 1-5
INTRODUCTION 55 8 34 56 8 24 57 8 14 60 8 4 61 7 44 62 7 35 63 7 26 64 7 17 65 7 10 66 7 1 67 9 44 70 9 33 71 9 22 72 9 11 73 9 0 74 18 44 75 18 22 76 18 0 77 unused (causes an illegal instruction trap) ______________________________________________________________________ You cannot use indexing or indirect addressing with one-word global byte pointers. 1.2.5 File Handles and File Designators A file handle is also known as a job file number, or JFN. It is an 18-bit number that, within the context of a job, uniquely identifies a file. An indexable file handle, or full-word JFN, has a JFN in the right half and flags in the left half. This file handle is useful for handling several files in sequence. See Section 2.2.3 for a more complete discussion of file handles. 1.2.6 Source/Destination Designators Some monitor calls act upon bytes or strings of bytes, or transfer bytes from one place to another. Such calls often use source/destination designators to identify where the bytes are sent or obtained. A source/destination designator is a 36-bit quantity that can have the 1-6
INTRODUCTION formats given in Table 1-2. The paragraphs following the table describe each designator. Note that byte pointers are also source/destination designators. Table 1-2: Source/Destination Designators ______________________________________________________________________ Symbol Left Half Right Half Meaning ______________________________________________________________________ (none) 0 JFN a job file number. The JFN is the job's handle on a file, and is assigned with the GTJFN monitor call. (Refer to Section 2.2.3.) .PRIIN 0 100 primary input designator .PRIOU 0 101 primary output designator .NULIO 0 377777 null designator .TTDES 0 4xxxxx universal terminal designator .SIGIO 0 677777 signal JFN. When a fork's I/O designator is .SIGIO, then any attempt to perform I/O to that JFN will freeze the fork and cause a channel 19 (fork termination) interrupt to be sent to that fork's superior. .CTTRM 0 777777 the job's controlling terminal .DVDES 6xxxxx xxxxxx universal device designator (for use only in section 0) 777777 address implicit byte pointer. TOPS-20 changes left half to 440700. (Refer to Sections 1.2.4 and 1.2.6.2.) .b.i-35 777777 777777 universal default 5xxxxx xxxxxx numeric value Note: The designators .PRIIN and .PRIOU are legal wherever a JFN is expected. You cannot assign them as JFN's, however. GTJFN and GNJFN never assign 100 or 101. ______________________________________________________________________ 1-7
INTRODUCTION The most commonly used source/destination designators are: 1. A JFN, identifying a particular file. Before a JFN can be used, it must be obtained by means of the GTJFN monitor call. (See Section 2.2.3.) 2. The primary input and output designators. (Refer to Section 2.2.9.) These designators are the ones recommended for use in referring to the job's controlling terminal because they can be changed to cause terminal input and/or output to be taken from and/or sent to a file. The controlling terminal designator .CTTRM (0,-1) cannot be redirected in this way, and its use is not recommended in normal situations. 3. A byte pointer to the beginning of the string being read or written. 1.2.6.1 File Designator - A file designator indicates that I/O to be done by the monitor call is to be done as though to a terminal. A file designator can be any of the following: .PRIIN, .PRIOU, .NULIO, .TTDES, .CTTRM, or .DVDES. 1.2.6.2 Byte Pointers and ASCII Strings - Many monitor calls deal specifically with ASCII strings. The following conventions apply to such strings. 1. A file designator can be used if the file is in 7-bit ASCII format. This is the usual format for text files. 2. One of the following is used to designate a string in the caller's address space: a. -1,,ADR to designate a 7-bit ASCII string beginning in the leftmost byte of ADR. This is for convenience, making HRROI 1,ADR functionally equivalent to MOVE 1,[POINT 7,ADR]. b. A byte pointer with a byte size of 7 bits. If the byte size is not 7 bits, the results might be incorrect. This is because monitor calls use the ILDB and IDPB instructions to reference byte strings, and do no additional checking to see that the data is in the correct format. Note, however, that for historical reasons some monitor calls accept byte pointers with byte sizes larger or smaller than 7 bits. 1-8
INTRODUCTION NOTE Unless otherwise noted, the term "byte pointer" is used in this manual to indicate an ILDB/IDPB byte pointer that points to an ASCIZ string. The following example generates such a byte pointer: POINT 7,[ASCIZ/character string/] The term "pointer" is usually used to refer to an address, except in discussions that must make repeated references to the term "byte pointer". In the latter case, some of the occurrences of "byte pointer" will be shortened to "pointer" to avoid monotonous repetition. In these cases, however, it will be clear from the context that "pointer" implies "byte pointer". Normally, monitor calls assume that ASCII strings are terminated with a byte containing zeroes (an ASCIZ string). A few calls terminate on other ASCII characters because of context (the NIN call, for example), and some optionally accept an explicit byte count or allow you to determine the terminating byte. These latter calls (SIN and SOUT calls, for example) are generally those that can handle non-ASCII strings and byte sizes other than 7 bits. After a monitor call is used to read a string, the source byte pointer argument is updated such that an ILDB would read the character following the terminating character; an LDB would reread the terminating character. After a monitor call is used to write a string, the destination byte pointer argument is updated to point to the character following the last nonnull character written. If there is room, a null byte is appended to the string, but the byte pointer returned is such that an IDPB will overwrite the null. 1.2.6.3 Special Designators - The universal default designator of -1 is used to indicate the current designator, such as the current job or the connected directory. For example, the GETJI monitor call accepts an argument of -1 as the designator for the current job. 1.2.6.4 Numeric Designators - The designator 5xxxxx xxxxxx (where a numeric value is in bits 3-35) is used to supply a numeric designator as an argument to a call. Numeric designators are used to identify account numbers, directory numbers, user numbers, and the like. The DIRST monitor call, for example, accepts a user number as 5B2+33-bit number. 1-9
INTRODUCTION 1.2.7 Device Designator Many monitor calls dealing with devices (refer to Section 2.4) take a device designator as an argument. A device designator can be either LH: .DVDES(600000)+device type number RH: unit number for devices that have units, arbitrary code for structures, or -1 for nonstructure devices that do not have units or LH: 0 RH: .TTDES(400000)+ terminal number, or .CTTRM(777777) for controlling terminal Thus, terminals can be represented in two ways; the second way is provided for compatibility with the source/destination designator. Because designators for structures contain an arbitrary code, these designators must always be obtained from the monitor (by means of the STDEV call) and cannot be created by the program. Section 2.4 describes the various devices and their type numbers. 1.2.7.1 Restrictions for Extended Addressing - A restriction on arguments passed to monitor calls executed in sections other than section 0 concerns universal device designators and numeric designators, which have the format 5xxxxx,,xxxxxx or 6xxxxx,,xxxxxx (.DVDES). These designators are only legal in section 0. This is because of the existence of one-word global byte pointers, which can have the same format. Thus, monitor calls that accept either this type of designator or a byte pointer when called from section 0 do not accept these designators in any other section. Other device designators, such as .TTDES (0,,4xxxxx), can be used in any section. Conversely, these monitor calls that can accept either device/numberic designators or byte pointers do not accept one-word global byte pointers in section 0. 1.2.8 Process Handles Several monitor calls accept an 18-bit argument called a process handle. The following fork handles are defined within the context of a job. 1-10
INTRODUCTION Value Symbol Meaning 400000 .FHSLF Current process 400000+n - Process n, relative to the current process 200000 FH%EPN Extended page number. When used in conjunction with the above two forms, this bit indicates that addresses and/or page numbers are interpreted as absolute, NOT relative to the PC section of the program executing the JSYS. This bit has no meaning for programs that do not use extended addressing. -1 .FHSUP Superior process -2 .FHTOP Top-level process -3 .FHSAI Current process and all of its inferiors -4 .FHINF All of the current process's inferiors -5 .FHJOB All processes in the job Use of the superior process argument (.FHSUP) is legal only if the process has the superior process access capability (SC%SUP) enabled in its capability word. Meaningful operations may usually be performed with the top level process argument (.FHTOP) only if the process has WHEEL or OPERATOR capability enabled (SC%WHL or SC%OPR) in its capability word. Refer to Section 2.7.1 for information on the capability word. Process handles in the range 400001 to 400777 are called relative process handles, and are generated by the monitor to refer to specific processes. (See the CFORK monitor call description.) These handles are valid only within the context of the process to which they are given. Thus, they may not be passed between processes. GFRKH may be used to convert process handles for use by another process. 1.2.8.1 Process/File Handle - Some monitor calls accept an 18-bit argument called a process/file handle. This handle is either a process handle (as defined in Section 1.2.8), or a JFN. Note that string pointers and terminal identifiers cannot be used in this context. This is not a limitation, however, because the operations that use the process/file handle are used for changing page maps. Such operations are not meaningful for string pointers or terminals. 1.3 SYSTEM DATE AND TIME The internal system date and time is a 36-bit quantity. It can be passed to a monitor call as an argument, or returned as a value. The internal date-and-time word has the following format: day,,n 1-11
INTRODUCTION where day is the number of days since November 17, 1858, and *n is the fractional part of the day elapsed since midnight, Greenwich Mean Time. n is the numerator of a fraction that has a denominator of 2**18. Thus the fraction *n/2**18 represents the portion of the day elapsed since midnight. This format conforms to the Smithsonian Astronomical Date Standard. Because the time is stored as Greenwich Mean Time, the monitor adds the value of the TIMEZONE offset to the internal date and time to obtain your local time. The TIMEZONE offset is specified in <SYSTEM>CONFIG.CMD. (See the Installation Guide for more information on the TIMEZONE offset.) Monitor calls convert local dates and times to internal dates and times, and internal dates and times to local dates and times. Refer to Section 2.9.2 for more information about date and time conversion. 1.4 PROCESSING ERRORS TOPS-20 provides a consistent way to handle all JSYS errors. Upon a successful return of most monitor calls, the instruction following the call is executed. If an error occurs during the execution of the call, the monitor examines the instruction following the call. If the instruction is a JUMP instruction with the AC field specified as 12-17, the monitor transfers control to a user-specified address. If the instruction is not a JUMP instruction, the monitor generates an illegal instruction trap indicating an illegal instruction, which the user's program can process via the software interrupt system (refer to Chapter 4 of the Monitor Calls User's Guide). If the user's program is not prepared to process the instruction trap, the program execution halts, and a message is output stating the reason for failure. To place a JUMP instruction in his program, the user can include a statement using one of six predefined symbols. These symbols are: ERJMPR address (= JUMP 12,address) ERCALR address (= JUMP 13,address) ERJMPS address (= JUMP 14,address) ERCALS address (= JUMP 15,address) ERJMP address (= JUMP 16,address) ERCAL address (= JUMP 17,address) and cause the assembler to generate a JUMP instruction. The JUMP instruction is a non-operation instruction (that is, a no-op) as far as the hardware is concerned. However, the monitor executes the JUMP instruction by transferring control to the address specified, which is normally the beginning of an error processing routine written by the 1-12
INTRODUCTION user. If the user includes the ERJMP symbol, control is transferred as though a JUMPA instruction had been executed, and control does not return to his program after the error routine is finished. If the user includes the ERCAL symbol, control is transferred as though a PUSHJ 17, address instruction had been executed. If the error routine executes a POPJ 17, instruction, control returns to the user's program at the location following the ERCAL. If the user includes the ERJMPR symbol, the monitor behaves the same as it would if the ERJMP symbol had been included, except that the last error encountered by the process is stored in the user's AC1. (Refer to Appendix B for the list of error codes, mnemonics, and message strings.) The ERCALR symbol functions the same as ERCAL except the error code encountered is returned in the user's AC1. ERJMPS and ERCALS function similarly except the monitor suppresses the storing of the error code in the user's AC1. Instead, AC1 is preserved and contains either the original contents from when the monitor call was given, or a partially updated value prior to the error. Prior to the implementation of the ERJMP/ERCAL facilities, certain monitor calls returned control to the user's program at various locations after the calling address. Approximately one third of the JSYSs return to the +1 address only on failure, and to the location immediately following that (the +2 address) on successful execution of the call. A few calls return +1, +2, or +3, dependent on varying conditions of success or failure (for examples, see ERSTR% or GACTF%); and some calls do not return at all (see HALTF% or WAIT%). Refer to Chapter 3 the possible returns for each monitor call. When a failure occurs during the execution of a monitor call, the monitor stores an error code. The error code indicates the cause of the failure. This error code is usually stored in the right half of AC1, but can also be stored in the monitor's data base or a user's data block. In either case, you can obtain the message associated with the error by using the GETER% or ERSTR% call. The ERJMP/ERCAL facilities can also be used following a machine instruction, and will trap for the following conditions: o Illegal instruction o Illegal memory read o Illegal memory write o Pushdown list overflow The ERJMP/ERCAL facilities can be used after all monitor calls, regardless of whether the call has one or two returns. To handle errors consistently, users are encouraged to employ either the ERJMPR, ERCALR, ERJMPS, or ERCALS symbol with all calls. All of the six predefined jump symbols are no-ops, unless they immediately follow a 1-13
INTRODUCTION monitor call or instruction that fails. Error codes can be obtained by the program and translated into their corresponding error mnemonic and message strings with the GETER% and ERSTR% monitor calls. TOPS-20 provides convenient macros and subroutines for handling monitor call error routines. They can be found in the system file MACSYM.MAC. Two such macros are EJSERR and EJSHLT. EJSERR prints out an error message and returns control to the next instruction following the failing monitor call. EJSHLT prints out an error message and halts processing of the program. 1-14
CHAPTER 2 FUNCTIONAL ORGANIZATION OF MONITOR CALLS 2.1 ACCOUNTING FUNCTIONS The monitor calls in this group initiate and delete jobs from the system. They also change and read accounting information about these jobs. The following monitor calls perform accounting functions. Calls marked with an asterisk ("*") require privileges for specific functions. GACCT* Reads a file's account GACTF Reads a file's account LOGIN Logs a job into the system SACTF Sets a file's account USAGE Writes entries into the system's accounting data file VACCT Validates an account 2.2 REFERENCING FILES All files in the system, including the system's file directory, are normally referenced with the calls in this group. Section 2.11 describes the privileged calls for referencing the disk directly, without using the TOPS-20 file system. 2.2.1 File Specifications A file in TOPS-20 is identified by its node name, device name, directory name, filename, file type, and generation number. These five items uniquely identify any file on the system that is accessible to a user. The device name identifies the device on which the file is stored. The directory name identifies the directory containing the file. The filename, type, and generation number identify a particular file in the directory. 2-1
FUNCTIONAL ORGANIZATION OF MONITOR CALLS A file can also have attributes associated with it to further specify information about the file. See the description of the long-form GTJFN JSYS for a list of the possible file attributes. The general format of a file specification is: node::dev:<directory>name.typ.gen;attribute-1;attribute-2... Refer to the TOPS-20 User's Guide for the complete description of file specifications. If a field of the file specification (or filespec) is omitted, it can be supplied by the program or from standard system values. (Refer to Section 2.2.3.) Whenever an ESC is encountered in the file specification string, the system looks for a file whose specification matches the fields input thus far. A match is indicated if the input string either exactly matches an entry in the appropriate table, or is an initial substring of exactly one entry. In the latter case, the portion of the matching entry not appearing in the input string is output to a specified output file. The field terminator is output also. Recognition is done on successive fields with the fields being defaulted if need be. If the file specification cannot be uniquely determined, the system recognizes as many entire fields as are unique, and outputs a bell to the terminal, signifying that more input is required from the user. CTRL/F behaves like ESC except recognition stops after the current field. This allows the filename to be recognized, for example, but not the file type. If recognition is not used, then each field must be included as indicated in the general format above. The input must exactly match some existing file specification unless the program specifies in the GTJFN call that new specifications are allowed (output files). Without ESC or CTRL/F, no recognition is done. The system substitutes the default values supplied by your program for fields completely omitted from the file specification. The file specification is complete whenever all fields have been recognized or a terminator has been input. File specification terminators are described in the GTJFN call description. The following editing characters are recognized during the input of file specifications: DELETE erases one character. If no more characters remain in the input, a bell is output. CTRL/W deletes back to the last punctuation character. If no more characters remain in the input, a bell is output. 2-2
FUNCTIONAL ORGANIZATION OF MONITOR CALLS CTRL/U aborts the entire filename-gathering operation. CTRL/R retypes the entire input as specified so far and awaits further input. 2.2.2 Logical Names Logical names are user-specified default values for one or more fields in a file specification. Through the use of logical names, the user can override standard file specification fields built into TOPS-20 programs because logical name fields take precedence over default fields set by a program. However, the user can still specify any fields explicitly since a logical name defines values to be used only if none are given by the user. The user defines logical names with the DEFINE command or the CRLNM monitor call. Refer to the TOPS-20 User's Guide for the complete description of logical names. 2.2.3 File Handles It is necessary to have file handles that can be contained in a few bits and do not require extensive lookup procedures for each reference. The file specification is the fundamental handle on a file, but this specification fits neither criterion above. Therefore in TOPS-20, files are referenced by handles called JFNs (Job File Numbers). The JFN is a small number and is valid within the context of the job (that is, within any process of the job to which it is assigned). However, the handle is not valid between jobs. That is, JFN 2 in job 11 will generally be a handle on a completely different file than JFN 2 in job 18. A JFN is associated with a file with either the GTJFN or GNJFN monitor call. The GTJFN call accepts a file specification and returns a JFN for the indicated file. If a field of the specification is omitted, it may be supplied by the program defaults or from standard system values. If the file specification refers to a group of files (because of wildcard characters, see below), the GNJFN call can be used to associate the JFN to the next file in the group. A logical name can apply to one or more fields of the file specification passed to the GTJFN call. The logical name must be the first identifier passed to GTJFN and must be terminated with a colon. The GTJFN call uses a certain search order when obtaining a field in a file specification. This order is as follows: 2-3
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 1. Use the field explicitly typed by the user or the one specified in the primary input string. 2. Use the value for the field that is specified in the logical name specification. 3. Use the value for the field that is specified in the default block by the program. This is only for the long form of the GTJFN call. 4. Use the system default value if all of the above searches fail. In the special case of a device field specification, where the device name has been obtained from either the program default or the system default, the device field is checked to see if it is actually a logical name. If it is, then the values specified in its definition become defaults for all fields, including the device field. If the specific call to GTJFN permits, wildcard characters (either an asterisk or a percent sign) can appear in the device, directory, filename, type, or generation number fields. (The percent sign cannot appear in the generation number field.) An asterisk matches any occurrence of the field, including a null field. An asterisk as part of a field matches 0 or more characters anywhere in the field. A percent sign matches any single existing character in the field. Upon completion of the operation, the JFN returned references the first file found when scanning in the following order: In order by structure name (PS: is first, arbitrary order for others) In alphabetic order by directory name In alphabetic order by filename In alphabetic order by file type In ascending numeric order by generation number Note that for structures, only the construct DSK*: can be used. This means all available structures on the system. The GNJFN call can then be given to associate the JFN to the next file that matches the file specification. The fullword JFN (flags,,JFN) is termed an "indexable file handle" because it accepts a generic file specification (one including wildcard characters) and can be successively associated (by GNJFN) with each file matching the specification. Thus the JFN is "indexed" through a range of files. The number and type of files in the range are limited by the file specification, the privileges of the program, and the protection of individual files and directories within the file system. A program with WHEEL capabilities enabled can access any file in the TOPS-20 file system. 2-4
FUNCTIONAL ORGANIZATION OF MONITOR CALLS The maximum number of JFN's allowed depends upon the space reserved for JFN-related information in the Job Storage Block (JSB). Currently the maximum number of JFN's allowed is 140 (octal). The JFN's 100 (.PRIIN) and 101 (.PRIOU) are reserved for the primary input and output designators, respectively, and are never returned by the GTJFN (or GNJFN) call. The JFN 377777 (.NULIO) is reserved for the null designator. Ordinarily, the process of getting a file handle with GTJFN consists of the following: 1. The user specifies the file name string. 2. GTJFN checks the file name string for grammatical correctness. 3. GTJFN checks the file for validity (For example, does the file actually exist?) 4. If the file name passes these two checks, GTJFN returns a JFN or handle for the file. Thus a JFN is associated with an actual file in the TOPS-20 file system. It is sometimes desirable to skip the step of checking a JFN for validity. This is necessary any time that the association between the JFN and the physical file cannot be made, as happens when a JFN is requested for a file on magnetic tape. Also, it may be that the user himself wishes to prevent the JFN/file association from being made in order to check the file specification for grammatical correctness and then manipulate the file specification by adding or removing selected fields, or comparing it against another file specification. This type of JFN is termed a "parse-only" JFN. As it is not associated with any file, no file operations may be performed on it. Only the following JSYSs accept a parse-only JFN: 1. JFNS - converts a JFN to its file specification (in characters) 2. WILD% - compares character strings and file specifications 2.2.4 File References All file operations are initiated by acquiring a JFN on a file using the GTJFN (or GNJFN) call. Some file operations, such as deleting, 2-5
FUNCTIONAL ORGANIZATION OF MONITOR CALLS renaming, and status queries about the file, may be performed immediately after the JFN is acquired. Certain operations, particularly data transfers, require that the file be opened with an OPENF call on the JFN. When the user opens a file, he specifies the byte size to be used for byte I/O operations and the access requested to the file. Several implicit initialization operations, which affect subsequent references to the file, are also invoked when a file is opened. For example, a file's position pointer is normally reset to the beginning of the file such that the first sequential input operation reads the beginning data of the file. Access to files on regulated structures (those being tracked by the accounting system) cannot be given until the mount count for that structure is incremented with the .MSIMC function of the MSTR JSYS (or with the TOPS-20 MOUNT STRUCTURE command). All JFN's must be released before the mount count can be decremented with the .MSDMC function of the MSTR JSYS (or the TOPS-20 DISMOUNT STRUCTURE command). All structures are regulated by default except the primary structure (PS:). 2.2.4.1 Files and Devices - Under TOPS-20, most devices may be treated as if they were files. For example, a GTJFN, OPENF, CLOSF, etc. may be performed directly on magnetic tape device MTA1: without specifying a file name. This is because the device name itself is the file name. Disk devices, however, have multiple directories and multiple files, and the device name itself is not sufficient to uniquely identify a file. The general rule is that, for a complete TOPS-20 file specification, only those fields necessary to make the file unique for that device are required to get a JFN for the file. Thus, for most devices, the device name itself is sufficiently unique to get a JFN for the file. In this manual, when the phrase "opening a device" is used, it is in reference to the feature described above. For TOPS-20, disk devices are the only major exception to the rule that devices can be treated as files. Labeled tapes on MT: devices may be referenced either by device name alone (which gives access to all files on the tape) or by device name and file name (which gives access only to the specified file). 2.2.5 Sample Program The following sample program acquires JFN's, opens both an input and an output file, and then copies data from the input file to the output file in 7-bit bytes until the end of the input file is encountered. 2-6
FUNCTIONAL ORGANIZATION OF MONITOR CALLS ;*** PROGRAM TO COPY INPUT FILE TO OUTPUT FILE. *** ; (USING BIN/BOUT AND IGNORING NULL'S) TITLE FILEIO ;TITLE OF PROGRAM SEARCH MONSYM,MACSYM ;SEARCH SYSTEM JSYS-SYMBOL ;LIBRARIES ;*** IMPURE DATA STORAGE AND DEFINITIONS *** INJFN: BLOCK 1 ;STORAGE FOR INPUT JFN OUTJFN: BLOCK 1 ;STORAGE FOR OUTPUT JFN PDLEN=3 ;STACK HAS LENGTH 3 PDLST: BLOCK PDLEN ;SET ASIDE STORAGE FOR STACK STDAC. ;DEFINE STANDARD JSYS ACs ;*** PROGRAM INITIALIZATION *** START: RESET% ;CLOSE FILES AND INITIALIZE PROCESS MOVE P,[IOWD PDLEN,PDLST] ;ESTABLISH STACK ;*** GET INPUT-FILE *** INFIL: HRROI T1,[ASCIZ / INPUT FILE: /] ;PROMPT FOR INPUT FILE PSOUT% ;ON CONTROLLING TERMINAL MOVX T1,GJ%OLD+GJ%FNS+GJ%SHT;SEARCH MODES FOR GTJFN ;[EXISTING FILE ONLY , FILE-NR'S IN B ; SHORT CALL ] MOVE T2,[.PRIIN,,.PRIOU] ;GTJFN'S I/O WITH ; CONTROLLING TERMINAL GTJFN% ;GET JOB FILE NUMBER (JFN) ERJMP [ PUSHJ P,WARN ;IF ERROR, GIVE WARNING JRST INFIL] ;AND LET HIM TRY AGAIN MOVEM T1,INJFN ;SUCCESS, SAVE THE JFN ;*** GET OUTPUT-FILE *** OUTFIL: HRROI T1,[ASCIZ / OUTPUT FILE: /] ;PROMPT FOR OUTPUT FILE PSOUT% ;PRINT IT MOVX T1,GJ%FOU+GJ%MSG+GJ%CFM+GJ%FNS+GJ%SHT ;GTJFN ; SEARCH MODES [DEFAULT TO NEW ; GENERATION , PRINT MESSAGE , ; REQUIRE CONFIRMATION ; FILE-NR'S IN B , SHORT CALL ] MOVE T2,[.PRIIN,,.PRIOU] ;I/O WITH CONTROLLING TERMINAL GTJFN% ;GET JOB-FILE NUMBER ERJMP [ PUSHJ P,WARN ;IF ERROR, GIVE WARNING JRST OUTFIL] ;AND LET HIM TRY AGAIN 2-7
FUNCTIONAL ORGANIZATION OF MONITOR CALLS MOVEM T1,OUTJFN ;SAVE THE JFN ;NOW, OPEN THE FILES WE JUST GOT ; INPUT MOVE T1,INJFN ;RETRIEVE THE INPUT JFN MOVX T2,FLD(7,OF%BSZ)+OF%RD ;DECLARE MODES FOR OPENF ;[7-BIT BYTES + INPUT] OPENF% ;OPEN THE FILE ERJMP FATAL ;IF ERROR, GIVE MESSAGE AND STOP ; OUTPUT MOVE T1,OUTJFN ;GET THE OUTPUT JFN MOVX T2,FLD(7+OF%BSZ)+OF%WR ;DECLARE MODES FOR OPENF ;[7-BIT BYTES + OUTPUT] OPENF% ;OPEN THE FILE ERJMP FATAL ;IF ERROR, GIVE MESSAGE AND STOP ;*** MAIN LOOP :COPY BYTES FROM INPUT TO OUTPUT *** LOOP: MOVE T1,INJFN ;GET THE INPUT JFN BIN% ;TAKE A BYTE FROM THE SOURCE ERJMP DONE ;IF ERROR, CHECK FOR END OF FILE. JUMPE T2,LOOP ;SUPRESS NULLS MOVE T1,OUTJFN ;GET THE OUTPUT JFN BOUT% ;OUTPUT THE BYTE TO DESTINATION ERJMP FATAL ;IF ERROR, GIVE MESSAGE AND STOP JRST LOOP ;LOOP, STOP ONLY ON A 0 BYTE ;(FOUND AT LOOP+2) ;*** TEST FOR END OF FILE, ON SUCCESS FINISH UP *** DONE: GTSTS% ;GET THE STATUS OF INPUT FILE. TXNN T2,GS%EOF ;AT END OF FILE? PUSHJ P,FATAL ;NO, I/O ERROR CLOSIF: MOVE T1,INJFN ;YES, RETRIEVE INPUT JFN CLOSF% ;CLOSE INPUT FILE ERJMP FATAL ;IF ERROR, GIVE MESSAGE AND STOP CLOSOF: MOVE T1,OUTJFN ;RETRIEVE OUTPUT JFN CLOSF% ;CLOSE OUTPUT FILE ERJMP FATAL ;IF ERROR, GIVE MESSAGE AND STOP HRROI T1,[ASCIZ/ [DONE]/] ;SUCCESSFULLY DONE PSOUT% ;PRINT IT JRST ZAP ;STOP ;*** ERROR HANDLING *** 2-8
FUNCTIONAL ORGANIZATION OF MONITOR CALLS FATAL: HRROI T1,[ASCIZ/ ?/] ;FATAL ERRORS PRINT ? FIRST PUSHJ P,ERROR ;THEN PRINT ERROR MESSAGE, JRST ZAP ;AND STOP WARN: HRROI T1,[ASCIZ/ %/] ;WARNINGS PRINT % FIRST AND FALL ; THRU 'ERROR' BACK TO CALLER ERROR: PSOUT% ;PRINT THE ? OR % MOVE T1,[.PRIOU] ;DECLARE PRINCIPAL OUTPUT DEVICE ;FOR ERROR MESSAGE MOVE T2,[.FHSLF,,-1] ;CURRENT FORK,, LAST ERROR SETZB T3,T4 ;NO LIMIT,, FULL MESSAGE ERSTR% ;PRINT THE MESSAGE JFCL ;IGNORE UNDEFINED ERROR NUMBER JFCL ;IGNORE ERROR DURING EXECUTION ;OF ERSTR POPJ P, ;RETURN TO CALLER ZAP: HALTF% ;STOP JRST START ;WE ARE RESTARTABLE END START ;TELL LINKING LOADER ;START ADDRESS 2.2.6 File Access TOPS-20 provides a general mechanism for protecting files against unauthorized access. This mechanism includes the ability to protect access to files on a directory-wide basis as well as on an individual-file basis. Generally, access to a file depends on the kind of access desired and the relationship of the user making the access to the directory containing the file. The possible relationships a user may have to the file's directory are: 1. The directory containing the file is the user's connected or one of the user's accessed directories. Users satisfying this relationship have owner access to the files in the directory. 2. The directory containing the file is in the same group as the user. Users satisfying this relationship have group member access to the files in the directory. 3. The directory containing the file is outside the group membership. Users satisfying this relationship have world access to the files in the directory. 2-9
FUNCTIONAL ORGANIZATION OF MONITOR CALLS Both users and directories may belong to groups. The group-member relationship is satisfied if both the directory and the user belong to one or more of the same groups. Groups are assigned by the system manager or operator. (Refer to the TOPS-20 System Manager's Guide.) The type of access permitted to a file for each relationship is represented by the value of a 6-bit field. The possible values are: Value Symbol Meaning 40 FP%RD Read access 20 FP%WR Write access 10 FP%EX Execute access 4 FP%APP Append access 2 FP%DIR Directory listing access. If a user does not have at least this type of access, a GTJFN will find the file only if wildcards are not used. A GNJFN will not find the file. The following table illustrates some useful combinations of the values shown above: Value Symbol Meaning 12 FP%EX+FP%DIR Execute-only access 42 FP%RD+FP%DIR Usual protection allowing users to access a file without being able to modify it. 60 FP%RD+FP%WR Good for hiding files that specific programs can write to. Programs should be execute-only and the program should set the "restricted" access bit in the GTJFN so as not to reveal the filename. The 6-bit field and the three relationships (owner, group, remaining users) are represented by an 18-bit code, with bits 0-5 being the owner, bits 6-11 being the group, and bits 12-17 being the remaining users. When a particular bit is on, the corresponding access is permitted for the particular relationship. The access given to a group member includes the access given to all members outside the group. Also, the access given to the owner includes the access given to group members. Thus, the owner of a file or a user in the owner's group cannot have less access than users outside the group. 2.2.7 Directory Access Access to a directory is protected in a manner similar to, but distinct from, that of a file. An 18-bit code, containing three 6-bit fields, is associated with each directory. Each of the three fields 2-10
FUNCTIONAL ORGANIZATION OF MONITOR CALLS controls access by users in the same way that access to files is controlled. For directories, however, each 6-bit field can have one of the following values. Value Symbol Meaning 40 DP%RD Accessing files in the directory according to the access code on the individual files is allowed. A GTJFN call for a file in the directory will fail if the user does not have this access. 10 DP%CN Connecting to the directory without giving a password is allowed. With this access, a group member can change the FDB (as the owner) as well as times, dates, and accounting information for files in the directory. Other operations on the files are subject to the access codes of the files. If the user is connected to the directory, he has ownership access to the files; if he is not connected, he has group membership access. 4 DP%CF Creating files in the directory is allowed. When a user requests access to a file, the monitor checks the directory access code first. If the directory code allows the desired access, the monitor then checks the access code of the individual file. The access actually granted to a file is specified when the user opens the file with the OPENF call. If the access specified in the OPENF call is the same as or less than the access permitted by the 18-bit access code, the user is granted access to the file. Thus, for a user to be granted access to a specific file, two conditions must be met: 1. The access code (both directory and file) must permit the user to access the file in the desired manner (for example, read, write). 2. The file must not be open for a conflicting type of access. 2.2.8 File Descriptor Block Each file has an associated File Descriptor Block (FDB) that contains various information about the file. The format of the FDB is shown in Table 2-1. The description of each word or bit in the FDB indicates whether the user can change it, and if so, what types of access are required. The types of access are: 2-11
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 1. WRITE - write access 2. OWNER - owner access 3. W/OPR - WHEEL or OPERATOR capabilities enabled In some cases, separate JSYSs are required to read, set, and/or clear various words or bits. These functions are indicated by: 1. (R) - read 2. (S) - set 3. (C) - clear 4. (SC) - set/clear Table 2-1: File Descriptor Block (FDB) ______________________________________________________________________ Word Symbol Meaning ______________________________________________________________________ 0 .FBHDR FDB header word. Individual fields are as follows: B0-B28 Reserved for DIGITAL. UNCHANGEABLE B29-35(FB%LEN) Length of this file's FDB UNCHANGEABLE 1 .FBCTL B0(FB%TMP) File is temporary. JSYS WRITE OWNER W/OPR CHFDB N Y Y B1(FB%PRM) File is permanent. The contents of the file may be deleted, but the FDB may not. JSYS WRITE OWNER W/OPR CHFDB N Y Y 2-12
FUNCTIONAL ORGANIZATION OF MONITOR CALLS B2(FB%NEX) File does not yet have a file type; file does not really exist. UNCHANGEABLE B3(FB%DEL) File is deleted. JSYS WRITE OWNER W/OPR CHFDB N Y* Y *This bit may be changed by the owner providing that bit FB%ARC (in .FBCTL) is not set. B4(FB%NXF) File does not exist because it has not yet been closed. UNCHANGEABLE B5(FB%LNG) File is longer than 512 pages. UNCHANGEABLE B6(FB%SHT) Reserved for DIGITAL. UNCHANGEABLE B7(FB%DIR) File is a directory. UNCHANGEABLE B8(FB%NOD) File is not to be saved by the backup system. JSYS WRITE OWNER W/OPR CHFDB Y Y Y B9(FB%BAT) File may have one or more bad pages. This bit indicates that I/O errors have occurred for a page (or pages) of a file and the contents of these pages are suspect. This bit is set whenever the system has a disk I/O error on a page of an open file. The faulty disk address is also added to the list in the system's BAT blocks for that disk structure. 2-13
FUNCTIONAL ORGANIZATION OF MONITOR CALLS If an EXPUNGE is performed for a file for which bit FB%BAT is set, the system performs an additional function as it releases the pages of the file back to the available resource pool: it checks each disk address in the file against the list of bad regions in the structure's BAT blocks and if it finds a match, it leaves that page marked as "in use" in the bit map of available disk pages, so that the faulty page is not reused. UNCHANGEABLE B10(FB%SDR) Directory has subdirectories. UNCHANGEABLE B11(FB%ARC) File has archive status. Appropriate words in the FDB (below) specify where the file is archived. JSYS WRITE OWNER W/OPR ARCF N N Y B12(FB%INV) File is invisible. Invisible files can be seen only by using the G1%IIN option to GTJFN. JSYS WRITE OWNER W/OPR CHFDB N Y Y B13(FB%OFF) File is offline. This is set by DELF when it removes the contents from disk and cleared when ARCF restores the contents to disk. JSYS WRITE OWNER W/OPR DELF(S) N N Y ARCF(C) N N Y B14-B17(FB%FCF) File class field. If value of field is 0(.FBNRM), file is not an RMS file. If value of field is 1(.FBRMS), file is an RMS file. 2-14
FUNCTIONAL ORGANIZATION OF MONITOR CALLS JSYS WRITE OWNER W/OPR CHFDB Y Y Y B18(FB%NDL) Do not delete this file. Do not delete even if overwritten by a write or a rename. JSYS WRITE OWNER W/OPR CHFDB N N Y B19(FB%WNC) Last write not closed. File has not been closed by all writers. Page count may be incorrect. JSYS WRITE OWNER W/OPR CHFDB N N Y B20(FB%FOR) File has FORTRAN-style line printer carriage control characters. JSYS WRITE OWNER W/OPR CHFDB Y Y Y | | B21(FB%SEC) File is secure. 2 .FBEXL Link to FDB of next file with the same name but different file type. UNCHANGEABLE 3 .FBADR Disk address of file index block. UNCHANGEABLE 4 .FBPRT File access code. LH: 500000 UNCHANGEABLE RH: file access bits. JSYS WRITE OWNER W/OPR CHFDB N Y N 5 .FBCRE Date and time that the file was closed after the last write to the file. Modified when any program writes to the file. 2-15
FUNCTIONAL ORGANIZATION OF MONITOR CALLS JSYS WRITE OWNER W/OPR CHFDB N N Y 6 .FBAUT Pointer to string containing the name of the author. This word is not under direct user control. It is only changed indirectly, when the file author string is changed. JSYS WRITE OWNER W/OPR GFUST(R) Y Y Y SFUST(SC) N Y N 7 .FBGEN Generation and directory numbers of file. LH(FB%GEN): generation number of the file. UNCHANGEABLE RH(FB%DRN): monitor internal directory number of the file (only if B7 of .FBCTL is on). UNCHANGEABLE 10 .FBACT Account information. This word contains a byte pointer to an alphanumeric account designator; it can be changed with the SACTF monitor call. JSYS WRITE OWNER W/OPR SACTF Y Y Y 11 .FBBYV File I/O information. B0-B5(FB%RET) Number of generations to retain (retention count). If two generations of the same file have different retention counts, the count is taken from the generation currently being used. JSYS WRITE OWNER W/OPR CHFDB Y Y Y B6-B11(FB%BSZ) File byte size. This field can be changed by user with write access. 2-16
FUNCTIONAL ORGANIZATION OF MONITOR CALLS JSYS WRITE OWNER W/OPR CHFDB Y Y Y B14-B17(FB%MOD) Data mode of last open of file. This field can be changed by user with write access. JSYS WRITE OWNER W/OPR CHFDB Y Y Y B18-B35(FB%PGC) Page count of file. Note that the monitor keeps the page count updated, so under normal circumstances a user need not and should not alter this count. JSYS WRITE OWNER W/OPR CHFDB N N Y 12 .FBSIZ Number of bytes in the file. (Refer to Section 2.2.11.) JSYS WRITE OWNER W/OPR CHFDB Y Y Y 13 .FBCRV Date and time of creation of file. JSYS WRITE OWNER W/OPR CHFDB Y Y Y 14 .FBWRT Date and time that the file was opened when the last write to the file was made. JSYS WRITE OWNER W/OPR CHFDB Y Y Y 15 .FBREF Date and time of last nonwrite access to file. JSYS WRITE OWNER W/OPR CHFDB Y Y Y 16 .FBCNT Count word. LH: number of writes to file. 2-17
FUNCTIONAL ORGANIZATION OF MONITOR CALLS JSYS WRITE OWNER W/OPR CHFDB N N Y RH: number of references to file. JSYS WRITE OWNER W/OPR CHFDB N N Y 17 .FBBK0 Used by DUMPER for backup purposes. JSYS WRITE OWNER W/OPR CHFDB N N Y 20 .FBBK1 Reserved for DEC. UNCHANGEABLE 21 .FBBK2 Reserved for DEC UNCHANGEABLE 22 .FBBBT The right half contains the number of pages in the file when the contents were deleted from disk. UNCHANGEABLE The left half is used for the following flags: B1(AR%RAR) User request for a file to be archived. JSYS WRITE OWNER W/OPR ARCF Y Y Y B2(AR%RIV) System request for an involuntary migration of a file. JSYS WRITE OWNER W/OPR ARCF N N Y B3(AR%NDL) Do not delete the contents of the file from disk when the archival is complete. JSYS WRITE OWNER W/OPR ARCF N Y Y 2-18
FUNCTIONAL ORGANIZATION OF MONITOR CALLS B4(AR%NAR) Resist involuntary migration. This bit is a note from the user to the system access control program asking that the file not be moved offline if possible. JSYS WRITE OWNER W/OPR ARCF N Y Y B5(AR%EXM) File is exempt from involuntary migration. JSYS WRITE OWNER W/OPR ARCF N N Y B6(AR%1ST) First pass of an archival-collection run is in progress. JSYS WRITE OWNER W/OPR CHFDB N N Y B7(AR%RFL) Restore failed. Set by ARCF to indicate that the restore it is waiting for has failed. JSYS WRITE OWNER W/OPR ARCF N N Y B10(AR%WRN) Generate a message warning that the file's off-line expiration date is approaching. 7B17(AR%RSN) Reason file was moved offline: .AREXP(1) file expired .ARRAR(2) archiving was requested .ARRIR(3) migration was requested JSYS WRITE OWNER W/OPR ARCF(W) N N Y GTFDB(R) Y Y Y B18-B35(AR%PSZ) The right half of .FBBBT is used to 2-19
FUNCTIONAL ORGANIZATION OF MONITOR CALLS store the number of pages in a file when the contents were removed from disk. JSYS WRITE OWNER W/OPR ARCF(W) N N Y GTFDB(R) Y Y Y 23 .FBNET On-line expiration date and time. Specifies the date and time at which a file is considered expired, or specifies an interval (in days) after which the file is considered expired. JSYS WRITE OWNER W/OPR SFTAD N Y Y 24 .FBUSW User-settable word. JSYS WRITE OWNER W/OPR CHFDB N Y Y 25 .FBGNL Address of FDB for next generation of file. UNCHANGEABLE 26 .FBNAM Pointer to filename block. UNCHANGEABLE 27 .FBEXT Pointer to file type block. UNCHANGEABLE 30 .FBLWR Pointer to string containing the name of the user who last wrote to the file. This name is read with the GFUST monitor call and can be changed with the SFUST monitor call. Note that word .FBLWR may only be changed indirectly (by specifying a new name string). This word cannot be changed directly. JSYS WRITE OWNER W/OPR GFUST(R) Y Y Y SFUST(CS) N N Y 31 .FBTDT Archive or collection tape-write date and time. This is the date and time (in internal format) 2-20
FUNCTIONAL ORGANIZATION OF MONITOR CALLS that file was last written to tape (for either archiving or migration). JSYS WRITE OWNER W/OPR ARCF N N Y 32 .FBFET Offline expiration date and time. Specifies the date and time (or interval) after which a file in the archives or on virtual disk is considered expired. Used for tape recycling. Modified by SFTAD. JSYS WRITE OWNER W/OPR SFTAD Y Y Y 33 .FBTP1 Contains the tape ID for the first archive or collection run. JSYS WRITE OWNER W/OPR ARCF N N Y 34 .FBSS1 Contains the saveset and tape file numbers for the first tape. The left half is the number of the saveset in which the file is recorded, and the right half is the tape file number within that saveset. JSYS WRITE OWNER W/OPR ARCF N N Y 35 .FBTP2 Tape ID for second archive or collection run. Otherwise similar to .FBTP1. JSYS WRITE OWNER W/OPR ARCF N N Y 36 .FBSS2 Saveset and tape file numbers for the second archive or collection run. Otherwise similar to .FBSS1. JSYS WRITE OWNER W/OPR ARCF N N Y ______________________________________________________________________ 2-21
FUNCTIONAL ORGANIZATION OF MONITOR CALLS The maximum length FDB block that TOPS-20 will create (37 octal) may be specified with the symbol .FBLEN. 2.2.9 Primary Input and Output Files Each process in a job has a primary input file and a primary output file. Both files are normally the controlling terminal, but can be changed to other files (with the SPJFN call). The primary input and output files are referenced with designators .PRIIN (JFN 100) and .PRIOU (JFN 101), respectively. Programs should be coded to do their "terminal" I/O to these designators, so that they can be used with command files without modification. Only in extreme cases should a program reference its controlling terminal (.CTTRM) directly. 2.2.10 Methods of Data Transfer The most simple form of I/O is sequential byte I/O, as shown in the sample program. (Refer to Section 2.2.5.) This form of data transfer may be used with any file. A pointer maintained in the monitor is implicitly initialized when a file is opened and advanced as data is transferred. For files on disk, there are two other methods of data transfers. First, random access byte I/O is possible by using the SFPTR call or the RIN/ROUT calls. Second, entire pages of data may be mapped with the PMAP call. 2.2.11 File Byte Count For disk files, TOPS-20 maintains a file byte count (.FBSIZ) in the FDB. This count is set by the monitor when sequential output (for example, BOUT, SOUT) occurs to the file and thus, on sequential output, reflects the number of bytes written in the file. When output occurs to the file using the PMAP call, the monitor does not set the file byte count. In this case, the number of bytes in the file may be different from the file byte count stored in the FDB. To allow sequential I/O to occur later to the file, the program should update the file byte count (.FBSIZ) and the file byte size (FB%BSZ) in the FDB before closing the file. This is done with the CHFDB monitor call. When output occurs to the file using random output calls (ROUT, for example), the file byte count is a number one greater than the highest byte number in the file. The file byte count is interpreted according to the byte size stored in the FDB, not the byte size specified when the file is opened. When a new file is opened, the byte size stored 2-22
FUNCTIONAL ORGANIZATION OF MONITOR CALLS in the FDB is 36 bits, regardless of the byte size specified in the OPENF call. If the program executes a CHFDB call to change the file byte count, it must usually change the byte size (FB%BSZ) so that both values reflect the same size bytes. 2.2.12 EOF Limit There is an EOF limit associated with every opening of a file. This limit is the number of bytes that can be read with a sequential input call (for example, BIN, SIN). When the program attempts to read beyond this limit using sequential input, the call returns a 0 byte and an end-of-file condition. This condition may generate a software interrupt (refer to Section 2.6) if the user has not included an ERJMP or ERCAL as the next instruction following the call. (Refer to Chapter 1.) The EOF limit is computed when the file is opened with the OPENF call. The monitor computes this limit by determining the total number of words in the file and dividing this number by the byte size given in the OPENF call. The total number of words in the file is determined from the file byte count (.FBSIZ) and the file byte size (FB%BSZ) stored in the FDB. Note that page-mode I/O JSYSs, such as PMAP, ignore the EOF limit and can read any existing page of the file. However, page-mode JSYSs can only read pages within an existing file section (the address space of a file delimited by 1 index block - 512 pages). 2.2.13 Input/Output Errors While performing I/O or I/O-related operations, it is possible to encounter one or more error conditions. Some of these are user-caused errors (for example, illegal access attempts), and others are I/O device or medium errors. TOPS-20 indicates such error conditions by setting error bits in the JFN status word (refer to the GTSTS call) and by initiating a software interrupt request (refer to Section 2.6) if the user has not included an ERJMP or ERCAL after the call. If the process in which an I/O error occurs is not prepared to process the interrupt, the interrupt is changed into a process terminating condition with the expectation that the process' immediate superior will handle the error condition. The TOPS-20 Command Language is prepared to detect and diagnose I/O errors; thus, a process running directly beneath the process containing the Command Language need not do its own I/O error handling unless it chooses to do something special. I/O errors can occur while a process is executing ordinary machine instructions as well as JSYSs. For example, if a PMAP operation is 2-23
FUNCTIONAL ORGANIZATION OF MONITOR CALLS performed that maps a page of a file into a page of a process, the file I/O transfer does not usually occur until a reference is made by the process to that particular page of the file. If there is an I/O error in the transfer, it is detected at the time of this reference. An attempt to do I/O to a terminal that is assigned to another job (as a controlling terminal or with the ASND call) normally results in an error, but is legal if the process has the WHEEL capability enabled. 2.2.13.1 Testing for End-of-File - The GTSTS JSYS, used in conjunction with ERCAL (or ERJMP), is used to test for end-of-file. The following code fragment illustrates this: MOVE T1,INJFN ;Get input JFN BIN% ;Read a byte ERCAL EOFTST . . ;Process byte . EOFTST: MOVE T1,INJFN ;Get input JFN GTSTS% ;Get status of that JFN TXNN T2,GS%EOF ;Did end of file occur? PUSHJ P,FATAL ; No, I/O error occurred MOVE T1,INJFN ; Yes, close file CLOSF% ERCAL FATAL ;If can't close, issue message POPJ P, ;OK to return FATAL: . ;Here to issue error messages . ; on fatal file errors . HALTF% ;Halt on fatal error In the example above, the ERCAL after the BIN is executed only if a file error condition arises. The code that is entered as a result of the ERCAL can then do a GTSTS for the appropriate file and test for end-of-file. An alternate method to test for end-of-file is to use the GETER JSYS and determine if the last error for the process is IOX4 (end of file reached). The following monitor calls used in referencing files (including I/O functions). Calls marked with an asterisk ("*") require privileges for specific functions. ACCES* Specifies access to a directory BIN Reads the next byte BKJFN Backspaces file's pointer BOUT Writes the next byte 2-24
FUNCTIONAL ORGANIZATION OF MONITOR CALLS CHFDB* Changes a File Descriptor Block CHKAC Checks access to a file CLOSF Closes a file CLZFF Closes a process's files CRDIR* Creates or modifies a directory CRLNM* Creates a logical name DELDF* Expunges deleted files DELF* Deletes a file DELNF Retains specified number of generations of file DIRST Translates directory or user number to a string DUMPI Reads data in unbuffered data mode DUMPO Writes data in unbuffered data mode FFFFP Finds first free file page FFUFD Finds first used file page FLIN Reads a floating-point number FLOUT Writes a floating-point number GACTF Reads a file's account GFUST Reads the author or last writer name string GNJFN Assigns a JFN to the next file GPJFN Returns primary JFN's GTFDB Reads a File Descriptor Block GTJFN Assigns a JFN to a file GTSTS Reads file's status INLNM Writes logical names JFNS Translates a JFN to a string LNMST Translates logical name to string MRECV* Retrieves IPCF message MSEND* Sends IPCF message MSTR* Performs structure-related functions MUTIL* Performs IPCF functions NIN Reads a number NOUT Writes a number OPENF Opens a file PBIN Reads byte from primary input designator PBOUT Output byte to primary output designator PMAP Maps pages PSOUT Writes string to primary output designator QUEUE% Communicates with spooling system and operator RCDIR Translates directory name to number RCUSR Translates user name to number RCVIN% Receives an Internet message RDTTY Reads data from primary input designator RFBSZ Reads file's byte size RFPTR Reads file's pointer RFTAD Reads file's time and dates RIN Reads a byte nonsequentially RLJFN Releases a JFN RNAMF Renames a file ROUT Writes a byte nonsequentially RSCAN Reads and outputs rescan buffer SACTF Sets a file's account SFBSZ Sets file's byte size 2-25
FUNCTIONAL ORGANIZATION OF MONITOR CALLS SFPTR Sets file's pointer SFTAD* Sets file's time and dates SFUST* Changes the author or last writer name string SIN Reads a string SINR Reads a record SIZEF Obtains file's length SMAP% Maps sections SNDIN% Sends an Internet message SPJFN Sets primary JFN's SOUT Writes a string SOUTR Writes a record STI* Simulates terminal input STSTS Sets file's status SWJFN Transposes two JFN's TEXTI Reads data from terminal or file TTMSG* Sends message to terminal(s) UFPGS Updates file's pages WILD% Compares a wild file specification against a non-wild file specification. Also compares strings. 2.3 OBTAINING INFORMATION The monitor calls in this group are used to obtain information from the system, such as the time of day, resources used by the current job, error conditions, and the contents of system tables. Several of these calls return time values (intervals and accumulated times, for example). Unless otherwise specified, these values are integer numbers in units of milliseconds. 2.3.1 Error Mnemonics and Message Strings Each failure for a JSYS is associated with an error number identifying the particular failure. These error numbers are indicated in the manual by mnemonics (DEVX1, for example), and are listed with the appropriate calls. Some calls return the error number in the right half of an accumulator, usually in AC1; however, all calls leave the number in the Process Storage Block for the process in which the error occurred. Thus, a process can obtain the number for the last error that occurred (by means of the GETER call). In addition to the mnemonic of six characters or less, each error number has a text message associated with it that describes the error in more detail. The ERSTR call can be used to return the message string associated with any given error number. This call should be used for handling error returns. 2-26
FUNCTIONAL ORGANIZATION OF MONITOR CALLS Refer to Chapter 3 and Appendix B for the listing of the error numbers, mnemonics, and messages. 2.3.2 System Tables The contents of several system tables are available to programs for such purposes as generating status reports and collecting system performance statistics. Each table is identified by a fixed name of up to six characters, and consists of a variable number of entries. The -1 entry in each table is the negative of the number of data entries in the table; the data entries are identified by an index that increments from 0. Two calls exist for accessing tables. The first, SYSGT, accepts a table name and returns the table length, its first data entry, and a number identifying the table. The second, GETAB, accepts the table number returned by SYSGT, or obtained from the MONSYM file, and returns additional entries from the table. The system tables are as follows. Numeric table indexes are given in octal. Parallel tables, those for which a given index produces related information, are indicated by "(Pn)" where n is a unique number for that set of parallel tables. Table 2-2: System Tables ______________________________________________________________________ Name Index Contents ______________________________________________________________________ APRID Processor serial number ACTJOB Range of active jobs on the system from lowest job in use to highest job in use (not including Job 0). BLDTD Date and time system was generated CSTAT CI statistics table 0 CI packets sent 1 CI packets received 2 SCA overhead messages sent 3 SCA overhead messages received 4 MSCP driver messages sent 5 MSCP driver messages received 6 MSCP server messages sent 7 MSCP server messages received 2-27
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 10 CFS messages sent 11 CFS messages received 12 SCS% messages sent 13 SCS% messages received 14 CI command queue 0 15 CI command queue 1 16 CI command queue 2 17 CI command queue 3 20 IP datagrams sent 21 IP datagrams received 22 DECnet datagrams sent 23 DECnet datagrams received 24 SCS% datagrams sent 25 SCS% datagrams received 26 MSCP driver datagrams received 27 HSCP error-log datagrams received (ppd byte 5) DBUGSW Debugging information 0 state of system operation 0 = normal 1 = debugging 2 = standalone 3 = standalone fast startup 1 state of BUGCHK handling 0 = proceed 1 = breakpoint DEVCHR (P1) Device characteristics word, as described under the DVCHR JSYS in Chapter 3, except that B5 (DV%AV) is not meaningful. DEVNAM (P1) SIXBIT device name including unit number, e.g., MTA3 DEVUNT (P1) LH: Job number to which device is assigned (with ASND), or -1 if device is not assigned, or -2 if reserved for device allocator. RH: unit number, or -1 if device has no units (for example, DSK:) DRMERR Information on drum errors 0 number of recoverable errors 1 to n varies depending on type of drum being used DSKERR Information on disk errors 2-28
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 0 number of recoverable disk errors 1 to n varies depending on type of disk being used DWNTIM Downtime information 0 date and time when system will be shut down next 1 date and time when system will subsequently be up HQLAV High queue load averages JBONT Job # Owning job for CRJOB-created jobs. JOBNAM Job # LH: reserved for DEC RH: index into the system program tables for the system program being used by this job (determined by the last SETSN call executed by the job) JOBPNM Job # SIXBIT name of program running in this job JOBRT Job # CPU time used by the job (negative if no such job) JOBTTY Job # LH: controlling terminal line number, or -1 if none (job is detached) RH: reserved for Digital LOGDES Logging information 0 designator for logging information 1 designator for job 0 and error information LQLAV Low queue load averages MONVER Monitor version number (contents of location 137) NCPGS One-word table containing number of pages of real (physical) user core available in system. Note that this value includes resident variables, and thus not all of the pages can be assigned to a user process. NETRDY ARPANET operational status table 2-29
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 0 0 IMP down .GT.0 IMP going down -1 IMP up 1 0 = network off, non-zero = network on 2 flags for NETSER (not for user) 3 time of last NCP cycle up 4 last IMP GOING DOWN message B0-15 reserved B16-17 0 panic 1 scheduled hardware PM 2 software reload 3 emergency restart B18-21 number of 5-minute intervals before IMP goes down B22-31 number of 5-minute intervals IMP will be down 5 time of last IMP ready drop 6 time of last IMP ready up 7 time of IMP GOING DOWN message NSWPGS Default swapping pages PTYPAR Pseudo-TTY parameter information 0 LH: number of PTYs in system RH: TTY number of first PTY QTIMES 0 to n Accumulated runtime of jobs on the n scheduler queues SCOUNT (P3) Count of SETSN JSYSs for each subsystem SNAMES (P3) SIXBIT name of system program, or 0 if this entry is unused in this and the corresponding four tables. SNBLKS (P3) Number of samples in working set size integral SPFLTS (P3) Total number of page faults of system program SSIZE (P3) Time integral of working set size STIMES (P3) Total runtime of system program SYMTAB SIXBIT table names of all GETAB tables 2-30
FUNCTIONAL ORGANIZATION OF MONITOR CALLS SYSTAT Monitor statistics. The entries in this table are as follows: 0 time with no runnable jobs 1 waiting time with 1 or more runnable jobs (waiting for page swapping) 2 time spent in scheduler 3 time spent processing pager traps 4 number of drum reads 5 number of drum writes 6 number of disk reads 7 number of disk writes 10 number of terminal wakeups 11 number of terminal interrupts 12 time integral of number of processes in the balance set 13 time integral of number of runnable processes 14 exponential 1-minute average of number of runnable processes 15 exponential 5-minute average of number of runnable processes 16 exponential 15-minute average of number of runnable processes 17 time integral of number of processes waiting for the disk 20 time integral of number of processes waiting for the drum 21 number of terminal input characters 22 number of terminal output characters 23 number of system core management cycles 24 time spent doing postpurging 25 number of forced balance set process removals 26 time integral of number of processes in swap wait 27 scheduler overhead time (same as entry 2) in high precision units 30 idle time (same as entry 0) in high precision units 31 lost time (same as entry 1) in high precision units 32 user time 33 time integral of number of processes on high queue. (High queue is high priority, low numerical value.) 34 time integral of number of processes on low queue. (Low queue is low priority, high numerical value.) 2-31
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 35 sum of process disk-write waits 36 number of forced adjustments to balance set 37 integral of number of reserve pages of all processes in memory 40 integral of number of pages on replaceable queue. The replaceable queue contains pointers to all free memory pages. 41 high precision pager trap time 42 number of context switches 43 high precision time spent on background tasks. These tasks include low-level data transfer in communications layers, including network and terminal service routines. 44 total system page traps 45 total saves from replacement queue. A "save" occurs when a desired page is found on the replacement queue and need not be paged in. 46 number of pages removed from memory during system-wide garbage collection 47 integral of number of working sets in memory 50 wait time without swap waits in high precision units 51 count of working set loads 52 count of runable processes removed from balance set 53 number of pages removed from memory during process-wide garbage collection 54 count of terminal input wakeups 55 count of read-after-write disk verifications 56 lowest,,highest active job on the system (does not include job 0) 57 operator,,user jobs logged into this system (does not include not logged in jobs) NOTE This table is subject to change (usually additions) as measuring routines are added to the system. 2-32
FUNCTIONAL ORGANIZATION OF MONITOR CALLS SYSVER An ASCIZ string identifying the system name, version, and date. The string has the following format: string, TOPS-20 Monitor n.m(o)-p where "string" is the text contained in the file structure:<SYSTEM>MONNAM.TXT, "n" is the major version number (1 to 3 digits), "m" is the minor version number (0 to 2 digits), "o" is the edit number (1 to 6 digits), and "p" is the number of the group that last edited the version (0 or 1 digit). If "m" is zero, it and its preceding period are omitted. If "p" is zero, it and its preceding hyphen is omitted. Otherwise, the period and the hyphen are stored along with the other information, including the spaces and parentheses as shown, in the table. TICKPS One-word table containing number of clock ticks per second. TTYJOB line # LH: positive job number for which this is the controlling terminal, or -1 for unassigned line, or -2 for line currently being assigned, or job number to which this line is assigned. RH: -1 if no process is waiting for input from this terminal; other than -1 if some process is waiting for input. WHOJOB Number of operator jobs and user jobs logged in (not including Job 0). ______________________________________________________________________ The system program being run by a specific job may be determined from SNAMES, using an index obtained from table JOBNAM. The following monitor calls are used for obtaining information. Calls marked with an asterisk ("*") require privileges for specific functions. 2-33
FUNCTIONAL ORGANIZATION OF MONITOR CALLS CNFIG% Returns system configuration information ERSTR Translates an error number to a string ESOUT Returns an error string GETAB Returns a word from a system table GETER Returns the last error condition GETJI Returns job information for specified job GETNM Returns the program name being used by the job GJINF Returns job information for current job GTAD Returns the system's date GTDAL Returns the disk allocation of a directory GTDIR* Returns directory information GTRPI Returns the paging trap information GTRPW Returns the trap words HPTIM Returns the high-precision clock values LATOP%* Performs Local Area Transport (LAT) functions MRECV* Retrieves IPCF message MSEND* Sends IPCF message MSTR* Performs structure-related functions MUTIL* Performs IPCF functions NTINF% Returns generic network information SKED* Manipulates scheduler data base SYSGT Returns values for a system table RUNTM Returns the runtime of a job or process TIME Returns the time since the system was restarted 2.4 COMMUNICATING WITH DEVICES The monitor calls in this group are used to communicate with the devices on the system. Some of these devices are line printers, magnetic tapes, terminals, and card readers. Many of the monitor calls in this group take a device designator as an argument. This designator can be either LH: .DVDES(600000)+device type number RH: unit number for devices that have units, arbitrary code for structures, or -1 for non-structure devices that do not have units or LH: 0 RH: .TTDES(400000)+terminal number, or .CTTRM(0,,-1) for controlling terminal The STDEV monitor call is used to convert a string to its corresponding device designator. The various devices are listed in the following table. 2-34
FUNCTIONAL ORGANIZATION OF MONITOR CALLS Table 2-3: Device Types ______________________________________________________________________ Name Description Type Symbol Units ______________________________________________________________________ DSK: disk structure 0 .DVDSK no MTA: magnetic tape 2 .DVMTA yes MT: logical magnetic tape 2 .DVMTA yes LPT: spooled line printer 7 - yes PLPT: physical line printer 7 .DVLPT yes CDR: spooled card reader 10 - yes PCDR: physical card reader 10 .DVCDR yes FE: front-end pseudo-device 11 .DVFE no TTY: terminal 12 .DVTTY yes PTY: pseudo-terminal 13 .DVPTY yes NUL: null device 15 .DVNUL no TCP: ARPA network 16 .DVNET no CDP: spooled card punch 21 - yes PCDP: physical card punch 21 .DVCDP yes DCN: DECnet active component 22 .DVDCN no SRV: DECnet passive component 23 .DVSRV no ______________________________________________________________________ Device-designators may be formed for the devices shown above by taking the given symbolic device-type and adding .DVDES (600000). The null device is an infinite sink for unwanted output and returns an EOF on input. Device-dependent status bits are defined for some devices. These bits can be set or returned with the SDSTS or GDSTS call, respectively. When an assignable device is assigned (by the ASND call) or opened (by the OPENF call) by one job, other jobs cannot do the following: 1. Assign the device with ASND. 2. Execute an OPENF call for the device, even if the JFN properly represents the device. Structures are not restricted to these limitations; more than one user can simultaneously execute the OPENF call for files on structures. There are some restrictions on the use of universal device designators and numeric designators in extended sections. Refer to Section 1.2.7.1 for this information. 2-35
FUNCTIONAL ORGANIZATION OF MONITOR CALLS The following sections describe many of the devices listed in the table above. The sections are in alphabetic order by generic device type (thus PCDR: and CDR: are listed under "c"). 2.4.1 Physical Card Reader (PCDR:) The following device-dependent status bits are defined for the card reader. These bits can be obtained with the .MORST function of the MTOPR call. Table 2-4: PCDR: Status Bits ______________________________________________________________________ Bit Symbol Meaning ______________________________________________________________________ B0 MO%COL Device is on line. B10 MO%FER Fatal hardware error. This error generates an interrupt on software channel .ICDAE. (Refer to Section 2.6.1.) B12 MO%EOF Card reader is at end of file. B13 MO%IOP I/O in progress. B14 MO%SER Software error. (Would generate an interrupt on an assignable channel.) B15 MO%HE Hardware error. (Would generate an interrupt on software channel .ICDAE.) B16 MO%OL Device is off line. B17 MO%FNX Device is nonexistent. B31 MO%SFL Output stacker full. B32 MO%HEM Input hopper empty. B33 MO%SCK Stack check. B34 MO%PCK Pick check. B35 MO%RCK Read check. ______________________________________________________________________ 2-36
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 2.4.2 Spooled Card Reader (CDR:) On most systems, the physical card reader devices (PCDR: devices) are under the control of the card reader spooler, SPRINT, and thus the ordinary user cannot open a PCDR: device, and must instead open a spooled card reader device (CDR:). When a GTJFN is performed on device CDR:, the device characteristics (returned by DVCHR) are the same as those for device PCDR:. Thus, CDR: devices have units, and a unit number may be specified for the GTJFN. When the OPENF is performed, However, the device characteristics become the same as device DSK:. This is because data read from device CDR: is actually read from a file in the spool directory <SPOOL>. The file is spooled from the PCDR: device to the spool directory by SPRINT. Thus device CDR: is effectively a disk device, and no monitor call that can be used only to set the characteristics of a PCDR: device can be used for a CDR: device. Also, disk-only operations (such as PMAP) should not be done for a CDR: device. Both ASCII and image mode are supported for CDR: devices. 2.4.3 Physical Card Punch (PCDP:) The following device-dependent bits are defined for the card reader. These functions can be obtained with the .MORST function of the MTOPR monitor call. Table 2-5: PCDP: Status Bits ______________________________________________________________________ Bit Symbol Meaning ______________________________________________________________________ B10 MO%FER Fatal error condition. B12 MO%EOF All pending output has been processed. B13 MO%IOP Output in progress. B14 MO%SER Software error has occurred (would generate interrupt on an assignable channel). B15 MO%HE Hardware error has occurred (would generate interrupt on channel .ICDAE). 2-37
FUNCTIONAL ORGANIZATION OF MONITOR CALLS B16 MO%OL Card-punch is off-line. This bit is set when operator intervention is required (card jam, hopper empty, stacker full). B17 MO%FNX Card punch doesn't exist. B32 MO%HEM Stacker is full or hopper is empty. B33 MO%SCK Stacker is full or hopper is empty (same as above). B34 MO%PCK Pick check. ______________________________________________________________________ 2.4.4 Spooled Card Punch (CDP:) On most systems, the physical card punch devices (PCDP: devices) are under the control of the card punch spooler, SPROUT, and thus the ordinary user cannot open a PCDP: device, and must instead open a spooled card punch device (CDP:). When a GTJFN is performed on device CDP:, the device characteristics (returned by DVCHR) are the same as those for device PCDP:. Thus, CDP: devices have units, and a unit number may be specified for the GTJFN. However, when the OPENF is performed, the device characteristics become the same as device DSK:. This is because data written to device CDP: is actually written to a file in the spool directory <SPOOL>. The file is then spooled from the spool directory to the PCDR: device by SPROUT. Thus device CDP: is effectively a disk device, and no monitor call that can be used only to set the characteristics of a PCDP: device can be used for a CDP: device. Also, disk-only operations (such as PMAP) should not be done for a CDP: device. Both ASCII and image mode are supported for CDP: devices. 2.4.5 Physical Line Printer (PLPT:) The line printer normally accepts the 128 7-bit ASCII character codes (0-177 octal). However, by specifying a byte size of 8 when opening the printer, a program can transfer 8-bit bytes. Thus, the program can take advantage of printers that have more than 128 characters. Each code sent usually causes a graphic to be printed. (Note that on a 64-character printer, lower case letters are represented as upper case.) However, the carriage control characters do not cause a graphic 2-38
FUNCTIONAL ORGANIZATION OF MONITOR CALLS to be printed; instead they cause specific actions to be taken. The actions taken are determined by the translation RAM and the Vertical Formatting Unit. These actions can be redefined by the installation, and the method by which they are redefined depends on the type of printer being used. For the LP10 printer, which has a carriage control tape, the installation must change the tape to redefine the resulting actions. For the LP05 and LP14 printers, which have a direct access Vertical Formatting Unit and a programmable translation RAM, the installation can redefine the resulting actions by: 1. Reprogramming the VFU by changing the VFU file with the MAKVFU program and reloading this file and the RAM. 2. Reprogramming the translation RAM by changing the RAM file with the MAKRAM program and reloading this file. Refer to the LPINI and MTOPR monitor calls for the functions used in loading the VFU and RAM files. The default actions taken on the carriage control characters, along with the default channels that determine these actions, are as follows: Table 2-6: PLPT: Control Characters ______________________________________________________________________ ASCII Character Default Default Code Channel Name Action ______________________________________________________________________ 11 Tab No vertical motion. Skips to the beginning of every 8th column on the same line. 12 8 Line feed Skips to column 1 on the next line. The last six lines of each page are skipped. 13 7 Vertical tab Skips to column 1 on the line at the next third of a page. 14 1 Form feed Skips to column 1 on the top of the next page. 2-39
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 15 Carriage return No vertical motion. Returns to column 1 of the current line and does not advance the paper. 20 2 Half page Skips to column 1 on the next half page. 21 3 Alternate lines Skips to column 1 on the next even line. 22 4 Three lines Skips to column 1 on the next of every third line. 23 5 Next line Skips to column 1 on the next line without skipping the last six lines on a page. 24 6 Sixth page Skips to column 1 on the next sixth of a page. ______________________________________________________________________ The association between the ASCII code and the channel is determined by the RAM. The association between the channel and the default action is determined by the VFU. Therefore, a change in the VFU changes the association between the channel and the action, which causes the ASCII code to be associated with the new action. 2.4.5.1 PLPT: Status Bits - The following device-dependent status bits are defined for the line printer. These bits can be obtained with the .MORST function of the MTOPR call. Table 2-7: PLPT: Status Bits ______________________________________________________________________ Bit Symbol Meaning ______________________________________________________________________ B0 MO%LCP Lower case printer. B10 MO%FER Fatal hardware error. This error generates an interrupt on software channel .ICDAE (refer to Section 2.6.1). B12 MO%EOF All data sent to the printer has actually been printed. 2-40
FUNCTIONAL ORGANIZATION OF MONITOR CALLS B13 MO%IOP I/O in progress. B14 MO%SER Software error (for example, interrupt character, page counter overflow). B15 MO%HE Hardware error. Forms must be realigned. This error generates an interrupt on software channel .ICDAE. B16 MO%OL Device is off line. B17 MO%FNX Device is nonexistent. B30 MO%RPE RAM parity error. B31 MO%LVU Optical VFU. B33 MO%LVF VFU error. B34 MO%LCI Character interrupt. This generates an interrupt on channel .ICDAE. B35 MO%LPC Page counter register overflow. ______________________________________________________________________ 2.4.6 Spooled Line Printer (LPT:) On most systems, the physical line printer devices (PLPT: devices) are under the control of the line printer spooler, LPTSPL and thus the ordinary user cannot open a PLPT: device and must, instead, open a spooled line printer device (LPT:) When a GTJFN is performed on device LPT:, the device characteristics (returned by DVCHR) are the same as those for device PLPT:. Thus, LPT: devices have units, and a unit number may be specified for the GTJFN. However, when the OPENF is performed, the device characteristics become the same as device DSK:. This is because data written to device LPT: is actually written to a file in the spool directory PS:<SPOOL>. When device LPT: is closed, the file in <SPOOL> is closed and a message sent to the line printer spooler LPTSPL causing it to print the file on the line printer. Thus device LPT: is effectively a disk device, and none of the monitor calls that can be used only to set the characteristics of a PLPT: device can be used for a LPT: device. Also, disk-only operations (such as PMAP) should not be performed for LPT: devices. Note that LPTSPL writes only 7-bit bytes, so opening a LPT: device with any other byte size will cause erroneous results. Also, only ASCII mode is supported for LPT: devices. 2-41
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 2.4.7 Physical Magnetic Tape (MTA:) The following device-dependent bits are defined for magnetic tape. Table 2-8: MTA: Status Bits ______________________________________________________________________ Bit Symbol Meaning ______________________________________________________________________ 18 MT%ILW Drive is write protected 19 MT%DVE Device error (hung or data late) 20 MT%DAE Data error 21 MT%SER Suppress automatic error recovery procedures 22 MT%EOF Device EOF (file) mark 23 MT%IRL Incorrect record length (not the same number of words as specified by the read operation or not a whole number of words) 24 MT%BOT Beginning of tape 25 MT%EOT End of tape 26 MT%EVP Even parity 29-31 MT%CCT Character counter if MT%IRL is on. In the case of an error generated by an incorrect record length, this field contains the number of bytes actually transferred. 32 MT%NSH The selected data mode or density is not supported by the hardware (such as using ANSI-ASCII mode on a TMO3 controller). ______________________________________________________________________ Data transfers to and from the magnetic tape can be performed using either buffered or unbuffered I/O. 2.4.7.1 Buffered I/O - The monitor uses buffered I/O when the sequential I/O calls (for example, BIN/BOUT, SIN/SOUT) are used to read from or write to the magnetic tape. When the tape is opened for sequential I/O (data mode .GSNRM on the OPENF call), the monitor 2-42
FUNCTIONAL ORGANIZATION OF MONITOR CALLS reserves buffer space large enough to hold two records of data. The maximum size of the records is specified with the SET TAPE RECORD-LENGTH command or the .MOSRS function of the MTOPR monitor call. The maximum record lengths for magnetic tapes supported by TOPS-20 are listed in the description of the .MOSRS function of the MTOPR monitor call. The buffers reserved by the monitor allow the user's program to overlap computation with the transfer of data to and from the tape. The BIN monitor call is used to read one byte from the tape, with the monitor filling one buffer with data as the user program is reading bytes from the other buffer. A program reading data from the tape with successive BIN calls obtains a stream of bytes until a tape mark is read. The SIN monitor call is used to read a specified number of bytes with the monitor again performing the double buffering. Both the BIN and the SIN calls read across record boundaries on the tape. The SINR monitor call is used to read variable-length records from the tape because each call returns one record to the user program. If the record on the tape contains more data than the SINR call requests, the remaining bytes in the record are discarded. The SINR call never reads across record boundaries on the tape. Thus, each SINR call begins reading at the first byte of the next record on the tape. With all three calls, the specified record size must be at least as large as the largest record being read from the tape. The BOUT monitor call is used to write one byte on the tape. A program writing data on the tape with successive BOUT calls writes a stream of bytes packed into records of the specified size. The SOUT monitor call is used to write a specified number of bytes into one record equal to the given record size. The SOUTR call is used to write variable-length records on the tape because each call writes at least one record. The size of the record is equal to either the number of bytes specified in the SOUTR call or the number of bytes specified in the maximum record size, whichever is smaller. If the number of bytes requested in the call is greater than the specified record size, then records of the maximum size are written, plus another record containing the remaining bytes. If the end of tape marker is reached during sequential mode output, the data is written and an error return is given. Bit MT%EOT (bit 25) in the device status word will be set to indicate this condition. When a CLOSF monitor call is executed for a magnetic tape to which buffered output is being done, any data remaining in the monitor's buffers will be written to the tape. The monitor writes two tape marks after the last record written and backspaces over the second mark. This allows a subsequent write operation to overwrite the last tape mark, and always leaves two tape marks (a logical end of tape) after the last record written. The monitor does not write records of less than four words long. Thus if the user requests less than four words to be written on a SOUTR or DUMPO (see below) call, the monitor writes a four-word record, 2-43
FUNCTIONAL ORGANIZATION OF MONITOR CALLS completing it with zeros. On a SOUT call, if less than four words remain in the buffer at the time of the CLOSF call, the monitor again fills the record with zeros. 2.4.7.2 Unbuffered I/O - The DUMPI and DUMPO monitor calls are used to read from or write to the magnetic tape without using buffered I/O. (Unbuffered I/O is sometimes called dump mode I/O.) Unbuffered I/O uses a program-supplied command list to determine where to transfer data into or out of the program's address space. The command list can contain three types of entries: 1. IOWD n, loc transfers n words from loc through loc+n-1. The next command is obtained from the location following the IOWD. Each IOWD word reads or writes a separate magnetic tape record. 2. XWD 0, y takes the next command from location y. 3. 0 terminates the command list. Refer to the DUMPI call description for more information. On input, a new record is read for each IOWD entry in the command list. If the IOWD request does not equal the actual size of the record on the tape, an error (IOX5) is returned. The GDSTS monitor call can then be executed to examine the status bits set and to determine the number of bytes transferred. In addition, if a tape mark is read, an error (IOX4) is returned. On output, a new record is written for each IOWD entry in the command list. There are two modes available in unbuffered I/O. In the normal mode, the monitor waits for the data transfer to complete before returning control to the program. In the no-wait mode, the monitor returns control immediately after queuing the first transfer so that the program can set up the second transfer. The monitor then waits for the first transfer to complete before queuing the second. If the first transfer is successful, the second one is started, and control is returned to the program. If the first transfer is not successful, an error is returned in AC1, and the second one is not started. The desired mode is specified by bit DM%NWT in AC1 on the DUMPI or DUMPO call. 2.4.7.3 Magnetic Tape Status - The status word of a magnetic tape can be obtained with the GDSTS call or individual status bits can be obtained with the MTOPR call. The GDSTS call waits for all activity to stop during sequential mode output, dump mode, and spacing operations before obtaining the status. A GDSTS call executed during sequential mode input returns the status of the current record. 2-44
FUNCTIONAL ORGANIZATION OF MONITOR CALLS Reading from or writing to a magnetic tape cannot be done if there are any errors set in the device status word. The program can clear errors with the SDSTS call or the .MOCLE function of the MTOPR call. 2.4.7.4 Reading a Tape in the Reverse Direction - With the .MOSDR function of the MTOPR call, the program can cause the tape to move in the reverse direction (toward the beginning of the tape) during read operations. The data in each record are returned in the forward order, but the records themselves are returned in the reverse order. The sensing-foil marking the beginning of tape is treated as an EOF tape mark. When the SIN call is used to read data in the reverse direction, the byte size and record length specified in the call should equal the byte size and record length of the records on the tape. If the record characteristics specified in the call do not equal the characteristics of the records on tape, the bytes are returned out of phase with the bytes in the tape record. When the SINR call is used to read data in the reverse direction, the number of bytes requested by the call should be at least as large as the size of the record on the tape. If the requested number is smaller than the number of bytes in the tape record, the remaining bytes in the record are discarded from the beginning of the record and not from the end of the record. 2.4.7.5 Hardware Data Modes - By using the .MOSDM function of the MTOPR call, the program can set the mode for storing data on a magnetic tape. The following descriptions indicate how bits are stored in the tracks and the number of frames required to store a 36-bit word of data. The parity bit is represented in the diagrams by "P". NOTE Data undergoes 2 transformations before it is actually written to magnetic tape. The first transformation occurs when a word of data is formed into frames by the tape controller. The formats of these frames are illustrated in the diagrams below. A second transformation occurs when the tape drive receives a frame of data from the controller, and physically writes that frame to tape: the bits within the frame are rearranged and then written. This final format is standardized throughout the computer industry and is designed to (among other things) place 2-45
FUNCTIONAL ORGANIZATION OF MONITOR CALLS the parity bit in the center of the tape (the "safest" part of the tape). Because this final format is standardized, it is "invisible" and does not affect user programs in any way. Programmers who must deal with the problem of transferring data between DEC machines and the machines of other vendors need only concern themselves with the formats shown below. Thus, while it is technically incorrect to think of the diagrams below as showing the physical format of a word stored on magnetic tape, it is convenient to do so, and this simplification is made in this manual. Unbuffered (Dump) Mode This mode stores a word of data as a 36-bit byte in five frames of a 9-track tape. Note that the fifth frame is partially used. This mode is normally the default mode. TRACKS FRAMES 9 8 7 6 5 4 3 2 1 B0 B1 B2 B3 B4 B5 B6 B7 P 1 B8 B9 B10 B11 B12 B13 B14 B15 P 2 B16 B17 B18 B19 B20 B21 B22 B23 P 3 B24 B25 B26 B27 B28 B29 B30 B31 P 4 B32 B33 B34 B35 0 1 0 0 P 5 Industry Compatible Mode This mode stores a word of data as four 8-bit bytes in four frames of a 9-track tape. On a read operation, four frames of 8-bit bytes are read, left-justified, into a word. The remaining four bits of the word are 0, or are copies of the parity bits, depending on the hardware; these bits are not data. On a write operation, the leftmost four 8-bit bytes (bits 0 through 31) of the word are written in four frames on the tape. The rightmost four bits (bits 32 through 35) of the word are ignored and are not written on the tape. This mode is compatible with any machine that reads and writes 8-bit bytes. TRACKS FRAMES 9 8 7 6 5 4 3 2 1 B0 B1 B2 B3 B4 B5 B6 B7 P 1 B8 B9 B10 B11 B12 B13 B14 B15 P 2 B16 B17 B18 B19 B20 B21 B22 B23 P 3 B24 B25 B26 B27 B28 B29 B30 B31 P 4 2-46
FUNCTIONAL ORGANIZATION OF MONITOR CALLS ANSI ASCII Mode This mode stores a word of data as five 7-bit bytes in five frames of a 9-track tape. On a read operation, five frames of 7-bit bytes are read, left-justified, into a word. The remaining bits (bits 35) of each frame are ORed together, and the result is placed in bit 35 of the word. On a write operation, the leftmost five 7-bit bytes of the word are written in five frames on the tape. Bit 35 of the word must be zero to conform to ANSI standards. It is written into the high-order bit of the fifth frame, and the remaining high-order bits of the first four frames are 0. This mode is useful when transferring ASCII data from TOPS-20 to machines that read 8-bit bytes. This mode is available on any 9-track drive connected to a TM02 or DX20 tape controller. TRACKS FRAMES 9 8 7 6 5 4 3 2 1 0 B0 B1 B2 B3 B4 B5 B6 P 1 0 B7 B8 B9 B10 B11 B12 B13 P 2 0 B14 B15 B16 B17 B18 B19 B20 P 3 0 B21 B22 B23 B24 B25 B26 B27 P 4 B35 B28 B29 B30 B31 B32 B33 B34 P 5 SIXBIT Mode This mode stores a word of data as six 6-bit bytes in six frames of a 7-track tape. This mode is the only supported hardware mode for 7-track tapes. TRACKS FRAMES 7 6 5 4 3 2 1 B0 B1 B2 B3 B4 B5 P 1 B6 B7 B8 B9 B10 B11 P 2 B12 B13 B14 B15 B16 B17 P 3 B18 B19 B20 B21 B22 B23 P 4 B24 B25 B26 B27 B28 B29 P 5 B30 B31 B32 B33 B34 B35 P 6 High Density Mode In this mode, two 36-bit words are stored in 9 frames. High density mode is available on any 9-track drive connected to a DX20 controller. 2-47
FUNCTIONAL ORGANIZATION OF MONITOR CALLS TRACKS FRAMES 9 8 7 6 5 4 3 2 1 B0 B1 B2 B3 B4 B5 B6 B7 P 1 B8 B9 B10 B11 B12 B13 B14 B15 P 2 B16 B17 B18 B19 B20 B21 B22 B23 P 3 B24 B25 B26 B27 B28 B29 B30 B31 P 4 B32 B33 B34 B35 B0 B1 B2 B3 P 5 B4 B5 B6 B7 B8 B9 B10 B11 P 6 B12 B13 B14 B15 B16 B17 B18 B19 P 7 B20 B21 B22 B23 B24 B25 B26 B27 P 8 B28 B29 B30 B31 B32 B33 B34 B35 P 9 2.4.8 Logical Magnetic Tape (MT:) Logical magnetic tape devices are used so that the system operator can fulfill a MOUNT request with any available tape drive that meets the requirements of the MOUNT request. The user never knows and need not know which physical drive (MTA:) is mapped to the logical drive (MT:). Some JSYS functions available for MTA: devices are not available for MT: devices. Also, MT: devices are commonly used in a tape-labeled environment which causes further restrictions in the JSYS functions available for MT: devices. See the appropriate JSYSs for any restrictions that may apply. 2.4.9 Terminal (TTY:) Most monitor calls in this group return an error if the device referenced is assigned to another job. However, a process with WHEEL capability enabled can reference a terminal assigned to another job (as controlling terminal or with ASND). The monitor calls pertaining to terminals have no effect, or return default-value information, when used with other devices. The following status bits are defined for TTYs. Bit Symbol Meaning B35 GD%PAR The TTY will tolerate a parity bit. Any program producing binary output for a TTY should check this bit to determine if it should apply parity. If parity is to be applied, the TTY must be opened with an 8-bit bytesize; otherwise, a 7-bit bytesize must be used. DECnet NVTs will not accept a parity bit. 2-48
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 2.4.9.1 JFN Mode Word - Each terminal in TOPS-20 is associated with a mode word. This word can be read with the RFMOD call and changed with the SFMOD and STPAR calls. The SFMOD call affects only the modes that are program-|related: wakeup control, echo mode, and terminal data mode; thus a program can execute a SFMOD call without affecting previously-|established device modes. The STPAR call, on the other hand, affects fields that describe device parameters (mechanical characteristics, page length and width, case conversion, and duplex control). Table 2-9 shows the format of the JFN mode word. Table 2-9: JFN Mode Word ______________________________________________________________________ Bit Symbol Changed by Function ______________________________________________________________________ 0 TT%OSP SFMOD output suppress control (1=ignore output; 0=allow output) 1 TT%MFF STPAR has mechanical form feed 2 TT%TAB STPAR has mechanical tab 3 TT%LCA STPAR has lower case 4-10 TT%LEN STPAR page length 11-17 TT%WID STPAR page width 18-23 TT%WAK SFMOD wakeup control on: B18: not used TT%IGN B19: ignore the other TT%WAK bits TT%WKF B20: formatting control character TT%WKN B21: non-formatting control character TT%WKP B22: punctuation character TT%WKA B23: alphanumeric character 24 TT%ECO SFMOD echos on 25 TT%ECM STPAR echo mode 26 TT%ALK TLINK accept links 27 TT%AAD TLINK accept advice 28-29 TT%DAM SFMOD terminal data mode .TTBIN 00: no translation .TTASC 01: translate both echo and output .TTATO 10: translate output only .TTATE 11: translate echo only 30 TT%UOC STPAR upper case output control 0: do not indicate 1: indicate by 'X 31 TT%LIC STPAR lower case input control 0: no conversion 1: convert lower to upper 32-33 TT%DUM STPAR duplex mode .TTFDX 00: Full duplex 2-49
FUNCTIONAL ORGANIZATION OF MONITOR CALLS .TTHDX 10: Character half duplex .TTLDX 11: Line half duplex 01: Reserved for DEC 34 TT%PGM STPAR pause-on-command mode (1=enable pause-on-command mode, 0=disable pause-on-command mode.) This function enables/disables the TOPS-20 feature that allows a user to manually stop TTY output with ^S and resume it with ^Q. See MTOPR function .MOXOF for pause-at-end-of-page mode. 35 TT%CAR system carrier state; on if line is a dataset and the carrier is on. ______________________________________________________________________ Bit 0 (TT%OSP) implements the CTRL/O function. If this bit is set, all program output directed to the terminal is discarded. When the bit is off, program output is buffered and sent as usual. The current contents of the output buffer are not cleared when this bit is set; clearing the buffer must be done explicitly (by means of the CFOBF call) if output is to be stopped immediately. Any input function clears this bit. Bits 1, 2, and 3 (TT%MFF, TT%TAB, and TT%LCA) define several of the mechanical capabilities of the terminal and affect character handling on both input and output. Form feeds and tabs are simulated if the terminal does not have the required mechanical capability, or if simulation has been requested by the SFCOC call. Bits 4-10 (TT%LEN) determine the number of line feeds necessary to simulate a formfeed, or the number of lines to fit on the display screen. A 0 value means the declared length of the page is indefinitely large. Bits 11-17 (TT%WID) determine the point at which the output line must be continued on the next line by inserting a carriage return-line feed. If 0, no line folding occurs. Bits 18-23 (TT%WAK) define the particular class of characters that, when input from the terminal, will wake up a waiting program. Refer to Section 2.4.9.3 for the definitions of the wakeup classes. Note that the class-wakeup scheme is maintained for compatibility with older programs. Newer programs should use the .MOSBM function of the MTOPR JSYS as it has more resolution and causes less system load. Bit 24 (TT%ECO) defines if echos are to be given. If this bit is off, echoing is turned off. This is useful when the program is accepting a password or is simulating non-standard echoing procedures. 2-50
FUNCTIONAL ORGANIZATION OF MONITOR CALLS Bit 25 (TT%ECM) defines when the echo will occur. If this bit is off, the echo will occur when the program reads the character. That is, the echo occurs immediately if the program is waiting for input or is deferred if the program is not waiting for input. This is the standard echo mode which produces a correctly ordered typescript (i.e., program input and output appear in the order in which they occurred). If this bit is on, the echo occurs as soon as the character is typed. Note that this mode may cause editing to appear out of order on the typescript. This occurs because editing is performed as the program reads the character and not necessarily when the echo occurs. Bits 28-29 (TT%DAM) define the terminal data mode. The four possible data modes are: 00 Binary (.TTBIN), 8-bit input and output. There is no format control or control group translation and no echoing. However, ^S and ^Q are still under control of TT%PGM. 01 ASCII (.TTASC), 7-bit input and output, plus parity on for control group output. There is format control as well as simulation and translation of control group for input (echo) and output according to the control words given on the SFCOC JSYS. This is the usual terminal data mode. 10 Disable the translation of echo (.TTATO). In all other respects, same as .TTASC. 11 Disable the translation of output (.TTATE). Obeys the CCOC word on input only. In all other respects, same as .TTASC. The last two data modes allow the user to selectively disable the translation of control characters for input or output. When translation is disabled, control characters are always sent. Simulation of formatting control characters is still performed if requested by the control words of the RFCOC or SFCOC JSYS or if the device does not have the required mechanical capability. The translation typically results in some control characters being indicated by graphics instead of being sent as is. For example, disabling the translation of output characters is appropriate for some display terminals when the program must send untranslated control characters to control the display, but requires that the control characters typed by the user be indicated in the usual way. Bit 30 (TT%UOC) specifies that upper case terminal output is to be indicated by 'X (single quote preceding character that is upper case) if TT%LCA is not set. This is primarily intended for terminals that are not capable of lower case output. Bit 31 (TT%LIC) specifies that lower case terminal input is to be translated to upper case and that codes 175 and 176 are to be converted to code 33. This is useful for older terminals that send codes 175 or 176 in response to the ALT or ESC key. 2-51
FUNCTIONAL ORGANIZATION OF MONITOR CALLS Bits 32-33 (TT%DUM) define the three duplex modes presently available. Full duplex (.TTFDX) requires the system to generate the appropriate echo for each character typed in. Character half duplex (.TTHDX) assumes the terminal will internally echo each character typed but will require an additional echo for formatting characters such as carriage return. Line half duplex (.TTLDX) is similar to character half duplex but does not generate a line feed echo after a carriage return. Bit 34 (TT%PGM) specifies the output mode. In display mode, the user can create a pause in the output while he reads material that would otherwise quickly disappear off the screen. The output is stopped with the CTRL/S character and started with the CTRL/Q character. Also, output automatically stops whenever a page, as defined by TT%LEN, has been output; output is resumed with CTRL/Q. Bit 35 (TT%CAR) indicates the carrier state. If the line is a dataset, this bit is on if the carrier is on. If the line is not a dataset, this bit is undefined. 2.4.9.2 Control Character Output Control - Each terminal has two control character output control (CCOC) words. Each word consists of 2-bit bytes, one byte for each of the control characters (ASCII codes 0-37). The bytes are interpreted as follows: 00: ignore (send nothing) 01: indicate by ^X (where X is the character) 10: send character code 11: simulate format action The RFCOC and SFCOC monitor calls read and manipulate the CCOC words. Table 2-10 lists the ASCII code for each character. 2.4.9.3 Character Set - The following information describes each character in the TOPS-20 character set that is pertinent to the monitor calls in this group. The wakeup class (refer to TT%WAK in Section 2.4.9.1) is abbreviated as follows: F formatting control character C non-formatting control character P punctuation character A alphanumeric character Refer to Section 2.4.9.2 for the explanation of the control character output control (CCOC) words. The following table lists the wakeup classes for the TOPS-20 character set (ASCII): 2-52
FUNCTIONAL ORGANIZATION OF MONITOR CALLS Table 2-10: Wakeup Classes/CCOC Word Bits ______________________________________________________________________ ASCII Wakeup CCOC Code Class Word(bits) Character or Control Character ______________________________________________________________________ 0 C 1(B0,1) Ctrl/@ null,break 1 C 1(B2,3) Ctrl/A 2 C 1(B4,5) Ctrl/B 3 C 1(B6,7) Ctrl/C 4 C 1(B8,9) Ctrl/D 5 C 1(B10,11) Ctrl/E 6 C 1(B12,13) Ctrl/F 7 C 1(B14,15) Ctrl/G bell 10 F 1(B16,17) Ctrl/H backspace 11 P 1(B18,19) Ctrl/I horizontal tab 12 F 1(B20,21) Ctrl/J line feed 13 C 1(B22,23) Ctrl/K vertical tab 14 F 1(B24,25) Ctrl/L form feed 15 F 1(B26,27) Ctrl/M carriage return 16 C 1(B28,29) Ctrl/N 17 C 1(B30,31) Ctrl/O 20 C 1(B32,33) Ctrl/P 21 C 1(B34,35) Ctrl/Q 22 C 2(B0,1) Ctrl/R 23 C 2(B2,3) Ctrl/S 24 C 2(B4,5) Ctrl/T 25 C 2(B6,7) Ctrl/U 26 C 2(B8,9) Ctrl/V 27 C 2(B10,11) Ctrl/W 30 C 2(B12,13) Ctrl/X 31 C 2(B14,15) Ctrl/Y 32 C 2(B16,17) Ctrl/Z 33 All 2(B18,19) Escape (Altmode) 34 C 2(B20,21) Ctrl/Backslash 35 C 2(B22,23) Ctrl/Right Square Bracket 36 CxD 2(B24,25) Ctrl/Uparrow 37 F 2(B26,27) Ctrl/Backarrow 40 P Space 41 P ! 42 P " 43 P # 44 P $ 45 P % 46 P & 47 P ' 50 P ( 51 P ) 52 P * 53 P + 54 P , 2-53
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 55 P - 56 P . 57 P / 60-71 A 0-9 72 P : 73 P ; 74 P < 75 P = 76 P > 77 P ? 100 P @ 101-132 A Upper Case Letters A-Z 133 P [ 134 P \ 135 P ] 136 P ^ 137 P _ 140 P Accent (Grave) 141-172 A Lower Case Letters a-z 173(1) P Left Brace 174(1) P Vertical Bar 175(1) P Right Brace 176(1) P Tilde 177 All Delete (Rubout) ______________________________________________________________________ NOTE 1. Escape(33) and Delete(177) are considered to be in all wakeup classes. 2. If the terminal has B31(TT%LIC) on in the JFN mode word, codes 175 and 176 are converted to code 33 on input. 3. The class-wakeup scheme is maintained for compatibility with older programs. New programs should use the .MOSBM function of the MTOPR JSYS, as it has more resolution (it allows a 4-word character mask to specify individual wakeup characters) and causes less system load (low-level monitor I/O routines are subjected to fewer wakeups). Both the SFMOD JSYS and the .MOSBM function set the same mask; however, SFMOD computes wakeup classes from the mask while .MOSBM uses character-oriented wakeups. 2-54
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 2.4.9.4 Terminal Characteristics Control - The various types of terminals have different characteristics for output processing, depending on their type and speed. The characteristics that can be associated with terminals are: 1. Mechanical form feed and tab 2. Lower case 3. Padding after carriage return 4. Padding after line feed 5. Padding after mechanical tab 6. Padding after mechanical form feed 7. Page width and length 8. Cursor commands Instead of setting each of these parameters for his line, the user can specify a terminal type number, which causes the appropriate parameters to be set. Refer to the STTYP monitor call. The defined terminal types, along with their characteristics, are listed below. Table 2-11: Terminal Characteristics ______________________________________________________________________ Number Terminal Symbol Characteristics ______________________________________________________________________ 0 TTY model 33 .TT33 No mechanical form feed or tab, has upper case only, no padding after carriage return and line feed, padding after tab and form feed, page width 72, page length 66 1 TTY model 35 .TT35 Has mechanical form feed and tab, has upper case only, no padding after carriage return and line feed, padding after tab and form feed, page width 72, page length 66 2 TTY model 37 .TT37 No mechanical form feed or tab, lower case, no padding after carriage return and line feed, 2-55
FUNCTIONAL ORGANIZATION OF MONITOR CALLS padding after tab and form feed, page width 72, page length 66 3 TI/EXECUPORT .TTEXE No mechanical form feed or tab, lower case, padding after carriage return only page width 80, page length 66 4-7 Reserved for customer 8 Default .TTDEF No mechanical form feed or tab, lower case, full padding, page width 72, page length 66 9 Ideal .TTIDL Has mechanical form feed and tab, lower case, no padding, no specified width and length 10 VT05 .TTV05 No mechanical form feed, has mechanical tab, has upper case only, no padding after carriage return and tab, padding after line feed and form feed, page width 72, page length 20, has cursor commands 11 VT50 .TTV50 No mechanical form feed or tab, has upper case only, no padding, page width 80, page length 12, has cursor commands 12 LA30 .TTL30 No mechanical form feed or tab, has upper case only, full padding, page width 80, page length 66 13 GT40 .TTG40 No mechanical form feed or tab, lower case, no padding, page width 80, page length 30 14 LA36 .TTL36 No mechanical form feed or tab, lower case, no padding, page width 132, page length 66 15 VT52 .TTV52 No mechanical form feed, has mechanical tab, lower case, no padding, page width 80, page length 24 16 VT100 .TT100 No mechanical form feed, has mechanical tab, lower case, no padding, page width 80, page length 24, has cursor commands 2-56
FUNCTIONAL ORGANIZATION OF MONITOR CALLS When used in VT52 mode, the terminal type should be set to .TTV52. 17 LA38 .TTL38 No mechanical form feed, has mechanical tab, lower case, no padding, page width 132, page length 66. 18 LA120 .TT120 Has mechanical form feed and tab, lower case, no padding, page width 132, page length 60 35 VT125 .TT125 No mechanical form feed, has mechanical tab, lower case, no padding, page width 80, page length 24, has cursor commands and graphics capabilities 36 VK100 .TTK10 No mechanical form feed, has mechanical tab, lower case, no padding, page width 84, page length 24, has cursor commands and color graphics capabilities 37 VT102 .TT102 No mechanical form feed, has mechanical tab, lower case, no padding, page width 80, page length 24, has cursor commands 39 VT131 .TT131 No mechanical form feed, has mechanical tab, lower case, no padding, page width 80, page length 24, has cursor commands 40 VT200 series .TT200 No mechanical form feed, has mechanical tab, lower case, no padding, page width 80, page length 24, has cursor commands; some models may have additional features 52 VT300 .TT300 No mechanical form feed, has mechanical tab, lower case, no padding, page width 80, page length 24, has cursor commands; some models may have additional features ______________________________________________________________________ The STTYP monitor call sets the terminal type number for a line, and the GTTYP monitor call obtains the terminal type number. 2-57
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 2.4.9.5 Terminal Linking - It is possible to link the output of any line to up to four other lines. The refuse/accept link bit TT%ALK (bit 26) in the JFN mode word controls terminal linking. If the bit is off for a particular terminal, a user cannot link to that terminal unless the user has WHEEL or OPERATOR privileges enabled. Although this bit can be read with the RFMOD monitor call, the bit can only be set with the TLINK call. Refer to the TLINK monitor call for a description of terminal linking. 2.4.9.6 Terminal Advising - It is possible to receive advice from any terminal line in the system. The refuse/accept advice bit TT%AAD (bit 27) in the JFN mode word controls terminal advising. If this bit is off for a particular terminal, users cannot simulate typing on that terminal by means of the STI monitor call unless the user has WHEEL or OPERATOR privileges enabled. Although this bit can be read with the RFMOD monitor call, it can only be set with the TLINK call. Refer to the TLINK monitor call for a description of terminal advising. 2.4.10 Transmission Control Protocol (TCP:) The TCP: interface is consistent with other TOPS-20 network interfaces and uses standard TOPS-20 JSYSs for most functions. Any TCP: specific functions are accessible through the TCOPR% JSYS. The programmer using the TCP: interface must provide information to the operating system about the virtual connection as well as various parameters dealing with the type and quality of service required. Connections are established using the GTJFN and OPENF JSYSs. Input/output is performed with the BIN, BOUT, SIN, SOUT, SINR, SOUTR, and TCOPR% calls. Status information is obtained from the TCOPR%, SOBF, and GDSTS calls. 2.4.10.1 GTJFN JSYS - The GTJFN JSYS is used to obtain an indexable file handle on a TCP: connection. The format of the GTJFN call for TCP: is the same as for any other GTJFN call (refer to GTJFN description in Chapter 3). The file name string for a TCP: GTJFN call specifies data about the desired connection. The format for the GTJFN file specification is as follows: 2-58
FUNCTIONAL ORGANIZATION OF MONITOR CALLS TCP:[LOCALHOST-][LOCALPORT[#]].[FOREIGNHOST-][FOREIGNPORT][;A1...] Bracket pairs indicate optional parameters. "LOCALHOST-" specifies the local host address for this connection. This is useful for hosts that have multiple local addresses. The default for this field is the Internet address of the local host. This field can be specified using the alphanumeric host name or the octal host number. The "-" after the host name is required to delimit between the host name/number and the port number, and must be included even if the port number is omitted. "LOCALPORT" specifies the local port number to use for this connection. The port number specified is in decimal. This field is optional. Port numbers are in the range 1 to 65535. Ports in the range 1 to 255 are special ports that require special privileges in order to be assigned. The "#" (must be preceeded by a control-V) must be appended to a port in the range 1 to 255 and in the range 32768 to 65535 to prevent accidental assignment. Ports in the range 256 to 32767 are reserved for users. Ports in the range 32768 to 65535 are assigned as default port numbers on an as-needed basis. If no local port is specified, a number in the range 32768 to 65535 is assigned. A local port in the range 1 to 255 requires SC%WHL, SC%OPR, SC%NAS, or SC%NWZ privileges. The "." is a delimiter separating the local host connection values from the foreign host connection values. "FOREIGNHOST-" is used to specify the foreign host for which this connection is destined. It is an optional field. If the FOREIGNHOST is not specified, any host using any port is allowed to use this connection. "FOREIGNPORT" is used is used to specify the foreign port for which this connection is destined. If this field is omitted, any foreign port is allowed to use this connection. ";A1..." specifies various attributes that this connection will use. The valid attributes are detailed in the GTJFN JSYS description in Chapter 3. 2.4.10.2 OPENF JSYS - The OPENF JSYS is used to force the TOPS-20 monitor to initiate the connection. The OPENF call is issued after a GTJFN call. Many parameters pertaining to this connection can also be set using the TCOPR% JSYS. Some parameters (for example, security levels) must be set before the OPENF JSYS is issued. The format of the OPENF call for TCP is the same as for other devices. In TCP a connection is identified by both the foreign port and the local port. Two connections from system A to system B are allowed to 2-59
FUNCTIONAL ORGANIZATION OF MONITOR CALLS have the same local port or the same foreign port, but the connections cannot have both the same local and foreign ports simultaneously. A connection using a default local port will always be different from any other connection using a default local port. Wild connections (connections that allow any foreign host and/or foreign port) can be duplicated in multiple JFNs (in this job or other jobs). 2.4.10.3 Other JSYSs - The SOUTR JSYS has the same functionality as the SOUT JSYS with one addition. The SOUTR JSYS sets the TCP PUSH flag for the last message generated by this call. This also forces all data currently held in local buffers to be sent immediately. The SINR JSYS has the same functionality as the SIN JSYS with one addition. The SINR JSYS returns when a TCP message returns with the PUSH flag set. SINR also returns when the byte count is exhausted. The following monitor calls are used for device control. Calls marked with an asterisk ("*") require privileges for specific funcitons. ASND Assigns a device ATACH* Attaches controlling terminal to a job CFIBF Clears terminal's input buffer CFOBF Clears terminal's output buffer DEVST Translates a device designator to a string DIBE Dismisses until terminal input buffer is empty DOBE Dismisses until terminal output buffer is empty DTACH Detaches controlling terminal from a job DVCHR Returns device characteristics GDSKC Returns disk usage GDSTS Returns the device status GTTYP Returns terminal type number LPINI Loads VFU or translation RAM MSTR Performs structure-dependent functions MTOPR* Performs device-dependent functions MTU% Performs functions for logical tape devices (MT: devices) RELD Releases a device RELIQ% Releases ownership of an Internet queue RFCOC Returns control character output control words RFMOD Returns the JFN mode word RFPOS Returns current position of the terminal SDSTS Sets the device status SFCOC Sets control character output control words SFMOD Sets program-related fields in the JFN mode word SFPOS Sets current position of the terminal SIBE Skips if input buffer is empty SOBE Skips if output buffer is empty SOBF Skips if output buffer is full SPOOL Defines and initializes input spooling STDEV Translates a string to a device designator 2-60
FUNCTIONAL ORGANIZATION OF MONITOR CALLS STPAR Sets device-related fields in the JFN mode word STTYP Sets terminal type number TLINK Controls terminal linking 2.5 SOFTWARE DATA MODES I/O may be performed in one of several modes, depending on the device. (The mode is specified with the OPENF call.) The range of possible I/O modes is from 0 to 17 (octal). However, except for the TCP: device and less common hardware devices (such as paper-tape punches/readers) the only meaningful modes are 0, 10, and 17. The following discussion lists the major devices supported by TOPS-20 and the applicable I/O modes: Device Mode Symbol Explanation CDP: PCDP: 0 .GSNRM Normal mode - allows unit-record output. For card punches, this mode converts each 7-bit ASCII character to a 12-bit card-column code (Hollerith code) and outputs that code to the device. 10 .GSIMG Image mode - sends an "image" (rather than converting to Hollerith) of each byte. These are 12-bit bytes and are assumed to be in Hollerith code. If the device is opened with a byte size smaller than 12-bits, each byte sent is zero-padded on the left to form a 12-bit byte. CDR: PCDR: 0 .GSNRM Normal mode - allows unit-record input. For card readers, this mode converts each 12-bit card-column code (Hollerith code) to a 7-bit ASCII character and returns the ASCII character to the program. 10 .GSIMG Image mode - returns an "image" (rather than converting to ASCII) of the 12-bit card-code for each character read. In order to receive the full 12 bits, the program must use 12-bit bytes. Augmented image mode - this is a 16-bit version of image mode. The leftmost 4 bits are returned by the card reader controller. The first bit indicates that the column has a Hollerith error (and thus the card should 2-61
FUNCTIONAL ORGANIZATION OF MONITOR CALLS be rejected). The next 3 bits contain a value ranging from 0 to 7. If the value is from 1 to 7, it indicates that a punch occurred in that row. If the value is 0, it indicates that no punch occurred in columns 1 - 7. Effectively, a zero value indicates that a non-ASCII character was punched. This mechanism allows conversion to ASCII using a table with only 256 entries as opposed to a table with 4096 entries for 12-bit characters. This mode is available on PCDR: devices only and is used by specifying mode .GSIMG with a 16-bit bytesize. DCN: SRV: 0 .GSNRM Normal mode - allows byte I/O. This device may be opened with 7, 8 or 36-bit bytes. However, all transfers are actually done with 8-bit bytes, and opening the device with an 8-bit bytesize will give the greatest efficiency. Requires DECnet software. .b.i-15 1 .GSSMB Small Buffer mode - allows small data segments to be transmitted to terminals. This mode is used by DECnet in communication with terminals, SRV:, and DCN: devices. DSK: 0 .GSNRM Normal mode - allows buffered byte, string, and paged I/O in 1 to 36-bit bytes. By definition, a DSK: device may be opened in any I/O mode, however the effect is the same as mode 0. LPT: PLPT: 0 .GSNRM Normal mode - allows buffered byte and string output. PTY: 0 .GSNRM Normal mode - for a PTY, the "mode" is merely used to open the device. The PTY will receive data according to the I/O mode of the TTY associated with it. MTA: MT: 0 .GSNRM Normal mode - allows buffered byte and string I/O. This is the most common I/O mode. 17 .GSDMP Dump mode - this mode is unbuffered by default (it can be set up for double-buffering) and is usually used to transfer blocks of data from tape to disk or disk to tape. For tape, a dump-mode read 2-62
FUNCTIONAL ORGANIZATION OF MONITOR CALLS (performed by DUMPI JSYS) performs reads on the basis of physical records. If less than a physical record is read, the data is transferred and an error is returned. A subsequent DUMPI will begin reading the tape at the start of the next physical record. TCP: For TCP/IP systems only. All TCP data transfers are made with 8-bit bytes. 32-bit mode is only provided as an easy way to lower byte instructions required for data transfer. TCP: connections are full duplex. OF%RD and OR%WR must be set in the OPENF call. 0 .TCMWD Default mode - Same as .TCMWI. 1 .TCMWI Interactive mode. Wait for connection to be fully open before returning from the OPENF JSYS. Wait for the connection to be fully closed before returning from the CLOSF JSYS. Send all bytes as soon as possible (send data after each SOUT or BOUT). This mode attempts to give the most interactive response possible by sending many small messages. .ts 9,16,26 2 .TCMWH High throughput mode. Same action as mode zero for OPENF and CLOSF. Hold data in local buffers until accumulated bytes are sufficient for efficient transmission, or until transmission is requested with the TCOPR% or SOUTR JSYS. This mode attempts to give high throughput at low overhead by sending large messages. 3 .TCMII Immediate return mode. Return to user program immediately without waiting for a OPENF or CLOSF JSYS. Send all bytes as soon as possible (interactive mode). 4 .TCMIH Buffered immediate return mode. Same as mode 2 except that OPENF and CLOSF return immediately. NUL: 0 .GSNRM Normal mode 10 .GSIMG Image mode 17 .GSDMP Dump mode The NUL device is a pseudo device used to "throw away" unwanted output from a program. The device may be opened in any mode. 2-63
FUNCTIONAL ORGANIZATION OF MONITOR CALLS TTY: 0 .GSNRM Normal mode - allows buffered byte and string I/O. In this mode, format control and simulation and translation of control characters are performed by the monitor for input (echo) and output. (These services can be turned off by setting the appropriate bit in the JFN mode word.) Using an 8-bit bytesize in this mode implicitly changes the mode to .GSIMG (see below). 10 .GSIMG Image mode - allows buffered byte and string I/O, but disables format control and simulation and translation of control characters. On input, if the byte size is 8 bits, a parity bit (odd) is returned with the character. The parity bit is the high-order bit. On output, attempting to send an 8-bit byte that has incorrect parity may cause a device error. However, most terminals ignore a user-supplied parity bit. This mode can cause some reduction in the CPU time charged to a job for doing TTY output. The reduction is small, however, for TTY input. This is because the average process outputs many more characters than it inputs (the average ratio is approximately 20 characters output for each character input). 2.6 SOFTWARE INTERRUPT SYSTEM The monitor calls in this group are used for controlling the software interrupt system. Note that if the program has an ERJMP or ERCAL after a monitor call that normally causes an interrupt on failure, the ERJMP or ERCAL overrides the interrupt. Refer to the TOPS-20 Monitor Calls User's Guide for an overview and description of the software interrupt system. 2.6.1 Software Interrupt Channels Each interrupt is associated with one of 36 software interrupt channels below. The user program can assign channels 0-5 and 23-35 to various conditions, such as terminal interrupts, IPCF interrupts, ENQ/DEQ interrupts, PTY conditions, and terminal buffers becoming empty. The remaining channels are permanently assigned to certain error conditions. Any channel may be used for program-initiated interrupts (IIC call). 2-64
FUNCTIONAL ORGANIZATION OF MONITOR CALLS Table 2-12: Software Interrupt Channels ______________________________________________________________________ Channel Symbol Meaning ______________________________________________________________________ 0-5 Assignable by user program 6 .ICAOV Arithmetic overflow (includes NODIV) 7 .ICFOV Arithmetic floating point overflow (includes FXU) 8 Reserved for DIGITAL 9 .ICPOV Pushdown list (PDL) overflow[1] 10 .ICEOF End of file condition 11 .ICDAE Data error file condition[1] 12 .ICQTA Disk full or quota exceeded when creating a new page[1] 13-14 Reserved for DIGITAL 15 .ICILI Illegal instruction[1] 16 .ICIRD Illegal memory read[1] 17 .ICIWR Illegal memory write[1] 18 Reserved for DIGITAL 19 .ICIFT Inferior process termination or forced freeze 20 .ICMSE System resources exhausted[1] 21 Reserved for DIGITAL 22 .ICNXP Reference to non-existent page 23-35 Assignable by user program [1] These channels are panic channels and cannot be completely deactivated. (Refer to Section 2.6.5.) ______________________________________________________________________ 2-65
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 2.6.2 Software Interrupt Priority Levels Each channel is assigned to one of three priority levels. The priority levels are numerically referenced as level 1, 2, or 3 with level 1 being the highest level interrupt. Level 0 is not a legal priority level. If an interrupt request occurs in a process where the level associated with the channel is 0, the system considers the process not prepared to handle the interrupt. The process is then frozen or terminated according to the setting of SC%FRZ (bit 17) in its capabilities word. (Refer to Section 2.7.1.) 2.6.3 Software Interrupt Tables Before using the software interrupt system, a process must set up the following two tables and declare their addresses with the XSIR% or SIR calls. LEVTAB A 3-word table, indexed by priority level minus 1. There are two forms of this table. In the general form, each word contains the 30-bit address of the first word of a two-word block in the process address space. The block addressed by word n of LEVTAB is used to store the global PC flags and address when an interrupt of level n+1 occurs. The PC flags are stored in the first word of the PC block, and the PC address is stored in the second. This form of the table must be used with the XSIR% and XRIR% monitor calls, and can be used in any section. The older form of the interrupt level table can be used in any single-section program, and must be used with the SIR and RIR calls. This table also contains three words, indexed by the priority level minus 1. Each word contains zero in the left half, and the 18-bit address of the word in which to store the one-word section-relative PC in the right half. CHNTAB A 36-word table, indexed by channel number. This table also has two formats. The general format, for use with the XSIR% and XRIR% calls, can be used in any section of memory. Each word contains, in bits 0-5, the priority level (1, 2, or 3) to assign to interrupts generated on that channel; and in bits 6-35, the starting address of the routine to process interrupts generated on that channel. 2-66
FUNCTIONAL ORGANIZATION OF MONITOR CALLS In the older format, for use with the SIR and RIR calls by any single-section program, the left half of each word contains the priority level (1, 2, or 3) for that channel. The right half contains the address of the interrupt routine that will handle interrupts on that channel. 2.6.4 Terminating Conditions If an interrupt is received on a channel that is activated, but the interrupt cannot be initiated, then one of the following conditions exist: 1. The interrupt system for the process is not enabled (EIR JSYS) and the channel on which the interrupt occurred is a panic channel. 2. The table addresses have not been defined (SIR call). 3. No priority level has been assigned to the channel (i.e., left half of channel's word in CHNTAB is 0). 4. The channel has been "reserved" by the superior process (refer to the SIRCM call description). This interrupt is considered a process termination condition. In this case the process that was to have received the interrupt is halted or frozen according to the setting of SC%FRZ (bit 17) in its capabilities word, and a process termination interrupt is sent to its superior. The superior process can then execute the RFSTS call to determine the status of the inferior process. 2.6.5 Panic Channels Panic channels (refer to Section 2.6.1) cannot be completely deactivated by disabling the channel or the entire interrupt system. A software interrupt received on a panic channel that has been deactivated will be considered a process terminating condition. However, panic channels will respond normally to the channel on/off and read channel mask monitor calls. 2.6.6 Terminal Interrupts There are 36 (decimal) codes used to specify terminal characters or conditions on which interrupts can be initiated. A process can assign a character or condition to any one of the program-assignable interrupt channels with the ATI call. Once the particular code is 2-67
FUNCTIONAL ORGANIZATION OF MONITOR CALLS assigned to a channel and the channel is activated (by means of AIC), occurrence of the character or condition corresponding to the code causes an interrupt to be generated. The terminal codes, along with their associated conditions, are shown in the table below. Table 2-13: Terminal Interrupt Codes ______________________________________________________________________ Terminal Code Symbol Character or Condition ______________________________________________________________________ 0 .TICBK CTRL/@ or break 1 .TICCA CTRL/A 2 .TICCB CTRL/B 3 .TICCC CTRL/C 4 .TICCD CTRL/D 5 .TICCE CTRL/E 6 .TICCF CTRL/F 7 .TICCG CTRL/G 8 .TICCH CTRL/H 9 .TICCI CTRL/I (tab) 10 .TICCJ CTRL/J (line feed) 11 .TICCK CTRL/K (vertical tab) 12 .TICCL CTRL/L (form feed) 13 .TICCM CTRL/M (carriage return) 14 .TICCN CTRL/N 15 .TICCO CTRL/O 16 .TICCP CTRL/P 17 .TICCQ CTRL/Q 18 .TICCR CTRL/R 19 .TICCS CTRL/S 20 .TICCT CTRL/T 21 .TICCU CTRL/U 22 .TICCV CTRL/V 23 .TICCW CTRL/W 24 .TICCX CTRL/X 25 .TICCY CTRL/Y 26 .TICCZ CTRL/Z 27 .TICES Escape (altmode) 28 .TICRB Delete (rubout) 29 .TICSP Space 30 .TICRF Dataset Carrier Off 31 .TICTI Typein 32 .TICTO Typeout 33 .TITCE Two-character escape sequence (see MTOPR%) 34-35 Reserved for Digital ______________________________________________________________________ 2-68
FUNCTIONAL ORGANIZATION OF MONITOR CALLS The terminal code .TICRF (30) is used to generate an interrupt when the dataset carrier state changes from on to off. Although any process can enable for this interrupt, only the top-level process in an attached job is guaranteed to receive it when the carrier state changes. However, a detached process is not guaranteed to receive this interrupt. If other processes enable for the interrupt, they can receive the interrupt either when the carrier state changes to off or later when the job is reattached after the detach caused by the carrier-off condition. In general, the occurrence of the change in the dataset carrier state is usable only by the top-level process. The terminal codes .TICTI (31) and .TICTO (32) are used to generate interrupts on receipt of any character instead of a specific character. The .TICTI code generates an interrupt when the terminal's input buffer becomes nonempty (that is, when a character is typed and the buffer was empty before the input of the character). The .TICTO code generates an interrupt when the terminal's output buffer becomes nonempty. Note that neither one of these codes generates an interrupt if the buffer is not empty when the character is placed into it. The SIBE and SOBE calls can be used to determine if the buffers are empty. The .TITCE code (33) generates an interrupt when the user types a special two-character escape sequence. It is set by the .MOTCE function of the MTOPR JSYS. The frozen or unfrozen state (refer to Section 2.7.3.1) of a process determines if the interrupt is initiated immediately. Terminal interrupts are effectively deactivated when a process is frozen, even though the interrupts are indicated in the process' terminal interrupt word (obtained with the RTIW JSYS). When the process is unfrozen, the terminal interrupts are automatically reactivated. When an operation is completed that explicitly changes the terminal interrupt word for the job (for example, a process freeze or unfreeze operation), the interrupt word for the job (and for the terminal line if the job is attached) is set to the inclusive OR (IOR) of all the unfrozen processes in the job. When an interrupt character is received, frozen processes are not considered when searching for a process to interrupt. The user cannot directly access the actual terminal interrupt word. However, by specifying a process identifier of -5 as an argument to the RTIW or STIW JSYSs, he can read or change the terminal interrupt enable mask. The function of this mask is to allow processes to turn off interrupt codes activated by superior processes. Normally, the mask is -1, thereby enabling all terminal interrupts to be activated. A zero in any position of the mask prevents the corresponding terminal interrupt from being active. However, the fact that a code has been activated is remembered, and the code is activated when the mask is changed with a one in the corresponding position. Note that the process must have SC%CTC enabled in its capabilities word (refer to Section 2.7.1) to activate the terminal code for CTRL/C interrupts. 2-69
FUNCTIONAL ORGANIZATION OF MONITOR CALLS The SCTTY monitor call can be used to change the source of terminal interrupts for a process. Note that the process must have SC%SCT enabled in its capabilities word (refer to Section 2.7.1) to change the source of terminal interrupts. 2.6.6.1 Terminal Interrupt Modes - TOPS-20 handles the receipt of a terminal interrupt character in either immediate mode or deferred mode. An interrupt character handled in immediate mode causes the initiation of a software interrupt immediately upon its receipt by the system (as soon as the user types it). An interrupt character handled in deferred mode is placed in the input stream and initiates a software interrupt only when the program attempts to read it from the input buffer. In either case, the character is not passed to the program. If two occurrences of the same deferred interrupt character are received without any intervening character, the interrupt has an immediate effect. To detect this situation, the system maintains a separate one-character buffer in case the input buffer is otherwise full. The system assumes that interrupts are to be handled immediately unless the process has declared them deferred with the STIW monitor call. The purpose of deferred mode is to allow interrupt actions to occur in sequence with other actions in the input stream. However, with multiple processes, the deferred interrupt occurs when any process of the job reads the interrupt character. If this process is the one enabled for the interrupt, it will be interrupted before any more characters are passed to the program. If the process to be interrupted is the top process, then the interrupt occurs before more characters are passed to the program, unless another process is also reading from the same source (usually an abnormal condition). If neither of the above situations applies, then the process doing terminal input continues to run and may receive several characters before the interrupt can take effect. This is unavoidable since the process doing input and the process to be interrupted are logically running in parallel. 2.6.7 Dismissing an Interrupt Once the processing of an interrupt is complete, the user's interrupt routine returns control to the interrupted process by means of the DEBRK call. When the DEBRK call is executed, the monitor examines the contents of the return PC word to determine where to resume the process. If the PC word has not been changed, the process is restored to its state prior to the interrupt. For example, if the process was dismissed waiting for I/O to complete, it is restored to that state after execution of the DEBRK call. If the PC word has been changed, the process resumes execution at the new PC location. 2-70
FUNCTIONAL ORGANIZATION OF MONITOR CALLS The process can determine if an interrupt occurred during the execution of monitor code or user code by examining the user/exec mode bit (bit 5) of the return PC word. If the bit is on, the process was executing user code; if the bit is off, the process was executing monitor code (i.e., a JSYS). If the interrupt routine changes the return PC during the processing of an interrupt, the user-mode bit of the new PC word must be on. Note that the process may be executing monitor code but that the address portion of the PC is referencing a location in user code. To return to that user code location (i.e., to interrupt the execution of a monitor call), the process must turn on the user-mode bit. The following monitor calls are used for controlling signals and synchronization. Calls marked with an asterisk ("*") require privileges for specific functions. AIC Activates interrupt channels ATI Assigns terminal code to channel CIS Clears the interrupt system DEBRK Dismisses current interrupt DEQ* Releases a resourcee locked by ENQ DIC Deactivates interrupt channels DIR Disables the interrupt system DTI Deassigns terminal code EIR Enables the interrupt system ENQ* Places a request in ENQ/DEQ resource queue ENQC* Returns status of a resource GTRPI Returns page trap information for specified process GTRPW Returns trap words IIC Initiates interrupts on specific channels in a process MSTR* Performs structure-related functions MTOPR* Performs device dependent functions MUTIL* Performs IPCF functions NODE* Performs DECnet functions RCM Reads activated channel word mask RFSTS Returns status of specified process RIR Reads the interrupt table addresses for a single-section program RIRCM Reads inferior reserved channel mask RTIW Reads terminal interrupt word RWM Reads waiting channel word mask SCTTY Changes source of terminal interrupts SIR Sets the interrupt table addresses for a single-section process SIRCM Sets inferior reserved channel mask SKPIR Skips if the interrupt system is enabled STIW Sets terminal interrupt word SWTRP% Intercepts arithmetic overflow or underflow conditions TFORK* Sets and removes monitor call intercepts TIMER Controls amount of time either a process within a job or the entire job can be run XGTPW% Returns page-fail words 2-71
FUNCTIONAL ORGANIZATION OF MONITOR CALLS XRIR% Reads the interrupt table addresses for a multiple-section program XSIR% Sets the interrupt table addresses for a multiple-section process 2.7 PROCESS CAPABILITIES The TOPS-20 system allows capabilities, such as the ability to examine the monitor and to enable for CTRL/C interrupts, to be given to certain processes. Each capability is separately protected and activated. The capabilities are assigned on a per-process basis, and their status is kept in the process' PSB. The number of capabilities is limited to 36, and two words are used to store the status. For each capability, there is a bit in the first word that is set if the capability is available to the process. If the corresponding bit in the other word is also set, the capability is currently enabled. This allows the user to protect himself against accidental use without actually giving up the capability. Inferior processes are created by superior processes (by means of the CFORK monitor call) with either no special capabilities or the capabilities of the creating process. Most capabilities relate to system functions and may be passed from superior to inferior process only if the superior itself has the capability. Some capabilities relate the inferior to the superior process, and may be given to an inferior whether or not available in the superior. 2.7.1 Assigned Capabilities The following table lists the capabilities available for processes and jobs. Table 2-14: Process/Job Capabilities ______________________________________________________________________ Bit Symbol Meaning ______________________________________________________________________ B0-8 Job Capabilities 0 SC%CTC Process can enable for CTRL/C software interrupts. 1 SC%GTB Process can examine monitor tables with the GETAB call. 2-72
FUNCTIONAL ORGANIZATION OF MONITOR CALLS Note that the possession of this capability allows the process to do a GETAB. The capability need not be enabled. 3 SC%LOG Process can execute protected log functions (by means of the LGOUT JSYS). Note that the possession of this capability allows the process to do a LGOUT. The capability need not be enabled. 6 SC%SCT Process can change the source of terminal interrupts for other processes. B9-17 Capabilities that can be given to an inferior whether or not the superior itself has them. Of these, SC%FRZ (B17) cannot be changed by a process for itself. 9 SC%SUP Process can manipulate its superior process. 17 SC%FRZ Unprocessed software interrupts can cause the process to be frozen instead of terminated. B18-35 User capabilities 18 SC%WHL User has wheel privileges. 19 SC%OPR User has operator privileges. 20 SC%CNF User has confidential information access. 21 SC%MNT User has maintenance privileges. 22 SC%IPC User has IPCF privileges. 23 SC%ENQ User has ENQ/DEQ privileges. 24 SC%NWZ User has ARPANET wizard privileges. 25 SC%NAS User has absolute ARPANET socket privileges. 26 SC%DNA User has access to DECnet. 27 SC%ANA User has access to ARPANET. 28 SC%SEO User has access to SEMI-OPERATOR. ______________________________________________________________________ User capabilities are originally established when the user's logged-in directory is created. (Refer to the CRDIR monitor call.) 2-73
FUNCTIONAL ORGANIZATION OF MONITOR CALLS The capability word can be read with the RPCAP monitor call. Capabilities can be enabled with the EPCAP monitor call. 2.7.2 Access Control It is often necessary for an installation to have more control over system resources than that offered by the process capability word. The following JSYSs allow each installation to write its own access-control program: o GETOK% o GIVOK% o RCVOK% o SMON o TMON The access-control facility works as follows: 1. The installation writes its own access-control program. This program uses the SMON JSYS (privileged) to (1) enable or disable access checking for a variety of system resources and (2) allow or disallow access by default for those resources that are not explicitly checked by the access-control program. 2. The access-control program initializes itself and then issues the .SFSOK function of the SMON JSYS (privileged) to enable various types of access checking and to define itself as the access-control program. 3. The access-control program issues a RCVOK% JSYS (privileged). As the request queue is empty until a GETOK% request has been made, the RCVOK% JSYS causes the access-control program to block. 4. A system program or the monitor issues a GETOK% JSYS, causing an access request block to be appended to the GETOK% request queue (maintained by the monitor). The system program or monitor then blocks. 5. The monitor wakes up the access-control program and the blocked RCVOK% JSYS completes execution, retrieving the access request block from the GETOK% request queue. This block contains information supplied by the GETOK% call, plus certain job parameters. 2-74
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 6. The access-control program determines whether to allow or deny the request and issues the GIVOK% JSYS (privileged) with the appropriate response for this request. The access-control program now issues another RCVOK% JSYS, which blocks or completes, depending on whether or not any additional requests are in the queue. 7. The system program or the monitor unblocks and gets a +1 return from the original GETOK% JSYS if the request has been granted, or gets an illegal instruction trap if the request has been denied. Note the following characteristics of the access-control facility: 1. The GETOK% JSYS is imbedded in the code that is being protected against unauthorized use. For example, a DIGITAL-supplied GETOK% function allows access-control of the CRJOB JSYS; thus the TOPS-20 code that implements CRJOB will itself execute a GETOK% JSYS. An installation can also place GETOK% JSYSs in appropriate places in other software to provide additional access control. However, this entire process is invisible to the ordinary user program. The only change such a program would encounter in an access-controlled environment would be the illegal instruction trap generated if the program attempted to use a protected resource that it was not entitled to use. 2. JSYSs performed by the access-control program or job 0 will not invoke access control. 3. After a system has been brought up, the first fork to execute the .SFSOK function of the SMON JSYS defines itself as the access-control fork. Any other fork that subsequently tries to issue a RCVOK% JSYS, a GIVOK% JSYS, or an SMON JSYS with function .SFSOK will receive an error. 4. The access-control facility has two timers associated with it: 1. The time period between the execution of a GETOK% JSYS and its corresponding GIVOK% JSYS is measured. If the period exceeds a maximum, a BUGINF is generated on the CTY. 2. The time period between the GETOK entry into the queue and the RCVOK% being executed is measured. If the period exceeds a maximum, a BUGCHK is generated on the CTY, all defaults are reestablished, the GETOK% request queue is flushed (the defaults are in effect for those requests also), and the monitor will no longer place GETOK% requests in the GETOK% queue. 2-75
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 2.7.3 Processes and Scheduling These monitor calls deal with establishing and interrogating the process structure of a job. Refer to the Monitor Calls User's Guide for an overview and description of the process structure. 2.7.3.1 Process Freezing - A superior process can cause one or all of its inferior processes to be frozen. A frozen process is one whose execution is suspended (as soon as it is stoppable from the system's point of view) in such a way that it can be continued at the point it was suspended. A process can be frozen directly or indirectly. A process is directly frozen when its superior makes an explicit request to freeze it. A process is indirectly frozen when its superior is frozen. When a process is directly frozen, all of its inferior processes are indirectly frozen. Therefore, a process can be both directly frozen by its superior process and indirectly frozen if its superior process is subsequently frozen. The explicit unfreezing of a process clears both its direct freeze and the indirect freeze on all its inferior processes unless an inferior process has a direct freeze. The indirect unfreezing of a process clears only the freeze on that process. This means that an explicit freeze of a process prevents the running of any of its inferior processes, and an explicit unfreezing of a process automatically resumes its inferiors. The FFORK and RFORK monitor calls are used to freeze and unfreeze processes, respectively. An argument of -4 to these calls directly freezes or resumes all immediately inferior processes, and any processes below the immediately inferior ones are indirectly frozen or resumed. (The freeze and unfreeze operations are never legal on any process that is not inferior to the one executing the monitor call.) The frozen or unfrozen state of a process can only be changed directly. Thus, monitor calls like SFORK and HFORK change other states of a process but do not affect the frozen state. If the process is frozen and a call is executed that changes one of its states, the process remains frozen and does not begin operating in the changed state until it is resumed. For example, a program can change a frozen process's PC with the SFORK call, but the process will not begin running at the new PC until it is unfrozen. Similarly, the HFORK call can be executed on a frozen process, but the process will not be in the halted state until it is unfrozen. The changed status is always reflected in the information returned by the RFSTS call. In the first example above, RFSTS would return the changed PC, and in the second, it would return the halted code in the status word. The following monitor calls are associated with capabilities and processes. Calls marked with an asterisk ("*") require privileges for specific functions. 2-76
FUNCTIONAL ORGANIZATION OF MONITOR CALLS ADBRK Controls address breaks CFORK Creates inferior process CRJOB* Creates a new job DEQ* Releases a resource locked by ENQ DISMS Dismisses process for specified amount of time ENQ* Places a request in the ENQ/DEQ resource queue ENQC* Returns status of a resource EPCAP Enables process capabilities word FFORK Freezes one or more processes GETER Returns last error condition for a process GETNM Returns program name currently in use by job GFRKH Gets process handle GFRKS Gets current process structure GTRPI Returns page trap information for a specified process HALTF* Halts a process HFORK Halts an inferior process KFORK Kills one or more processes LGOUT* Logs a job out PRARG Sets or returns process argument block RESET Resets and initializes current process RFACS Returns process' accumulators RFORK Resumes one or more processes RFRKH Releases process handles RFSTS Returns process' status RMAP Obtains a handle on a page in a process RPACS Returns accessibility of page RPCAP Returns process capabilities word RSMAP% Returns information about the mapping of one section of a process RTFRK Returns the handle of the process suspended because of a monitor call intercept RWSET Releases working set SETJB* Sets job parameters SETER Sets the last error condition encountered by process SETNM Sets private name of program in use by job SETSN Sets system name or private name of program in use by job SFACS Sets process' accumulators SFORK Starts a process in section zero SPACS Sets accessibility of page SPLFK Splices a process structure TFORK* Sets and removes monitor call intercepts UTFRK Resumes a process suspended because of a monitor call intercept WAIT Dismisses process until interrupt occurs WFORK Waits for process to terminate WSMGR% Manages working set of a process XRMAP% Extended read mapping XSFRK% Starts a process in a non-zero section 2-77
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 2.7.3.2 Execute-Only Files and Execute-Only Processes - The basic definition of an execute-only file is one that cannot be copied, read, or manipulated in the usual manner, but can be run as a program. An execute-only file has the following characteristics: 1. The file must be protected with execute access allowed, but with read access not allowed. 2. The file cannot be read or written using any of the file-oriented monitor calls (SIN, SOUT, BIN, BOUT, PMAP, for example). 3. The file can be mapped into a process (using GET), but only in its entirety and only into a virgin process. A process so created is called an execute-only process. NOTE A virgin process is one that has just been created (using CFORK). Furthermore, if a process is virgin, no operations have been performed on the process. This means no changes have been made to its address space, PC, ACs, interrupt system, or traps, and the process has not been mapped to a file or another address space. 4. Only disk-resident files can be considered execute-only. 5. A process with WHEEL or OPERATOR capabilities enabled can gain read access to any file and can thus circumvent the execute-only features of an execute-only file. An execute-only process has the following characteristics: 1. An execute-only process can be started only at its entry vector. 2. A process that is created by an execute-only process and shares the same address space becomes execute-only itself. 3. No other process can read from an execute-only process' address space or accumulators. 4. No other process can change any part of an execute-only process' context in such a way as to cause the execute-only process to unintentionally reveal any part of its address space. 5. An execute-only process can not be prevented from mapping pages of its own address space into an inferior process. It is the programmer's responsibility to avoid revealing an execute-only process through its inferior forks. 2-78
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 6. No JSYS explicitly indicates that a given process is execute-only. However, the RFACS JSYS will always fail for an execute-only process and can be used to determine this information, if it is required. A program is execute-only for particular users based on its file protection. If a user tries to run a file and cannot read it, but does have execute access, a process is created as usual. The file is mapped into this virgin process, circumventing the read protection on the file. This process is then an execute-only process. Users may select a file to be execute-only by allowing execute but not read access to the file. This can be done by setting the protection field for the desired class of users (owner, group, or world) to FP%EX+FP%DIR, or 12 octal. For example, to make a file execute-only for everybody except the owner of the file, the user would set the protection to 771212 octal. The following JSYSs do not work for execute-only programs: 1. ADBRK - referring to an execute-only process 2. GET - referring to an execute-only process 3. PMAP - with either source or destination an execute-only process 4. SCVEC - referring to an execute-only process 5. SDVEC - referring to an execute-only process 6. SEVEC - referring to an execute-only process 7. SMAP% - with either source or destination an execute-only process 8. SPACS - referring to an execute-only process 9. XGVEC% - referring to an execute-only process 10. XSVEC% - referring to an execute-only process The START command cannot be used with a start address argument for an execute-only process. A program that is execute-only must be written to protect itself. The program should not map itself out to inferior processes unless the entire address space is mapped. The program should not do a GET and execute programs in its address space over which it has no control. 2-79
FUNCTIONAL ORGANIZATION OF MONITOR CALLS Some programs cannot be made execute-only. Some major examples are: o Any object-time system, such as LIBOL or FOROTS. They must be merged into the address space and thus violate the restriction of reading an execute-only file into a virgin address space. Note that an execute-only process can merge in an object-time system, however. o The TOPS-10 compatibility package (PA1050). This has the same restriction that object-time systems have. o Any program that uses the TOPS-10 RUN or GETSEG UUOs. These UUOs require mapping into a non-virgin address space. o Any program that needs to be started at any location other than its entry vector (START or REENTER address). 2.8 SAVE FILES A save file is a method of storing an executable memory image on disk. TOPS-20 handles two formats of save files: nonsharable (primarily intended for compatibility with TOPS-10) and sharable. Save files use data compression to reduce the size of the on-disk copy. Non-sharable save files use word-oriented compression: memory words containing zero are not stored in the disk file. Sharable save files use page-oriented compression: memory pages in which all words contain zero are not stored in the disk file. Shareable save files are generated with the TOPS-20 SAVE command or the SSAVE JSYS. Non-sharable save files are generated with the TOPS-20 CSAVE command or the SAVE JSYS. The formats of the two types of save files are discussed below. 2.8.1 Format for Nonsharable Save Files The format of a nonsharable save file is as follows: IOWD length, address at which to put "length" data words "length" data words IOWD length, address at which to put "length" data words "length" data words . . . 2-80
FUNCTIONAL ORGANIZATION OF MONITOR CALLS XWD length of entry vector, pointer to first word of entry vector 2.8.2 Format of Sharable Save Files A sharable save file is divided into two main areas: the directory area contains information about the structure of the file, and the data area contains the data of the file. The following diagram illustrates the general format of a sharable save file: Directory ======================== Area: | Directory Section | | | | | ------------------------ | Entry Vector Section | ------------------------ | Program Data Vector | | Section | ------------------------ | Terminating Section | ======================== | | Data Area: | Data Section | | | | | | | | | | | | | | | | | ======================== The directory area of the save file has four sections: the directory section, the entry vector section, the program data vector section, and the terminating section. The directory area may be from 1 to 3 pages long, depending on the access-characteristics of the pages in the data area of the save file. Although SSAVE% creates a directory area that is only one page long, there is no limit to the size of a directory area created with the SAVE% monitor call. Each of the four sections in the directory area begins with a word containing its identifier code in the left half and its length in the right half. Each section is described in the paragraphs below. 2-81
FUNCTIONAL ORGANIZATION OF MONITOR CALLS The directory section is the first of the three sections and describes groups of contiguous pages that have identical access. The length of this section varies according to the number of groups that can be generated from the data portion of the save file. The more data pages that can be combined into a single group, the fewer groups required, and the smaller the directory section. The format of the directory section is as follows: 0 8 9 17 18 35 |=======================================================| | Identifier code | Number of words | | 1776 | (including this word) | | | in directory section | |=======================================================| | Access | Page number in file, or 0 if group | | bits | of pages is all zero | |=======================================================| | Repeat | Page number in the process | | count | | |=======================================================| / additional word pairs (as necessary) / / to describe each group of pages / / in the process address space / |=======================================================| | Access bits | Page number in the file | |=======================================================| | Repeat count | Page number in the process | |=======================================================| The access bits are determined from the access bits specified by the user on the SSAVE monitor call. The bits currently defined in the directory section are: B1 The process pages in this group are sharable B2 The process pages in this group are writable The remaining access bits in the directory section are zero. The repeat count is the number (minus 1) of consecutive pages in the group described by the word pair. Pages are considered to be in a group when the following three conditions are met: 1. The pages are contiguous. 2. The pages have the same access. 3. The pages either are all zero or are all existent and readable. 2-82
FUNCTIONAL ORGANIZATION OF MONITOR CALLS A page is considered to be all zero if it is nonexistent or is not readable. A page containing all zeros is considered to be existent. A group of all zero pages is indicated by a file page number of 0. The word pairs are repeated for each group of pages in the address space. The entry vector section follows the directory section, and points to the entry vector. The format of the entry vector section is as follows: 0 17 18 35 |=======================================================| | Identifier code | Number of words | | 1775 | (including this word) | | | in entry vector section | |=======================================================| | Number of words in entry vector | |=======================================================| | Address of entry vector | |=======================================================| This section contains the address of the entry vector. Refer to Section 2.8.3 for a description of the entry vector. The program data vector section follows the entry vector section. The program data vector section contains the addresses at which the program data vectors begin (PDVAs). This section is optional, and only appears if the program declares some program data vectors. The format of the program data vector section is as follows: 0 17 18 35 |=======================================================| | Identifier code | Number of words | | 1774 | (including this word) | | | in data vector section | |=======================================================| | Address of data vector 1 | |=======================================================| | Address of data vector 2 | |=======================================================| / . / / . / / . / |=======================================================| | Address of data vector n | |=======================================================| 2-83
FUNCTIONAL ORGANIZATION OF MONITOR CALLS The terminating section follows the program data vector section. Its format is as follows: |=======================================================| | Identifier code | | | 1777 | 1 | |=======================================================| The remaining words in the last page of the save file are filled with zeros and are ignored by the monitor. 2.8.3 Entry Vector The entry vector is a block of data that describes entry conditions to be used when the program in the process is executed. The first word of the entry vector contains the program start instruction, the second word contains the program reenter instruction, and the third word contains the program version number. (The version number format is: B0-B2(VI%WHO) containing the group who last modified the program, B3-B11(VI%MAJ) containing major version number, B12-B17(VI%MIN) containing minor version number, and B19-B35(VI%EDN) containing edit number. If B18(VI%DEC) is set, the version number fields are printed in decimal by the TOPS-20 command processor). Subsequent words in the entry vector can contain data applicable to the particular entry (refer to the GCVEC and GDVEC monitor calls). Typically, the entry vector looks like this: JRST start-addr JRST reenter-addr version number . . . Each process has an entry vector word in its process storage block. The format of the entry vector word is: LH: length of the entry vector (1-777) RH: address of the first word of the entry vector. The data for this word is obtained from the entry vector in the save file when a GET monitor call is executed for the file. Note that if the left half of the entry vector (usually the length) is 254000 (octal), then there is no real entry vector. The program start address is in the right half of location 120, the reenter address is in the right half of location 124, and the program version is in 2-84
FUNCTIONAL ORGANIZATION OF MONITOR CALLS location 137. This format is not recommended, but is maintained for compatability with older monitors. 2.8.4 Program Data Vector The program data vector (PDV) is a block of data that LINK writes into memory when loading and linking a program. The PDV resides in memory as a part of the program, and starts at a program data vector address (PDVA). User programs can use this data. Although TOPS-20 currently does not use the data in the PDV, words 13, 14, and 15 of the PDV are provided for possible future system use. The format of the program data vector is as follows: Word Symbol Meaning 0 .PVCNT Length of the PDV (including this word). 1 .PVNAM Name of the program for which this data vector exists. The name is word-aligned ASCII, which means that the characters in the name are represented by seven-bit bytes, and that the first byte in each word begins with bit zero. 2 .PVEXP Address of the exported information vector. 3 .PVREE Reserved for DIGITAL. 4 .PVVER Program version number. 5 .PVMEM Address of a block of memory that contains data describing the program memory (a memory map). See the LINK manual, Appendix G, for a description of this block. 6 .PVSYM Address of the program symbol table. 7 .PVCTM Time at which the program was compiled. 10 .PVCVR Version number of the compiler. 11 .PVLTM Time at which the program was loaded. 12 .PVLVR Version number of LINK. 13 .PVMON Address of a monitor data block. (Not currently used.) 14 .PVPRG Address of a program data block. (Not currently used.) 15 .PVCST Address of a customer-defined data block. The PDVOP% monitor call manipulates PDVs. When loading a program into memory, LINK executes a PDVOP% call to give the monitor the addresses of the PDVs for that program. The PDVAs are the only data regarding PDVs that the monitor keeps in its data base. Once the monitor knows the PDVAs for a program, other programs and other processes can use PDVOP% to obtain those PDVAs from the monitor. An inquiring program or process must use the PDVA (and another PDVOP% call) to obtain the data in the PDV. 2-85
FUNCTIONAL ORGANIZATION OF MONITOR CALLS The PDVOP% call also allows you to add PDVAs to, or delete PDVAs from, the monitor's data base. Refer to Chapter 3 for a complete description of PDVOP%. The following monitor calls are used in conjunction with save files. Calls marked with an asterisk ("*") require privileges for specific functions. GCVEC Gets compatibility package entry vector GDVEC Gets RMS entry vector GET* Obtains a saved file GEVEC Gets process entry vector of a single-section program PDVOP% Obtains information about execute-only programs SAVE Saves a process as nonsharable SCVEC Sets compatibility package entry vector SDVEC Sets RMS entry vector SEVEC Sets the entry vector for a single-section program SFRKV Starts process using its entry vector SSAVE Saves a process as sharable XGSEV% Gets extended special entry vector XGVEC% Gets process entry vector for a multiple-section program XSFRK% Starts a process using a user-supplied, global PC XSSEV% Sets extended special entry vector XSVEC% Sets the entry vector for a multiple-section program 2.9 INPUT/OUTPUT CONVERSION The monitor calls in this group perform input/output conversion. Calls are available to convert in both directions between ASCII text (in core or in a file) and integer numbers, floating point numbers, and TOPS-20 internal dates and times. 2.9.1 Floating Output Format Control 2.9.1.1 Free Format - The most common format control used with the FLOUT JSYS is free format. This is specified by setting B18-23 (FL%FST) of the format control word to 0. (Refer to Section 2.9.1.2.) Normally, the entire format control word is set to 0; however, certain fields may be specified to force a particular output. Most numbers greater than or equal to 10^-4 but less than 10^6 (with some exceptions) are output in a typical FORTRAN F format. If the number is an exact integer, it is output with no terminating decimal point unless B6(FL%PNT) is on. If the number is a fraction, it is output as .xxxx with no leading zeros. Nonsignificant trailing zeros in the fraction are never output. A maximum of seven digits is output if the second field (FL%SND) is not specified. The sign of the number is output only if negative. 2-86
FUNCTIONAL ORGANIZATION OF MONITOR CALLS If the number is outside the range above, it is output in a typical FORTRAN E format (with some exceptions). The exponent is output as Esxx, where s is the sign output only on negative exponents and xx are the digits of the exponent. The above exceptions about outputting the decimal point and suppressing trailing, nonsignificant zeros apply. Another free format similar to that above is invoked by specifying a nonzero value for B13-17 (FL%RND) of the format control word. The value in this field specifies the place at which rounding should occur. If this value is 7, the output is the same as if the value were 0 as above. If this value is less than 7, rounding occurs at the specified place, but the output will be as above with a maximum of 7 digits (for example, 12360 with a rounding specification of 3 will output as 12400). If this value is greater than 7, rounding occurs at the specified position, but more than 7 digits are output. In this case, digits are output until either the rounding specification number is reached or until trailing, nonsignificant zeros are reached. 2.9.1.2 General Format Control - The format control word specifies the format for floating point output when free format is not desired. The control word indicates the desired output for the three fields of the number, plus additional control for items such as rounding. The first field of the number is up to the decimal point. The second field is from the decimal point to the exponent. The third field is the exponent. The format control word is as follows: Table 2-15: Floating-Point Format Control ______________________________________________________________________ Bit Symbol Meaning ______________________________________________________________________ 0-1 FL%SGN Sign control for first field. The first character position is always used for the minus for negative numbers. For positive numbers, the first character position is defined according to the values below: Value Symbol Meaning 0 .FLDIG First character is digit. 1 .FLSPC First character is space. 2 .FLPLS First character is plus sign. 3 .FLSPA First character is space. 2-87
FUNCTIONAL ORGANIZATION OF MONITOR CALLS 2-3 FL%JUS Justification control for first field. Value Symbol Meaning 0 .FLLSP Right justify number using leading spaces. 1 .FLLZR Right justify number using leading zeros. 2 .FLLAS Right justify number using leading asterisks. 3 .FLTSP Left justify number up to decimal point using trailing spaces after third field. 4 FL%ONE Output at least one digit (0 if necessary) in first field. 5 FL%DOL Prefix the number with a dollar sign ($). 6 FL%PNT Output a decimal point. 7-8 FL%EXP Third (exponent) field control. Value Symbol Meaning 0 .FLEXN No exponent field. 1 .FLEXE Output E as first character of exponent field. 2 .FLEXD Output D as first character of exponent field. 3 .FLEXM Output *10^ as first characters of exponent field. 9-10 FL%ESG Exponent sign control. The first character position is always used for the minus for negative exponents. For positive exponents, the first character position is defined according to the values below: Value Symbol Meaning 0 .FLDGE First character after exponent prefix is digit. 1 .FLPLE First character after prefix is plus sign. 2 .FLSPE First character after prefix is space. 3 .FLDGT First character after exponent prefix is digit. 11 FL%OVL Use free format on overflow of the first field and expand exponent on overflow of the third 2-88
FUNCTIONAL ORGANIZATION OF MONITOR CALLS field. If this bit is not set, no additional output occurs on column overflow. 13-17 FL%RND Digit position at which rounding will occur. If field is 0, rounding occurs at the 12th digit. If field is 37, no rounding occurs. 18-23 FL%FST Number of characters in first field, including a dollar sign ($) if FL%DOL is set. (refer to FL%JUS). 24-29 FL%SND Number of characters in second field. 30-35 FL%THD Number of characters in third field. ______________________________________________________________________ As an example, to output a number in the format xx.yy, the following bits should be set in AC3 of the FLOUT monitor call. B4(FL%ONE) output at least one digit in the first field B6(FL%PNT) output a decimal point B13-B17(FL%RND) do not round the number B22 output a maximum of two digits in the first field B28 output a maximum of two digits in the second field Examples of numbers output in this format are: 43.86 4.24 0.43 2.9.2 Date And Time Conversion Monitor Calls TOPS-20 internal date and time is maintained in a 36-bit word and is based on Greenwich Mean Time. The date is in the left half and is the number of days since November 17, 1858; the time is in the right half and is represented as a fraction of a day. This allows the 36-bit value to be in units of days with a binary point between the left and right halves. The resolution is approximately one-third of a second; that is, the least significant bit represents approximately one-third of a second. The date changes at the transition from 11:59:59 PM to 12:00:00 midnight. For conversions between local and internal date and time, the time zone in which the installation is located is normally used, with daylight savings applied from 2AM on the last Sunday in April to 1:59:59AM on the last Sunday in October. 2-89
FUNCTIONAL ORGANIZATION OF MONITOR CALLS Two monitor calls in this group, IDTIM and ODTIM, convert date and time between text strings (in core or in a file) and internal format. These should satisfy most users. However, there are four more calls, which are subsets of IDTIM and ODTIM. The calls ODTNC, IDTNC, ODCNV, and IDCNV make available separately the conversion between internal format date and time and separate numbers for local year, month, and day, and the conversion between those numbers and text strings. They also provide additional options, which give the caller more control over the conversion performed than IDTIM and ODTIM. Time zones occur in the calling sequences of the latter four JSYSs. A time zone is represented internally as a number between -12 and 12 decimal, representing the number of hours west of Greenwich. For example, EST is zone 5. Zones -12 and 12 represent the same time but different days because the zones are on opposite sides of the international date line. The following are examples of valid dates and times: 6-FEB-76 FEB-6-76 FEB 6 76 FEB 6, 1976 6 FEB 76 6/2/1976 2/6/76 Below are examples of valid times: 1:12:13 1234 16:30 (4:30PM) 1630 1234:56 1:56AM 1:56-EST 1200NOON 12:00:00AM (midnight) 11:59:59AM-EST (late morning) 12:00:01AM (early morning) "AM" or "PM" can follow a time specification that is not greater than 12:59:59. "NOON" or "MIDNIGHT" can follow 12:00:00. Any time specification can be followed by a dash and a time zone. Table 2-16 lists the time zones defined within TOPS-20, their abbreviations, and the left half of the word generated or accepted by the calls that read, write, or convert dates and times. The right half of the word ordinarily contains the time expressed as seconds after midnight. 2-90
FUNCTIONAL ORGANIZATION OF MONITOR CALLS Table 2-16: Time Zones ______________________________________________________________________ Zone Name Abbreviation Left half ______________________________________________________________________ GREENWICH DAYLIGHT TIME GDT 700000 GREENWICH MEAN TIME GMT 500000 GREENWICH STANDARD TIME GST 500000 ATLANTIC DAYLIGHT TIME ADT 700004 ATLANTIC STANDARD TIME AST 500004 EASTERN DAYLIGHT TIME EDT 700005 EASTERN STANDARD TIME EST 500005 CENTRAL DAYLIGHT TIME CDT 700006 CENTRAL STANDARD TIME CST 500006 MOUNTAIN DAYLIGHT TIME MDT 700007 MOUNTAIN STANDARD TIME MST 500007 PACIFIC DAYLIGHT TIME PDT 700010 PACIFIC STANDARD TIME PST 500010 YUKON DAYLIGHT TIME YDT 700011 YUKON STANDARD TIME YST 500011 ALASKA-HAWAII DAYLIGHT TIME HDT 700012 ALASKA-HAWAII STANDARD TIME HST 500012 BERING DAYLIGHT TIME BDT 700013 BERING STANDARD TIME BST 500013 LOCAL DAYLIGHT TIME DAYLIGHT 600000 ______________________________________________________________________ All strings (for example, months, time zones, AM-PM-NOON-MIDNIGHT) can be represented by any nonambiguous abbreviation (for example, D-DECEMBER, M-MIDNIGHT). Spaces are ignored before and between fields whenever they do not terminate the input string. This means spaces are not allowed before colons, AM,PM,NOON, and MIDNIGHT, the dash before the time zone, or the time zone. A tab is also allowed between the date and time. The input string can be terminated by any nonalphanumeric character. Monitor calls relating to date and time are as follows: IDTIM Inputs date and time, converting to internal format ODTIM Outputs date and time, converting from internal format to text IDTNC Inputs date and time without converting to internal format ODTNC Outputs date and time in internal format IDCNV Converts from day, month, year to internal date and time ODCNV Converts from internal date and time to day, month, year 2-91
FUNCTIONAL ORGANIZATION OF MONITOR CALLS GTAD Gets current date and time in internal format 2.10 ARCHIVE/VIRTUAL DISK SYSTEM The following section defines terms that are used in the description of the archive/virtual disk system: Virtual disk A storage technique in which the contents of some files reside on disk, while the contents of other files may reside on tape. When a file is "migrated" to tape, a copy of its FDB is left on disk and the file is deleted from disk. Note that the term "migration" applies only to files transferred to tape by the virtual disk system. Archived file A file of unchanging data stored on magnetic tape. Although copies of the file may exist on disk, the original is stored on magnetic tape. When a file gains archive status, it can no longer be changed. If a writeable copy is desired, the COPY command must be used. When a file is archived, the file contents are usually deleted from disk, leaving only the FDB on disk. However, it is possible to override the deletion process. Offline/online A file is said to be offline if the file has been moved to tape by either the virtual disk system or the archive system. A file is said to be online if the original or a copy of it is on disk. A file may be offline, online, or both. A file that is offline and not online will have only its FDB stored on disk. In the last case, the FDB will contain pointers to the saveset and tape file number. This provides a link between the FDB on disk and the file on tape. Invisible/visible An invisible file is one that does not appear in a simple DIRECTORY listing, and is not accessable to programs (unless the GTJFN specifically sets bit G1%IIN) and EXEC commands. A visible file appears in a DIRECTORY listing and is accessable to programs and EXEC commands. 2-92
FUNCTIONAL ORGANIZATION OF MONITOR CALLS The concept of an invisible file is primarily designed to make offline-only files transparent to the user. However, the invisible/visible status of a file may be changed regardless of whether the file is online, offline, archived, not archived, migrated, or not migrated. The virtual disk system is designed to conserve disk space by moving selected files from disk to tape. Files are marked for migration to tape by the REAPER program. At the option of the system administrator, REAPER may mark files in any of the following three categories: 1. Files that have not been referenced within a specified period of time. 2. Online copies of migrated or archived files that have not been referenced within a specified period of time. 3. Files in a directory that is over permanent disk quota. If the directory contains a file named MIGRATION.ORDER, then REAPER uses that file as an order list for marking files. Otherwise REAPER follows the order given in the REAPER command list. Two REAPER passes are made with the first pass using the order specified in MIGRATION.ORDER or the REAPER command string. If the first pass fails to bring the directory under quota, the second pass will consider any file in the directory for migration. The actual migration of disk files to tape is performed by a special DUMPER run. The actual run will occur periodically, with the length of the period determined by the system administrator. File archiving is designed to write unalterable "permanent" copies of disk files on tape. The user voluntarily marks a file for archiving, and the next archive/virtual disk DUMPER run will archive the file. For added security two tape copies of each archived or migrated file are made. The following monitor calls are used to implement the archive/virtual disk system. Calls marked with an asterisk ("*") require privileges for specific functions. ARCF* Performs archive/virtual disk operations CRDIR* Creates or modifies a directory DELDF* Expunges deleted files DELNF Retains specified number of generations of file GNJFN Assigns a JFN to the next file GTJFN Assigns a JFN to a file JFNS Translates a JFN to a string 2-93
FUNCTIONAL ORGANIZATION OF MONITOR CALLS OPENF Opens a file RFTAD Reads file's time and dates SETJB* Sets job parameters SFTAD* Sets file's time and dates TMON Reads monitor flags 2.11 PRIVILEGED MONITOR CALLS The following monitor calls are privileged and require the process to have WHEEL or OPERATOR capability enabled. ALLOC Allocates a device to a particular job ASNIQ% Assigns TCP/IP Internet queue ASNSQ Assigns TCP/IP special message queue BOOT Performs functions required for loading front-end software DIAG Reserves and releases hardware channels DSKAS Assigns specific disk addresses DSKOP Allows hardware address specification in disk transfers GIVOK% Allows/denies access to a protected system resource HSYS Halts the monitor IPOPR% Performs Internet network management operations LLMOP% Low level maintenance operations LPINI Loads line-printer VFU MDDT% Enters MDDT program MSFRK Starts a process in monitor mode MTALN Associates magnetic tape drive with logical unit number MTU% Performs MT-device functions NI% TOPS-20 user interface to the Ethernet NTMAN% Performs DECnet network management functions PEEK Reads monitor data PLOCK Locks physical pages PMCTL Controls physical memory RCVOK% Services GETOK% requests SCS% Interface to System Communications Services SJPRI Sets job priority SMON Sets monitor flags SNOOP Performs system performance analysis SPOOL Performs spooling-related functions SPRIW Sets process priority STAD Sets system date/time SYERR Places information in the System Error file TCOPR% Internet terminal control operations USAGE Makes entries in accounting file USRIO Places program in user I/O mode UTEST Monitors executed instructions XPEEK% Monitor data retrieval functions The capabilities for a process are enabled by the EPCAP JSYS. 2-94
CHAPTER 3 TOPS-20 MONITOR CALLS Gives a particular type of access to a given directory. The possible types of accesses are: 1. Connecting to a directory on a given structure. 2. Gaining owner and group access rights to directories on a structure without actually connecting to a directory on that structure. 3. Relinquishing owner and group access rights to directories on a structure without disconnecting from a directory on that structure. RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. Some functions require WHEEL or OPERATOR capability enabled. When this call is used in any section other than section zero, one-word global byte pointers used as arguments must have a byte size of seven bits. ACCEPTS IN AC1: B0(AC%CON) Connect the job to the specified directory. After successful completion of the call, the job is connected to and has owner access to the directory. The job's default directory becomes this directory. B1(AC%OWN) Give the job owner access to the specified directory and group access to directories in the same groups as the specified directory. The job's connected directory is unchanged. This function cannot be given for another job or for a files-only directory. 3-1
TOPS-20 MONITOR CALLS (ACCES) B2(AC%REM) Relinquish owner access (obtained with the AC%OWN function) to the specified directory and group access to directories in the same group. The job's connected directory is unchanged. This function cannot be given for another job or for a files-only directory. The settings of B0 and B1 are ignored if B2 is on and the job number given is for the current job. B3(AC%PWD) Validate password by encrypting user-supplied password before doing compare. B18-35 Length of the argument block AC2: Address of the argument block RETURNS +1: Always Access cannot be given to a regulated structure unless the MSTR JSYS has been first used to increment the mount count. All structures are regulated by default except the primary structure or any structure that has been made nonregulated with the MSTR JSYS. Access rights and all JFNs on the regulated structure must be released before the mount count can be decremented. The format of the argument block is as follows: Word Symbol Meaning 0 .ACDIR Byte pointer to ASCIZ string containing the structure and directory name or a 36-bit directory number. The ASCIZ string must be of the form structure:<directory>. 1 .ACPSW Byte pointer to ASCIZ string containing the password of the specified directory. The password is not required if: 1. The directory is on a domestic structure and has the same name as the user's logged-in directory. 2. Function AC%CON is being done and the directory does not require a password for connecting. 2 .ACJOB Number (decimal) of job or -1 for the current job. The process must have WHEEL or OPERATOR capability enabled to give a specific job number other than its own. 3-2
TOPS-20 MONITOR CALLS (ACCES) The ACCES monitor call can be given for another job if the type of access being requested is for connecting the job (AC%CON) and if the process executing the call has WHEEL or OPERATOR capability enabled. The ACCES monitor call is used to implement the CONNECT, ACCESS, and END-ACCESS commands of the TOPS-20 Command Language. Generates an illegal instruction interrupt on error conditions below. ACCES ERROR MNEMONICS: ACESX1: Argument block too small ACESX3: Password is required ACESX4: Function not allowed for another job ACESX5: No function specified for ACCES ACESX6: Directory is not accessed ACESX7: Directory is "files-only" and cannot be accessed CNDIX1: Invalid password CNDIX5: Job is not logged in STRX01: Structure is not mounted STRX02: Insufficient system resources STRX03: No such directory name STRX04: Ambiguous directory specification STRX09: Prior structure mount required STRX10: Structure is offline LGINX2: Directory is "files-only" and cannot be logged into CAPX1: WHEEL or OPERATOR capability required RCDIX2: Invalid directory specification ARGX07: Invalid job number ARGX08: No such job Controls address breaks. An address break is the suspension of a process when a specified location is referenced in a given manner. ACCEPTS IN AC1: Function code in the left half and process handle in the right half AC2: Function-specific argument AC3: Function-specific argument RETURNS +1: Always This JSYS is useful when debugging a program. For example, consider the problem of debugging a program consisting of a fork running 3-3
TOPS-20 MONITOR CALLS (ADBRK) several inferior forks mapped to the same address space. One (or more) of the inferior forks is erroneously referencing a particular address. To find out which fork(s) are referencing that address, do the following: 1. Set up the software interrupt system for interrupts on channel 19. 2. Perform the ADBRK .ABSET function for each inferior process, using the handle of the inferior process and the address being erroneously referenced. 3. When a channel 19 interrupt occurs, perform an RFSTS JSYS for each inferior process. The interrupted process that caused the address break will have a code 7 (.RFABK) returned in its status word. 4. Perform the ADBRK .ABGAD function for each process that caused an address break. This returns the address of the instruction that erroneously referenced the break address. 5. Perform the RFORK JSYS to restart the process(es) halted by address break(s). 6. Continue running the program and repeating the last three steps until the program completes execution, or it no longer generates address breaks. The ADBRK JSYS can also be used to find which instruction in a process references a wrong memory location. The available functions are as follows: Code Symbol Meaning 0 .ABSET Set address break. 1 .ABRED Read address break. 2 .ABCLR Clear address break. 3 .ABGAD Return address of break instruction. 4 .ABSRG Set address break range. 5 .ABRRG Read address break range. 6 .ABGBR Return address break data. Each function is described in the following paragraphs. 3-4
TOPS-20 MONITOR CALLS (ADBRK) Setting address breaks - .ABSET This function initializes the address break facility for the specified process. When the process references the location in the manner for which the break has been set, it is suspended. Its superior receives a software interrupt on channel 19 (.ICIFT) if it has enabled for that channel. After processing the interrupt, the superior process can resume the inferior by executing the RFORK monitor call. Only one address break can be in effect for a process at any one time, and the break affects only the process for which it is set. If another process references the location on which a break is set, it is not affected by the break. When an address break is set in a page shared among processes and each process is to be suspended when it references the location, the ADBRK call must be executed for each process. Breaks cannot be specified for the accumulators. The .ABSET function requires the following arguments to be given: AC2: address of location on which to break. AC3: flag word indicating the type of reference on which to break. The following flags are currently defined: B0(AB%RED) Break on a read reference. B1(AB%WRT) Break on a write reference. B2(AB%XCT) Break on an execute (instruction fetch) reference. Reading address breaks - .ABRED This function returns the current address break information for the specified process. It returns the following information on a successful return: AC2: address of location on which a break is set AC3: flag word indicating the type of reference on which the break will occur. The following flags are currently defined: B0(AB%RED) Break will occur on a read reference. B1(AB%WRT) Break will occur on a write reference. B2(AB%XCT) Break will occur on an execute (instruction fetch) reference. 3-5
TOPS-20 MONITOR CALLS (ADBRK) If no address break has been set for the process, the contents of AC2 and AC3 are zero on return. Clearing address breaks - .ABCLR This function removes any address break that was set for the specified process. A program can also remove a break by executing the .ABSET function with AC2 and AC3 containing zero. Returning the address of the break instruction - .ABGAD This function returns in AC2 the address of the location on which the process encountered a break. When the location on which the break occurred is in a JSYS routine, the address returned is a monitor PC, not the address of the JSYS. The program can obtain the address of the JSYS by executing an RFSTS monitor call. Setting an address break range - .ABSRG This function is the same as .ABSET except it allows for the setting of a range of addresses on which to break. Currently the range is restricted to a single address location. This function requires that AC2 contain the address of an argument block. The format of the argument block is: Word Symbol Contents 0 .ABHDR Flags,,length of block B0 AB%RED Break on read reference B1 AB%WRT Break on write reference B2 AB%XCT Break on an execute (instruction fetch) reference B3 AB%SEC Break on this address in any section 1 .ABLOB Lower bound address 2 .ABUPB Lower bound address Read address break range - .ABRRG This function is the same as .ABRED except it returns the current address break information for a range of addresses. Currently the range is restricted to a single address location. This function requires that AC2 contain the address of an argument block. The user 3-6
TOPS-20 MONITOR CALLS (ADBRK) fills in word 0; the monitor supplies the remaining information. The format of the argument block is: Word Symbol Contents 0 .ABHDR Length of the block 1 .ABLOB Lower bound address (return) 2 .ABUPB Upper bound address (return) 3 .ABFLG Flags (return), same as those for .ABSRG Return address break data - .ABGBR This function is the same as .ABGAD except the address on which the break occurred is an address within the break range provided by the user. AC2 contains the address of an argument block with the following format: Word Symbol Contents 0 .ABHDR Length of the block 1 .ABBPC Break PC (return) 2 .ABBAD Break address (return) Generates an illegal instruction interrupt on error conditions below. ADBRK ERROR MNEMONICS: ABRKX1: Address break not available on this system ARGX02: Invalid function FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle FRKHX8: Illegal to manipulate an execute-only process Activates specific software interrupt channels. (See Section 2.6.) 3-7
TOPS-20 MONITOR CALLS (AIC) ACCEPTS IN AC1: Process handle AC2: 36-bit word Bit n on means activate channel n RETURNS +1: Always The DIC monitor call can be used to deactivate specified software interrupt channels. Generates an illegal instruction interrupt on error conditions below. AIC ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle FRKHX8: Illegal to manipulate an execute-only process Allocates a device to a job or to the device pool of the monitor's resource allocator. A device under control of the monitor's resource allocator cannot be opened or assigned by any job other than the one to which it is currently allocated. When the allocated device is deassigned, it is returned to the monitor's resource allocator. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Function code (.ALCAL) AC2: Device designator AC3: Job number, -1, or -2 RETURNS +1: Failure, error code in AC1 +2: Success If AC3 contains a job number, then the designated device is allocated to that job. If AC3 contains -1, then the device is returned to the pool of devices available to all users of the system (the device is no longer allocated). This is the initial state of all devices. If AC3 contains -2, then the device is assigned to the monitor resource allocator's pool of devices. 3-8
TOPS-20 MONITOR CALLS (ALLOC) Once a job assigns or opens a nonallocated device (a device not under control of the resource allocator), the resource allocator cannot take the device from the job. The resource allocator can allocate the device, however, to the job that currently has it. Then, when the job releases the device, the resource allocator gets control of the device. When a job returns control of a device to the system resource allocator, the allocator receives an IPCF packet. The flag word (.IPCFL) of the packet descriptor block contains a code that indicates the message was sent by the monitor. This code is 1(.IPCCC) in the IP%CFC field (bits 30-32). The first word of the IPCF packet data block contains .IPCSA, which means that the second and subsequent words contain designators for devices returned to the control of the resource allocator. .IPCFL/<.IPCCC>B32 DATA/.IPCSA DATA+1/device designator DATA+2/device designator The ALLOC monitor call requires the process to have WHEEL or OPERATOR capability enabled. ALLOC ERROR MNEMONICS: ALCX1: Invalid function ALCX2: WHEEL or OPERATOR capability required ALCX3: Device is not assignable ALCX4: Invalid job number ALCX5: Device already assigned to another job ALCX6: Device assigned to user job, but will be given to allocator when released DEVX1: Invalid device designator Performs operations pertaining to the archive and virtual disk systems. These include requesting archival and migration, requesting retrieval, and setting archive status and tape information for a file. RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: JFN AC2: Function code. 3-9
TOPS-20 MONITOR CALLS (ARCF) The available functions and their argument blocks are described below. AC3: (Function-dependent, normally 0) Code Symbol Function 0 .ARRAR Sets/clears AR%RAR (in .FBBBT of the FDB), activating or deactivating a user request for archival. The value .ARSET (1) in AC3 requests an archive while .ARCLR (0) clears the request. Specifying .ARSET in AC3 sets AR%NDL (in .FBBBT of the FDB) and requests that the contents of the file not be flushed from disk upon archival. 1 .ARRIV Sets/clears AR%RIV (in .FBBBT of the FDB), activating or deactivating a system request to migrate a file from disk to tape. The value .ARSET in AC3 requests migration while .ARCLR clears the request. This function requires WHEEL or OPERATOR capability to be enabled. 2 .AREXM Sets/clears AR%EXM (in .FBBBT of the FDB), activating or deactivating exemption from involuntary migration. Code .ARSET (1) in AC3 sets AR%EXM, while code .ARCLR (0) in AC3 clears AR%EXM. This function requires WHEEL or OPERATOR capability to be enabled. 3 .ARRFR Request that the contents of a file be restored to disk. The contents of AC3 determine if .ARRFR waits or returns without waiting for the contents of the file to be restored to disk. Options for AC3 B0 AR%NMS Do not wait for the file to be restored. B1 AR%WAT Wait until the file is restored. 4 .ARDIS Discard tape information. Clears FB%ARC (if set), .FBTP1, .FBTP2, .FBTSN, .FBTFN, and .FBTDT. The file must be on line for the function to succeed. Options for AC3 (which require WHEEL or OPERATOR capability enabled to be used separately): B0 AR%CR1 Clear information for run 1. B1 AR%CR2 Clear information for run 2. 3-10
TOPS-20 MONITOR CALLS (ARCF) 5 .ARSST Set tape information for a file. This function is used to set information for the first, second, or both tape runs. AR%O1 and AR%O2 are used together when restoring files to disk. It requires enabled WHEEL or OPERATOR privileges. AC3 contains a pointer to an argument block as follows: Word Symbol Contents 0 .AROFL Flags: B0(AR%O1) Set information for run 1. B1(AR%O2) Set information for run 2. B2(AR%OFL) Delete disk contents of file when done. Requires both run 1 and run 2 tape information to be set. B3(AR%ARC) Set FB%ARC in the FDB (archive the file.) B4(AR%CRQ) Clear archive and/or migration requests (clear AR%RAR and AR%RIV.) 1 .ARTP1 Tape 1 identification. 2 .ARSF1 TSN 1,,TFN 1 - Tape saveset number in the left half and tape file number in the right half. 3 .ARTP2 Tape 2 identification. 4 .ARSF2 TSN 2,,TFN 2 - similar to .ARSF1. 5 .ARODT time and date of tape write in internal format; 0 implies present time. 3-11
TOPS-20 MONITOR CALLS (ARCF) 6 .ARPSZ Number of pages in the file. This word can be set only if AR%O1 and AR%O2 are set first. 6 .ARRST Restore contents of a file to disk. AC3 contains a JFN for a temporary file (created by DUMPER) that contains the data for an archived file that is currently off-line. After .FBADR, .FBBSY, and .FBSIZ are copied, the temporary file is deleted. Both files must be on the same device or structure, and enabled WHEEL or OPERATOR capability is required. 7 .ARGST Get tape information for file. AC3 contains the address of an argument block that has the same format as the block for .ARSST. 10 .ARRFL The restore for this file has failed. Sets AR%RFL in .FBBBT to notify a waiting process that the retrieval request cannot be completed. Requires WHEEL or OPERATOR capability. 11 .ARNAR Resist involuntary migration. Sets or clears AR%NAR in .FBBBT. Using .ARSET in AC3 causes resist to be set, while using .ARCLR clears resist. ARCF ERROR MNEMONICS: CAPX1: WHEEL or OPERATOR capability required ARGX02: Invalid function code ARCFX2: File already has archive status ARCFX3: Cannot perform ARCF functions on nonmultiple directory devices ARCFX4: File is not on line ARCFX5: Files are not on the same device or structure ARCFX6: File does not have archive status ARCFX7: Invalid parameter for .ARSST ARCFX8: Archive not complete ARCFX9: File not off line ARCX10: Archive prohibited ARCH11: Archive requested, modification prohibited ARCH12: Archive requested, delete prohibited ARCX13: Archive system request not completed ARCX14: Restore failed ARCX15: Migration prohibited ARCX16: Cannot exempt off-line file ARCX17: FDB improper format for ARCF ARCX18: Retrieval wait cannot be fulfilled for waiting process ARCX19: Migration already pending 3-12
TOPS-20 MONITOR CALLS (ASND) Assigns a device to the caller. The successful return is given if the device is already assigned to the caller. ACCEPTS IN AC1: Device designator RETURNS +1: Failure, error code in AC1 +2: Success The RELD call can be used to release devices assigned to the caller. ASND ERROR MNEMONICS: DEVX1: Invalid device designator DEVX2: Device already assigned to another job ASNDX1: Device is not assignable ASNDX2: Illegal to assign this device ASNDX3: No such device DSMX1: File(s) not closed Assigns Internet queues for the TCP/IP interface. RESTRICTIONS: For TCP/IP systems only. Requires NET WIZARD, WHEEL, or OPERATOR capability enabled. ACCEPTS IN AC1: Flags in the left half and a pointer to the Queue Descriptor Block in the right half. AC2: Unused, must be 0 AC3: Unused, must be 0 RETURNS +1: Failure, with error code in AC1 and conflicting job number in AC2 +2: Success, with internet queue handle in AC1 and the maximum SNDIN% count in AC2 ASNIQ% Flags Bit Symbol Meaning B1 AQ%SPT Single-port protocol 3-13
TOPS-20 MONITOR CALLS (ASNIQ%) B2 AQ%ICM Deliver ICMP error datagrams to this queue Queue Descriptor Block Format: Word Symbol Meaning 0 .IQPRV B0-23 Must be 0 B24-31 Internet protocol number 1 .IQFHV B0-31 Internet foreign host value word 2 .IQSHV B0-31 Internet source host value word; used for logical host selection 3 .IQPTV Internet port value word B0-15 Local port value B16-31 Foreign port value; ignored if bit AQ%SPT is set 4 .IQPRM Mask word corresponding to .IQPRV 5 .IQFHM Mask word corresponding to .IQFHV 6 .IQSHM Mask word corresponding to .IQSHV 7 .IQPTM Mask word corresponding to .IQPTV; use 0 for portless protocols 8 .IQLEN Length of argument block. Mask words specify those bit positions where an exact match is required. Note that an error will occur unless the current Queue Descriptor Block differs in masked bits from all other Internet queues which are assigned at the time the ASNIQ% JSYS is executed. ASNIQ% ERROR MNEMONICS: ARGX22: Invalid flags Assigns a special message queue to a job. RESTRICTIONS: For TCP/IP systems only. Requires NET WIZARD capability (SC%NWZ). ACCEPTS IN AC1: Mask 3-14
TOPS-20 MONITOR CALLS (ASNSQ) AC2: Header value RETURNS +1: Failure, error code in AC1 +2: Success, special message queue assigned with special queue handle in AC1 ASNSQ ERROR MNEMONICS: NTWZX1: NET WIZARD capability required ASNSX1: Insufficient system resources (All special queues in use) ASNSX2: Link(s) assigned to another special queue Detaches the specified job from its controlling terminal (if any) and optionally attaches it to a new controlling terminal. A console-attached entry is appended to the accounting data file. RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: B0(AT%CCJ) Generate a CTRL/C interrupt to the lowest process in the job that is enabled for a CTRL/C interrupt if the job is currently attached to another terminal. If this bit is not set or if the job is currently not attached to another terminal, the job simply continues running when it is attached. B1(AT%NAT) Do not attach. Prevents both the detaching of the job from its terminal and the attaching of a remote job to the local terminal. Is a no-op unless the remote job has a controlling terminal, in which case the remote job is detached and remains detached. This bit in effect makes ATACH like a remote DTACH. B2(AT%TRM) Attach the given job to the terminal specified in AC4. If this bit is not set, the job is attached to the controlling terminal of the caller. B18-35 Job number of the desired job. (AT%JOB) 3-15
TOPS-20 MONITOR CALLS (ATACH) AC2: User number under which the job to be attached is logged in. The user number can be obtained with the RCUSR monitor call. AC3: Byte pointer to an ASCIZ password string in the caller's address space. AC4: Number of the terminal to be attached to the specified job. This argument is required if B2(AT%TRM) is set. RETURNS +1: Failure, error code in AC1. +2: Success. If there is a logged-in job currently attached to the specified terminal, it is detached and primary I/O for that job is not redirected. Thus, if a process has primary I/O from the controlling terminal, it will block when it attempts primary I/O and will continue when it is reattached and a character is typed. A job attached to the terminal but not logged in is killed. It is legal to attach to a job that has a controlling terminal if one of the following conditions exists: 1. The job is logged in under the same user name as the job executing the ATACH. 2. The job executing the ATACH supplies the correct password of the job it is attaching to. 3. The job executing the ATACH has WHEEL or OPERATOR capability enabled. 4. The job executing the ATACH has ownership of the job because it created the job (and maintained ownership) with the CRJOB call. If the controlling terminal is a PTY, a password is not required in the following cases: 1. The owner of the PTY has WHEEL or OPERATOR capability enabled. 2. The specified job is logged in with the same name as the owner of the PTY. The DTACH monitor call can be used to detach the controlling terminal from the current job. 3-16
TOPS-20 MONITOR CALLS (ATACH) ATACH ERROR MNEMONICS: ATACX1: Invalid job number ATACX2: Job already attached ATACX3: Incorrect user number ATACX4: Invalid password ATACX5: This job has no controlling terminal ATACX6: Terminal is already attached to a job ATACX7: Illegal terminal number Assigns a terminal code to a software interrupt channel. (Refer to Section 2.6.) This call also sets the corresponding bit in the process's terminal interrupt mask. (Refer to the STIW and RTIW monitor calls.) ACCEPTS IN AC1: Terminal interrupt code,,channel number (Refer to Section 2.6.6.) RETURNS +1: Always If there is no controlling terminal (if the job is detached), the assignments are remembered and are in effect when a terminal becomes attached. The DTI monitor call can be used to deassign a terminal code. Generates an illegal instruction interrupt on error conditions below. ATI ERROR MNEMONICS: TERMX1: Invalid terminal code ATIX1: Invalid software interrupt channel number ATIX2: Control-C capability required Creates the Network Virtual Terminal (NVT) connection. RESTRICTIONS: For TCP/IP systems only. ACCEPTS IN AC1: Flag bits in the left half and the JFN of the opened receive connection in the right half AC2: JFN of the opened send connection 3-17
TOPS-20 MONITOR CALLS (ATNVT) RETURNS +1: Failure, with error code in AC1 +2: Success, with terminal designator specific to this NVT in AC1 Flags for AC1: Bit Symbol Meaning B0 AN%TCP If set, this bit indicates that the right half of AC1 contains the TCP JCN instead of a JFN. ATNVT ERROR MNEMONICS: ATNX1: Invalid receive JFN ATNX2: Receive JFN is not open for read ATNX3: Receive JFN is not open ATNX4: Receive JFN is not a network connection ATNX5: Receive JFN has been used ATNX6: Receive connection has been refused ATNX7: Invalid send JFN ATNX8: Send JFN is not open for write ATNX9: Send JFN is not open ATNX10: Send JFN is not a network connection ATNX11: Send JFN has been used ATNX12: Send connection has been refused ATNX13: Insufficient system resources (no NVTs) Inputs the next byte from the specified source. When the byte is read from a file, the file must first be opened, and the size of the byte given, with the OPENF call. When the byte is read from memory, a pointer to the byte is given. This pointer is updated after the call. ACCEPTS IN AC1: Source designator RETURNS +1: Always, with the byte right-justified in AC2 If the end of the file is reached, AC2 contains 0 instead of a byte. The program can process this end-of-file condition if an ERJMP or ERCAL is the next instruction following the BIN call. The BOUT monitor call can be used to output a byte sequentially to a destination. Can cause several software interrupts or process terminations on certain file conditions. (Refer to bit OF%HER of the OPENF call description.) 3-18
TOPS-20 MONITOR CALLS (BIN) BIN ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX5: File is not open IOX1: File is not open for reading IOX4: End of file reached IOX5: Device or data error Backs up the source designator's pointer by one byte. ACCEPTS IN AC1: Source designator RETURNS +1: Failure, error code in AC1 +2: Success, updated string pointer in AC1, if pertinent. (This return actually decrements the pointer.) The BKJFN call, when referring to a terminal, can be executed only once per TTY to back up one character. The BKJFN call cannot be issued again for the same TTY unless the input buffer has been cleared (with the CFIBF JSYS) or an input JSYS is executed for the TTY. BKJFN, when referring to other designators, can be executed more than once in succession. This call cannot be used with the DECnet devices SRV: or DCN:. BKJFN ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX5: File is not open BKJFX1: Illegal to back up terminal pointer twice SFPTX2: Illegal to reset pointer for this file SFPTX3: Invalid byte number TTYX01: Line is not active Performs basic maintenance and utility functions required for loading and dumping communications software. The TOPS-20 system process that performs these functions uses a DIGITAL-supplied protocol to perform them. 3-19
TOPS-20 MONITOR CALLS (BOOT) On KL10 Model B hardware, the BOOT JSYS is used to load and dump a PDP-11 connected to a DTE20. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. Some functions are hardware specific. ACCEPTS IN AC1: Function code AC2: Address of argument block RETURNS +1: Always The available functions and their argument blocks are described below. Code Symbol Meaning 0 .BTROM Activate the hardware ROM bootstrap in the communications front end. Argument Block: 0 .BTDTE DTE-20 number 1 .BTERR Error status flags returned on failure of the call 1 .BTLDS Load a secondary bootstrap program into the communications front end. The secondary bootstrap, with a maximum size of 256 PDP-11 words, is loaded using the ROM bootstrap. The data to be loaded must be packed as two 16-bit PDP-11 words left justified in each 36-bit word. The entire bootstrap program must be loaded at once, and the caller blocks until the transfer is complete. Argument Block: 0 .BTDTE DTE-20 number 1 .BTERR Error status flags returned on failure of the call 2 .BTSEC Address of bootstrap program to be loaded 2 .BTLOD Load the communications front-end memory using the previously loaded secondary or tertiary bootstrap program. The bootstrap program in the front end must abide by the protocol for DTE-20 transfers: 3-20
TOPS-20 MONITOR CALLS (BOOT) the first two bytes of data supplied by the caller must be a count of the remaining number of data bytes. Argument Block: 0 .BTDTE DTE-20 number 1 .BTERR Error status flags returned on failure of the call 2 Not used and must be zero 3 .BTFLG User-supplied flag word. This word is not used and must be zero. 4 .BTCNT Number of bytes to transfer 5 .BTDPT Pointer to where the data is to be dumped in TOPS-20 4 .BTIPR Initialize the protocol to be used with this communications front end. After successful execution of this function, TOPS-20 processes interrupts from the given DTE-20. Argument Block: 0 .BTDTE DTE-20 number 1 .BTPRV Version number of the protocol to be used Protocol types: Symbol Meaning .VN20F (0) RSX20F protocol .VNMCB (1) MCB DECNET protocol 5 .BTTPR Stop the protocol currently running on this communications front end or line. Stop the protocol currently running on this communications front end or line. After successful execution of this function, TOPS-20 ignores interrupts from the given DTE-20 or line. Argument Block: 0 .BTDTE DTE-20 number 3-21
TOPS-20 MONITOR CALLS (BOOT) 6 .BTSTS Return the status type of the protocol running on the communications front end to the specified DTE or line. Also returns the name of the adjacent DECNET node for this front end. Argument Block: 0 .BTDTE DTE-20 number 1 .BTCOD Returned protocol version type. If no protocol is running, this word contains -1. Protocol types: Symbol Meaning .VN20F (0) RSX20F protocol .VNMCB (1) MCB DECNET protocol 7 .BTBEL Block until a signal (doorbell) to TOPS-20 is initiated by the communications front end. This function is used to synchronize the caller with the bootstrap program in the front end. Argument Block: 0 .BTDTE DTE-20 number 10 .BTRMP Read data from the communications front end using the previously loaded secondary or tertiary bootstrap program. The bootstrap program must abide by the protocol for DTE-20 transfers. The first two bytes of data are interpreted as a count of the remaining number of bytes of data. Argument Block: 0 .BTDTE DTE-20 number 1 .BTERR Error status flags returned on failure of the call 2 Not used and must be zero 3 .BTFLG User-supplied flag word B0(BT%BEL) Send a signal (doorbell) to TOPS-20 to indicate the transfer is finished. 3-22
TOPS-20 MONITOR CALLS (BOOT) 4 .BTCNT Maximum number of bytes to transfer. After successful execution of this function, this word is updated to reflect the actual number of bytes transferred. 5 .BTMPT Pointer to where data is to be placed 14 .BTCLI Convert line id to port number Argument Block: 0 .BTPRT Port number 1 .BTLID Pointer to ASCIZ line id 15 .BTCPN Convert NSP port number to line id Argument Block: 0 .BTPRT Port number 1 .BTLID Pointer to ASCIZ line id 16 .BTD60 Send a message to or receive a message from a front end (a DN60) using the .VND60 protocol. The argument block controls whether this function sends or receives a message. (Requires DN60) Argument Block: 0 .BT6DTE DTE number 1 .BT6ERR Error flags (returned): 30 D6%BDP The data byte pointer passed in the argument block is bad. 31 D6%ARD The PDP-11 attempted to send data when none was expected. 32 D6%TRS DTESRV timed out waiting for response header from the front end. 33 D6%TDT DTESRV timed out waiting for data from the front end. 34 D6%TPO DTESRV timed out waiting for the DTE to be free. Another job is using the DTE and is probably hung. 3-23
TOPS-20 MONITOR CALLS (BOOT) 35 D6%NT6 The front end is not running DN60 protocol. 2 .BT6HBC Number of bytes in the DN60 header. 2 .BT6HDR Address at which the DN60 header begins. This header contains 4 words, which contain 4 8-bit bytes each. 3 .BT6DBC Number of bytes of data. 4 .BT6PTR Pointer to the first byte of the data. 5 .BT6TMR Time the request was made (returned). 6 .BT6TAS Time DTE was assigned (returned). 7 .BT6THQ Time TOPS-20 queued the header to the DTE. 10 .BT6TRD Time TOPS-20 was done for response header. 11 .BT6TDD Time TOPS-20 was done for data. 12 .BT6TFR Time TOPS-20 satisfied the request. The error status flag returned in word .BTERR on failure of a BOOT call contains front-end reload status bits recorded in the system error file. Refer to the SPEAR manual for an explanation of these status bits. Note that error logging is not performed for group A processors. Generates an illegal instruction interrupt on error conditions below. BOOT ERROR MNEMONICS: BOTX01: For group A processors, this message indicates an illegal line number. For group B processors, this message indicates an invalid DTE-20 number. BOTX02: Invalid byte size BOTX03: Invalid protocol version number BOTX04: Byte count is not positive BOTX05: Protocol initialization failed BOTX06: GTJFN failed for dump file BOTX07: OPENF failed for dump file BOTX08: Dump failed BOTX09: To -10 error on dump BOTX10: To -11 error on dump BOTX11: Failed to assign page on dump BOTX12: Reload failed BOTX13: -11 didn't power down BOTX14: -11 didn't power up BOTX15: ROM did not ACK the -10 BOTX16: -11 boot program did not make it to -11 3-24
TOPS-20 MONITOR CALLS (BOOT) BOTX17: -11 took more than 1 minute to reload; will cause retry BOTX18: Unknown BOOT error CAPX1: WHEEL or OPERATOR capability required ARGX02: invalid function Outputs a byte sequentially to the specified destination. When the byte is written to a file, the file must first be opened, and the size of the byte given, with the OPENF call. When the byte is written to memory, AC1 contains a pointer to the location in which to write the byte. This pointer is updated after the call. ACCEPTS IN AC1: Destination designator AC2: Byte to be output, right-justified RETURNS +1: Always The BIN monitor call can be used to input a byte sequentially from a source. Can cause several software interrupts or process terminations on certain file conditions. (Refer to bit OF%HER of the OPENF call description.) BOUT ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX5: File is not open IOX2: File is not open for writing IOX5: Device or data error IOX6: Illegal to write beyond absolute end-of-file IOX11: Quota exceeded IOX33: TTY input buffer full IOX34: Disk full IOX35: unable to allocate disk - structure damaged Changes the account for the current job. RESTRICTIONS: When this call is used in any section other than section zero, one-word global byte pointers used as arguments must have a byte size of seven bits. 3-25
TOPS-20 MONITOR CALLS (CACCT) ACCEPTS IN AC1: Byte pointer that points to the new account string in the calling program's address space. This call reads the string until a null byte is read, or until 39 characters are read. If executed in section 0, this AC can contain a local byte pointer or an account number. The account number must be in bits 3-35, and bits 0-2 must contain 5. RETURNS +1: Failure, error code in AC1 +2: Success, updated string pointer in AC1 The CACCT call sets the current account for the job to the specified account. Subsequent session charges will be to this new account. This call also validates the account given if the account validation facility is enabled. (Refer to the .SFAVR function of the SMON/TMON monitor call.) The GACCT monitor call can be used to return the account for the current job. CACCT ERROR MNEMONICS: CACTX1: Invalid account identifier CACTX2: Job is not logged in VACCX0: Invalid account VACCX1: Account string exceeds 39 characters Clears the designated file input buffer. ACCEPTS IN AC1: Source designator RETURNS +1: Always Is a no-op if the source designator is not associated with a terminal. The CFOBF monitor call can be used to clear a designated file output buffer. Generates an illegal instruction interrupt on error conditions below. CFIBF ERROR MNEMONICS: DESX1: Invalid source/destination designator 3-26
TOPS-20 MONITOR CALLS (CFIBF) DESX3: JFN is not assigned DESX5: File is not open DEVX2: Device already assigned to another job TTYX01: Line is not active Clears the designated file output buffer. ACCEPTS IN AC1: Destination designator RETURNS +1: Always Is a no-op if the destination designator is not associated with a terminal. The CFIBF call can be used to clear a designated file input buffer. Generates an illegal instruction interrupt on error conditions below. CFOBF ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX3: JFN is not assigned DESX5: File is not open DEVX2: Device already assigned to another job TTYX01: Line is not active Creates a process inferior to the calling process. (Refer to Section 2.7.) ACCEPTS IN AC1: Characteristics for inferior,,PC address for inferior B0(CR%MAP) Make the inferior process's map the same as the current process's map by means of indirect pointers. If this bit is not on, the inferior process will have no pages in its map. If desired, the creating process can then use PMAP or GET to add pages to the inferior's map. B1(CR%CAP) Make the inferior process's capabilities the same as the current process's. If this bit is not on, the inferior process 3-27
TOPS-20 MONITOR CALLS (CFORK) has no capabilities (all bits of Job Capability Word are 0). B3(CR%ACS) Set the inferior process's ACs from the block whose address is in AC2. If this bit is not on, the inferior process's ACs are set to 0. B4(CR%ST) Set the PC of the inferior process to the value in the right half of AC1 and start the process. If this bit is not on, the inferior process is not started, and the right half of AC1 is ignored. (Also see the XSFRK% call.) B18-35 PC value for the inferior process if CR%ST (CR%PCV) is on. AC2: Address of 20 (octal) word block (optional). This block contains the AC values for the inferior process. (Refer to bit CR%ACS above.) RETURNS +1: Failure, error code in AC1 +2: Success, relative process handle in AC1 The inferior process receives the same primary input and output JFNs as the current process. However, the primary input and/or output files may be changed with the SPJFN monitor call. The CR%MAP argument in AC1 allows the inferior to see the same address space as that of the superior. The inferior process will have read and write access to the superior's address space. The pages are shared, and changes made by one process will be seen by the other. CFORK creates a nonvirgin process if: 1. CR%ST is set and 2. CR%ACS and/or CR%MAP is set. CFORK creates an execute-only process if bit CR%MAP is set and the creating process is an execute-only process. This is the only other way to create an execute-only process besides using the GET JSYS on a virgin process. The KFORK monitor call can be used to kill one or more processes. CFORK ERROR MNEMONICS: FRKHX6: All relative process handles in use 3-28
TOPS-20 MONITOR CALLS (CFORK) FRKHX8: Illegal to manipulate an execute-only process CFRKX3: Insufficient system resources Changes certain words in the file descriptor block (FDB) for the specified file. (Refer to Section 2.2.8 for the format of this block.) RESTRICTIONS: WHEEL or OPERATOR capability required to change some words in the FDB. (Refer to Table 2-1 for the words requiring capabilities.) ACCEPTS IN AC1: B0(CF%NUD) Do not wait for the disk copy of the directory to be updated. The specified changes are made to the directory in memory and are written to the disk as a part of the normal monitor disk updating procedure. (See below for more information.) B9-17 Index into FDB indicating word to be (CF%DSP) changed B18-35 JFN (for a disk file) (CF%JFN) AC2: Mask indicating bits to be changed. If changing a count value (in AC3), use -1 as a mask. AC3: New values for changed bits. These values must be given in the bit positions corresponding to the mask given in AC2. RETURNS +1: Always Because each CHFDB call changes only one word in the FDB, several calls must be executed to change several words. Each call causes disk I/O. To keep I/O to a minimum, the program should set bit CF%NUD on each call. The setting of this bit on each call permits the program to run faster by allowing several changes to be made to the FDB with minimum disk I/O. To ensure that all the changes have been written to the disk, the program can issue the last CHFDB call with bit CF%NUD off. Also, if the program requires the FDB on the disk to be updated after each call, it should execute each CHFDB call with bit CF%NUD off. 3-29
TOPS-20 MONITOR CALLS (CHFDB) There are a variety of calls used in manipulating the FDB; see the description of the FDB in Chapter 2 for information on these calls. Generates an illegal instruction interrupt on error conditions below. CHFDB ERROR MNEMONICS: CFDBX1: Invalid displacement CFDBX2: Illegal to change specified bits CFDBX3: Write or owner access required CFDBX4: Invalid value for specified bits CFDBX5: No FDB for non-directory devices DESX1: Invalid source/destination designator DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer DESX7: Illegal use of parse-only JFN or output wildcard-designators STRX10: Structure is offline Checks if a user is allowed access to files in a given directory. This monitor call determines if the user can access files that have a specified protection code if the user is logged in with the given capabilities and connected to the directory. RESTRICTIONS: When this call is used in any section other than section zero, one-word global byte pointers used as arguments must have a byte size of seven bits. ACCEPTS IN AC1: Length of the argument block in the right half. If B0(CK%JFN) is on, word .CKAUD of the argument block contains a JFN. AC2: Address of argument block RETURNS +1: Failure, error code in AC1 +2: Success, access check is completed, with AC1 containing -1 if access is allowed or 0 if access is not allowed. The format of the argument block is as follows: Word Symbol Meaning 0 .CKAAC Code of desired access to files. 1 .CKALD Byte pointer to user name string, or 36-bit user number of user whose access is being checked. 3-30
TOPS-20 MONITOR CALLS (CHKAC) 2 .CKACD Byte pointer to directory name string (with punctuation), or 36-bit directory number to which user whose access is being checked is connected. 3 .CKAEC Enabled capabilities of user whose access is being checked. (Refer to Section 2.7.1.) 4 .CKAUD Byte pointer to directory name string (with punctuation), or 36-bit directory number of the directory containing the files being accessed. If B0(CK%JFN) of AC1 is on, this word contains a JFN for the file being accessed. 5 .CKAPR Protection of the files being accessed. (Refer to Section 2.2.6.) This word is not required if a JFN is supplied in word .CKAUD. Access codes are as follows: 0 .CKARD read existing files 1 .CKAWR write existing files 2 .CKAEX execute existing files 3 .CKAAP append to existing files 4 .CKADL obtain directory listing of existing files 6 .CKADR read the directory 10 .CKACN connect to the directory 11 .CKACF create files in the directory CHKAC ERROR MNEMONICS: CKAX1: Argument block too small CKAX2: Invalid directory number CKAX3: Invalid access code CKAX4: File is not on disk STRX10: Structure is offline Clears the software interrupt system for the current process. Clears all interrupts in progress and all waiting interrupts. RETURNS +1: Always Closes a specific file or all files. 3-31
TOPS-20 MONITOR CALLS (CLOSF) ACCEPTS IN AC1: B0(CO%NRJ) Do not release the JFN. B6(CZ%ABT) Abort any output operations currently being done. Close the file but do not perform any cleanup operations normally associated with closing a file. (If output is to a magnetic tape, for example, do not output remaining buffers or write tape marks. If output is to a disk file, do not change the end-of-file pointer.) If output is to a new disk file that has not been closed (and is therefore nonexistent), the file is closed and then expunged. B7(CZ%NUD) Do not update the copy of the directory on the disk. (Refer to CF%NUD of the CHFDB call description for further information.) B18-35 JFN of the file being closed (CO%JFN) RETURNS +1: Failure, error code in AC1 +2: Success If AC1 contains -1, all files (and all JFNs) at or below this process (with the exception of the primary I/O files and files that cannot be closed by this process) are closed. This action is identical to that taken on a CLZFF call with AC1 containing the process handle .FHSLF (400000). The OPENF monitor call can be used to open a specific file. CLOSF ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer CLSX1: File is not open CLSX2: File cannot be closed by this process CLSX3: File still mapped CLSX4: Device still active ENQX20: Locked JFN cannot be closed IOX11: Quota exceeded IOX34: Disk full IOX35: Unable to allocate disk - structure damaged All output errors can occur. 3-32
TOPS-20 MONITOR CALLS (CLZFF) Closes process's files. Closes all files and/or releases all JFNs at and/or below a specified process. ACCEPTS IN AC1: B0(CZ%NIF) Do not close files of inferior. processes B1(CZ%NSF) Do not close files of this process. B2(CZ%NRJ) Do not release JFNs. B3(CZ%NCL) Do not close any files; only release nonopen JFNs B4(CZ%UNR) Unrestrict files opened with restricted access for specified process. The specified process must be the same as, or inferior to, the process executing the call. B5(CZ%ARJ) Wait until file can be closed, then close it, and release JFNs. B6(CZ%ABT) Abort any output operations currently being done. Close the file but do not perform any cleanup operations normally associated with closing a file (for example, do not output remaining buffers or write tape marks if output to a magnetic tape is aborted). If output to a new disk file that has not been closed (file is nonexistent) is aborted, the file is closed and then expunged. B7(CZ%NUD) Do not update the copy of the directory on the disk. (Refer to CF%NUD of the CHFDB call description for further information.) B18-35 Process handle (CZ%PRH) RETURNS +1: Always. No action is taken if the call is in any way illegal. If AC1 contains only the process handle .FHSLF, the action is identical to that taken on a CLOSF call with AC1 containing -1. Generates an illegal instruction interrupt on error conditions below. CLZFF ERROR MNEMONICS: 3-33
TOPS-20 MONITOR CALLS (CLZFF) FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle IOX11: Quota exceeded IOX34: Disk full IOX35: Unable to allocate disk - structure damaged Returns configuration information about the central processor and operating system environment for the system on which the monitor call is executed. ACCEPTS IN AC1: Function code AC2: Address of argument block RETURNS +1: Always The available functions and their argument blocks are described below. Code Symbol Meaning 0 .CFINF Return basic hardware and software information. Argument Block: 0 .CFLEN Number of words returned (CF%WDP),, length of argument block (CF%LOB) 1 .CFIPR Type of processor. ID for KL = .CFGKL(4) 2 .CFISE CPU serial number, right-justified 3 .CFIUC CPU microcode version number, right justified 4 .CFIHO CPU hardware options: B0(CF%50Z) Line power is 50 hertz. B1(CF%CHI) Cache is installed. B2(CF%CHN) Channel bit in the APRID word is on. B3(CF%EKL) CPU is an extended KL10. 3-34
TOPS-20 MONITOR CALLS (CNFIG) B4(CF%MOS) System has a master oscillator. B5(CF%MCA) System has MCA25 pager cache. B6(CF%CH1) Cache control bit 1. B7(CF%CH2) Cache control bit 2. B8(CF%CI) System has a CI. 5 .CFIMO CPU microcode options B0(CF%T20) TOPS-20 paging implemented. B1(CF%EAD) Microcode handles extended addresses. B2(CF%UCO) Non-standard microcode is loaded. 6 .CFISO TOPS-20 static software options B0(CF%CFS) CFS is installed. B1(CF%DCN) DECnet is installed. B2(CF%ARP) TCP/IP is installed. 7 .CFIVR TOPS-20 version number obtained from location .JBVER. The maximum length of the argument block is given by symbol .CFLIN. 1 .CFCIN Return CFS information Argument Block: 0 .CFLEN Number of words returned (CF%WDP),, length of argument block (CF%LOB). 1 .CFNCN Number of CFS nodes up, including the host system. 2 .CFCDO CFS dynamic options B0(CF%CFR) Host has connected to another CFS host at least once. 3-35
TOPS-20 MONITOR CALLS (CNFIG) The maximum length of the argument block is given by symbol .CFCLN. 2 .CFCSE Return CI node number and serial number of each CFS node. The numbers are returned right justified in APRID format. Bits 0-13 of each word are reserved for the future by DIGITAL. Information will be returned for a host, provided that the host is active and that there is valid information for the host. Information for the first host will always be returned. The number of hosts is determined by word .CFNCN of the .CFCIN function. Argument Block: 0 .CFLEN Number of words returned (CF%WDP),, length of argument block (CF%LOB). 1 .CFCS1 CI node number (CF%CIN),, serial number of first host (CF%HSN). 2 CI node number (CF%CIN),, serial number of next host (CF%HSN). n .CFCSn CI node number (CF%CIN),, serial number of last host (CF%HSN). 3 .CFCND Return node names of CFS hosts as 2-word ASCIZ strings. Information will be returned for a host provided that the host is active and that there is valid information for the host. Information for the first host will always be returned. The number of hosts is determined by word .CFNCN of the .CFCIN function. Argument Block: 0 .CFNND Number of nodes returned (CF%NND),, length of argument block (CF%LOB). 1 .CFBP1 Byte pointer to ASCIZ node name of first host. .CFBP1+n Start of area where node name strings are placed. 4 .CFHSC Returns the list of HSC node names. In the event that the argument block is not large enough, the 3-36
TOPS-20 MONITOR CALLS (CNFIG) CFGBTS error code is returned. Since the argument block must be long enough to contain all possible HSCs, it is suggested that it be set to the length C%SBLL*3+1. Argument Block: 0 .CFNHN Number of nodes returned (CF%NHN),,length of block (CF%LOB). 1 .CFHP1 Byte pointer to first node name string .CFHP1+n Start of an area in which the monitor placed node name strings. These are ASCIZ strings containing the node name. Generates an illegal instruction interrupt on error conditions below. CNFIG% ERROR MNEMONICS: CFGBFC: Function code out of range CFGBTS: Argument block too short CFGIAB: Invalid argument block address CFGAAB: Error accessing argument block CFGINA: Information not available for this function Parses one field of a command that is either typed by a user or contained in a file. When this monitor call is used to read a command from a terminal, it provides the following features: 1. Allows the input of a command (including the guide words) to be given in abbreviated, recognition (ESC and CTRL/F), and/or full input mode. 2. Allows the user to edit his input with the DELETE, CTRL/U, CTRL/W, and CTRL/R editing keys. 3. Allows fields of the command to be defaulted if an ESC or CTRL/F is typed at the beginning of any field, or if a field is omitted entirely. 4. Allows a help message to be given if a question mark (?) is typed at the beginning of any field. 3-37
TOPS-20 MONITOR CALLS (COMND) 5. Allows input of an indirect file (@file) that contains the fields for all or the remainder of the command. 6. Allows a recall of the correct portion of the last command (up to the beginning of the field where an error was detected) if the next command line begins with CTRL/H. The correct portion of the command is retyped, and the user can then continue typing from that point. 7. Allows input of a line to be continued onto the next line if the user types a hyphen (-) immediately preceding a carriage return. (The carriage return is invisible to the program executing the COMND call, although it is stored in the text buffer.) The user can type the hyphen while he is typing a comment. The comment is then continued onto the next line. A hyphen not immediately followed by a carriage return is parsed as ordinary text. The COMND call allows comments in the command line. A command line can contain a comment if the field before the comment has been terminated and the comment is preceded by an exclamation point or a semicolon. If the comment starts with an exclamation point, COMND ignores all text between the exclamation point and either the end of the line or the next exclamation point. If the comment starts with a semicolon, COMND ignores all text on the remainder of the line. A command line can contain the name of an indirect command file so long as the file name comes at the beginning of a field. It must, however, be the last item on the line, and its contents must complete the command. The user must follow the name of the indirect command file (after any recognition is performed) with a carriage return. If a carriage return does not end the command line immediately after the name of the indirect command file, the system outputs the message ?INDIRECT FILE NOT CONFIRMED. Also, if the user types a question mark (instead of the file specification of the indirect file) after he types the at-sign (@) character, the message FILESPEC OF INDIRECT FILE is output. If the indirect file itself contains an ESC or a carriage return, COMND treats them as spaces. COMND places the contents of the indirect file in the text buffer, but does not display them on the user's terminal. As the user types his command, the characters are placed in a command text buffer. This buffer can also include the command line prompt. Several byte pointers and counts reflect the current state of the parsing of the command. These pointers and counts are as follows: 3-38
TOPS-20 MONITOR CALLS (COMND) 1. Byte pointer to the beginning of the prompting-text buffer (.CMRTY). This pointer is also called the CTRL/R buffer byte pointer, since a CTRL/R causes COMND to redisplay the prompt contained in this buffer, along with anything the user typed on the command line before he typed the CTRL/R. The buffer that contains the prompt need not be contiguous with the buffer containing the remainder of the command line. 2. Byte pointer to the beginning of the buffer that contains the user's input (.CMBFP). This is the limit back to which the user can edit. 3. Byte pointer to the beginning of the next field of the command line to be parsed (.CMPTR). 4. Count of the space remaining in the text input buffer (.CMCNT). 5. Count of the number of characters in the buffer that have not yet been parsed (.CMINC). The following illustration is a logical arrangement of the byte pointers and counts. Remember that the prompting text buffer need not be adjacent to the text buffer. <------------- .CMCNT ----------> !=======================================================! ! ! ! ! ! ! ! ! ! ! !=======================================================! ^ ^ ^ | | | | | |<---- .CMINC ----> | | | | | | | .CMBFP .CMPTR .CMRTY These byte pointers and other information are contained in a command state block whose address is given as an argument to the COMND monitor call. The .CMINI function initializes these pointers. COMND Parses a command line field by field. COMND substitutes default values for missing fields in the command line when the user types a carriage return, ESC, CTRL/F, or question mark. These characters are called action characters because they cause the system to act on the command as typed so far. Other characters that terminate a field are space, tab, slash, comma, and any other nonalphanumeric character. 3-39
TOPS-20 MONITOR CALLS (COMND) Normally, parsing does not begin, and the COMND call does not return control to the program, until an action character is typed. But if B8(CM%WKF) is on in word .CMFLG when the COMND call executes, parsing begins after each field is terminated. A program parses a command line by repeated COMND calls. Each call specifies the type of field the program expects to be parsed. The program supplies this information, placing a function code and any data needed for the function in a function descriptor block. On successful completion of each call, the byte pointers and counts are updated in the command state block, and any data obtained for the field is returned. The program executing the COMND call should not reset the byte pointers in the command state block after it completes parsing a command line. It should set up the command state block before it begins to parse any commands, and then use the .CMINI function to initialize the command state block before parsing each command line. This allows the .CMINI function to use the CTRL/H error-recovery feature. If the program resets the pointers and counts in the command state block, instead of using the .CMINI function to do so, use of the CTRL/H feature is not possible. When a CTRL/H is typed, the .CMINI function allows recovery from an error in the last command only if the following are both true: 1. The pointer to the beginning of the user's input (.CMBFP) and the pointer to the beginning of the next field to be parsed (.CMPTR) are not equal. 2. The last character parsed in the previous command is not an end-of-line character. The COMND call allows the user to delete his typed input with the DELETE, CTRL/W, and CTRL/U keys without regard to field boundaries. When the user deletes part of a field that has already been parsed, the COMND call returns to the program with B3(CM%RPT) set in word .CMFLG, or the program resumes execution at the reparse address contained in word .CMFLG of the command state block. This address should be the place in the program at which parsing of the command line begins. If this address is zero, the program must test AC1 for this bit, and reparse the command line from the beginning, if necessary. (See the description of word .CMFLG of the command state block.) The calling sequence to the COMND call is as follows: ACCEPTS IN AC1: Address of the command state block AC2: Address of the first alternative function descriptor block 3-40
TOPS-20 MONITOR CALLS (COMND) RETURNS +1: Always (unless a reparse is needed and the right half of .CMFLG is nonzero), with AC1 containing flags in the left half and the address of the command state block in the right half. The flags are copied from word .CMFLG in the command state block. AC2 containing either the data obtained for the field or a monitor call error code if the field could not be parsed (CM%NOP is on in AC1). AC3 containing in the left half the address of the function descriptor block given in the call, and in the right half the address of the function descriptor block actually used. Note that the contents of the right half identify uniquely the type of atom that was parsed. The format of the command state block is shown below. 0 17 18 35 !=======================================================! .CMFLG ! Flag Bits ! Reparse Dispatch Address ! !-------------------------------------------------------! .CMIOJ ! Input JFN ! Output JFN ! !-------------------------------------------------------! .CMRTY ! Byte Pointer to CTRL/R Text ! !-------------------------------------------------------! .CMBFP ! Byte Pointer to Start of Text Buffer ! !-------------------------------------------------------! .CMPTR ! Byte Pointer to Next Input To Be Parsed ! !-------------------------------------------------------! .CMCNT ! Count of Space Left in Buffer ! !-------------------------------------------------------! .CMINC ! Count of Unparsed Characters in Buffer ! !-------------------------------------------------------! .CMABP ! Byte Pointer to Atom Buffer ! !-------------------------------------------------------! .CMABC ! Size of Atom Buffer ! !-------------------------------------------------------! .CMGJB ! Address of GTJFN Argument Block ! !=======================================================! 3-41
TOPS-20 MONITOR CALLS (COMND) Command State Block Word Symbol Meaning 0 .CMFLG Flag bits in the left half, and the reparse dispatch address in the right half. Some flag bits can be set by the program executing the COMND call; others can be set by the COMND call after its execution. The bits that can be set by the program are described following the Command State Block description. The reparse dispatch address is the location to which control is transferred when a reparse of the command is needed. This happens when a user edits characters in a field that was already parsed. If this field is zero, the COMND call sets B3(CM%RPT) in the left half of this word, and gives the +1 return when a reparse is needed. The program must then test the left half of AC1 to see if CM%RPT is set. If it is, the user must reenter the code that parses the first field of the command. The code at the reparse dispatch address should initialize the program's state to what it was after the last .CMINI function. This initialization should include resetting the stack pointer, closing and releasing any JFNs acquired since the last .CMINI function, and transferring control to the code immediately following the last .CMINI function call. 1 .CMIOJ Input JFN in the left half, and output JFN in the right half. These designators identify the source for the input of the command and the destination for the output of the typescript. These designators are usually .PRIIN (for input) and .PRIOU (for output). 2 .CMRTY Byte pointer to the beginning of the prompting text. 3 .CMBFP Byte pointer to the beginning of the user's input. The user cannot edit back past this pointer. 4 .CMPTR Byte pointer to the beginning of the next field to be parsed. 5 .CMCNT Count of the space remaining in the buffer after the .CMPTR pointer. 3-42
TOPS-20 MONITOR CALLS (COMND) 6 .CMINC Count of the number of unparsed characters in the buffer after the .CMPTR pointer. 7 .CMABP Byte pointer to the atom buffer, a temporary storage buffer that contains the last field parsed by the COMND call. The terminator of the field is not placed in this buffer. The atom buffer is terminated with a null. 10 .CMABC The size of the atom buffer in bytes. The atom buffer should be at least as large as the largest field the program must parse. 11 .CMGJB Address of a GTJFN argument block. This block must be at least 16(octal) words long and must be writable. If a longer GTJFN block is being reserved, the count in the right half of word .GJF2 of the GTJFN argument block must be greater than four. The GTJFN block is filled in by the COMND call with arguments for the GTJFN call if the specified COMND function requests a JFN (functions .CMIFI, .CMOFI, and .CMFIL). The user should store data in this block on the .CMFIL function only. The flag bits that can be set by the user in the left half of word .CMFLG in the Command State Block are described below. These bits apply to the parsing of the entire command and are preserved by COMND after execution. See the end of the COMND JSYS discussion for the bits that are returned by COMND in the left half of word .CMFLG. Bits Supplied in State Block on COMND Call Bit Symbol Meaning 6 CM%RAI Convert lowercase input to uppercase. 7 CM%XIF Do not recognize the at-sign (@) character as designating an indirect file; instead consider the character as ordinary punctuation. A program sets this bit to prevent the input of an indirect file. 8 CM%WKF Begin parsing after each field is terminated instead of only after an action character (carriage return, ESC, CTRL/F, question mark) is typed. A program sets this bit if it must change terminal characteristics in the middle of a command. Turning off echoing during the input of a password is an example of a use for this bit. 3-43
TOPS-20 MONITOR CALLS (COMND) Use of this bit is not recommended, however, because terminal wakeup occurs after each field is terminated, thereby increasing system overhead. The recommended method of changing terminal characteristics within a command is to input the field requiring the special characteristic on the next line with its own prompt. For example, if a program is accepting a password, it should turn off echoing after the .CMCFM function of the main command and perform the .CMINI function to type the prompt requesting a password on the next line. The format of the function descriptor block is shown below. 0 8 9 17 18 35 !=======================================================! ! function ! function ! address of next function ! .CMFNP! code ! flags ! descriptor block ! !-------------------------------------------------------! .CMDAT! Data for specific function ! !-------------------------------------------------------! .CMHLP! Byte pointer to help text for field ! !-------------------------------------------------------! .CMDEF! Byte pointer to default string for field ! !-------------------------------------------------------! .CMBRK! Address of 4-word break mask ! !=======================================================! Function Descriptor Block Word Symbol Meaning 0 .CMFNP Function code and pointer to next function descriptor block. B0-8(CM%FNC) Function code B9-17(CM%FFL) Function-specific flags B18-35(CM%LST) Address of the next function descriptor block, or zero if this is the last function descriptor block. 1 .CMDAT Data for the specific function, if any. 2 .CMHLP Byte pointer to the help text for this field. This word can be zero if the program is not supplying its own help text. CM%HPP must be set (in word 0) in order for this pointer to be used. 3-44
TOPS-20 MONITOR CALLS (COMND) 3 .CMDEF Byte pointer to the default string for this field. This word can be zero if the program is not supplying its own default string. CM%DPP must be on in word 0 in order for this pointer to be used. 4 .CMBRK Address of a 4-word break mask that specifies which characters terminate a field. Word .CMBRK is ignored unless CM%BRK (B13) is on in word 0 of the function descriptor block. The individual words in the function descriptor block are described in the following paragraphs. Words .CMFNP and .CMDAT of the function descriptor block Word .CMFNP contains the function code for the field to be parsed, and word .CMDAT contains any additional data needed for that function. The function codes, along with any required data for the functions, are described below. Code Symbol Meaning 0 .CMKEY Parse a keyword, such as a command name. Word .CMDAT contains the address of a keyword symbol table. The keyword table must be in alphabetical order. See the TBLUK monitor call description for more information on the format of the keyword table. The table entries point to argument blocks. The right half of the first word of each such block contains the following bits, which can be set when B0-6 of that first word are off and B7(CM%FW) is set: B35(CM%INV) Suppress this keyword in the list output on a question-mark (?). The program can set this bit to include entries in the table that should be output as part of the help text because they are not preferred keywords. This bit is also used with the CM%ABR bit to prevent an abbreviation from being output when a question mark (?) is typed. This bit can be set, for example, to allow the keyword LIST to be valid, even though the preferred keyword may be PRINT. The LIST keyword is not listed in the output given when a question mark (?) is typed. 3-45
TOPS-20 MONITOR CALLS (COMND) B34(CM%NOR) Do not recognize this keyword even if an exact match is typed by the user and suppress its listing in the list output when a question mark (?) is typed. (Refer to the TBLUK call description for more information on using this bit.) B33(CM%ABR) Consider this keyword a valid abbreviation for another entry in the table. The right half of this table entry points to the command table entry of the keyword for which this is an abbreviation. The program can set this bit to include entries in the table that are less than the minimum unique abbreviation. For example, this bit can be set to include the entry ST (for START) in the table. If the user then types ST as a keyword, COMND accepts it as a valid abbreviation for START even though there may be other keywords beginning with ST. To suppress the output of this abbreviation in the list of keywords output when a question mark (?) is typed, the program must also set the CM%INV bit. On a successful return, AC2 contains the address of the table entry where the keyword was found. Note that keywords in the table that contain trailing spaces (such as FORTRAN literals) are not recognized. 1 .CMNUM Parse a number. Word .CMDAT contains the radix (from 2 to 10) of the number. On a successful return, AC2 contains the number. 2 .CMNOI Parse a guide word string, but do not return an error if no guide word is input. Guide words are output if the user terminated the previous field with ESC. Guide words are not output, nor can they be input, if the user has caused parsing into the next field. 3-46
TOPS-20 MONITOR CALLS (COMND) For COMND to input a guide word, the guide word field must be delimited by parentheses. Word .CMDAT contains a byte pointer to an ASCIZ string that contains the guide word. This string does not contain parentheses. An error is returned only if a guide word is input that does not match the one expected by the COMND call. 3 .CMSWI Parse a switch. A switch field must begin with a slash, and can end with a colon or any legal field terminator. Word .CMDAT contains the address of a switch keyword symbol table. (Refer to the TBLUK monitor call description for the format of the table.) Switch entries in the keyword table must not contain a slash. If switch requires a value, however, its entry must end with a colon. The data bits CM%INV, CM%NOR, and CM%ABR, defined for the .CMKEY function, can also be set on this function. On a successful return, AC2 contains the address of the table entry where the switch keyword was found. 4 .CMIFI Parse an input file specification. This function causes the COMND call to execute a GTJFN call, which attempts to parse the specification for an existing file using no default fields. Hyphens in the file specification are treated as alphanumeric characters. The .CMGJB address (word 11 in the command state block) must be supplied, but the GTJFN block should be empty. Data stored in the GTJFN block is overwritten by the COMND JSYS, and GTJFN flags are set in the GTJFN block. On a successful return, AC2 contains the JFN assigned. See note following .CMFIL function. 5 .CMOFI Parse an output file specification. This function causes the COMND call to execute a GTJFN call, which parses the specification for either a new or an existing file. The default generation number 3-47
TOPS-20 MONITOR CALLS (COMND) is the generation number of the existing file plus 1. The .CMGJB address must be supplied, but the GTJFN block should be empty. (Data stored in the block will be overwritten by the COMND JSYS. Also, certain GTJFN flags are set.) On a successful return, AC2 contains the JFN assigned. Hyphens are treated as alphanumeric characters for this function. See note following .CMFIL function. 6 .CMFIL Parse a general (arbitrary) file specification. This function causes the COMND call to execute a GTJFN to attempt to parse the specification for the file. The .CMGJB address must be supplied, but data stored in certain words of the GTJFN block is overwritten by the COMND JSYS and certain GTJFN flags are set (see note below). On a successful return, AC2 contains the JFN assigned. Hyphens are treated as alphanumeric characters for this function. Note that portions of the GTJFN block used by functions .CMOFI, .CMIFI, and .CMFIL are controlled by COMND. The following list shows which words are under the control of COMND and which words are under the control of the user: GTJFN Controlled Characteristics Word(s) by .GJGEN COMND 1. .CMOFI sets flags GJ%FOU, GJ%MSG, and GJ%XTN and clears all other flags. 2. .CMIFI sets flags GJ%OLD, and GJ%XTN and clears all other flags. 3. .GMOFI and .GMIFI zero the right half of word .GJGEN. 4. .CMFIL sets flag GJ%XTN and clears GJ%CFM. .GJSRC COMND None .GJDEV - .GJJFN COMND/ USER Functions .CMIFI AND 3-48
TOPS-20 MONITOR CALLS (COMND) .CMOFI give COMND control of these words. .CMFIL gives the user control of these words. .GJF2 - .GJBFP COMND None .GJATR USER Function .CMFIL gives the user control of this word. .GJATR is not used for other functions. 7 .CMFLD Parse an arbitrary field. This function is useful for fields not normally handled by the COMND call. The input, as delimited by the first nonalphanumeric character, is copied into the atom buffer; the delimiter is not copied. Note the following: 1. This function will parse a null field 2. Hyphens are treated as alphanumeric characters for this function 3. No validation is performed (such as filename validation) 4. No standard help message is available (see description of word .CMHLP, below) 5. The FLDBK. and BRMSK. macros can be used for including other characters in the field (such as the asterisk (*) character) 10 .CMCFM Confirm. This function waits for the user to confirm the command with a carriage return and should be used at the end of parsing a command line. 11 .CMDIR Parse a directory name. Login and files-only directories are allowed. Word .CMDAT contains data bits for this function. The currently defined bit is as follows: B0(CM%DWC) Allow wildcard characters to be typed in a directory name. On a successful return, AC2 contains the 36-bit directory number. 3-49
TOPS-20 MONITOR CALLS (COMND) 12 .CMUSR Parse a user name. Only login directories are allowed. On a successful return, AC2 contains the 36-bit user number. 13 .CMCMA Parse a comma. This function sets B1(CM%NOP-no parse) in word .CMFLG of the command state block and returns an error if a comma is not the next item in the input. Blanks can appear on either side of the comma. This function is useful for parsing a list of arguments. 14 .CMINI Initialize the command line by setting up internal monitor pointers, typing the prompt, and checking to see if the user typed CTRL/H. This function should be used before beginning of parsing a command line, but not before reparsing a line. Reinitializing the command line with this function before starting to reparse the command line prevents the use of the CTRL/H feature. To use this function, the user first moves the needed data into the command state block and then issues .CMINI. If an error occurs while a line is being parsed, .CMINI is issued again by the COMND JSYS to reinitialize the line. For the second and all subsequent .CMINI function calls for a given line, the user should not alter the byte pointers and character counts in the command state block. To do so would disable the CTRL/H feature. This feature allows the user program, on parsing a bad atom, to print an error message, reissue the prompt, and parse the command line again without forcing the user to retype the entire line. If .CMINI reads a CTRL/H character, .CMINI resets all byte pointers and character counts except the .CMINC count to their original state. .CMINI sets the .CMINC count to the number of characters in the buffer up to the bad atom. These characters are output to the terminal and parsed again. Control then passes to the reparse address (if provided), and normal parsing resumes. The effect on the program is as if the bad atom had never been typed. 15 .CMFLT Parse a floating-point number. On a successful return, AC2 contains the floating-point number. 3-50
TOPS-20 MONITOR CALLS (COMND) 16 .CMDEV Parse a device name. A device name consists of up to six alphanumeric characters terminated by a colon (":"). On a successful return, AC2 contains the device designator. 17 .CMTXT Parse the input text up to the next carriage return, place the text in the atom buffer, and return. If an ESC or CTRL/F is typed, it causes the terminal bell to ring (because recognition is not available with this function) and is otherwise ignored. If a question mark (?) is typed, an appropriate response is given, and the question mark (?) is not included in the atom buffer. (A question mark can be included in the input text if it is preceded by a CTRL/V. However, if the input text is a user name, the CTRL/V cannot be used to precede a question mark.) 20 .CMTAD Parse a date and/or time field according to the setting of bits CM%IDA and CM%ITM. The user must input the field as requested. Any date format allowed by the IDTIM call can be input. If a date is not input, it is assumed to be the current date. If a time is not input, it is assumed to be 00:00:01. When both the date and time fields are input, they must be separated by one or more spaces. If the fields are input separately, they must be terminated with a space or carriage return. Word .CMDAT contains bits in the left half and an address in the right half as data for the function. The bits are: B0(CM%IDA) Parse a date B1(CM%ITM) Parse a time B2(CM%NCI) Do not convert the date and/or time to internal format. (Refer to Section 2.9.2.) The address in the right half is the beginning of a three-word block in the caller's address space. On a successful return, this block contains data returned from the IDTNC call executed by COMND if B2(CM%NCI) was on in the COMND call (if the input date and/or time field was not to be converted to internal format). If B2(CM%NCI) was off in the COMND call, on a successful return, AC2 contains the internal date and time format. 21 .CMQST Parse a quoted string up to the terminating quote. The delimiters for the string must be double quotation marks and are not copied to the atom buffer. A double quotation mark is input as part 3-51
TOPS-20 MONITOR CALLS (COMND) of the string if two double quotation marks appear together. This function is useful if the legal field terminators and the action characters are to be included as part of a string. The characters ?, ESC, and CTRL/F are not treated as action characters, and are included in the string stored in the atom buffer. Carriage return is an invalid character in a quoted string and causes B1(CM%NOP) to be set on return. 22 .CMUQS Parse an unquoted string up to one of the specified break characters. Word .CMDAT contains the address of a 4-word block of 128 break character mask bits. (Refer to word .RDBRK of the TEXTI call description for an explanation of the mask.) The characters scanned are not placed in the atom buffer. On return, .CMPTR is pointing to the break character. This function is useful for parsing a string with an arbitrary delimiter. The characters ?, ESC, and CTRL/F are not treated as action characters (unless they are specified in the mask) and can be included in the string. Carriage return can also be included if it is not one of the specified break characters. 23 .CMTOK Parse the input and compare it with a given string. Word .CMDAT contains the byte pointer to the given string. This function sets B1(CM%NOP) in word .CMFLG of the command state block and returns if the next input characters do not match the given string. Leading blanks in the input are ignored. This function is useful for parsing single or multiple character operators (for example, + or **). 24 .CMNUX Parse a number and terminate on the first nonnumeric character. Word .CMDAT contains the radix (from 2 to 10) of the number. On a successful return, AC2 contains the number. This function is useful for parsing a number that may not be terminated with a nonalphabetic character (for example, 100PRINT FILEA). Note that nonnumeric identifiers can begin with a digit (for example, 1SMITH as a user name). When a nonnumeric identifier and a number appear as alternates for a field, the order of the function descriptor blocks is important. The .CMNUX function, if given first, would accept the digit in the nonnumeric identifier as a valid number instead of as the beginning character of a nonnumeric identifier. 3-52
TOPS-20 MONITOR CALLS (COMND) 25 .CMACT Parse an account string. The input, as delimited by the first nonalphanumeric character, is copied into the atom buffer; the delimiter is not copied. No verification is performed nor is any standard help message available. The length of the string is checked, and if it exceeds 39 characters, an error is generated. 26 .CMNOD Parse a network node name. A node name consists of up to six alphanumeric characters followed by 2 colons ("::"). The node name must begin with an alphabetic character. Lowercase characters are converted to uppercase characters. The node name is copied into the atom buffer without the colons. In addition to the function code in bits 0-8 (CM%FNC), .CMFNP also contains function-specific flag bits in bits 9-17 (CM%FFL), and the address of another function descriptor block in bits 18-35 (CM%LST). The flag bits that can be set in bits 9-17 (CM%FFL) are as follows: Bit Symbol Meaning 11 CM%NOC Indicates that a semicolon does not begin a full-line comment and instead is matched with the specified function in the function descriptor block. If this bit is not set, the semicolon begins a full line comment. 12 CM%NSF Indicates that a suffix is optional. This bit is meaningful only with the .CMDEV and .CMNOD functions. If this bit is not set, the suffix is required. 13 CM%BRK Notifies COMND that word .CMBRK of the function descriptor block contains a pointer to a 4-word break mask. See description of word .CMBRK for more details. 14 CM%PO The field is to be parsed only, and the field's existence is not to be verified. This bit currently applies to the .CMDEV, .CMDIR, .CMNOD, and .CMUSR functions and is ignored for the remaining functions. On return, COMND sets B1(CM%NOP-no parse) only if the field typed is not in the correct syntax. Also, data returned in AC2 may not be correct. 15 CM%HPP A byte pointer to a program-supplied help message for this field is given in word 2 (.CMHLP) of this function descriptor block. 3-53
TOPS-20 MONITOR CALLS (COMND) 16 CM%DPP A byte pointer to a program-supplied default string for this field is given in word 3 (.CMDEF) of this function descriptor block. 17 CM%SDH The output of the default help message is to be suppressed if the user types a question mark. (See below for the default messages.) The address of another function descriptor block can be given in bits 18-35 (CM%LST) of the .CMFNP word. The use of this second descriptor block is described below. Usually one COMND call is executed for each field in the command. However, for some fields, more than one type of input may be possible (for example, after a keyword field, the next field could be a switch or a filename field). In these cases, all the possibilities for a field must be tried in an order selected to test unambiguous cases first. When the COMND call cannot parse the field as indicated by the function code, it does one of two things: 1. It sets the current pointer and counts such that the next call will attempt to parse the same input over again. It then returns with B1(CM%NOP) set in the left half of the .CMFLG word in the command state block. The caller can then issue another COMND call with a function code indicating another of the possible fields. After the execution of each call, the caller should test the CM%NOP flag to see that the field was parsed successfully. 2. If an address of another function descriptor block is given in CM%LST, the COMND call moves to this descriptor block automatically and attempts to parse the field as indicated by the function code contained in B0-8(CM%FNC) in word .CMFNP of that block. If the COMND call fails to parse the field using this new function code, it moves to a third descriptor block if one is given. This sequence continues until either the field is successfully parsed or the end of the chain of function blocks is reached. Upon completion of the COMND call, AC3 contains the addresses of the first and last function blocks used. By specifying a chained list of function blocks, the program can have the COMND call automatically check all possible alternatives for a field and not have to issue a separate call for each one. In addition, if the user types a question mark, a list is output of all the alternatives for the field as indicated by the list of function descriptor blocks. 3-54
TOPS-20 MONITOR CALLS (COMND) Word .CMHLP of the Function Descriptor Block This word contains a byte pointer to a program-supplied help text. The COMND call outputs this help if the user types a question mark when entering a command field. Bit 15(CM%HPP) must be set in word 0 (.CMFNP) of the function descriptor block for this pointer to be used. If B17(CM%SDH) is set in this word, COMND outputs only the program-supplied message. If B17(CM%SDH) is not set, COMND appends the default help message to the program-supplied message, and outputs them both. If .CMHLP is zero, COMND outputs only the default message. The default help message depends on the particular function being used to parse the current field. The following table lists the default help message for each function available in the COMND call. Default Help Messages Function Message .CMKEY (keyword) One of the following followed by the alphabetical list of valid keywords. If the user types a question mark in the middle of the field, only the keywords that can possibly match the field as currently typed are output. If no keyword can possibly match the currently typed field, the following message is output: keyword (no defined keywords match this input). If there is only 1 keyword, the keyword becomes the HELP message. .CMNUM (number) The help message output depends on the radix specified in .CMDAT in the descriptor block. If the radix is octal, the help message is octal number. If the radix is decimal, the help message is decimal number. If the radix is any other radix, the help message is a number in base nn where nn is the radix. .CMNOI (guide word) None .CMSWI (switch) One of the following followed by the alphabetical list of valid switch keywords. The same rules apply as for .CMKEY function, above. 3-55
TOPS-20 MONITOR CALLS (COMND) .CMIFI (input file) The help message output depends on the .CMOFI (output file) settings of certain bits in the GTJFN call. .CMFIL (any file) If bit GJ%OLD is off and bit GJ%FOU is on, the help message is output filespec. Otherwise, the help message is input filespec. .CMFLD (any field) None .CMCFM (confirm) Confirm with carriage return .CMDIR (directory) Directory name .CMUSR (user) User name .CMCMA (comma) Comma .CMINI (initialize) None .CMFLT (floating point) Number .CMDEV (device) Device name .CMTXT (text) Text string .CMTAD (date) The help message depends on the bits set in .CMDAT in the descriptor block. If CM%IDA is set, the help message is date. If CM%ITM is set, the help message is time. If both are set, the help message is date and time. .CMQST (quoted) Quoted string .CMUQS (unquoted) Unquoted string if "?" is a break character, otherwise none .CMTOK (token) None .CMNUX (number) Same as .CMNUM .CMACT (account) None .CMNOD (node) Node name Word .CMDEF of the Function Descriptor Block This word contains a byte pointer to the ASCIZ string to be used as the default for this field. For this pointer to be used, bit 16 (CM%DPP) must be set in word 0 (.CMFNP) of the descriptor block. The string is output to the destination, as well as copied to the text 3-56
TOPS-20 MONITOR CALLS (COMND) buffer, if the user types an ESC or CTRL/F as the first nonblank character in the field. If the user types a carriage return, the string is copied to the atom buffer, but is not output to the destination. When the caller supplies a list of function descriptor blocks, the byte pointer for the default string must be included in the first block. The CM%DPP bit and the pointer for the default string are ignored when they appear in subsequent blocks. However, the default string can be worded so that it applies to any of the alternative fields. The effect is the same as if the user had typed the given string. Defaults for fields of a file specification can also be supplied with the .CMFIL function. If both the byte pointer to the default string and the JFN defaults have been provided, the COMND default is used first, and then, if necessary, the GTJFN defaults are used. NOTE The function descriptor block, whose address is given in AC2, can be set up by the FLDDB. and FLDBK. macros defined in MACSYM. (See the end of the COMND section for a description of these macros.) Word .CMBRK of the Function Descriptor Block This word contains a pointer to a 4-word user-specified mask that determines which characters constitute end of field. The leftmost 32 bits of each word correspond to a character in the ASCII collating sequence (in ascending order). If the bit is on for a given character, typing that character causes the COMND JSYS to treat the characters typed so far as a separate field and to parse them according to the function being used. CM%BRK (B13) must be on in the first word of the function descriptor block, or COMND ignores word .CMBRK. Ordinarily, the user relies on COMND's default masks (varying according to function) to specify which characters signal end of field, and thus is not concerned with word .CMBRK of the function block. But for special purposes such as allowing "*" or "%" to be part of a field, rather than a field delimiter, the user must specify his own mask. (In this example, the bits for "*" and "%" would be off in the mask word.) The user may inspect COMND's default masks (defined in MONSYM) for help in designing a custom mask. The following is a list of the COMND functions that use masks: 3-57
TOPS-20 MONITOR CALLS (COMND) Mask COMND Changeable Symbols Function by User KEYB0. - KEYB3. .CMKEY Yes DEVB0. - DEVB3. .CMDEV Yes (only if parse-only) FLDB0. - FLDB3. .CMFLD Yes EOLB0. - EOLB3. .CMTXT Yes KEYB0. - KEYB3. .CMSWI Yes User-specified .CMTAD Yes USRB0. - USRB3. .CMUSR No FILB0. - FILB3. .CMFIL No FILB0. - FILB3. .CMIFI No FILB0. - FILB3. .CMOFI No internal .CMNUM No FILB0. - FILB3. .CMDIR No internal .CMFLT No ACTB0. - ACTB3. .CMACT No COMND will ignore any break masks that are specified for functions that do not allow user-modified masks. Note that specifying a zero mask with CM%BRK set will cause the TTY line buffer to fill up and generate an error. On a successful return, the COMND call returns flag bits in the left half of AC1 and preserves the address of the command state block in the right half of AC1. These flag bits are copied from word .CMFLG in the command state block and are described as follows. Bits Returned on COMND Call Bit Symbol Meaning 0 CM%ESC An ESC was typed by the user as the terminator for this field. 1 CM%NOP The field could not be parsed because it did not conform to the specified function(s). An error code is returned in AC2. If this bit is set, bits 0 (CM%ESC) and 2 (CM%EOC) might not contain valid information. 2 CM%EOC The field was terminated with a carriage return. 3 CM%RPT Characters already parsed need to be reparsed because the user edited them. This bit does not need to be examined if the program has supplied a reparse dispatch address in the right half of .CMFLG in the command state block. 3-58
TOPS-20 MONITOR CALLS (COMND) 4 CM%SWT A switch field was terminated with a colon. This bit is on if the user either used recognition on a switch that ends with a colon or typed a colon at the end of the switch. 5 CM%PFE The previous field was terminated with an ESC. When a field cannot be parsed, B1(CM%NOP) is set in AC1, and an error code is returned in AC2. Note that if a list of function descriptor blocks is given and an error code is returned, the error is associated with the function that had the largest atom buffer after all function blocks have been tried without a successful parse of the field. NPXAMB: Ambiguous NPXNSW: Not a switch - does not begin with slash NPXNOM: Does not match switch or keyword NPXNUL: Null switch or keyword given NPXINW: Invalid guide word NPXNC: Not confirmed NPXICN: Invalid character in number NPXIDT: Invalid device terminator NPXNQS: Not a quoted string - does not begin with double quote NPXNMT: Does not match token NPXNMD: Does not match directory or user name, or structure not mounted NPXCMA: Comma not given COMX18: Invalid character in node name COMX19: Too many characters in node name Macros Several macros (defined in MACSYM) are available to make using the COMND JSYS more convenient. These macros are as follows: FLDDB.(TYP,FLGS,DATA,HLPM,DEFM,LST) where: TYP = function type FLGS = function flags DATA = function-specific data HLPM = help message DEFM = default text LST = additional invocations of the FLDDB. macro (used only if multiple function blocks are required) This macro generates function descriptor blocks for COMND. For example, the following code performs a .CMINI function: MOVEI T1,STEBLK ;Get address of COMND state block MOVEI T2,[FLDDB.(.CMINI)] ;Get address of function block 3-59
TOPS-20 MONITOR CALLS (COMND) COMND The following code performs a .CMKEY function (assuming that the keyword table started at address CMDTAB: MOVEI T1,STEBLK ;Get address of COMND state block MOVEI T2,[FLDDB(.CMKEY,<CM%DPP+CM%HPP>,CMDTAB, <help text>,<default text>)] COMND FLDBK.(TYP,FLGS,DATA,HLPM,DEFM,BRKADR,LST) This is exactly the same as FLDDB., except that a provision has been made for the address of the first word of a 4-word character mask (BRKADR). This version is for use when a user-specified character mask is required. BRMSK.(INI0,INI1,INI2,INI3,ALLOW,DISALLOW) where: INI0 = first word of character mask INI1 = second word of character mask INI2 = third word of character mask INI3 = fourth word of character mask ALLOW = characters to allow in the mask DISALLOW = characters to disallow in the mask This macro generates 4-word character masks for use with those COMND functions that allow the user to specify his own mask. For example, executing the following code allows "*" in the predefined mask for the .CMFLD function (FLDB0 thru FLDB3): BRMSK.(FLDB0.,FLDB1.,FLDB2.,FLDB3.,<*>,) Also, the BRMSK. macro may be invoked within the FLDBK. macro: FLDBK.(TYP,FLGS,DATA,HLPM,DEFM,[ BRMSK.(INI0,INI1,INI2,INI3,ALLOW,DISALLOW)],LST) The COMND call causes other monitor calls to be executed, depending on the particular function that is requested. Failure of these calls usually results in the failure to parse the requested field. In these cases, the relevant error code can be obtained by the GETER and ERSTR monitor calls. Any TBLUK error can occur on the keyword and switch functions. Any NIN/NOUT and FLIN/FLOUT error can occur on the number functions. 3-60
TOPS-20 MONITOR CALLS (COMND) Any GTJFN error except for GJFX37 can occur on the file specification functions. Any IDTNC error can occur on the date/time function. Any RCDIR or RCUSR error can occur on the directory and user functions. Any STDEV error can occur on the device function. Generates an illegal instruction interrupt on error conditions below. COMND ERROR MNEMONICS: COMNX1: Invalid COMND function code COMNX2: Field too long for internal buffer COMNX3: Command too long for internal buffer COMNX5: Invalid string pointer argument COMNX8: Number base out of range 2-10 COMNX9: End of input file reached COMX10: Invalid default string COMX11: Invalid CMRTY pointer COMX12: Invalid CMBFP pointer COMX13: Invalid CMPTR pointer COMX14: Invalid CMABP pointer COMX15: Invalid default string pointer COMX16: Invalid help message pointer COMX17: Invalid byte pointer in function block VACCX1: Account string too long Creates, changes, or deletes a directory entry. RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Byte pointer to ASCIZ string containing the structure and directory name. The string must be of the form: structure:<directory>. AC2: B0(CD%LEN) Set flags and length of the argument block from the values given in word .CDLEN. B1(CD%PSW) Set password from argument block B2(CD%LIQ) Set working disk storage limit from argument block 3-61
TOPS-20 MONITOR CALLS (CRDIR) B3(CD%PRV) Set capability bits from argument block B4(CD%MOD) Set mode bits from argument block B5(CD%LOQ) Set permanent disk storage limit from argument block B6(CD%NUM) Set directory number from argument block (valid only when creating a directory) B7(CD%FPT) Set default file protection from argument block B8(CD%DPT) Set directory protection from argument block B9(CD%RET) Set default retention count from argument block B10(CD%LLD) Set last LOGIN date from argument block B11(CD%UGP) Set user groups from argument block B12(CD%DGP) Set directory groups from argument block B13(CD%SDQ) Set subdirectory quota from argument block B14(CD%CUG) Set user groups assignable by this directory from argument block B15(CD%DAC) Set default account from argument block B16(CD%PPN) Set project-programmer number from argument block B17(CD%DEL) Delete this directory entry B18-35(CD%APB) Address of the argument block AC3: Byte pointer to ASCIZ string containing the password of the directory. This pointer is required when a nonprivileged user is changing parameters for his directory. RETURNS +1: Always, with directory number in AC1 This monitor call requires the process to have WHEEL or OPERATOR capability enabled unless one of the following conditions is true: 3-62
TOPS-20 MONITOR CALLS (CRDIR) 1. The specified directory is one to which the caller has owner access, and the caller is changing any one of the following parameters: password (.CDPSW) default file protection (.CDFPT) directory protection (.CDDPT) default retention count (.CDRET) default account (.CDDAC) This feature is installation dependent and is enabled by issuing function .SFCRD of the SMON monitor call. 2. The specified directory is inferior to the one to which the caller is currently connected, and the caller has owner access to this inferior directory. Refer to Section 2.2.6 for the description of owner access. The format of the argument block is as follows: Word Symbol Meaning | | 0 .CDLEN Flag bits in the left half, and length of the | argument block in the right half. The following | bits are defined: B0(CD%NSQ) When restoring this directory, do not update its superior directory's quotas (permanent, working, and subdirectory quotas) to account for this directory. If this bit is off, the superior directory's quotas are updated. This bit is set by the DLUSER or DUMPER program to retain the superior directory's quotas when restoring its subdirectories. The process must have WHEEL or OPERATOR capability enabled to set this bit. B1(CD%NCE) When restoring or reconstructing this directory, do not change any directory parameters if the directory currently exists on disk; set the parameters only if the directory does not exist. If this bit is off, the directory parameters as saved are restored for the directory. This bit is set by the DLUSER or DUMPER program to restore or reconstruct directories from out-of-date files without causing 3-63
TOPS-20 MONITOR CALLS (CRDIR) existing directories to revert to older parameters. The process must have WHEEL or OPERATOR capability enabled to set this bit. B2(CD%NED) Set default on-line expiration date from word .CDDNE. B3(CD%FED) Set default off-line expiration date from word .CDDFE. B4(CD%RNA) Reserved for DIGITAL. B5(CD%PEN) Set password encryption version from word .CDPEV and encryption date from word .CDPDT. B6(CD%PED) Set password expiration date from word .CDPED. B7(CD%PMU) Set maximum password use count from .CDPMU. | | B8(CD%SNI) Set last non-interactive login date | and time from argument block. | | B9(CD%SFC) Set number of failed logins | (interactive and non-interactive) from | argument block. 1 .CDPSW Byte pointer to password string, which is a string from 1 to 39 alphanumeric characters (including hyphens). 2 .CDLIQ Maximum number of pages that can be used for working disk storage (also known as logged-in quota). 3 .CDPRV Capabilities for this user. (Refer to Section 2.7.1 for the capability bits.) 4 .CDMOD Mode word. B0(CD%DIR) Directory name can be used only to connect to (the directory is a files-only directory). If this bit is off, the directory name can be used for logging in and connecting to. B1(CD%ANA) Accounts are alphanumeric. This bit is not used and is provided for 3-64
TOPS-20 MONITOR CALLS (CRDIR) compatibility with systems earlier than TOPS-20 version 3. B2(CD%RLM) All messages from the file <SYSTEM>MAIL.TXT are repeated each time the user logs in. If this bit is off, only the messages not previously printed are output when the user logs in. B7(CD%DAR) If on, this bit indicates that the file should be archived rather than migrated to virtual disk when the on-line expiration date has been reached. | | B8(CD%SEC) If on, files created are set secure by | default. 5 .CDLOQ Maximum number of pages that can be used for permanent disk storage (also known as logged-out quota). 6 .CDNUM Directory number, valid only when creating a directory. An error code is returned if the user changes the number of an existing directory (CRDIX2) or gives a nonunique number (CRDIX8). 7 .CDFPT Default file protection (18 bits, right-justified). 10 .CDDPT Directory protection (18 bits, right-justified). 11 .CDRET Default number of generations of a file to be retained in the directory (retention count). Valid numbers are 0 to 63, with 0 being an infinite number. | 12 .CDLLD Date and time of last interactive login. 13 .CDUGP Address of user group list for this directory. 14 .CDDGP Address of directory group list. 15 .CDSDQ Maximum number of directories that can be created inferior to this directory. This parameter allows a user to create directories with the BUILD command. 16 .CDCUG Address of user group list. This list contains the group numbers that can be assigned to subdirectories. 3-65
TOPS-20 MONITOR CALLS (CRDIR) 17 .CDDAC Byte pointer to default account string for this user. 20 .CDDNE Default on-line expiration date and time, which can be an explicit date and time (internal format) or an interval (in days). In either case, the specified date/interval cannot exceed the system maximum. This parameter is read if CD%NED (1B2) or CD%FED (1B3) in .CDLEN are set. If a new directory is created and this parameter is not specified, the system default is used. An unprivileged user can modify his defaults to be less than or equal to those that are currently specified or the system maximum, whichever is greater. A user with WHEEL capability may override the system maximum. If no system maximum has been specified, there is no on-line expiration date and time associated with the directory. 21 .CDDFE Default off-line expunge date and time. Otherwise similar to .CDDNE (above). 22 .CDDRN Reserved for DIGITAL. 23 .CDPEV Version number of password encryption algorithm. 24 .CDPDT Date password was encrypted. 25 .CDPED Date password expires. 26 .CDPMU Maximum use count for password. 27 .CDPPN TOPS-10 Project-Programmer number: p,,pn requires WHEEL or OPERATOR capability to set project number (p) less than 10; project number cannot be 4. | | 30 .CDNLD Date and time of last non-interactive login. | | 31 .CDFPA Count of failed interactive logins for this user | in the left half,,count of failed non-interactive | logins in the right half. The format of each group list is a table with the first word containing a count of the number of words (including the count word) in the table and each subsequent word containing a group number. When CRDIR is being executed to create a directory, bits 0-17 of AC2 can optionally be on or off. If a particular bit is on, it indicates that the corresponding argument in the argument block should be 3-66
TOPS-20 MONITOR CALLS (CRDIR) examined. If the bit is off, it indicates that the argument should be defaulted. The following lists the bits and the corresponding argument defaults: Bits Argument Defaults B2(CD%LIQ) Maximum working disk file storage to 250 pages B3(CD%PRV) No special capabilities B4(CD%MOD) Directory name that can be used for logging in and that lists the messages from <SYSTEM>MAIL.TXT only once B5(CD%LOQ) Maximum permanent disk file storage to 250 pages B6(CD%NUM) The first unused directory number; B6 should normally be off. B7(CD%FPT) Default file protection to 777700 B8(CD%DPT) Directory protection to 777700 B9(CD%RET) Default file retention count to 1 B10(CD%LLD) Never logged in B11(CD%UGP) No user groups B12(CD%DGP) No directory groups B13(CD%SDQ) No ability to create inferior directories B14(CD%CUG) No assignable user groups for inferior directories B15(CD%DAC) No default account When CRDIR is being executed to change a directory and any of B0-17 of AC2 is off, the corresponding parameter is not affected. When CRDIR is being executed to delete a directory, the settings of B0-17 of AC2 are ignored. A CRDIR call cannot be given to delete a directory that has directories inferior to it. The GTDIR call can be used to obtain the directory information. Generates an illegal instruction interrupt on error conditions below. CRDIR ERROR MNEMONICS: ACESX3: Password required CRDIX1: WHEEL or OPERATOR capability required CRDIX2: Illegal to change number of old directory CRDIX3: Insufficient system resources (Job Storage Block full) CRDIX4: Superior directory full CRDIX5: Directory name not given CRDIX6: Directory file is mapped CRDIX7: File(s) open in directory CRDIX8: Invalid directory number CRDIX9: Internal format of directory is incorrect CRDI10: Maximum directory number exceeded; index table needs expanding 3-67
TOPS-20 MONITOR CALLS (CRDIR) CRDI11: Invalid terminating bracket on directory CRDI12: Structure is not mounted CRDI13: Request exceeds superior directory working quota CRDI14: Request exceeds superior directory permanent quota CRDI15: Request exceeds superior directory subdirectory quota CRDI16: Invalid user group CRDI17: Illegal to create nonfiles-only subdirectory under files-only directory CRDI18: Illegal to delete logged-in directory CRDI19: Illegal to delete connected directory CRDI20: WHEEL, OPERATOR, or requested capability required CRDI21: Working space insufficient for current allocation CRDI22: Subdirectory quota insufficient for existing subdirectories CRDI23: Superior directory does not exist CRDI24: Invalid subdirectory quota CRDI29: Illegal to disallow subdirectory user group while in use CRDI30: Invalid password length | CRDI31: Password expiration date is too far in the future | CRDI32: Password expiration is not enabled on this system | CRDI33; Password found in system password dictionary. ENACX5: Account validation data base file is empty STRX10: Structure is offline Creates a new job and optionally logs it in. This monitor call causes the functions that are normally performed when a job is created (for example, assignment of a JSB, the primary I/O designators, and the job controlling terminal) to be performed for the new job. RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. When this call is used in any section other than section zero, one-word global byte pointers used as arguments must have a byte size of seven bits. ACCEPTS IN AC1: Flag bits,,0 AC2: Address of argument block AC3: (optional) If CRJOB is to be used to release control over a job previously created with CRJOB (bit 17 in AC1 must be on), then AC3 contains the job number of the previously-created job. RETURNS +1: Failure, with error code in AC1 +2: Success, with the number of the new job in AC1 3-68
TOPS-20 MONITOR CALLS (CRJOB) The flag bits defined in the left half of AC1 are as follows: Bit Symbol Meaning 0 CJ%LOG Log in the new job. If this bit is off, the new job is created but not logged in. 1 CJ%NAM Set the user name and password from the argument block. If this bit is off, the user name of the caller is given to the new job. 2-3 CJ%ACT Set the account of the new job to the following: Code Symbol Meaning 0 .CJUCA Use current account of caller. 1 .CJUAA Use account from the argument block. 2 .CJUDA Use default account of user whose job is being created. 4 CJ%ETF If set, place the TOPS-20 command processor in the top-level process of the new job. The command processor reads its program argument block (see below) at the time it is started. CJ%FIL and CJ%ETF interact in the following ways: 1. If CJ%FIL is on and CJ%ETF is on, then a job is created with a top process consisting of the TOPS-20 command processor and an inferior process consisting of the file to which word .CJFIL points. 2. If CJ%FIL is off and CJ%ETF is on, then a job is created with a top process consisting of the TOPS-20 command processor. No inferior process is created. 3. If CJ%FIL is on and CJ%ETF is off, then a job is created with a top process consisting of the file to which word .CJFIL points. No inferior process is created. The format of the program argument block is as follows: 3-69
TOPS-20 MONITOR CALLS (CRJOB) Word Contents 0 Count of words in block, not including this word. 1 1B0+3B6+2B12+CR%PRA - indicates this is a program argument block created by the CRJOB JSYS. 2 1B0 + offset1 - offset1 is the offset in this block of the first argument being passed. 3 1B0 + offset2 - offset2 is the offset in this block of the second argument being passed. n (offset1) This argument is a copy of the flag bits from word 10 (.CJEXF) of the CRJOB argument block, which contains the flags for the command language processor. n+1 (offset2) This argument contains information about the process being started: the process handle in the left half, and the entry vector offset in the right half. The entry vector offset is from word .CJSVF (word 4) of the CRJOB argument block. The program argument block is created by the CRJOB monitor call and is passed to the process by a PRARG monitor call (performed internally by CRJOB). The user does not specify any of the information in the program argument block. Only the program at the top fork level of the job (usually the TOPS-20 EXEC) can read the PRARG block. 5 CJ%FIL Move the file to which a word in the argument block points into a process in the new job (by means of a GET call). If B4(CJ%ETF) is off, the file is placed in the top-level process of the new job. If B4(CJ%ETF) is on, the file is placed in the process designated in the Command Language Processor's PRARG argument block (see below). If B5(CJ%FIL) is off, no file is moved into a process of the new job, and the top-level process of the new job is the Command Language Processor. 3-70
TOPS-20 MONITOR CALLS (CRJOB) 6 CJ%ACS Load the ACs from the value in the argument block. The ACs are loaded only if a program other than the Command Language Processor is being run. 7 CJ%OWN Maintain ownership of the new job. This means that when the caller logs out, the new job is also logged out. However, the new job can also be logged out by the normal mechanisms. If this bit is off, control of the new job is released. 8 CJ%WTA Do not start the new job until it is attached (using ATACH JSYS) to a terminal. If this bit is off, the new job is started. 9 CJ%NPW Do not check the password given when the new job is logged in. If this bit is off, the password is checked unless the new job is being logged in with the same user name as the caller, or with WHEEL or OPERATOR capability enabled. 10 CJ%NUD Do not update the date of LOGIN for the user logging in to the new job. If this bit is off, the date of LOGIN is updated, unless the user is logging in with the same user name as the caller, or with WHEEL or OPERATOR capability enabled. 11 CJ%SPJ Set (by means of a SPJFN call) the primary input and output designators from the argument block before starting the job. The primary I/O designators are not changed for a Command Language Processor in the top-level process of the new job; they are changed only for inferior processes. If this bit is off, the primary I/O designators of the new job are the job's controlling terminal. 12 CJ%CAP Set the allowed user capabilities of the new job (right half) to be the same as the caller's currently enabled capabilities, until the new job is logged in. If this bit is off, the new job has the user capabilities associated with the user whose job is being created. 13 CJ%CAM Set the allowed user capabilities of the new job to the combination of (AND function) the capability mask in the argument block and the new job's user capabilities. If this bit is off, the new job has the capabilities associated with the user whose job is being created. 14 CJ%SLO Send an IPCF message to the PID supplied in the argument block when the new job is logged out. If 3-71
TOPS-20 MONITOR CALLS (CRJOB) this bit is off, no message is sent when the new job is logged out. The IPCF logout message has the following format: Word Contents 0 0,,.IPCLO 1 N,,# of job logged out. N is the count of the remaining words in this message (currently 10 octal). 2 flags,,reserved Bits Symbol Meaning B0 SP%BAT job is controlled by batch. B1 SP%DFS spooling is deferred. B2 SP%ELO the job executed LGOUT. B3 SP%FLO the job was forced to logout. If this bit is on, check word 10 of the IPCF message (gives code of most recent monitor call error). B3 will be on only if the job has an interrupt to be handled by MEXEC (Mini-EXEC). B4 SP%OLO the job was logged out by another job. Word 6 of the IPCF message contains the job number of the job that did the logout. 3 job connect time 4 job CPU time 5 TTY number of job at logout (-1 if detached) 6 job number of the job that did the logout 7 reserved 10 code of the most recent monitor call error 17 CJ%DSN Release ownership of the previously created job whose number is in AC3. If this bit is on, it overrides the setting of all other bits in AC1; and no change is made to the job's status other than the change in ownership. 3-72
TOPS-20 MONITOR CALLS (CRJOB) The format of the argument block (whose address is given in AC2) is as follows: Word Symbol Meaning 0 .CJNAM Byte pointer to the user name string. 1 .CJPSW Byte pointer to the password string. 2 .CJACT 5B2 + numeric account number or byte pointer to account string. 3 .CJFIL Byte pointer to the name of the file to be moved (by a GET call) into a process of the new job. The new job must have read access to the file. The process into which the file is placed depends on the setting of B4(CJ%ETF). 4 .CJSFV Offset in the entry vector to use as the start address of the file to which word .CJFIL points. This offset is the argument to the SFRKV call used to start the process. 5 .CJTTY Terminal designator of the new job's controlling terminal. This terminal must be assigned by the caller. The terminal is then released and assigned to the new job. If the new job is to be detached, the .NULIO designator (377777) is given. 6 .CJTIM Connect-time for new job before a LGOUT is forced on it; 0 indicates no limit. 7 .CJACS Address of a 16-word block whose contents are to be loaded in the new job's ACs if a program other than the Command Language Processor is being run. 10 .CJEXF Flag bits to be passed to the Command Language Processor in the top-level process of the new job. The bits are: B0 Suppress the herald printed by the Command Language Processor. B1 Move the file to which word .CJFIL points into the process whose handle is in the PRARG block (see below). B2 Start the process at the offset in the entry vector given in word .CJSFV. This 3-73
TOPS-20 MONITOR CALLS (CRJOB) process is started after the Command Language Processor is initialized. B3 Output the text printed when a LOGIN command is given (system messages, job number, or terminal number, for example). This word is copied into the PRARG argument block passed to the Command Language Processor (see below). 11 .CJPRI Primary input and output designators for the inferior processes of the new job. These designators must refer to device designators. The Command Language Processor in the top-level process of the new job executes an SPJFN call to set these designators. 12 .CFCPU Run-time limit for the new job. When this limit is reached, an interrupt is generated (by a TIMER call), and the Command Language Processor executes a LGOUT call for the new job. A zero in this word means there is no run-time limit on the job. 13 .CJCAM Capability mask for the new job. This mask is used only if CJ%CAM is set. 14 .CJSLO PID to which an IPCF message is to be sent when the new job is logged out. When CRJOB creates a new job, it also creates the top-level process, which is always a virgin process. Thus, an execute-only program can be run as the top-level fork. The CRJOB call causes other monitor calls to be executed, depending on the particular function that is performed. Any GTJFN and OPENF errors can occur when obtaining the specified file. Any SFRKV error can occur when starting the program in the specified file. Any LOGIN and account validation errors can occur when logging in the job. CRJOB ERROR MNEMONICS: CRJBX1: Invalid parameter or function bit combination 3-74
TOPS-20 MONITOR CALLS (CRJOB) CRJBX2: Illegal for created job to enter MINI-EXEC CRJBX4: Terminal is not available CRJBX5: Unknown name for LOGIN CRJBX6: Insufficient system resources Defines or deletes a logical name assignment. Logical names are used to specify a set of default values for each field requested by a GTJFN monitor call. When a logical name is passed to the GTJFN call, any fields not specified by the user are supplied from the fields defined in the logical name definition. (See Section 2.2.2 and to the INLNM and LNMST monitor call descriptions for more information on logical names.) RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Function code AC2: Byte pointer to the logical name (No terminating colon should be supplied.) AC3: Byte pointer to the logical name definition string RETURNS +1: Failure, error code in AC1 +2: Success, updated string pointer in AC3 The codes for the functions are as follows: Code Symbol Meaning 0 .CLNJ1 Delete one logical name from the job 1 .CLNS1 Delete one logical name from the system (WHEEL or OPERATOR capability required) 2 .CLNJA Delete all logical names from the job 3 .CLNSA Delete all logical names from the system (WHEEL or OPERATOR capability required) 4 .CLNJB Create a logical name for the job 5 .CLNSY Create a logical name for the system (WHEEL or OPERATOR capability required) 3-75
TOPS-20 MONITOR CALLS (CRLNM) CRLNM ERROR MNEMONICS: ARGX09: Invalid byte size CRLNX1: Logical name is not defined CRLNX2: WHEEL or OPERATOR capability required CRLNX3: Invalid function GJFX4: Invalid character in file name GJFX5: Field cannot be longer than 39 characters GJFX6: Device field not in a valid position GJFX7: Directory field not in a valid position GJFX8: Directory terminating delimiter is not preceded by a valid beginning delimiter GJFX9: More than one name field is not allowed GJFX10: Generation number is not numeric GJFX11: More than one generation number field is not allowed GJFX12: More than one account field is not allowed GJFX13: More than one protection field is not allowed GJFX14: Invalid protection GJFX15: Invalid confirmation character GJFX22: Insufficient system resources (Job Storage Block full) GJFX31: Invalid wildcard designator Dismisses the software interrupt routine in progress and resumes the process at the location specified by the PC stored in the priority level table. (See Section 2.6.7.) RETURNS +1: Only if no software interrupt is currently in progress and if an ERJMP or ERCAL instruction follows the DEBRK Generates an illegal instruction interrupt on error conditions below. DEBRK ERROR MNEMONICS: DBRKX1: No interrupts in progress Reclaims disk space by expunging disk files that have been marked for deletion with DELF. This call first checks to see that the user has connect access to the directory. The calling process must have connect access to the directory to expunge files from it. RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. 3-76
TOPS-20 MONITOR CALLS (DELDF) ACCEPTS IN AC1: B0(DD%DTF) Delete temporary files (;T) also B1(DD%DNF) Delete nonexistent files that are not now open B2(DD%RST) Rebuild the symbol table B3(DD%CHK) Check internal consistency of directory. If an error occurs, the symbol table should be rebuilt. If B2(DD%RST) is also set, it is ignored; and the DELDF call must be executed again with B2(DD%RST) set to rebuild the symbol table. AC2: Directory number RETURNS +1: Always The directory number given in AC2 must be that of the user's connected or logged-in directory unless the process has WHEEL or OPERATOR capability enabled, or the process has connect access to the directory being deleted. If errors still occur after the symbol table is rebuilt, the process should restore the directory from magnetic tape; or the user should request help from the operator. When a file with archive status is deleted and expunged, DELDF sends an IPCF message to GALAXY. This message contains all archive status information, which includes tape information, as well as the present file name, the user who expunged the file, and the time it was expunged. Generates an illegal instruction interrupt on error conditions below. DELDF ERROR MNEMONICS: ARGX26: File is off line DELDX1: WHEEL or OPERATOR capability required DELDX2: Invalid directory number DELFX2: File cannot be expunged because it is currently open DELFX4: Directory symbol table could not be rebuilt DELFX5: Directory symbol table needs rebuilding DELFX6: Internal format of directory is incorrect DELFX7: FDB formatted incorrectly; file not deleted DELFX8: FDB not found; file not deleted STRX10: Structure is offline 3-77
TOPS-20 MONITOR CALLS (DELF) Deletes the specified disk file and, if the file is closed, releases the JFN. The file is not expunged immediately, but is marked for later expunging either by the system or with the DELDF or LGOUT monitor calls. RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: B0(DF%NRJ) Do not release the JFN. B1(DF%EXP) Expunge the contents of the file. This also deletes the FDB entry in the directory. B0(DF%NRJ) and B1(DF%EXP) cannot be set simultaneously. B2(DF%FGT) Expunge the file but do not deassign its addresses. The process must have WHEEL or OPERATOR capability enabled to set this bit. This bit should be set only by an operator or system specialist to delete a file that has a damaged or inconsistent index block. B3(DF%DIR) Delete and expunge a directory file. The process must have WHEEL or OPERATOR capability enabled to set this bit. This bit should be set only by an operator or specialist to delete a bad directory. B4(DF%ARC) Allow a file with archive status to be deleted. B5(DF%CNO) Delete and expunge the contents of the file but preserve the file's name and FDB as they were (with the exception of the page count and the page table address). Setting this bit causes the DELF to fail if bit AR%NDL is set in word .FBBBT of the FDB, or if a complete set of tape back-up information is not in the FDB. B18-35 JFN of the file being deleted. (DF%JFN) RETURNS +1: Failure, error code in AC1 +2: Success, JFN is released unless B0(DF%NRJ) is on or the file is open. 3-78
TOPS-20 MONITOR CALLS (DELF) By setting B0(DF%NRJ), the user can delete multiple files by giving a JFN to GNJFN that represents a group of files and processing each file in the group. The DELF call takes the +1 return if the JFN is assigned to a nondirectory device. DELF ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer DESX7: Illegal use of parse-only JFN or output wildcard-designators DESX9: Invalid operation for this device DELFX1: Delete access required DELFX2: File cannot be expunged because it is currently opened DELFX3: System scratch area depleted; file not deleted DELFX4: Directory symbol table could not be rebuilt DELFX5: Directory symbol table needs rebuilding DELFX6: Internal format of directory is incorrect DELFX7: FDB formatted incorrectly; file not deleted DELFX8: FDB not found; file not deleted DELFX9: File is not a directory file DELF10: Directory still contains subdirectory DLFX10: Cannot delete directory; file still mapped DLFX11: Cannot delete directory file in this manner DELX12: File has no pointer to offline storage DELX13: File is marked "Never Delete" STRX10: Structure is offline WHELX1: WHEEL or OPERATOR capability required Deletes all but the specified number of generations of a disk file. The files are marked for deletion and are expunged at a later time, either automatically by the system or explicitly with the DELDF or LGOUT call. ACCEPTS IN AC1: B0(DF%NRJ) Do not release the JFN B4(DF%ARC) Allow a file with archive status to be deleted. B5(DF%CNO) Delete and expunge the contents of the file but preserve the file's name and FDB as they were (with the exception of the page count and the page table address). Setting this bit causes the DELNF to fail if bit AR%NDL is set in word .FBBBT of the 3-79
TOPS-20 MONITOR CALLS (DELNF) FDB or if a complete set of tape backup information is not in the FDB. B18-35 JFN of the file being deleted (DF%JFN) AC2: The number of generations to retain RETURNS +1: Failure, error code in AC1 +2: Success, with the number of files deleted in AC2 Starting at the file specified by the JFN, the DELNF call decrements the generation number, first retaining the specified number of generations before deleting the remaining generations. DELNF ERROR MNEMONICS: DELX13: File is marked "Never Delete" DESX1: Invalid source/destination designator DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer DESX7: Illegal use of parse-only JFN or output wildcard-designators DELFX1: Delete access required STRX10: Structure is offline Removes a request for a specific resource from the queue associated with that resource. The request is removed whether the process has a lock for the resource, or is only waiting in the queue for the resource. This call can be used to remove any number of requests. If one of the requests cannot be dequeued, the dequeueing procedure continues until all requests that can be dequeued have been. An error return is given for the last request found that could not be dequeued. The process can then execute the ENQC call to determine the current status of each request. However, if the process attempts to dequeue more pooled resources than it originally allocated, the error return is taken and none of the pooled resources are dequeued. See the TOPS-20 Monitor Calls User's Guide for an overview and description of the Enqueue/Dequeue facility. RESTRICTIONS: Some functions require enabled WHEEL or OPERATOR capability to release system resource locks, or enabled WHEEL, OPERATOR, or ENQ capability to release global resource locks. 3-80
TOPS-20 MONITOR CALLS (DEQ) When this call is used in any section other than section zero, one-word global byte pointers used as arguments must have a byte size of seven bits. ACCEPTS IN AC1: Function code AC2: Address of argument block (required only for the .DEQDR function) RETURNS +1: Failure, error code in AC1 +2: Success The available functions are as follows: Code Symbol Meaning 0 .DEQDR Remove the specified requests from the queue. This function is the only one requiring an argument block. 1 .DEQDA Remove all requests for this process from the queues. This action is taken on a RESET or LGOUT call. The error return is taken if the process has not given an ENQ call. 2 .DEQID Remove all requests that correspond to the specified request identifier(ID). This function allows the process to release a class of locks in one call without itemizing each lock in an argument block. It is useful when dequeueing in one call the same locks that were enqueued in one call. To use this function, the process places the 18-bit request ID in AC2. The format of the argument block for function .DEQDR is identical to that given on the ENQ call. (Refer to the ENQ monitor call description.) However, the .ENQID word of the argument block is not used on a DEQ call and must be zero. DEQ ERROR MNEMONICS: DESX5: File is not open ENQX1: Invalid function ENQX2: Level number too small ENQX3: Request and lock level numbers do not match ENQX4: Number of pool and lock resources do not match ENQX6: Requested locks are not all locked ENQX7: No ENQ on this lock ENQX9: Invalid number of blocks specified ENQX10: Invalid argument block length 3-81
TOPS-20 MONITOR CALLS (DEQ) ENQX11: Invalid software interrupt channel number ENQX13: Indirect or indexed byte pointer not allowed ENQX14: Invalid byte size ENQX15: ENQ/DEQ capability required ENQX16: WHEEL or OPERATOR capability required ENQX17: Invalid JFN ENQX18: Quota exceeded ENQX19: String too long ENQX20: Locked JFN cannot be closed ENQX21: Job is not logged in DESX8: File is not on disk Translates the given device designator to its corresponding ASCIZ device name string. The string returned contains only the alphanumeric device name; it does not contain a colon. ACCEPTS IN AC1: Destination designator AC2: Device designator RETURNS +1: Failure, error code in AC1 +2: Success, updated string pointer in AC1, if pertinent The STDEV monitor call can be used to translate a string to its corresponding device designator. DEVST ERROR MNEMONICS: DEVX1: Invalid device designator DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned IOX11: Quota exceeded IOX34: Disk full IOX35: Unable to allocate disk - structure damaged Inputs a double-precision, floating-point number, rounding if necessary. ACCEPTS IN AC1: Source designator RETURNS +1: Failure, error code in AC4 and updated string pointer in AC1, if pertinent. 3-82
TOPS-20 MONITOR CALLS (DFIN) +2: Success, double-precision, floating-point number in AC2 and AC3 and updated string pointer in AC1, if pertinent. DFIN ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX5: File is not open FLINX1: First character is not blank or numeric FLINX2: Number too small FLINX3: Number too large FLINX4: Invalid format Outputs a double-precision, floating-point number. ACCEPTS IN AC1: Destination designator AC2: First word of a normalized, double-precision, floating-point number AC3: Second word of a normalized, double-precision, floating-point number AC4: Format control word. (See Section 2.9.1.2.) RETURNS +1: Failure, error code in AC4 and updated string pointer in AC1, if pertinent. +2: Success, updated string pointer in AC1, if pertinent. DFOUT ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX5: File is not open FLOTX1: Column overflow in field 1 or 2 FLOTX2: Column overflow in field 3 FLOTX3: Invalid format specified IOX11: Quota exceeded IOX34: Disk full IOX35: Unable to allocate disk - structure damaged 3-83
TOPS-20 MONITOR CALLS (DIAG) WARNING: This JSYS can cause a system crash. Use with extreme caution. NOTE This JSYS is primarily intended for system use. The informaton returned may change in a future release. Reserves a channel and either a single device or all devices attached to that channel. This call is also used to release the channel and its devices. When the request is made, no new activity is initiated on the requested channel, and the monitor waits for current activity on all devices connected to the channel to be completed. When the channel becomes idle, the process requesting the channel continues running. The DIAG JSYS can also be used to get and release memory. The .DGGEM function is used by the system program TGHA for performing its spare bit substitution. RESTRICTIONS: Requires WHEEL, OPERATOR, or MAINTENANCE capability enabled. ACCEPTS IN AC1: Negative length of the argument block in the left half, and address of the argument block in the right half. RETURNS +1: Failure, error code in AC1 +2: Success The available functions are as follows: Function Symbol Meaning 1 .DGACU Assign the channel and a single device. Release the device after the time limit specified. Word Contents 0 function code 1 device address 2 time limit in milliseconds 2 .DGACH Assign the channel and all devices. Word Contents 0 function code 1 device address 3-84
TOPS-20 MONITOR CALLS (DIAG) 3 .DGRCH Release the channel and all assigned devices. Word Contents 0 function code 1 device address 4 .DGSCP Set up the channel program. The data transfer can be up to 50 pages. This function locks in memory the user page to which the channel control word points. This function also causes the system to update the Exec Process Table location corresponding to the channel with the appropriate channel control word (physical address). Word Contents 0 function code 1 device address 2 channel control word 0 3 channel control word 1 . . . n+2 channel control word n 5 .DGRCP Release the channel program. The page for the specified channel, to which page the channel control word points, is unlocked. This function is not required before specifying a new channel program. Word Contents 0 function code 1 device address 6 .DGGCS Return the status of the channel. The argument block contains the logout area for the channel. Word Contents 0 function code 1 device address 2-5 4-word channel logout area 7-77 Reserved for DIGITAL. 100 .DGGEM Get memory (for TGHA). 3-85
TOPS-20 MONITOR CALLS (DIAG) Word Contents 0 function code 1 first page in user address space 2 first physical memory page 3 number of pages 4 user address of AR/ARX parity trap routines Upon successful return, this function accomplishes the following: 1. TOPS-20 has requested that all of the front ends refrain from accessing common memory. 2. The hardware PI system has been turned off; no scheduling can occur. 3. The time base and interval timer have been turned off. 4. All DTE byte transfers have been completed. 5. All RH20 activity has ceased. 6. The designated pages of the process address space have been set up to address the designated physical memory. Note that this is not the same as requesting the pages with PLOCK. With the get memory function, the data in the physical memory pages have been retained, and ownership of the pages is unchanged. 7. The CST0 entries for each of the designated physical pages have been saved and set as follows: a) The age is set to the present age of the requesting process. b) The process use field is set to all ones. c) The modified bit is set to one. 8. The entire address space of the requesting process has been locked in memory. (Actually, only the pages that existed at the time of the DIAG call are locked. Therefore, the process must ensure that all of the pages it needs exist and are private when DIAG is executed.) 3-86
TOPS-20 MONITOR CALLS (DIAG) 9. The monitor has set up proper dispatch if TGHA specified an AR/ARX trap address. 101 .DGREM Release memory (for TGHA) Word Contents 0 function code 102 .DGPDL Inform the monitor that a device previously unknown to it is now available for use (is now online). This functon is used with devices interfaced through the DX20 (TX01, TX03, TX05, TU70, or TU72). Argument block: Word Contents 0 function code 1 primary channel number 2 primary unit number 3 primary controller number (-1 if no controller) 4 alternate channel number 5 alternate unit number (should be same as primary unit number) 6 alternate controller number (-1 if no controller) 103 .DGCSL Reserved for DIGITAL. 104 .DGUCD CI-20 microcode management. Word Contents 0 function code 1 subfunction code Code Symbol Meaning 0 .DGRIP microcode reload in progress 1 .DGRLC microcode reload complete 2 .DGDIP microcode dump in progress 3 .DGDMC microcode dump complete 105 .DGRST Reset any remote system on the CI 3-87
TOPS-20 MONITOR CALLS (DIAG) Word Contents 0 function code 1 system address: channel,,node where channel (which CI) is 7 for a KL, and node is the CI node address 2 0 to set the force-bit to 0; one to set the force-bit to 1. Normally, a remote system will only allow itself to be reset by the system on the CI that did a previous reset of this system. The force-bit allows the calling system to force a reset whether or not it did the previous reset of the remote system. Note: Remote system may not support this function. 106 .DGSTR Start remote system Word Contents 0 function code 1 system address: channel,,node where channel (which CI) is 7 for a KL, and node is the CI node address 2 0 to use default start address of remote system; or start address for remote system if other than default Note: Remote system may not support this function. 107 .DGCTR Port counter functions Word Contents 0 function code 1 channel,,function For the CI-20 (KLIPA), the channel is 7. Code Symbol Meaning 0 .DGGTC get counters 1 .DGGVC release counters 2 .DGPTC set counters. This function will set the nodes to capture data and the data to capture. Note: .DGCTR function 0 (.DGGTC) must be executed prior to .DGPTC. 3 .DGRDC read counters 3-88
TOPS-20 MONITOR CALLS (DIAG) 2 If releasing counters, then 0 = do not force release. Ownership of counters will be released only if current owner is current process. 1 = force release ownership of counters. If setting counters, then mask,, threshold 3 nodes to capture data if setting counters. Words 2 - 15 are returned only if port counter function = 3. 2 counter,, process number of owner. Counter is incremented whenever the port counters are set (initial value =-1) 3 CI-20 microcode version 4 path 0 ACKs 5 path 0 NAKs 6 path 0 no responses 7 path 1 ACKs 8 path 1 NAKs 9 path 1 no responses 10 number of datagrams discarded 11 total number of transmits 12 total number of receives 13 node on which data is being collected 14 packets received with CRC errors 15 mover parity errors,, CBUS parity errors 16 register PLIPE errors,, DATA PLIPE errors 17 channel errors,, EBUS parity errors 18 spurious channel errors,, CBUS available timeouts 19 spurious receive attentions,, spurious transmit attentions 20 transmit buffer parity errors,, transmit timeouts 110 .DGRSC Read SPEAR counter (the number of SPEAR packets queued to be written to the error file). The calling program should execute this function both before and after running any diagnostic test. If the value of the SPEAR counter changes, then SPEAR entries have been produced, some of which may be relevant to the diagnostic. This counter is never reset and never decremented. Word Contents 0 function code 1 returned value of SPEAR counter 3-89
TOPS-20 MONITOR CALLS (DIAG) 111 .DGENB Enable/disable use of .DGACH (assign controller and all devices). This function allows a diagnostic to gain control of the CI by allowing it to assign the CI to itself for the duration of the test. When the diagnostic has completed its testing, it should issue DIAG% function .DGRCH (release channel) and then issue .DGENB a second time to make the CI available to the system. Word Contents 0 function code 1 RH20 slot number (7 for CI-20) 2 0 to disable .DGACH and prevent further interruption of CI availability to system; -1 to enable .DGACH 112 .DGWMD Write maintenance data to a remote node Word Contents 0 function code 1 channel number 2 number of 8-bit bytes to be written 3 address in remote node to write data to 4 address of date to be written Note: Remote system may not support this function. 113 .DGRMD Read maintenance data from a remote node Word Contents 0 function code 1 channel number 2 number of 8-bit bytes to be read 3 address in remote node to read data from 4 address to which data should be written Note: Remote system may not support this function. The device address given in some of the argument blocks is a machine-dependent specification for the channel and device to be assigned. The devices that can be assigned must be attached to the RH20 controller and must be mounted by a process with either WHEEL, OPERATOR, or MAINTENANCE capability enabled. The format of the device address word is: 3-90
TOPS-20 MONITOR CALLS (DIAG) 0 2 3 9 10 23 24 29 30 35 !=======================================================! ! address ! device ! 0 ! unit ! subunit ! ! type ! code ! ! ! ! !=======================================================! DIAG ERROR MNEMONICS: DIAGX1: Invalid function DIAGX2: Device is not assigned DIAGX3: Argument block too small DIAGX4: Invalid device type DIAGX5: WHEEL, OPERATOR, or MAINTENANCE capability required DIAGX6: Invalid channel command list DIAGX7: Illegal to do I/O across page boundary DIAGX8: No such device DIAGX9: Unit does not exist DIAG10: Subunit does not exist DIAG11: Device is already on-line Dismisses the process until the designated file input buffer is empty. ACCEPTS IN AC1: File designator RETURNS +1: Always Returns immediately if the designator is not associated with a terminal. The DOBE monitor call can be used to dismiss the process until the designated file output buffer is empty. Generates an illegal instruction interrupt on error conditions below. DIBE ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX3: JFN is not assigned DESX5: File is not open DEVX2: Device already assigned to another job TTYX01: Line is not active 3-91
TOPS-20 MONITOR CALLS (DIC) Deactivates the specified software interrupt channels. (See Section 2.6.1.) ACCEPTS IN AC1: Process handle AC2: 36-bit word Bit n means deactivate channel n RETURNS +1: Always Software interrupt requests to deactivated channels are ignored except for interrupts generated on panic channels. Panic channel interrupts are passed to the closest superior process that has the specific channel enabled. The AIC monitor call is used to activate specified software interrupt channels. Generates an illegal instruction interrupt on error conditions below. DIC ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle FRKHX8: Illegal to manipulate an execute-only process Disables the software interrupt system for a process. ACCEPTS IN AC1: Process handle RETURNS +1: Always If software interrupt requests are generated while the interrupt system is disabled, the requests are remembered and take effect when the interrupt system is reenabled unless an intervening CIS call is executed. However, interrupts on panic channels will still be generated even though the system is disabled. In addition, if the CTRL/C terminal code is assigned to a channel, it will still generate an interrupt that cannot be disabled with a DIR call. CTRL/C interrupts can be disabled by deactivating the channel to which the code is assigned or by monitor action. The EIR monitor call can be used to enable the software interrupt system for a process. 3-92
TOPS-20 MONITOR CALLS (DIR) Generates an illegal instruction interrupt on error conditions below. DIR ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle FRKHX8: Illegal to manipulate an execute-only process Translates the specified 36-bit user or directory number to its corresponding string and writes it to the given destination. When a user number is given, the string returned is the corresponding user name without any punctuation. When a directory number is given, the string returned is the corresponding structure and directory name including punctuation (structure:<directory>). ACCEPTS IN AC1: Destination designator AC2: User or directory number RETURNS +1: Failure, with error code in AC1. +2: Success, string written to destination, updated string pointer, if pertinent, in AC1 The RCDIR monitor call can be used to translate a directory string to its corresponding directory number. The RCUSR monitor call can be used to translate a user name string to its corresponding user number. DIRST ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX5: File is not open DELFX6: Internal format of directory is incorrect DIRX1: Invalid directory number DIRX2: Insufficient system resources DIRX3: Internal format of directory is incorrect IOX11: Quota exceeded IOX34: Disk full IOX35: Unable to allocate disk - structure damaged STRX01: Structure is not mounted STRX10: Structure is offline 3-93
TOPS-20 MONITOR CALLS (DISMS) Dismisses this process for the specified amount of time. ACCEPTS IN AC1: Number of milliseconds for which the process is to be dismissed RETURNS +1: When the elapsed time is up The maximum argument specifiable in AC1 is 400,,0 (18 hours, 38 minutes, 28 seconds, and 864 milliseconds). If this value is exceeded, the argument is ignored and the maximum dismiss time is used. The time resolution is limited to the scheduling frequency (about 20 milliseconds). Manipulates the Dump-on-BUGCHK facility which provides information on non-fatal system errors. RESTRICTIONS: Requires WHEEL, OPERATOR, or MAINTENENCE privileges. ACCEPTS IN AC1: Address of argument block RETURNS +1: Success The format of the argument block is: Word Symbol Meaning 0 .DBCNT RH - Count of words in argument block, including this word. 1 .DBFNC Function code. 2-n Function specific arguments. The function codes for .DBFNC and their arguments are: Code Symbol Meaning 0 .DBENA Enable DOB 1 .DBDIS Disable DOB 2 .DBSBG Set configuration word for a particular BUGxxx. Possible words and their configurations are: 3-94
TOPS-20 MONITOR CALLS (DOB%) Word Contents 2 (.DBNAM) Name of the BUG in SIXBIT. 3 (.DBCFG) New configuration word, defined as follows: B0(DB%ENA) - if on, set the bits to 1. If off, set the bits to 0. B1(DB%REQ) - request a dump on this BUG. B2(DB%IGN) - ignore timeout period for this BUG. B3(DB%DON) - (set by monitor) - BUG is dumped. B9(DB%NND) - (set by monitor) - BUG is not dumpable. 3 .DBPAR Enable/Disable DOB parameters Word Contents 2 (.DBFLG) B4(DB%INF) - Dump on all BUGINFs B5(DB%CHK) - Dump on all BUGCHKs 4 .DBIMD Take a dump immediately (FORCED BUGINF) Word Contents 2 (.DBSTR) Pointer to optional 7-bit string with structure name 5 .DBSTA Return the status of DOB. The status is returned starting in word .DBSTS of the argument block. (The minimum size of the block for this function is 2 words.) Word Contents 2 (.DBSTS) Appropriate flags: B0(DB%DOB) - DOB is enabled B4(DB%CHK) - dumps are requested for all BUGCHKs B5(DB%INF) - dumps are requested for all BUGINFs B6(DB%DIP) - dump is in progress B7(DB%ERR) - dump in progress had an I/O error B8(DB%DML) - DUMP.EXE file chosen for 3-95
TOPS-20 MONITOR CALLS (DOB%) this dump was too small for memory size of this system. 3 (.DBNUM) Number of bugs for which dumping is requested,,Number of bugs returned 4 (.DBTOV) Timeout value in seconds The following two words are repeated for each BUG returned: 5 (.DBBNM) SIXBIT BUG name 6 (.DBBCF) BUG configuration word If the size of the user's block is 3, DOB% only returns words 2 and 3 to the user (the status word and the number of bugs requested). This enables a user to determine how big an argument block is needed for the call. 6 .DBTIM Set timeout value. Prevents continuous dumps from occurring within the timeout period. By default, this timer is set to 15 seconds. Word Contents 2 (.DBTVS) Timeout value in seconds Generates an illegal instruction interrupt on error conditions below. DOB% ERROR MNEMONICS: ARGX02: Invalid function ARGX03: Illegal to change specified bits ARGX04: Argument block too small ARGX17: Invalid argument block length CAPX2: WHEEL, OPERATOR, or MAINTENANCE capability required DOBX01: Not a BUGCHK or BUGINF DOBX02: DOB is disabled DOBX03: DOB already disabled DOBX04: DOB already enabled DOBX05: Dump was not requested for this BUG DOBX06: Dump was already requested for this BUG DOBX07: Structure is not dumpable DOBX08: DOB timeout out of range STRX01: Structure is not mounted STRX10: Structure is offline 3-96
TOPS-20 MONITOR CALLS (DOBE) Dismisses the process until the designated file output buffer is empty. ACCEPTS IN AC1: Destination designator RETURNS +1: Always Returns immediately if designator is not associated with a terminal. The DIBE monitor call can be used to dismiss the process until the designated file input buffer is empty. Generates an illegal instruction interrupt on error conditions below. DOBE ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX3: JFN is not assigned DESX5: File is not open DEVX2: Device already assigned to another job TTYX01: Line is not active Assigns or deassigns specific disk addresses. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: B0(DA%DEA) Deassign the specified address. If the address is currently assigned, control returns to the next instruction following the call (+1 return). If the address was not previously assigned, a BUGCHK occurs. B1(DA%ASF) Assign a free page near the specified address. Assignment is on the same cylinder as the specified address, if possible, or on a nearby cylinder. If the specified address is 0, a page is assigned on a cylinder that is at least one-half free. If the assignment is not possible because the disk is full, control returns to the next instruction following the call. B2(DA%CNV) Convert the specified address according to the setting of B3(DA%HWA). 3-97
TOPS-20 MONITOR CALLS (DSKAS) B3(DA%HWA) The specified address is a hardware address. If this bit is off, the specified address is a software address. B4(DA%INI) Initialize a private copy of the bit table. B5(DA%WRT) Write the private copy of the bit table to a new bit table file. B6(DA%AIN) Abort the initialization of a private copy of the bit table. B18-35 Disk address (DA%ADR) AC2: Device designator of structure. If DA%CNV is on in AC1, this argument is not required. RETURNS +1: Failure, address already assigned or cannot be assigned +2: Success, address assigned in AC1 Generates an illegal instruction interrupt on error conditions below. DSKAS ERROR MNEMONICS: WHELX1: WHEEL or OPERATOR capability required Allows the process to reference physical disk addresses when performing disk transfers. This monitor call requires the process to have WHEEL, OPERATOR, or MAINTENANCE capability enabled to read and write data. However, a process with only MAINTENANCE capability enabled can write data only if it is using physical addresses (.DOPPU) and writing to a unit that is not part of a mounted structure. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. Some functions can be performed with MAINTENANCE capability enabled. ACCEPTS IN AC1: B0-1(DOP%AT) Field indicating the address type. For physical channel and unit addresses, the value of the field is 1(.DOPPU) and the remainder of AC1 is: B2-6(DOP%CN) channel number 3-98
TOPS-20 MONITOR CALLS (DSKOP) B7-12(DOP%UN) unit number B13-35(DOP%UA) unit address For physical channel, controller, and unit numbers, refer to AC4. For a structure and a relative address, the value of the field is 2(.DOPSR) and the remainder of AC1 is: B2-10(DOP%SN) structure designator flag (0 is public structure). A value of -1 means the structure is indicated by the structure designator (see Section 2.4) in AC4. B11-35(DOP%RA) relative address Any other values for this field are illegal. AC2: Control flags in the left half and a count of the number of words to transfer in the right half. The control flags are: B9(DOP%NF) use values in AC4 for channel, controller, and unit numbers; otherwise, use values in AC1 (note: this bit must be on if DUP%AT has value .DOPSR). B10(DOP%EO) error if unit offline. (Note that this is always the case if doing multi-paged transfers.) B11(DOP%IL) inhibit error logging B12(DOP%IR) inhibit error recovery B13(DOP%PS) physical sector reference. Intended to permit homeblocks to be read/written when MSTR% JSYS function .MSRSP is not equal to MSTR% JSYS function .MSTSP. B14(DOP%WR) write data to the disk. If this bit is off, read data from the disk. B18-35 word count. If this count is less than (DOP%CT) or equal to 1000, the data to be transferred cannot straddle a page boundary. Thus the caller's buffer should start at a page boundary and cannot be longer than one page. If this count is more than 1000, the data to be transferred can straddle a 3-99
TOPS-20 MONITOR CALLS (DSKOP) page boundary, so the caller's buffer need not start on a page boundary, and the buffer can be larger than one page. Two restrictions apply, however. First, the buffer must be a multiple of the size of the sectors on the disk being read or written. (Obtain the sector size by using the .MSRUS function of the MSTR JSYS.) Second, no error processing is done (the JSYS executes as though the DOP%IL and DOP%IR bits were set). On an error, the pages must be read one at a time to determine which pages caused errors. AC3: Address in caller's address space from which data is written or into which data is read. AC4: Device designator of the structure. This word is used if the value given for DOP%SN is -1. or Physical channel, controller, and unit numbers if B9(DOP%NF) in AC2 is on. In this case, B0-11(DOP%C2) channel number B12-23(DOP%K2) controller number B24-35(DOP%U2) unit number RETURNS +1: Always, AC1 is nonzero if an error occurred, or zero if no error occurred. No more than 50 pages can be transferred at a time. In addition, a transfer cannot cross a cylinder boundary. If an error occurs and DOP%IL is on in the call, no error logging is performed. If DOP%IL is off, the standard system error logging is performed. If an error occurs and DOP%IR is on in the call, no retries or ECC corrections, if applicable, are attempted. If DOP%IR is off, the standard system error recovery procedure is followed. An error occurs if the format for channel, controller, and unit number is used with Release 4 or any previous monitor. Generates an illegal instruction interrupt on error conditions below. DSKOP ERROR MNEMONICS: DKOP01: Illegal disk address DKOP02: Transfer too large 3-100
TOPS-20 MONITOR CALLS (DSKOP) DKOP03: Invalid unit specified DKOP04: Illegal address specified DKOP05: Size not sector size DKOP06: Data or device error DKOP07: Device is offline DSKOX1: Channel number too large DSKOX2: Unit number too large DSKOX3: Invalid structure number DSKOX4: Invalid address type specified DECRSV: DEC-reserved bits not zero WHELX1: WHEEL or OPERATOR capability required STRX10: Structure is offline Detaches the controlling terminal from the current job. (The ATACH call with bit 1 (AT%NAT) of AC2 set can be used to detach a job other than the current job.) A console-detached entry is appended to the accounting data file. RETURNS +1: Always The DTACH call is ignored if the job is already detached. The ATACH monitor call is used to attach the controlling terminal to a specified job. Deassigns a terminal interrupt code. ACCEPTS IN AC1: Terminal interrupt code; see Section 2.6.6 RETURNS +1: Always The DTI call is a no-op if the specified terminal code was not assigned by the current process. The ATI monitor call is used to assign a terminal code. Generates an illegal instruction interrupt on error conditions below. DTI ERROR MNEMONICS: TERMX1: Invalid terminal code 3-101
TOPS-20 MONITOR CALLS (DUMPI) Reads data words into memory in unbuffered data mode. The file must be open for data mode 17. (See Section 2.4.7.5 for information about unbuffered magnetic tape I/O.) ACCEPTS IN AC1: JFN AC2: B0(DM%NWT) Do not wait for completion of requested operation B18-35 Address of command list in memory (DM%PTR) RETURNS +1: Failure, error code in AC1, pointer to offending command in AC2 +2: Success, pointer in AC2 updated to last command The use of B0(DM%NWT) allows data operations to be double-buffered with a resulting increase in speed. When this bit is on, DUMPI/DUMPO returns immediately after the request is queued. This allows the program to overlap computations with I/O transfers. If the second request is then made, the program is blocked until the first request is completed. Generally, for a sequence of overlapped DUMPI/DUMPO calls, return from the Nth call indicates that the Nth-1 request has completed and that the Nth request is now in progress. This bit is implemented only for magnetic tape. The GDSTS call can be used after the transfer is completed to determine the number of bytes read. If an error occurs on the Nth request, the failure return is given on the Nth+1 call, and the Nth+1 request is ignored. This means that the program will discover an error on a request only after making the next request. The next request is ignored to prevent improper operation and must be reissued after the error has been processed. The GDSTS call can be executed to determine the cause for the error. COMMAND LIST FORMAT: Three types of entries may occur in the command list. 1. IOWD n, loc - Causes n words to be transferred from the file to locations loc through loc+n-1 of the process address space. The next command is obtained from the location following the IOWD. For magnetic-tape files, 1 IOWD word reads 1 physical tape record. For labeled magnetic-tape files, the data format must be "U". The IOWD pseudo-op generates XWD -n,loc-1. 3-102
TOPS-20 MONITOR CALLS (DUMPI) 2. XWD 0, y - Causes the next command to be taken from location y. Referred to as a GOTO word. 3. 0 - Terminates the command list. DUMPI ERROR MNEMONICS: DUMPX1: Command list error DUMPX2: JFN is not open in dump mode DUMPX3: Address error (too big or crosses end of memory) DUMPX4: Access error (cannot read or write data in memory) DUMPX5: No-wait dump mode not supported for this device DUMPX6: Dump mode not supported for this device DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer DESX5: File is not open IOX1: File is not opened for reading IOX4: End of file reached IOX5: Device or data error Writes data words from memory in unbuffered data mode. The file must be open for data mode 17. (See Section 2.4.7.5 for information about unbuffered magnetic tape I/O.) ACCEPTS IN AC1: JFN AC2: B0(DM%NWT) Do not wait for completion of requested operation B18-35 Address of command list in memory (DM%PTR) RETURNS +1: Failure, error code in AC1, pointer to offending command in AC2 +2: Success, pointer in AC2 updated to last command This call locks in memory the pages to be transferred. Any attempt to write to these pages while DUMPO has them locked results in an illegal memory reference. The use of B0(DM%NWT) allows data operations to be double-buffered with a resulting increase in speed. When this bit is on, DUMPI/DUMPO returns immediately after the request is queued. This allows the program to overlap computations with I/O transfers. If the second 3-103
TOPS-20 MONITOR CALLS (DUMPO) request is then made, the program is blocked until the first request is completed. Generally, for a sequence of overlapped DUMPI/DUMPO calls, return from the Nth call indicates that the Nth-1 request has completed and that the Nth request is now in progress. This bit is implemented only for magnetic tape. COMMAND LIST FORMAT: Three types of entries may occur in the command list. 1. IOWD n, loc - Causes n words from loc through loc+n-1 to be transferred from the process address space to the file. The next command is obtained from the location following the IOWD. For mag-tape files, 1 IOWD word writes 1 physical tape record. For labeled mag-tape files, the data format must be "U". NOTE Dump mode output to a labeled tape can override the block-size limit specified in the GTJFN. If any write produces a block in excess of the specified block-size parameter, then the file can be read only in dump mode. The IOWD pseudo-op generates XWD -n,loc-1. 2. XWD 0, y - Causes the next command to be taken from location y. Referred to as a GOTO word. 3. 0 - Terminates the command list. The GDSTS call can be used after the transfer is completed to determine the number of bytes written. DUMPO ERROR MNEMONICS: DUMPX1: Command list error DUMPX2: JFN is not open in dump mode DUMPX3: Address error (too big or crosses end of memory) DUMPX4: Access error (cannot read or write data in memory) DUMPX5: No-wait dump mode not supported for this device DUMPX6: Dump mode not supported for this device DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer DESX5: File is not open IOX2: File is not opened for writing IOX5: Device or data error IOX11: Quota exceeded 3-104
TOPS-20 MONITOR CALLS (DUMPO) IOX34: Disk full IOX35: Unable to allocate disk - structure damaged Returns the characteristics of the specified device. ACCEPTS IN AC1: JFN or device designator RETURNS +1: Always, with AC1: Containing the device designator (even if a JFN was given). AC2: Containing the device characteristics word. AC3: Containing the job number to which the device is assigned in the left half and the unit number in the right half. If the device is a structure or does not have units, the right half is -1. The left half of AC3 contains -1 if the device is not assigned to any job or -2 if the device allocator has ownership of the device. Device Characteristics Word Bit Symbol Meaning 0 DV%OUT device can do output 1 DV%IN device can do input 2 DV%DIR device has a directory 3 DV%AS device is assignable with ASND 4 DV%MDD device has multiple directories 5 DV%AV device is available or assigned to this job 6 DV%ASN device is assigned by ASND 8 DV%MNT device is mounted 9-17 DV%TYP device type 0 .DVDSK disk 2 .DVMTA magnetic tape 7 .DVLPT line printer 10 .DVCDR card reader 11 .DVFE front-end pseudo-device 12 .DVTTY terminal 13 .DVPTY pseudo-terminal 15 .DVNUL null device 16 .DVNET ARPA network 22 .DVDCN DECnet active component 23 .DVSRV DECnet passive component 3-105
TOPS-20 MONITOR CALLS (DVCHR) 18 DV%PSD device is a pseudo-device 20-35 DV%MOD data mode in which device can be opened B20 DV%M17 dump mode B27 DV%M10 image mode B34 DV%M1 small buffer mode B35 DV%M0 normal mode Generates an illegal instruction interrupt on error conditions below. DVCHR ERROR MNEMONICS: DEVX1: Invalid device designator DESX1: Invalid source/destination designator DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer Enables the software interrupt system for a process. (See Section 2.4.) ACCEPTS IN AC1: Process handle RETURNS +1: Always The DIR monitor call can be used to disable the software interrupt system for a process. Generates an illegal instruction interrupt on error conditions below. EIR ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle FRKHX8: Illegal to manipulate an execute-only process Requests access to a specific resource by placing a request in the queue for that resource. This call can be used to request any number of resources. Refer to the Monitor Calls User's Guide for an overview and description of the Enqueue/Dequeue facility. 3-106
TOPS-20 MONITOR CALLS (ENQ) RESTRICTIONS: Some functions require enabled WHEEL or OPERATOR capability to acquire system resource locks, or enabled WHEEL, OPERATOR, or ENQ capability to acquire global resource locks. When this call is used in any section other than section zero, one-word global byte pointers used as arguments must have a byte size of seven bits. ACCEPTS IN AC1: Function code AC2: Address of argument block RETURNS +1: Failure, error code in AC1 +2: Success The available functions are as follows: Code Symbol Meaning 0 .ENQBL Queue the requests and block the process until all requested locks are acquired. The error return is taken only if the call is not correctly specified. 1 .ENQAA Queue the requests and acquire the locks only if all requested resources are immediately available. No requests are queued and the error return is taken if any one of the resources is not available. 2 .ENQSI Queue the requests. If all requested resources are immediately available, this function is identical to the .ENQBL function. If all resources are not immediately available, the request is queued and the the call fails with the ENQX6 error. A software interrupt will occur when all requested resources have been given to the process. 3 .ENQMA Modify the access of a previously queued request. (Refer to (Refer to EN%SHR below.) The access of each lock in this request is compared with the access of each lock in the previously queued request. If the two accesses are the same, no modification is needed or made. If the access in this request is shared and the access in the previous request is exclusive, the call succeeds. If the access in this request is exclusive and the access in the previous request 3-107
TOPS-20 MONITOR CALLS (ENQ) is shared, this function returns an error unless this process is the only user of the lock. If the caller is the only user of this lock, the call succeeds. The error return is also taken if: 1. Any one of the specified locks does not have a pending request. 2. Any one of the specified locks is a pooled resource. This function checks each lock specified, and the access is changed for all locks that were given correctly. If the call fails, the user must execute the ENQC call to determine the current state of each lock. 4 .ENECL Enable cluster-wide ENQ/DEQ functionality for all subsequent ENQ%/DEQ%/ENQC% JSYSes done by this process. This function does not require an argument block and so the contents of AC2 are ignored. The format of the argument block is as follows: Word Symbol Meaning 0 .ENQLN length of the header and the number of requested locks in the left half, and length of argument block in the right half. 1 .ENQID the request ID in the left half, and the software interrupt channel number in the right half. 2 .ENQLV flags and level number in the left half, and JFN, -1, -2, or -3 in the right half. (see word .ENQMS below) 3 .ENQUC pointer to a string or a 5B2+33-bit user code. (see word .ENQMS below) 4 .ENQRS number of resources in pool in the left half and number of resources requested in the right half, or 0 in the left half and a group number in the right half. (see word .ENQMS below) 5 .ENQMS address of a resource mask block. Words .ENQLV through .ENQMS should be repeated for each resource requested. 3-108
TOPS-20 MONITOR CALLS (ENQ) The argument block is divided into two logical sections: a header and individual requests for each desired lock. Words .ENQLN and .ENQID form the header. Word .ENQLV through word .ENQMS form the individual request and are repeated for each lock being requested. The words in the argument block are described in the following paragraphs. .ENQLN The length of the header (.ENHLN) is contained in bits 0 through 5. Currently, the length of the header is two words. (Note that a given length of zero or one is assumed to be equal to a length of two.) The number of locks being requested (.ENNLK) is contained in bits 6 through 17, and the length of the argument block (.ENALN) is contained in bits 18 through 35. .ENQID The software interrupt channel specifies the number of the channel on which to generate an interrupt with the .ENQSI function. The request ID is an 18-bit user-generated value used to identify the particular resource. This ID is not currently used by the system but, instead, is stored for future expansion of the facility. .ENQLV The following flags are defined: B0(EN%SHR) Access to this resource is to be shared. If this bit is not set, access to the resource is to be exclusive. B1(EN%BLN) Ignore the level number associated with this resource. Sequencing errors in level numbers will not be considered fatal, and execution of the call will continue. If a sequencing error occurs, the successful return is taken, and AC1 will contain an error code indicating the sequencing error that occurred. B2(EN%NST) Allow ownership of this lock to be nested to any level within a process. This means that a process can request this resource again even though it already owns it. If the process has a request in the resource's queue or if the process already owns the lock, the ownership of the lock is nested to a depth one greater than the current depth. If the process does not have a request in the resource's queue, the setting of this bit has no effect, and the execution of the ENQ call continues. When a process has a nested lock, it must DEQ the resource as many times as it ENQed it before the resource becomes available to other processes. 3-109
TOPS-20 MONITOR CALLS (ENQ) B3(EN%LTL) Allow a long-term lock on this resource. This notifies the system that this resource will be locked and unlocked many times in a short period of time. Setting this bit permits a program to run faster if it is doing multiple locks and unlocks on the same resource because the argument block data is not deleted immediately from the ENQ/DEQ data base when a DEQ call is executed. Thus, the time required to re-create the data is reduced. B9-17(EN%LVL) Level number associated with this resource. The request is not queued and the error return is taken if EN%BLN is not set and 1. A resource with a level number less than or equal to the highest numbered resource requested so far is specified. 2. The level number of the current request does not match the level number supplied on previous requests for this resource. The right half of .ENQLV specifies the type of access desired for the resource. If a JFN is given, the file associated with the JFN is subject to the standard access protection of the system. The file associated with the JFN in the right half of .ENQLV must be opened before the ENQ is performed or an error will be generated. If -1 is given, the resource can be accessed only by processes of the job. If -2 is given, the resource can be accessed by any job on the system. (The process must have ENQ capability enabled to specify -2.) If -3 is given, the resource can be accessed only by processes that have WHEEL or OPERATOR capability enabled. .ENQUC This word is either a byte pointer or a 33-bit user code, either of which serves to uniquely identify the resource to all users. This quantity is the second part of the resource name. (JFN, -1, -2, or -3 is the first part of the resource name.) The system makes no association between these identifiers and any physical resource. The string identified by the byte pointer can contain bytes of any size (from 1 to 36 bits), and is terminated by a null byte. The byte size is specified by the byte pointer. The maximum length of the string (including the terminating null byte) is 50 words. 3-110
TOPS-20 MONITOR CALLS (ENQ) .ENQRS This word is used to allocate multiple resources from a pool of identical resources. The left half contains the number of resources in the pool, and is a parameter agreed upon by all users. All requests for the same pooled resource must agree with the original count or the call fails. The number of resources requested from the pool must be greater than zero if a pool exists, and must be less than or equal to the number in the pool. If the left half of this word is zero, the system assumes only one resource of the specific type exists. In this case, if the right half of this word is positive, it is interpreted as the number of the group of users who can simultaneously access the resource. .ENQMS Obtains a single lock representing many specific resources. For example, a lock can be obtained on a particular data base, and the specific resources requested can be individual records in that data base. This word contains an address of a mask block, consisting of a count word and a group of mask words. The first word of the mask block contains a count (in the right half-word) of the number of words in the block, including the count word. The remaining words each contain 36 mask bits, where each bit represents a specific resource of the lock. The maximum length of the mask block is 16 words. All requests for the resources associated with the mask block must specify the same length for the block or an error return is taken. Also, when a mask block is specified, the ENQ call must request exclusive access to the resource and the left half of word .ENQRS of the lock request must be zero. The set of resources comprising the lock is a parameter agreed upon by all users. A process can obtain exclusive access to all or some of the specific resources comprising the lock. When a process requires exclusive access to all the resources, it executes an ENQ call (for exclusive access) and does not specify a mask block. A successful return is given if there are no other processes that have issued an ENQ call for that lock. Otherwise, the process blocks until the requested resources are available. When a process requires exclusive access to some of the specific resources comprising the lock, it sets up the mask block and sets the bits corresponding to the specific resources it wants to lock. The process then executes an ENQ call for exclusive access. On successful execution of the ENQ call, the process has an exclusive lock for the resources represented by the bits on in the mask. The process blocks if another process owns an exclusive lock on the resource and that process's ENQ call has not specified a mask block. 3-111
TOPS-20 MONITOR CALLS (ENQ) Once a mask block has been set up for a set of specific resources, subsequent requests for a different set of resources will be honored. The set of resources being requested is considered different if the bits on in one process's mask block are not on in another process's mask block. When a subsequent request is given for resources that are currently locked by a process, the process with the request blocked until the last of the currently locked resources is dequeued by the owner of the lock. A process can dequeue all or part of the original ENQ call request. When a DEQ call is executed, the bits on in the mask block of the DEQ call are compared with the bits on in the original ENQ call. The resources not being dequeued remain locked and must be dequeued by a subsequent DEQ call. This action allows a process to lock a number of resources all at once, and then to release individual resources as it finishes with them. However, a process cannot execute subsequent ENQ calls to request additional resources from those requested in its original ENQ call. ENQ ERROR MNEMONICS: DESX5: File is not open ENQX1: Invalid function ENQX2: Level number too small ENQX3: Request and lock level numbers do not match ENQX4: Number of pool and lock resources do not match ENQX5: Lock already requested ENQX6: Requested locks are not all locked ENQX7: No ENQ on this lock ENQX8: Invalid access change requested ENQX9: Invalid number of blocks specified ENQX10: Invalid argument block length ENQX11: Invalid software interrupt channel number ENQX12: Invalid number of resources requested ENQX13: Indirect or indexed byte pointer not allowed ENQX14: Invalid byte size ENQX15: ENQ/DEQ capability required ENQX16: WHEEL or OPERATOR capability required ENQX17: Invalid JFN ENQX18: Quota exceeded ENQX19: String too long ENQX20: Locked JFN cannot be closed ENQX21: Job is not logged in ENQX22: Invalid mask block length ENQX23: Mismatched mask block lengths ENQX24: Internal resources exhausted (No more SCA buffers) DESX8: File is not on disk 3-112
TOPS-20 MONITOR CALLS (ENQC) Returns the current status of the given resource and obtains information about the state of the queues. This monitor call also allows privileged processes to manipulate access rights to the queues and to perform other utility functions on the queue structure. Refer to the Monitor Calls User's Guide for an overview and description of the Enqueue/Dequeue facility. The ENQC monitor call has two calling sequences, depending on whether the process is obtaining status information or is modifying the queue structure. Obtaining Status Information RESTRICTIONS: When this call is used in any section other than section zero, one-word global byte pointers used as arguments must have a byte size of seven bits. ACCEPTS IN AC1: Function code (.ENQCS) AC2: Address of argument block AC3: Address of block in which to place status RETURNS +1: Failure, error code in AC1 +2: Success The function .ENQCS returns the status of the specified resources. The argument block is identical in format to the ENQ and DEQ argument blocks. (Refer to the ENQ monitor call description.) The status block has a 3-word entry for each resource specified in the argument block. This entry reflects the current status of the resource and has the following format: 0 17 18 35 !=======================================================! ! flag bits indicating status of resource ! !=======================================================! ! 36-bit time stamp ! !=======================================================! ! # of processes with lock ! request ID ! !=======================================================! 3-113
TOPS-20 MONITOR CALLS (ENQC) The following flag bits are currently defined. B0(EN%QCE) An error has occurred in the corresponding resource request and bits 18-35 contain an appropriate error code. B1(EN%QCO) This process owns the lock. B2(EN%QCQ) This process is in the queue waiting for this resource. This bit is set if B1(EN%QCO) is set because a request remains in the queue until a DEQ call is given. B3(EN%QCX) The lock has been allocated for exclusive access. B4(EN%QCB) This process is in the queue waiting for exclusive access to the resource. This bit is off if B2(EN%QCQ) is off. B9-17(EN%LVL) The level number of the resource. B18-35(EN%JOB) Global job number of the owner of the lock. This value may be a job number on another system within the cluster. For locks with shared access, this value will be the job number of one of the sharers. However, this value will be the current job's number if the current job is one of the sharers. If the lock is not owned, the value is -1. If B0(EN%QCE) is on, this field contains the appropriate error code. The time stamp indicates the last time a process was given access to the resource. The time is in the universal date-time standard. If no process currently has access to the resource, the word is zero. The number returned in the left half of the third word indicates the number of processes that currently have the resource locked for either exclusive access or shared access. The request ID is either the request ID of the current process if that process is in the queue, or the request ID of the owner of the lock. Modifying the Queue Structure RESTRICTIONS: These functions require enabled WHEEL or OPERATOR capability. When this call is used in any section other than section zero, one-word global byte pointers used as arguments must have a byte size of seven bits. ACCEPTS IN AC1: Function code 3-114
TOPS-20 MONITOR CALLS (ENQC) AC2: Address of argument block RETURNS +1: Failure, error code in AC1 +2: Success The available functions, along with their argument block formats, are as follows: Function Argument Block Meaning .ENQCG One word containing Return the ENQ/DEQ quota for a job number in the the specified job. The quota right half. The left is returned in AC1. A job half is ignored. number of -1 defines your own job. .ENQCC One word containing Change the ENQ/DEQ quota for the new quota in the the specified job. The process left half and a job executing the call must have number in the right WHEEL capability enabled or an half. error code is returned. .ENQCD A block of n words. Dump the ENQ/DEQ locks and The first word is the queue entries into the length of the block (n). argument block. The process Remaining words contain executing the call must have the returned WHEEL capability enabled or an data. (See below.) error code is returned. The data returned in the argument block concerns both the ENQ/DEQ locks and the queues. The data concerning the locks is in a 4-word block of the following format: 0 8 9 17 18 35 !=======================================================! .ENQDF ! flags !level number ! OFN, 40000+job#, -2, or -3! !=======================================================! .ENQDR ! total resources in pool ! # of resources remaining ! !=======================================================! .ENQDT ! time stamp of last request locked ! !=======================================================! .ENQDC ! user code of lock or beginning of string ! !=======================================================! 3-115
TOPS-20 MONITOR CALLS (ENQC) If there are no pooled resources, word .ENQDR has the format: 0 17 18 35 !=======================================================! .ENQDR ! 0 ! group number ! !=======================================================! The data concerning the queues is in a 2-word block of the following format: 0 8 9 17 18 35 !=======================================================! .ENQDF ! flags !software chan! job # creator queue entry ! !=======================================================! .ENQDI !group # or number requested! request ID ! !=======================================================! The flags returned in the first word of each block are as follows: B0(EN%QCL) This block concerns data about the locks. If this bit is off, the block concerns data about the queues. B1(EN%QCO) This process owns the lock. B2(EN%QCT) This lock contains a text string. B3(EN%QCX) This lock is for exclusive access. B4(EN%QCB) This process is blocked until exclusive access is available. B5(EN%QCC) This is a cluster-wide lock/request. B6(EN%QCN) This lock requires no vote. B7(EN%QCS) This lock requires a scheduling pass. ENQC ERROR MNEMONICS: ENQX1: Invalid function ENQX2: Level number too small ENQX3: Request and lock level numbers do not match ENQX4: Number of pool and lock resources do not match ENQX5: Lock already requested ENQX6: Requested locks are not all locked ENQX7: No ENQ on this lock ENQX8: Invalid access change requested ENQX9: Invalid number of blocks specified ENQX10: Invalid argument block length 3-116
TOPS-20 MONITOR CALLS (ENQC) ENQX11: Invalid software interrupt channel number ENQX12: Invalid number of resources requested ENQX13: Indirect or indexed byte pointer not allowed ENQX14: Invalid byte size ENQX15: ENQ/DEQ capability required ENQX16: WHEEL or OPERATOR capability required ENQX17: Invalid JFN ENQX18: Quota exceeded ENQX19: String too long ENQX20: Locked JFN cannot be closed ENQX21: Job is not logged in ENQX24: Internal resources exhausted (No more SCA buffers) DESX8: File is not on disk Enables the capabilities for the specified process. (Refer to Section 2.7.1 for a description of the capability word.) ACCEPTS IN AC1: Process handle AC2: Capabilities the process can enable AC3: Capabilities to enable RETURNS +1: Always The capabilities in bits 0-8 and bits 18-35 of AC2 are matched (ANDed) with the corresponding capabilities of both the calling process and the process specified in AC1. The calling process can only enable those capabilities that both the calling process and the object process have. The contents of AC2 are ignored if the process handle in AC1 is for the current process. The RPCAP monitor call can be used to obtain the capabilities of a process. Generates an illegal instruction interrupt on the following error conditions: EPCAP ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process 3-117
TOPS-20 MONITOR CALLS (ERSTR) Translates a TOPS-20 error number to its corresponding text string and writes the string to the specified destination. This error number is the one returned in an AC (usually in AC1) on a JSYS error and is associated with a unique error mnemonic and text string. The error numbers begin at 600010 and are defined in the system file MONSYM.MAC. (Refer to Appendix B for the list of error numbers, mnemonics, and text strings.) ACCEPTS IN AC1: Destination designator AC2: LH: Process handle RH: Error number, or -1 for the most recent error in the specified process. If an error number is specified, .FHSLF should be specified in the left half of AC2. AC3: LH: A negative count of the maximum number of bytes in the string to be transferred, or 0 for no limit RH: 0 RETURNS +1: Failure, undefined error number +2: Failure, string size out of bounds or invalid destination designator +3: Success, with updated byte pointer in AC1 Generates an illegal instruction interrupt on error conditions below. ERSTR ERROR MNEMONICS: DESX1: Invalid source/destination designator FRKHX1: Invalid process handle IOX11: Quota exceeded IOX34: Disk full IOX35: Unable to allocate disk - structure damaged Outputs an error string. This monitor call reports an error in the primary input stream, and resynchronizes the input transaction. This mechanism is convenient for communicating with a user who made a typing error and may have continued to type. It also allows error messages to have a standard format. ACCEPTS IN AC1: Byte pointer to a string in the caller's address 3-118
TOPS-20 MONITOR CALLS (ESOUT) space. The string is terminated with a null character. RETURNS +1: Always, with updated byte pointer in AC1 The ESOUT call waits for the primary output buffer to empty and then outputs a carriage return, line feed, and question mark to the primary output designator. Next, it clears the primary input buffer and outputs the error string to the primary output device. Can cause several software interrupts or process terminations on certain file conditions. (Refer to bit OF%HER of the OPENF call description.) Finds the first free page in the specified file. A free page is one that is marked as not being in use. The FFFFP call is useful for finding a nonused page in a file before a PMAP call is executed that writes into that page. ACCEPTS IN AC1: Starting page number in left half, JFN in right half. RETURNS +1: Always, with the JFN in the left half of AC1 and the page number in the right half of AC1, or a fullword -1 in AC1 if there is no free page. Generates an illegal instruction interrupt on the following error conditions: FFFFP ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX3: JFN is not assigned DESX4: Illegal use of terminal designator or string pointer DESX5: File is not open Freezes one or more processes. ACCEPTS IN AC1: Process handle RETURNS +1: Always This suspends the processes (as soon as they are stoppable from the monitor's point of view) in such a way that they can be continued at 3-119
TOPS-20 MONITOR CALLS (FFORK) the place they were suspended. However, they do not have to be continued; they could be killed. The FFORK call is ignored if the referenced process is already frozen. The RFORK monitor call can be used to resume one or more processes. Generates an illegal instruction interrupt on the following error conditions: FFORK ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle Finds the first used page of the file at or beyond the specified page number. ACCEPTS IN AC1: JFN in the left half, and the starting page number in the right half RETURNS +1: Failure, error code in AC1 +2: Success, page number in the right half of AC1. The left half of AC1 is unchanged. FFUFP ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX3: JFN is not assigned DESX4: Illegal use of terminal designator or string pointer DESX7: Illegal use of parse-only JFN or output wildcard-designators FFUFX1: File is not open FFUFX2: File is not on multiple-directory device FFUFX3: No used page found Inputs a floating-point number from the specified source. This call ignores leading spaces and terminates on the first character that cannot be part of a floating point number. If that character is a carriage return followed by a line feed, the line feed is also input. ACCEPTS IN AC1: Source designator 3-120
TOPS-20 MONITOR CALLS (FLIN) RETURNS +1: Failure, error code in AC3 and updated string pointer in AC1, if pertinent +2: Success, single-precision, floating-point number in AC2 and updated string pointer in AC1, if pertinent FLIN ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX5: file is not open FLINX1: first character is not blank or numeric FLINX2: number too small FLINX3: number too large FLINX4: invalid format Outputs a floating-point number to the specified destination. ACCEPTS IN AC1: Destination designator AC2: Normalized, single-precision, floating-point number AC3: Format control word. (Refer to Section 2.9.1.2.) RETURNS +1: Failure, error code in AC3 and updated string pointer in AC1, if pertinent +2: Success, updated string pointer in AC1, if pertinent FLOUT ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX4: File is not open FLOTX1: Column overflow in field 1 or 2 FLOTX2: Column overflow in field 3 FLOTX3: Invalid format specified IOX11: Quota exceeded IOX34: Disk full IOX35: Unable to allocate disk - structure damaged 3-121
TOPS-20 MONITOR CALLS (GACCT) Returns the current account for the specified job. RESTRICTIONS: Some functions require Confidential Information Access, WHEEL, or OPERATOR capability enabled. ACCEPTS IN AC1: Job number, or -1 for current job AC2: Byte pointer to string where alphanumeric account designator (if any) is to be stored RETURNS +1: Always, with updated pointer to account string in AC2 The GACCT monitor call requires the process to have Confidential Information Access, WHEEL, or OPERATOR capability enabled if the specified job number is not for the current job. The CACCT monitor call can be used to change the account for the current job. Generates an illegal instruction interrupt on the following error conditions: GACCT ERROR MNEMONICS: GACCX1: Invalid job number GACCX2: No such job GACCX3: Confidential Information Access capability required Returns the abccount designator to which the specified file is being charged. ACCEPTS IN AC1: JFN AC2: Byte pointer to string in caller's address space where account string (if any) is to be stored RETURNS +1: Failure, error code in AC1 +2: Success, account string returned, updated string pointer in AC2 +3: Success, 5B2+account number returned in AC2 The SACTF monitor call can be used to set the account designator to which the file is to be charged. 3-122
TOPS-20 MONITOR CALLS (GACTF) GACTF ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer DESX7: Illegal use of parse-only JFN or output wildcard-designators GACTX1: File is not on multiple-directory device GACTX2: File expunged GACTX3: Internal format of directory is incorrect Returns the entry vector and the UUO locations for the compatibility package. ACCEPTS IN AC1: Process handle RETURNS +1: Always, with entry vector length in the left half and entry vector address in the right half of AC2, and UUO location in the left half and PC location in the right half of AC3. If use of the compatibility package has been disabled, AC2 contains -1 on return. If the compatibility package is not available, AC2 and AC3 contain 0 on return. The SCVEC monitor call can be used to set the entry vector for the compatibility package. GCVEC ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle Returns information on the given structure's disk usage and availability. This call is useful in determining storage usage. ACCEPTS IN AC1: Device designator, must be a designator for a structure. If the generic designator DSK: is given, the connected structure is assumed. RETURNS +1: Always, with number of pages in use in AC1, and number of pages not in use in AC2. 3-123
TOPS-20 MONITOR CALLS (GDSKC) GDSKC ERROR MNEMONICS: DEVX1: Invalid device designator Returns the status of a device for user I/O. (Refer to Section 2.4 for the descriptions of the status bits.) This call requires that the device be opened. Also, this call will not return the status of a device for monitor I/O. For example, if GDSTS is executed after a tape mark is written (a monitor I/O operation) the GDSTS call will return the status of the last user record written. ACCEPTS IN AC1: JFN RETURNS +1: Always, with device-dependent status bits in AC2, and device-dependent information in AC3. For magnetic tape, AC3 contains the positive count of number of hardware bytes actually transferred in the left half and zero in the right half. For the line printer, AC3 contains the last value of the page counter register, or -1 if there is no page counter register. For TCP/IP, the return sequence for network-connection files is: AC2: Connection state .TCNOT Connection not open .TCFIN Connection closed .TCSYA Connection openable .TCSYS Connection opening .TCSYN Connection open AC3: Foreign host number (octal) AC4: Foreign port number (octal) The GDSTS call is a no-op for devices without device-dependent status bits. The SDSTS monitor call can be used to set the status bits for a particular device. Generates an illegal instruction interrupt on error conditions below. 3-124
TOPS-20 MONITOR CALLS (GDSTS) GDSTS ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer DESX5: File is not open Returns the entry vector for the Record Management System (RMS). (Refer to the RMS Manual for more information on the Record Management System.) RESTRICTIONS: Requires RMS software. ACCEPTS IN AC1: Process handle RETURNS +1: Always, with entry vector length in the left half and the entry vector address in the right half of AC2. The SDVEC monitor call can be used to set the entry vector for RMS. The XGSEV% monitor call can be used to get an extended special entry vector for RMS entry vectors in nonzero sections. Generates an illegal instruction interrupt on error conditions below. GDVEC ERROR MNEMONICS: ILINS5: RMS facility is not available Gets a save file, copying or mapping it into the process as appropriate. It updates the monitor's data base for the process by copying the entry vector and the list of program data vector addresses (PDVAs) from the save file. (See the .POADD function of the PDVOP% monitor call.) This call can be executed for either sharable or nonsharable save files that were created with the SSAVE or SAVE monitor call, respectively. The file must not be open. RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Process handle,, flag bits and a JFN. 3-125
TOPS-20 MONITOR CALLS (GET) AC2: Lowest process page number in left half, and highest process page number in right half; or the address of an argument block. If this AC contains page numbers, those page numbers control the parts of memory that are loaded when GT%ADR is on. RETURNS +1: Always The defined bits in AC1 are as follows: Bit Symbol Meaning 19 GT%ADR Use the memory address limits given in AC2. If this bit is off, all existing pages of the file (according to its directory) are mapped. 20 GT%PRL Preload the pages being mapped (move the pages immediately.) If this bit is off, the pages are read in from the disk when they are referenced. 21 GT%NOV Do not overlay existing pages and do return an error. If this bit is off, existing pages will be overlaid. 22 GT%ARG If this bit is on, AC2 contains the address of an argument block. 24-35 GT%JFN JFN of the save file The format of the argument block follows: Word Symbol Meaning 0 .GFLAG Flags that indicate how the rest of the argument block is to be used. 1 .GLOW Number of the lowest page in the process into which a file page gets loaded. This page must be within the section specified by .GBASE. 2 .GHIGH Number of the highest page in the process into which a file page gets loaded. This page must be within the section specified by .GBASE. 3 .GBASE Number of the section into which the file pages are loaded. You can specify the section for single-section save files only; use of this word with a multiple-section save file causes an error. The file pages are loaded into this section of memory regardless of the section specified in the save file. 3-126
TOPS-20 MONITOR CALLS (GET) The following flag bits are defined for use in .GFLAG: Bit Symbol Meaning 0 GT%LOW .GLOW contains the number of the lowest page within the process to use. 1 GT%HGH .GHIGH contains the number of the highest page within the process to use. 2 GT%BAS .GBASE contains the number of the section to use. 3 GT%CCH Clear the system's program cache. (WHEEL or OPERATOR capability is required for use of this bit.) 4 GT%CSH Place in cache the name of the program being loaded into memory. (WHEEL or OPERATOR capability is required for use of this bit.) When the GET call is executed for a sharable save file, pages from the file are mapped into pages in the process, and the previous contents of the process's page are overwritten. If the file contains data for only a portion of the process's page, the remainder of the page is zeroed. Pages of the process not used by the file are unchanged. When the GET call is executed for a nonsharable save file, individual words of the file are written into the process. Since these files usually do not have words containing all zeros, a GET call executed for a nonsharable file never clears memory. The GET call never loads the accumulators. The GET JSYS interacts with the JFN of the file that the GET is performed upon in the following ways: 1. If the GET is performed on a CSAVE file, a file on a non-disk device, or a file that has another JFN open on it, the JFN is released. 2. Under normal conditions for a file with only one JFN open on it, if the GET succeeds, it will eventually cause an implicit CLOSF for the file on which the GET was performed. This occurs through the following mechanism: GET changes the owner of the file from the process that issued the GET to the process into which the file is mapped. When the latter process is killed, the JFN is released. Because a program can not be sure that GET has or has not released the JFN, the program should not attempt to release the JFN itself or attempt to use the JFN again (assuming that the GET actually succeeded). At the time that a program tried to erroneously release 3-127
TOPS-20 MONITOR CALLS (GET) the JFN itself, the JFN might be associated with a file other than the file on which the GET was performed. This can be a source of program errors that are difficult to trace. This call can cause several software interrupts or process terminations on some file conditions. A GET call performed on an execute-only process is illegal unless the process is .FHSLF. If the JFN specified in the GET call refers to a file for which the user only has execute-only access, then the process specified must be a virgin process. Generates an illegal instruction interrupt on the following error conditions: GET ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle FRKHX8: Illegal to manipulate an execute-only process GETX1: Invalid save file format GETX2: System Special Pages Table full GETX3: Illegal to overlay existing pages GETX4: Illegal to specify .GBASE for multisection file. SSAVX1: Illegal to save files on this device OPNX2: File does not exist All file errors can occur. Returns a word from the specified system table. (Refer to Section 2.3.2.) ACCEPTS IN AC1: Index into table in the left half, and table number in the right half RETURNS +1: Failure, error code in AC1 +2: Success, 36-bit word from the specified table in AC1 If -1 is given as the index, this call returns the negative of the length of the specified table. The table number can be obtained with the SYSGT call. However, the recommended procedure is to use the symbol definition from the MONSYM file for the table number. (Refer to Chapter 2 for the system table definitions.) 3-128
TOPS-20 MONITOR CALLS (GETAB) The GETAB monitor call requires the process to have GETAB capability available, but not enabled (SC%GTB in the process capability word). GETAB ERROR MNEMONICS: GTABX1: Invalid table number GTABX2: Invalid table index GTABX3: GETAB privileges required Returns the most recent error condition encountered in a process. The most recent error is always saved in the Process Storage Block. ACCEPTS IN AC1: Process handle RETURNS +1: Always, with process handle in left half of AC2 and most recent error condition in right half of AC2. The SETER monitor call can be used to set the most recent error condition encountered in a process. GETER ERROR MNEMONICS: LSTRX1: Process has not encountered any errors Obtains information about the specified job. RESTRICTONS: Requires SC%GTB capability in the process capability word. ACCEPTS IN AC1: Job number, or -1 for current job, or 400000+TTY number AC2: Negative of the length of the block in which to store the information in the left half, and the beginning address of the block in the right half AC3: Word number (offset) of first entry desired from job information table RETURNS +1: Failure, error code in AC1 +2: Success, with updated pointer in AC2 and requested entries stored in specified block; if the job does 3-129
TOPS-20 MONITOR CALLS (GETJI) not exist, returns +2, with -1 in Word 0 of the specified block When a terminal designator is given in AC1, the information returned is for the job running on that terminal. The system begins copying the entries from the job information table, starting with the offset given in AC3, into the address specified in the right half of AC2. The number of entries copied is minus the number given in the left half of AC2, or is the number remaining in the table, whichever is smaller. Because AC2 is updated on a successful return, it cannot be used for the returned data. The format of the job information table is as follows: Word Symbol Meaning 0 .JIJNO Job number 1 .JITNO Job's terminal number (-1 means the job is detached) 2 .JIUNO Job's user number 3 .JIDNO Job's connected directory number 4 .JISNM Subsystem name (SIXBIT) 5 .JIPNM Program name (SIXBIT) 6 .JIRT Run time (in milliseconds) 7 .JICPJ Controlling PTY job number (-1 means the job is not controlled by a PTY) 10 .JIRTL Run time limit (as set by the TIMER call) A zero means no time limit is in effect. 11 .JIBAT Job is controlled by Batch, if -1 (as set by the MTOPR call) 12 .JIDEN Default for magnetic tape density (as set by the SETJB call) 13 .JIPAR Default for magnetic tape parity (as set by the SETJB call) 14 .JIDM Default for magnetic tape data mode (as set by the SETJB call) 15 .JIRS Default number for magnetic tape record size in bytes (as set by the SETJB call) 16 .JIDFS Deferred spooling in effect, if 1 (as set by the SETJB call) 17 .JILNO Job's logged-in directory number 20 .JISRM Byte pointer to area to receive job's session remark. This pointer is supplied by the user before issuing the GETJI call. 21 .JILLN The date and time of the user's last login before the user logged in the current job 22 .JISRT Job CPU time at start of last session. To compute CPU time for this session, subtract .JISRT value from current job CPU time (.JIRT). 3-130
TOPS-20 MONITOR CALLS (GETJI) 23 .JISCT Console time at start of last session. To compute the console time for this session, subtract .JISCT value from current console time (obtainable with RUNTM monitor call). 24 .JIT20 Indicates if job is at EXEC level or program level. (-1 = EXEC, 0 = program) 25 .JISTM Returns time when job was created (when CTRL/C was performed). A -1 is returned if the system time and date were not set when the job started. 26 .JIBCH Batch stream number and batch flags B0-1 OB%WTO Write-to-operator capabilities 0 .OBALL WTO (write-to-operator) and WTOR (write-to-operator with reply) 1 .OBNWR No WTOR allowed 2 .OBNOM No message allowed B10 OB%BSS Indicates that field OB%BSN (below) contains a batch-stream number B11-17 OB%BSN Batch-stream number 27 .JILLO Logical location (node name). This word indicates the logical location of the job. This job location is typically used to cause output to be routed to a remote station, such as an IBM termination station or a DN200 remote station. 30 .JILJI Local job index. Index into system-wide job tables. 31 .JIBSN Batch sequence number. 32 .JIBJN Batch job name. 33 .JIBID Batch request ID. | 34 .JICT Job's connect time. | 35 .JINLD Job's last non-interactive login. The current highest GETJI offset is given by symbol .JIMAX. GETJI ERROR MNEMONICS: GTJIX1: Invalid index GTJIX2: Invalid terminal line number GTJIX3: Invalid job number GTJIX4: No such job Returns the name of the program currently being used by the job. This name will have been declared previously with the SETNM or SETSN monitor call. 3-131
TOPS-20 MONITOR CALLS (GETNM) RETURNS +1: Always, with SIXBIT name of program in AC1 Requests access to the specified system resource from the installation's access-control program. ACCEPTS IN AC1: Function code AC2: Address of argument block (if required) AC3: Length of the argument block (the maximum permissible length is specified by symbol .GOKMZ) AC4: Job number or user number request is for RETURNS +1: Always, with 0 in first word of status block if access granted 1B18 set to one + error number in first word of status block if request denied. An illegal instruction trap is generated. Function Codes: Code Symbol Meaning 1 .GOASD Assign a device Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GEADD Device designator 2 .GOCAP Enable capabilities (right half privileges only) Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GENCP New capability word 3-132
TOPS-20 MONITOR CALLS (GETOK%) 3 .GOCJB Allow CRJOB JSYS to be executed Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 4 .GOLOG Allow LOGIN Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GELUN User number 5 .GOCFK Allow CFORK (only done after n'th fork). N is an installation-defined parameter specified by monitor symbol DGOFKN. Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GEFCT Number of forks already in use by job 6 .GOTBR Set terminal baud rate Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GELIN Line number 2 .GESPD Input speed ,, Output speed 7 .GOLGO Inform the access-control program of a logout. Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GEUSD Number of pages used 2 .GEQUO Directory quota 3 .GERLG Number of the job to be logged out, or -1 if the requesting job is to be logged out. 3-133
TOPS-20 MONITOR CALLS (GETOK%) 10 .GOENQ Allow setting of ENQ quota Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GEEQU Desired quota 2 .GEEUN Job number | | 11 .GOCRD Allow directory creation | | Argument block (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GECFL CRDIR% flags (this is the argument | the user has passed into CRDIR% in | AC 2) | 2 .GEDIR Block of 11 words containing | STR:<DIRECTORY> | 15 .GECAB Block of 25 words containing the | actual CRDIR% argument block. | Note any byte pointers in the | argument block are meaningless | since they point to addresses in | the user's own address space. 12 .GOSMT Allow MOUNT of structure Must be given once to increment the mount count and once to decrement the mount count. Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GESDE Device designator 13 .GOMDD Allow entry to MDDT Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 14 .GOCLS Set scheduler class for a job 3-134
TOPS-20 MONITOR CALLS (GETOK%) Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GEJOB Job number 2 .GECLS Class desired 15 .GOCL0 Set scheduler class at login This function is executed by the monitor when a login occurs and class scheduling is enabled (but not by accounts). The access-control program must then determine which class to put the user in. Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 16 .GOMTA MT: access request Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GEACC Access code from HDR1 label 2 .GEUSN User number 3 .GEUNT MT: unit number 4 .GEACD Desired access bits (FP%xxx) 5 .GELTP Label type (.LTxxx) 17 .GOACC Allow ACCESS or CONNECT Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GOAC0 Flags from ACCES JSYS 2 .GOAC1 Directory number 20 .GOOAD Allow device assignment due to OPENF Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GEADD Device designator 3-135
TOPS-20 MONITOR CALLS (GETOK%) 21 .GODNA Allow access to DECNET Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 22 .GOANA Allow TCP/IP access Argument block (user-specified): Word Symbol Contents 0 .GEERB error block address 23 .GOATJ Allow ATTACH Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GOTJB Target job number 2 .GOTTY Source TTY number 24 .GOINF Allow INFO% execution Argument block (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GEJOB Job number 2 .GECIN CI node to execute INFO% function 3 .GEINF INFO% function number 25 .GOLAT Allow execution of LATOP% JSYS Argument block format (user-specified): Word Symbol Contents 0 .GEERB Error block address 1 .GEJOB Job number 2 .GEFUN Flags,,Function Code Flags included here are LA%PSI, LA%QUE, LA%SYS, and LA%JOB. See LATOP% functions .LARHC and .LATHC for additional information. 3-136
TOPS-20 MONITOR CALLS (GETOK%) 3 .GELTN Four words, containing the ASCIZ node name (or 0) 7 .GELTP Four words, containing the ASCIZ port name (or 0) 11 .GELTS Four words, containing the ASCIZ service name (or 0) | | 26 .GOCTM Allow incoming CTERM connection | | Argument block format (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GEWHO 13 (octal) words containing the | string NODE::USER who is | attempting the incoming CTERM | connection. If the username is | not easily determined, then the | string will simply be the node. | | 27 .GOTTM Allow use of TTMSG% monitor call | | Argument block (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GEDTY AC1 as given to the TTMSG% JSYS | | 30 .GOSMN Allow system parameters to be set with SMON% | | Argument block (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GESMF SMON% function number | 2 .GESMV New value for function | | 31 .GOHSY Allow use of the HSYS% monitor call | | Argument block (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GESDT Shutdown time (internal format) | 2 .GERES System resume time (internal | format) 3-137
TOPS-20 MONITOR CALLS (GETOK%) | 32 .GOSGT Allow access of information via SYSGT% | | Argument block (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GETBN SIXBIT table name | | 33 .GOGTB Allow access of information via GETAB% | | Argument block (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GETBN Index into table,,table number | | 34 .GOOPN Allow opening a file that is set secure | | | Argument block (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GEOAC AC 2 of OPENF% | 2 .GEFIL 226 (octal) words containing | STR:<DIRECTORY>NAME.EXT.VER of | file being opened | | 35 .GORNF Allow renaming a file that is set secure | | Argument block (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | 1 ------ Not used | 2 .GEFIL 226 (octal) words containing | STR:<DIRECTORY>NAME.EXT.VER of | file being renamed | | 36 .GODLF Allow deleting a file that is set secure (either | through DELF% or DELNF% monitor calls) | | Argument block (user-specified): 3-138
TOPS-20 MONITOR CALLS (GETOK%) | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GEDAC Bits selected in user's AC 1 | 2 .GEFIL 226 (octal) words containing | STR:<DIRECTORY>NAME.EXT.VER of | file being deleted | | 37 .GOTLK Allow use of the TLINK% monitor call | | Argument block (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GETTB TLINK% flags,,object designator | 2 .GERMT Remote designator | | 40 .GOCRL Allow use of the .CLNS1, .CLNSA or .CLNSY | functions of the CRLNM% monitor call | | Argument block (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GECFN CRLNM% function | 2 .GELNM Block of 16 words that contain the | logical name for .CLNS1 and .CLNSY | functions | | 41 .GODTC Inform access control job of DTACH% | | Argument block (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | | 42 .GOCFD Allow CHFDB% to set or clear FB%SEC on a file | | Argument block (user-specified): | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GESFS Contents of .FBCTL in file's FDB | 2 .GEFIL 226 (octal) words containing | STR:<DIRECTORY>NAME.EXT.VER of | file being deleted 3-139
TOPS-20 MONITOR CALLS (GETOK%) | 43 .GOGTD GTDIR% JSYS | | Argument block | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GEDNO Directory number | | 44 .GOSTD STAD% JSYS | | Argument block | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GESTT Time to set | | 45 .GODSK DSKOP% JSYS | | Argument block | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GEST1 User AC1 | 2 .GEST2 User AC2 | 3 .GEST3 User AC3 | 4 .GEST4 User AC4 | | 46 .GOSJP SJPRI% JSYS | | Argument block | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GEST1 User's AC1 (job number) | 2 .GEST2 User's AC2 (priority word) | | 47 .GOSPR SPRIW% JSYS | | Argument block | | Word Symbol Contents | | 0 .GEERB Error block address | 1 .GEST1 User's AC1 (process handle) | 2 .GEST2 User's AC2 (priority word) 3-140
TOPS-20 MONITOR CALLS (GETOK%) 400000+n Customer-reserved functions The argument block (user-specified) has the same format as the error block format shown below. The contents of word 1 are ignored. Error block format (returned): Word Symbol Contents 0 .GESIZ Count of words in this block (including this word) 1 .GEERN Error Number 2 .GEPTR Byte pointer to error string location 3 .GEBSZ Maximum bytes user can accept in error string The format of the status block for user-defined functions will depend on the design of the particular access-control program. The user supplies all arguments in the argument block. In the error block, the user supplies words 0, 2, and 3. If an error string is provided by the program doing the GIVOK%, then the byte pointer and count are updated. If the user is not interested in the reason for the rejection, the address of the error block can be 0. If the error block is less than 4 words, only the available words will be used. If the byte pointer is 0, no string will be returned. Error codes are of the form 1B18+n. They are not standard TOPS-20 error codes and therefore cannot be given to ERSTR to produce a string. The access-control program must supply a string if one is needed. Generates an illegal instruction interrupt on the following error conditions: GETOK% ERROR MNEMONICS: ARGX04: Argument block too small ARGX05: Argument block too long ARGX26: File is off line MONX01: Insufficient system resources GOKER1: Illegal function GOKER2: Request denied by Access Control Facility 3-141
TOPS-20 MONITOR CALLS (GEVEC) Returns the section-relative entry vector of the specified process. (See Section 2.7.3.) The process must be one that runs in a single section of memory. See the XGVEC% monitor call to obtain the entry vector of a multisection program. ACCEPTS IN AC1: Process handle RETURNS +1: Always, with specified process's entry vector word in AC2 The SEVEC monitor call can be used to set the process's entry vector. (See the PDVOP% monitor call for a description of the program data vector.) Generates an illegal instruction interrupt on the following error conditions: GEVEC ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle Gets a handle on a process that currently is not known to the caller but is known to another process. The handle returned can then be used by the caller to refer to the process of interest. ACCEPTS IN AC1: Handle of the process that has a handle on the process of interest AC2: Process handle, used by the process named in AC1, that refers to the process of interest. This handle must be a relative handle (in the range 400000 to 400777) and must refer to an existing process. RETURNS +1: Failure, with error code in AC1. +2: Success, with a handle in AC1 that is usable by the caller to refer to the desired process. This handle is not the same as the one given in AC2 (is different from the one used by the process in AC1 to refer to the desired process). 3-142
TOPS-20 MONITOR CALLS (GFRKH) Generates an illegal instruction interrupt on error conditions below. GFRKH ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle FRKHX6: All relative process handles in use GFRKX1: Invalid process handle Returns the process structure of the current job from a given process downward. RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Process handle of the starting point AC2: B0(GF%GFH) Return relative process handles for each process B1(GF%GFS) Return status for each process AC3: The left half contains the negative of the number of words in the block in which to store the process structure, and the right half contains the address of the first word of the block RETURNS +1: Failure, error code in AC1 +2: Success, all process handles are returned The handle of the current process is always returned as .FHSLF regardless of the setting of GF%GFH. Any user can specify a process handle of .FHTOP (causing GFRKS to start with the top level process). However, the user must have WHEEL or OPERATOR capability enabled to specify .FHTOP, set GF%GFH and receive relative handles for all processes from .FHTOP on down. Otherwise, only process handles that the issuing process is entitled to receive will be returned. Also, if the request will cause the monitor to exceed the per-process fork handle limit, only that number of handles that will fit within the limit will be returned. 3-143
TOPS-20 MONITOR CALLS (GFRKS) Table Format =============================================== ! ! ! 3 words ! parallel ! inferior ! per entry ! pointer ! pointer ! ! ! ! =============================================== ! ! ! ! superior ! process handle ! ! pointer ! or 0 if GF%GFH ! ! ! was off, or when no ! ! ! more process handles ! ! ! are left for the ! ! ! process ! ! ! ! =============================================== ! ! This word is ! status word ! -1 if GF%GFS ! ! is off. ! ! ! ! =============================================== NOTE Pointers in table are memory addresses of other table entries, or 0 if no such structure exists. The execution of the GFRKS call terminates before the entire process structure has been returned if the block in which to store the structure information is too small. If this happens, this call returns as much of the structure as can fit in the block, then generates an error message. If all process handles are in use, this call returns the entire structure, but the extra handles will not be assigned (will be zero). Generates an illegal instruction interrupt on error conditions below. GFRKS ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle FRKHX6: All relative process handles in use GFKSX1: Area too small to hold process structure 3-144
TOPS-20 MONITOR CALLS (GFUST) Returns the name of either the author of the file or the user who last wrote to the file. ACCEPTS IN AC1: Function code in the left half, and JFN of the file in the right half AC2: Pointer to the string in which to store the name RETURNS +1: Always, with an updated string pointer in AC2 The defined functions are as follows: Code Symbol Meaning 0 .GFAUT Return the name of the author of the file. 1 .GFLWR Return the name of the user who last wrote to the file. The SFUST monitor call can be used to set the name of either the author of the file or the user who last wrote to the file. Generates an illegal instruction interrupt on error conditions below. GFUST ERROR MNEMONICS: GFUSX1: Invalid function GFUSX2: Insufficient system resources GFUSX3: File expunged GFUSX4: Internal format of directory is incorrect DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer DESX5: File is not open DESX7: Illegal use of parse-only JFN or output wildcard-designators DESX8: File is not on disk DESX10: Structure is dismounted DELFX6: Internal format of directory is incorrect DIRX2: Insufficient system resources DIRX3: Internal format of directory is incorrect 3-145
TOPS-20 MONITOR CALLS (GIVOK%) Allows a privileged access-control program (written by the installation) to allow or disallow a user program's access to a specified system resource. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Request number (from RCVOK% message) AC2: 0 = request granted 1B18 + error number = request denied AC3: Pointer to ASCIZ string (maximum of 80 characters) or 0. This string is an error message or information message to be returned to the user. RETURNS +1: Always Generates an illegal instruction interrupt on error conditions below. GIVOK% ERROR MNEMONICS: CAPX1: WHEEL or OPERATOR capability required GOKER3: JSYS not executed within ACJ fork Returns information pertaining to the current job. RETURNS +1: Always, with AC1 Containing the user number under which the job is running. AC2 Containing the directory number to which the job is connected. AC3 Containing the job number. AC4 Containing the terminal number attached to the job, or -1 if no terminal is attached to job. 3-146
TOPS-20 MONITOR CALLS (GNJFN) Assigns the JFN to the next file in a group of files that have been specified with wildcard characters. The next file in the group is determined by searching structures and directories in the order described in Section 2.2.3. The flags returned from the GTJFN call are given to the GNJFN call as an argument to indicate the fields of the file specification that contain wildcard characters. ACCEPTS IN AC1: Indexable file handle returned by GTJFN flags returned by GTJFN in the left half and the JFN in the right half) RETURNS +1: Failure, including no more files in the group. JFN is released if there are no more files in the group. This return occurs on the first call to GNJFN if no flags indicating wildcard fields are on in the left half of AC1. +2: Success, same JFN is assigned to the next file in the group. The following flags are set (if appropriate) in the left half of AC1: B13 GN%STR structure changed B14 GN%DIR directory changed B15 GN%NAM name changed B16 GN%EXT file type changed The GNJFN call uses the flags returned in the left half of AC1 on a GTJFN call to determine the fields containing wildcards and the default generation number. Note that the GNJFN call returns a different set of flags in the left half of AC1 than the GTJFN call returns. Because all calls to GNJFN should use the flags originally returned by GTJFN, programs must save the returned GTJFN flags for use in the GNJFN call. The file currently associated with the JFN must be closed when the GNJFN call is executed. The indexable file handle for a file that has been renamed cannot be used as an argument to GNJFN. GNJFN will not find invisible files unless bit G1%IIN was set in the GTJFN call. GNJFN ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer GNJFX1: No more files in this specification GNJFX2: Could not step to next file because current file no longer exists 3-147
TOPS-20 MONITOR CALLS (GNJFN) OPNX1: File is already open STRX09: Prior structure mount required Returns the primary JFNs of the specified process. ACCEPTS IN AC1: Process handle RETURNS +1: Always, with primary input JFN in the left half of AC2, and the primary output JFN in the right half of AC2. Unless the primary JFNs have been reset, AC2 contains -1 (777777,,777777), indicating TTY: as the primary I/O source/destination. The SPJFN monitor call can be used to set the primary JFNs. Generates an illegal instruction interrupt on error conditions below. GPJFN ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle Returns the current date in the internal system format. (See Section 2.9.2.) RETURNS +1: Always, with day in the left half of AC1, and fraction of day in right half of AC1 If the system does not have the current date set, AC1 contains -1. The STAD monitor call can be used to set the system's date. 3-148
TOPS-20 MONITOR CALLS (GTDAL) Returns the disk allocation for the specified directory. ACCEPTS IN AC1: Directory number (-1 indicates the connected directory) RETURNS +1: Always, with AC1 Containing the working disk storage limit (logged-in quota) for the directory. AC2 Containing the number of pages being used. AC3 Containing the permanent disk storage limit (logged-out quota) for the directory. Generates an illegal instruction interrupt on error conditions below. GTDAL ERROR MNEMONICS: DIRX1: Invalid directory number DELFX6: Internal format of directory is incorrect STRX10: Structure is offline Returns information about the given directory. RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Directory number (36-bit) AC2: Address of argument block in caller's address space in which to return the directory information AC3: Byte pointer to the password string RETURNS +1: Always, with updated byte pointer in AC3 The argument block returned to the caller has the same format as the CRDIR call's argument block. Word zero (.CDLEN) of the argument block must contain the length of the argument block in which GTDIR is to store the directory information being returned. If this word is zero, 3-149
TOPS-20 MONITOR CALLS (GTDIR) GTDIR assumes the length of the argument block is 15 (octal) words long, and returns only 15 (octal) words. The password of the directory must be placed in the string to which AC3 points. Word 1(.CDPSW) of the returned argument block also points to this string. The count of words to be returned in the user group list is given in word 14 (.CDDGP) of the argument block. This count must be one more than the number of words to be returned in the group list. This is because GTDIR returns a zero word as the last word in the group list. If the directory number given is zero, the GTDIR monitor call returns the system default settings for the following directory parameters: working disk storage quota (.CDLIQ) permanent disk storage quota (.CDLOQ) default file protection (.CDFPT) default directory protection (.CDDPT) default file retention count (.CDRET) maximum number of subdirectories allowed (.CDSDQ) online expiration period (.CDDNE) offline expiration period (.CDDFE) | date and time of last interactive login (.CDLLD) | date and time of last non-interactive login (.CDNLD) | count of failed logins, RH: interactive, LH: non-interactive | (.CDFPA) Either one of the following conditions must be satisfied for the caller to obtain all information (including the password) about the given directory: 1. The caller has WHEEL or OPERATOR capability enabled. 2. The caller has owner access to the directory. Note that if password encryption is enabled, the returned password will be encrypted. To obtain all other information (other than the password) of the given directory, the caller must have at least owner access to the directory. (See Section 2.2.6 for a description of owner access.) Generates an illegal instruction interrupt on error conditions below. GTDIR ERROR MNEMONICS: GTDIX1: WHEEL or OPERATOR capability required GTDIX2: Invalid directory number MSTX32: Structure was not mounted STRX10: Structure is offline 3-150
TOPS-20 MONITOR CALLS (GTFDB) Returns some or all of the file descriptor block for the specified file. (See Section 2.2.8 for the format of this block.) ACCEPTS IN AC1: JFN AC2: Number of words to be read in the left half and the word number (offset) of the first entry desired from the file descriptor block in the right half. AC3: Address in caller's address space for storing the data returned RETURNS +1: Always The following instruction will set up AC2 for reading the entire FDB: HRLZI AC2,.FBLEN The program receives an error (GFDBX2) if it requests more words than there are words remaining in the FDB. For TOPS-20 V4, the size of the FDB has been increased. If the left half of AC2 contains the current maximum size of the FDB (.FBLEN), but the FDB is an older, small FDB, then the extra words will contain zeroes. See Section 2.2.8 for the various JSYSs used to modify the FDB. Generates an illegal instruction interrupt on error conditions below. GTFDB ERROR MNEMONICS: GFDBX1: Invalid displacement GFDBX2: Invalid number of words GFDBX3: List access required DESX1: Invalid source/destination designator DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer DESX7: Illegal use of parse-only JFN or output wildcard-designators STRX10: Structure is offline Obtains information about TCP/IP hosts. 3-151
TOPS-20 MONITOR CALLS (GTHST%) RESTRICTIONS: For TCP/IP systems only. | | ACCEPTS IN AC1: Function code. | The following bits are defined to be supplied in AC1 | with the function code: | | 1B14(GH%QCL) Class argument supplied (functions | .GTHMX,.GTHVN, .GTHOS only). If not | specified, the class for a DNS query | is assumed to be Internet. | | 1B16(GH%STA) Return status code in AC1 on success | or partial success. If this bit is | not set, only total success will | result in a successful return. The | codes that are returned are: | | Value Symbol Meaning | | 0 .GTHVS Total success. | 1 .GTHVF Not found in namespace | (authoritative). This value is | returned instead of GTHSX8. | 2 .GTHVT Timeout while waiting for name | server response. This value is | returned instead of GTHSX7 | (non-authoritative) or GTHSX4. AC2: Function-specific argument AC3: Function-specific argument AC4: Function-specific argument RETURNS +1: Failure, error code in AC1 +2: Success, function-specific data returned in AC's Function Symbol Meaning 0 .GTHSZ Returns negative number of host names, negative length of HSTSTS table, and local host number. User-supplied arguments: None Returned data: AC2: -number host names,,0 AC3: -length of HSTSTS table,,0 AC4: local host number (in 32-bit Internet format) 3-152
TOPS-20 MONITOR CALLS (GTHST%) 1 .GTHIX Returns the name string associated with the host, the host number, and the host status. If the name returned is a nickname, HS%NCK is on in the status word. User-supplied arguments: AC2: destination byte pointer AC3: index into name table (returned by GETAB) Returned data: AC2: updated byte pointer AC3: host number AC4: host status 2 .GTHNS Returns the primary name for the given host number. User-supplied arguments: AC2: destination byte pointer AC3: host number Returned data: AC2: updated byte pointer AC3: host number AC4: host status 3 .GTHSN Translates the specified host name string to its host number. If the name specified is a nickname, HS%NCK will be on in the status word. User-supplied arguments: AC2: source byte pointer Returned data: AC2: updated byte pointer AC3: host number AC4: host status 4 .GTHHN Returns the current status of the given host. User-supplied arguments: AC3: host number 3-153
TOPS-20 MONITOR CALLS (GTHST%) Returned data: AC3: host number AC4: host status 5 .GTHHI Returns the host number and status of the host having the specified index into the host status table. User-supplied arguments: AC3: index into HSTSTS (returned by GETAB) Returned data: AC3: host number AC4: host status 6 .GTHLN Returns the host number of this host on an Internet network. User-supplied arguments: AC2: network number, or host number of a network Returned data: AC3: host number on specified network 7 .GTHNT Returns status table of an Internet network. User-supplied arguments: AC2: network number, or host number of a network AC3: address to store data AC4: length,,offset 10 .GTHLA Returns address of network interfaces. User-supplied arguments: AC3: address to store data AC4: count of words available Returned data: AC4: list of all addresses host has (actual count of words) 3-154
TOPS-20 MONITOR CALLS (GTHST%) | 14 .GTHPN Translates the specified host name string to its | host number. The host's primary name and IP | address is returned. | | User-supplied arguments: | | AC2: source designator to host name string | | AC4: destination designator for primary name | string | | Returned data: | | AC2: updated source designator | | AC3: primary host number | | AC4: updated destination designator | | 15 .GTHMX Return mail exchange data. This data is intended | for use only by programs wishing to deliver mail. | | User-supplied arguments: | | AC2: source designator to name for query | | AC3: destination byte pointer to name block | | AC4: address of argument block | | Returned data: | | AC2: updated source designator | | AC3: updated byte pointer | | Format of argument block | | Word Symbol Meaning | | 0 .GTHLN On call, length of argument block in | words including this word. On | return, number of words returned | including this word. | | 1 .GTHTC On call, class for MX records if | GH%QCL is on in AC1. | | 2 .GTHBC On call, length of name block | (pointed to by AC3) in bytes. On | return, remaining length of buffer | in bytes. 3-155
TOPS-20 MONITOR CALLS (GTHST%) | 3 .GTHNM On return, the pointer to the first | mail exchange name. Words after | this one contain pointers to the | remaining mail exchange names. Each | returned word is a byte pointer into | the name block of a null terminated | ASCII string. | | 16 .GTHAA Authenticate address. This function checks to see | if an address is among those associated with the | specified name. This is the right way to validate | the host name associated with an open network | connection. A success return indicates that the | address was authenticated. | | User-supplied arguments: | | AC2: source designator to host name string | | AC3: address of host or -1 for local host | | Returned data: | | AC2: updated source designator | | 20 .GTHVN Validate name. This function checks to see if a | name is found in one or more DNS resource records | (RRs). | | User-supplied arguments: | | AC2: source designator for name to be validated | | AC3: LH: DNS class to match (if GH%QCL is on in | AC1) | RH: DNS type to match | | AC4: destination designator for canonical name | | Value Symbol DNS class | | 1 .GTHCI Internet class | | Value Symbol DNS type | | 1 .GTHTA A host address (type A RR) | | 2 .GTHTN An authoritative name server (type | NS RR) | | 5 .GTHTC A canonical name (type CNAME RR) 3-156
TOPS-20 MONITOR CALLS (GTHST%) | 6 .GTHTS Start of a zone of authority (type | SOA RR) | | 13 .GTHTW Well known service description (type | WKS RR) | | 14 .GTHTP A domain name pointer (type PTR RR) | | 16 .GTHTH Host information (type HINFO RR) | | 17 .GTHTM Mail exchange (type MX RR) | | 200001 .GTHVH Validate host (match on any | type A, MX, WKS, or HINFO RRs) | | 200002 .GTHVZ Validate zone (match on any | type SOA or NS RRs) | | Returned data: | | AC2: updated source designator | | AC3: class,,type pair that matched | | AC4: updated destination designator | | 23 .GTHOS Operating system. Extracts the operating system | name as a string from the DNS HINFO RR for a host | name. | | User-supplied arguments: | | AC2: source designator for host name | | AC3: destination designator for operating system | name | | AC4: class (if GD%QCL is on in AC1) | | Returned data: | | AC2: updated source pointer | | AC3: updated destination pointer | | 24 .GTHDN Get DNS nameserver host information. This | function is intended primarily for SYSDPY. | | User-supplied arguments: | | AC2: Index into DNS host table, starting at 0 3-157
TOPS-20 MONITOR CALLS (GTHST%) | AC3: Address of four word block to store data | | AC4: Number of words to return (1-4) | | Returned data in argument block: | | Word Symbol Meaning | | 0 .GTHDA IP address of DNS host | | 1 .GTHDT Timeout in seconds for DNS host | | 2 .GTHDS Success count for DNS host | | 3 .GTHDF Failure count for DNS host Flags in host status word: Bits Symbol Meaning 1B0 HS%UP Host is up 1B1 HS%VAL Valid status 7B4 HS%DAY Day when up if currently down 37B9 HS%HR Hour 17B13 HS%MIN 5 minute interval 17B17 HS%RSN Reason 1B18 HS%SRV Host is server 1B19 HS%USR Host is user 1B20 HS%NCK Nickname 77B26 HS%STY System type mask 1B27 HS%NEW RAS, RAR, RAP, etc 1B29 HS%SLF Host is an alias 1B30 HS%NET Host is a network name 1B31 HS%GAT Host is a gateway | 1B32 HS%DNS Host name added from DNS data (as opposed to | SYSTEM:HOSTS.TXT) | 1B33 HS%INA DNS PTR RR data was used (implies | non-authoritative data) | 1B34 HS%AUT Authoritative answer from nameserver System Type Flags (HS%STY): Bits Symbol Meaning 1B26 .HS10X TENEX 2B26 .HSITS ITS 3B26 .HSDEC TOPS-10 4B26 .HSTIP TIP 5B26 .HSMTP MTIP 3-158
TOPS-20 MONITOR CALLS (GTHST%) 6B26 .HSELF ELF 7B26 .HSANT ANTS 10B26 .HSMLT MULTICS 11B26 .HST20 TOPS-20 12B26 .HSUNX UNIX 13B26 .HSNET Network 14B26 .HSFUZ Fuzzball 15B26 .HSVMS VMS 16B26 .HSTAC TAC 17B26 .HSDOS MSDOS GTHST% ERROR MNEMONICS: | | GTHSX1: No DNS name servers configured | GTHSX2: Unknown host number | GTHSX3: Unknown host name | GTHSX4: Format error in DNS message | GTHSX5: No interface to specified network | GTHSX6: Invalid class for function | GTHSX7: Server failed to find data (non-authoritative) | GTHSX8: Data not found in namespace (authoritative) | GTHSX9: String argument is too long | GTHX10: System host tables full | GTJIX1: Invalid index | ARGX02: Invalid function | ARGX04: Argument block too small | ARGX24: Invalid count Returns a JFN for the specified file. Accepts the specification for the file from a string in memory or from a file, but not from both. ACCEPTS IN AC1: GJ%SHT plus other flag bits in the left half, and default generation number in the right half AC2: Source designator from which to obtain the file specification. (See flag bit GJ%FNS for specific values.) RETURNS +1: Failure, error code in AC1 +2: Success, flags in the left half of AC1, and the JFN assigned in the right half of AC1. (This word is 3-159
TOPS-20 MONITOR CALLS (GTJFN Short Form) called an indexable file handle and is given to the GNJFN call as an argument.) Updated string pointer in AC2, if pertinent. All I/O errors can occur. These errors cause software interrupts or process terminations, and only a single return (+1) is given. The string can represent the complete specification for the file: dev:<directory>name.typ.gen;attributes For parse-only JFNs, the file specification is also allowed to be node::dev:<directory>name.typ.gen;attributes One or more fields of the specification can be defined by a logical name. (See Section 2.2.2.) If any fields are omitted from the specification, the system will provide the values shown below. device connected structure directory connected directory NOTE If neither device nor directory is specified, the default is DSK:, not the user's connected directory. If either device or directory is specified, the other is the user's connected structure/directory. name no default; this field must be specified type null generation highest existing number if the file is an input file. Next higher number if the file is an output file. protection protection of the next lower generation or for new files, protection as specified in the directory. account account specified when user logged in, unless changed by the CACCT or SACTF call. The JFNS monitor call can be used to obtain the file specification string associated with a given JFN. The flag bits that can be specified in AC1 are described as follows. 3-160
TOPS-20 MONITOR CALLS (GTJFN Short Form) GTJFN Flag Bits Bit Symbol Meaning 0 GJ%FOU The file given is to be assigned the next higher generation number. This bit indicates that a new version of a file is to be created, and is usually set if the file is for output use. 1 GJ%NEW The file specification given must not refer to an existing file (the file must be a new file). This bit has no effect on a parse-only JFN. 2 GJ%OLD The file specification given must refer to an existing file. This bit has no effect on a parse-only JFN. 3 GJ%MSG One of the appropriate messages is to be printed after the file specification is obtained, if the system is performing recognition on the file specification and the user ends his input by typing an ESC. !NEW FILE! !NEW GENERATION! !OLD GENERATION! !OK! if GJ%CFM (bit 4) is off !CONFIRM! if GJ%CFM (bit 4) is on 4 GJ%CFM Confirmation from the user will be required (if GJ%FNS is on) to verify that the file specification obtained is correct. (See below for the valid confirmation characters.) 5 GJ%TMP The file specified is to be a temporary file. 6 GJ%NS Only the first specification in a multiple logical name assignment is to be searched for the file (do not search beyond the first name in a multiple logical name assignment). 7 GJ%ACC The JFN specified is not to be accessed by inferior processes in this job. However, another process can access the file by acquiring a different JFN. To prevent the file from being accessed by other processes, the user's program should set OF%RTD(B29) in the OPENF call. 8 GJ%DEL Files marked as deleted are to be considered by the system when it is searching for a file to assign to the JFN. 3-161
TOPS-20 MONITOR CALLS (GTJFN Short Form) 9-10 GJ%JFN These bits are off in the short form of the GTJFN call. 11 GJ%IFG The file specification given is allowed to have one or more of its fields specified with a wildcard character (* or %). This bit is used to process a group of files and is generally used for input files. The monitor verifies that at least one value exists for each field that contains a wildcard and assigns the JFN to the first file in the group. The monitor also verifies that fields not containing wildcards represent a new or old file according to the setting of GJ%NEW and GJ%OLD. The GNJFN call can then be used to obtain the next file in the group. (See Section 2.2.3 for more information on wildcard characters in file specifications.) 12 GJ%OFG The JFN is to be associated with the given file specification string only and not to the actual file. The string may contain wildcard characters (* or %) in one or more of its fields. It is checked for correct punctuation between fields, but is not checked for the validity of any field. This bit allows a JFN to be associated with a file specification even if the file specification does not refer to an actual file. The JFN returned cannot be used to refer to an actual file (for example, cannot be used in an OPENF call) but can be used to obtain the original input string (via JFNS). The fields in this string can then be used in a GTJFN-long form call as program defaults. However, if the original string contains the temporary file attribute (;T), this attribute is not "remembered" and thus is not returned on the JFNS call even though the bit indicating temporary status (JS%TMP) is set. All other fields (including the protection and account fields) can be returned by JFNS. When both B11(GJ%IFG) and B12(GJ%OFG) are on, the GTJFN call parses the specification given, verifying the existence of each field. When a wildcard character appears in a field, the GTJFN call checks the remaining fields for correct punctuation and returns a JFN for the file specification string only. That is, once a wildcard character is seen, the action taken is identical to that taken when only B12(GJ%OFG) is set. If no wildcard character appears in the string, the action is the same as if both bits were off. 3-162
TOPS-20 MONITOR CALLS (GTJFN Short Form) 13 GJ%FLG Flags are to be returned in the left half of AC1 on a successful return. 14 GJ%PHY Job-wide logical names (those defined by the user) are to be ignored by the monitor for this call. 15 GJ%XTN This bit is off in the short form of the GTJFN call. 16 GJ%FNS The contents of AC2 are to be interpreted as follows: 1. If this bit is on, AC2 contains an input JFN in the left half and an output JFN in the right half. The input JFN is used to obtain the file specification to be associated with the JFN. The output JFN is used to indicate the destination for printing the names of any fields being recognized. To omit either JFN, specify .NULIO (377777). 2. If this bit is off, AC2 contains a byte pointer to an ASCIZ string in memory that specifies the file to be associated with the JFN. 17 GJ%SHT This bit must be on for the short form of the GTJFN call. 18-35 The generation number of the file (between 1 and 377777) or one of the following: 0(.GJDEF) to indicate that the next higher generation number of the file is to be used if GJ%FOU (bit 0) is on, or to indicate that the highest existing generation number of the file is to be used if GJ%FOU is off. (This value is usually used in this field.) -1(.GJNHG) to indicate that the next higher generation number of the file is to be used if no generation number is supplied. -2(.GJLEG) to indicate that the lowest existing generation number of the file is to be used. -3(.GJALL) to indicate that all generation numbers (*) of the file are to be 3-163
TOPS-20 MONITOR CALLS (GTJFN Short Form) used and that the JFN is to be assigned to the first file in the group. (Bit GJ%IFG must be set.) The GTJFN monitor call always reads the terminating character after the file specification string. (This character can be obtained by executing the BKJFN call followed by a BIN call.) The valid terminating characters are: line feed left parenthesis CTRL/L right parenthesis CTRL/Z plus sign carriage return comma exclamation point slash double quotation marks equals sign number sign at sign (@) ampersand space single quotation mark ESC All of these characters except for ESC are also confirmation characters (see bit GJ%CFM above) and are called confirming terminators. If a confirming terminator is typed after the string, a confirmation message will not be typed to the user nor will the user be required to confirm the string obtained, regardless of the setting of GJ%MSG and GJ%CFM. On a successful return, the following flags are returned in the left half of AC1 if flag bit GJ%IFG, GJ%OFG, or GJ%FLG was on in the call. Bits Returned on Successful GTJFN Call Bit Symbol Meaning 0 GJ%DEV The device field of the file specification contained wildcard characters. 1 GJ%UNT The unit field of the file specification contained wildcard characters. This bit will never be set because wildcard characters are not allowed in unit fields. 2 GJ%DIR The directory field of the file specification contained wildcard characters. 3 GJ%NAM The filename field of the file specification contained wildcard characters. 3-164
TOPS-20 MONITOR CALLS (GTJFN Short Form) 4 GJ%EXT The file type field of the file specification contained wildcard characters. 5 GJ%VER The generation number field of the file specification contained wildcard characters. 6 GJ%UHV The file used has the highest generation number because a generation number of 0 was given in the call. 7 GJ%NHV The file used has the next higher generation number because a generation number of 0 or -1 was given in the call. 8 GJ%ULV The file used has the lowest generation number because a generation number of -2 was given in the call. 9 GJ%PRO The protection field of the file specification was given. 10 GJ%ACT The account field of the file specification was given. 11 GJ%TFS The file specification is for a temporary file. 12 GJ%GND Files marked for deletion were not considered when assigning JFNs. This bit is set if GJ%DEL was not set in the call. 13 GJ%NOD The node name field of the file specification was given. 17 GJ%INV Invisible files were not considered when assigning JFNs. This bit is always on for the short form GTJFN. GTJFN ERROR MNEMONICS: GJFX1: Desired JFN invalid GJFX2: Desired JFN not available GJFX3: No JFNs available GJFX4: Invalid character in filename GJFX5: Field cannot be longer than 39 characters GJFX6: Device field not in a valid position GJFX7: Directory field not in a valid position GJFX8: Directory terminating delimiter is not preceded by a valid beginning delimiter 3-165
TOPS-20 MONITOR CALLS (GTJFN Short Form) GJFX9: More than one name field is not allowed GJFX10: Generation number is not numeric GJFX11: More than one generation number field is not allowed GJFX12: More than one account field is not allowed GJFX13: More than one protection field is not allowed GJFX14: Invalid protection GJFX15: Invalid confirmation character GJFX16: No such device GJFX17: No such directory name GJFX18: No such filename GJFX19: No such file type GJFX20: No such generation number GJFX21: File was expunged GJFX22: Insufficient system resources (Job Storage Block full) GJFX23: Exceeded maximum number of files per directory GJFX24: File not found GJFX27: File already exists (new file required) GJFX28: Device is not on-line GJFX30: Account is not numeric GJFX31: Invalid wildcard designator GJFX32: No files match this specification GJFX33: Filename was not specified GJFX34: Invalid character "?" in file specification GJFX35: Directory access privileges required GJFX36: Internal format of directory is incorrect GJFX37: Input deleted GJFX38: File not found because output-only device was specified GJFX39: Logical name loop detected GJFX40: Undefined attribute in file specification GJFX41: File name must not exceed 6 characters GJFX42: File type must not exceed 3 characters GJFX43: More than one ;T specification is not allowed GJFX44: Account string does not match GJFX45: Illegal to request multiple specifications for the same attribute GJFX46: Attribute value is required GJFX47: Attribute does not take a value GJFX48: GTJFN input buffer is empty GJFX49: Invalid attribute for this device GJFX51: Byte count too small GJFX55: Illegal to use node name IOX11: Quota exceeded IOX34: Disk full IOX35: Unable to allocate disk - structure damaged DESX9: Invalid operation for this device STRX09: Prior structure mount required STRX10: Structure is offline TCPXX1: No IP free space for TCB TCPXX2: Unable to decode local side TCP of specification TCPXX3: Unable to decode foreign side TCP of specification TCPXX4: Generation found in TCP specification 3-166
TOPS-20 MONITOR CALLS (GTJFN Short Form) TCPXX5: TCP specification attribute not known to TCP TCPXX6: Unable to decode CONNECTION attribute in TCP specification TCPXX7: Unable to decode FOREIGN-HOST attribute in TCP specification TCPXX8: Unable to decode LOCAL-HOST attribute in TCP specification TCPXX9: Unable to decode PERSIST attribute in TCP specification TCPX10: Unable to decode TIMEOUT attribute in TCP specification TCPX11: Unable to decode TYPE-OF-SERVICE attribute in TCP specification TCPX12: Unable to decode SECURITY attribute in TCP specification TCPX13: Unable to decode COMPARTMENTS attribute in TCP specification TCPX14: unable to decode HANDLING-RESTRICTIONS attribute in TCP specification TCPX15: Unable to decode TRANSMISSION-CONTROL attribute in TCP specification TCPX16: TCP not initialized and available Returns a JFN for the specified file. Accepts the specification for the file from both a string in memory and from a file. If both are given as arguments, the string is used first, and then the file is used if more fields are needed to complete the specification. This form also allows the program to specify nonstandard values to be used for omitted fields and to request the assignment of a specific JFN. ACCEPTS IN AC1: 0 in the left half, and address of the beginning of the argument table in the caller's address space in the right half AC2: Byte pointer to ASCIZ file specification string in the caller's address space, or 0 if none RETURNS +1: Failure, error code in AC1 +2: Success, flags in the left half of AC1, and the JFN assigned in the right half of AC1. (This word is called an indexable file handle and is given to the GNJFN call as an argument.) Updated string pointer in AC2, if pertinent. All I/O errors can occur. These errors cause software interrupts or process terminations, and only a single return (+1) is given. The format of the argument table specified by the right half of AC1 is described below. Words 0 through 10 (.GJGEN-.GJJFN) must be supplied 3-167
TOPS-20 MONITOR CALLS (GTJFN Long Form) in the long form of the GTJFN call. The remaining words are optional, and if they are supplied, B15(GJ%XTN) of word .GJGEN must be on. Word Symbol Meaning 0 .GJGEN Flag bits in the left half and generation number in the right half. (See below.) 1 .GJSRC Input JFN in the left half and output JFN in the right half. To omit either JFN, specify .NULIO (377777). 2 .GJDEV Byte pointer to ASCIZ string that specifies the default device to be used when none is given. If this word is 0, the user's connected structure will be used. 3 .GJDIR Byte pointer to ASCIZ string that specifies the default directory to be used when none is given. The string should not include brackets around the name. If this word is 0, the user's connected directory will be used. 4 .GJNAM Byte pointer to ASCIZ string that specifies the default filename to be used when none is given. If this word is 0, either the string or the input JFN must supply the filename. 5 .GJEXT Byte pointer to ASCIZ string that specifies the default file type to be used when none is given. If this word is 0, the null file type will be used. 6 .GJPRO Byte pointer to ASCIZ string that specifies the default protection to be used when none is given. If this word is 0, the default protection as specified in the directory or the protection of the next lower generation will be used. 7 .GJACT Byte pointer to ASCIZ string that specifies the default account to be used when none is given. If this word is 0, the user's LOGIN account (unless changed) will be used. 10 .GJJFN The JFN to associate with the file specification if flag GJ%JFN is set in word 0 (.GJGEN) of the argument block. 3-168
TOPS-20 MONITOR CALLS (GTJFN Long Form) 11 .GJF2 Extended argument block if B15(GJ%XTN) is on in the left half of .GJGEN. This word contains a second group of flags in the left half and the count of the number of words following this word in the argument block in the right half. The flags in the left half specify additional control over the GTJFN process. The following flags are defined: B0(G1%RND) Return to the caller if the filename buffer becomes empty, and the user attempts to delete a character. This can occur if the user, when giving the filename, types a CTRL/U or types a DELETE or CTRL/W and there are no more characters in the buffer. B2(G1%NLN) Filenames cannot be longer than 6 characters and file types cannot be longer than 3 characters. In addition, the generation number, temporary status, protection, and account fields cannot be specified in the string or the input data. B3(G1%RCM) Return the confirmation message to the caller by placing it in the destination buffer. B4(G1%RIE) Return to the caller if the input buffer becomes empty, and the user attempts to delete a character. B5(G1%IIN) Files marked as invisible are to be considered by the system when it is searching for a file to assign to the JFN. B6(G1%SLN) Prohibit the expansion of logical names. If, for example, user DBELL defines logical name ME: to be PSA:<DBELL> and does a GTJFN for file ME:FOO.BAR, the file specification stored in the JFN block will be: PSA:<DBELL>FOO.BAR In this case, the logical name ME: has been expanded to PSA:<DBELL>. However, if bit G1%SLN is set, and a GTJFN performed on file FOO.BAR, the file 3-169
TOPS-20 MONITOR CALLS (GTJFN Long Form) specification stored in the JFN block is: ME:FOO.BAR In this case, the logical name has not been expanded. B7(G1%LOC) The node name cannot be specified. 12 .GJCPP Byte pointer to string where GTJFN is to store the exact copy of the user's typescript (destination string pointer). This string will contain logical names, if they were typed by the user, and will not contain the default fields unless they were generated through recognition. This string allows the caller to obtain a true copy of the user's typescript. 13 .GJCPC Number of bytes available in the destination string to which .GTCPP (word 12) points. If a pointer has been specified but this word is 0, the monitor assumes the string contains 130 bytes. 14 .GJRTY Byte pointer to the text to be output when the user types a CTRL/R (pointer to the CTRL/R buffer). This pointer cannot be equal to the pointer given in AC2. (See the TEXTI call for the definition of CTRL/R text.) 15 .GJBFP Byte pointer to the beginning of the destination buffer. (obsolete) 16 .GJATR Pointer to the file specification attribute block. The attribute block has the following format: Word Contents 0 Count of words in attribute block (including this word). 1 Byte pointer to argument string. 1+n Byte pointer to argument string. The ASCIZ argument strings are specified as: keyword:attribute The possible keywords and attribute values are as follows: 3-170
TOPS-20 MONITOR CALLS (GTJFN Long Form) Keyword Attribute Value A: Installation-defined account string BDATA: DECnet binary optional data BLOCK-LENGTH: Magnetic-tape block length (in bytes) BPASSWORD: DECnet binary password CHARGE: DECnet account string COMPARTMENTS:n Connection compartmentalization: 16-bit, defaults to 0 (TCP:) CONNECTION:ACTIVE CONNECTION:PASSIVE Local to foreign connection attribute; defaults to ACTIVE (TCP:) DATA: DECnet optional data EXPIRATION-DATE: Magnetic-tape expiration date FOREIGN-HOST:a.b.c.d Alternative specification for 32-bit foreign host address. "a", "b", "c", and "d" are decimal octets forming the host number. The "." is a required delimiter. A field of zero must be represented as zero. (TCP:) FORMAT: Magnetic-tape record format. The argument may be one of the following: Format Meaning F Fixed-length records D Variable-length records S Spanned U Binary files with 36-bits per word HANDLING-RESTRICTIONS:n Connection handling-restrictions option: 16-bit (TCP:) LOCAL-HOST:a.b.c.d Alternate specification for 32-bit local host number. See FOREIGN-HOST:a.b.c.d (TCP:) OFF-LINE NONE - display-only keyword. The attribute is set by setting bit FB%OFF in word .FBCTL of the FDB block. P: Octal file protection value 3-171
TOPS-20 MONITOR CALLS (GTJFN Long Form) PASSWORD: DECnet password string PERSIST:n PERSIST:(n,m) Connection opening attempt parameters: 0 to keep trying until successful, n to try for n seconds (default 30), m to try every m seconds (default 5). If no persistence is given, 30 seconds is used. (TCP:) POSITION: File sequence number to position magnetic-tape to. RECORD-LENGTH: Magnetic-tape record length (in bytes) SECURITY:n Connection security field; 16-bit, system default if omitted (TCP:) T NONE - display-only keyword. The attribute is set by setting bit GJ%TMP in word .GJGEN of the GTJFN block. TIMEOUT:n Amount of time allowed to pass while waiting for a message from a foreign system. Default is 30 seconds; no timeout if n=0. (TCP:) TRANSMISSION-CONTROL:n Connection transmission-control option; n is a 24-bit number used by IP (TCP:) TYPE-OF-SERVICE:n Connection type-of-service indicating tradeoffs made in providing data transmission; n is the low-order 8 bits: default is 0; NET WIZARD, WHEEL or OPERATOR required for other than 0. (TCP:) USERID: DECnet user ID string 17 .GJNOD Default node The flag bits accepted in the left half of .GJGEN (word 0) of the argument block are basically the same as those accepted in the short form of the GTJFN call. The entire set of bits is listed below. (See GTJFN - SHORT FORM for more detailed explanations of these bits.) The flags that are different in the two forms are GJ%JFN, GJ%XTN, GJ%FNS, and GJ%SHT. Bit Symbol Meaning 0 GJ%FOU Create a new version of the file. 3-172
TOPS-20 MONITOR CALLS (GTJFN Long Form) 1 GJ%NEW The file must not exist. 2 GJ%OLD The file must exist. 3 GJ%MSG Type a message if the user presses ESC to terminate input. 4 GJ%CFM Confirmation from the user is required. 5 GJ%TMP The file is temporary. 6 GJ%NS Search only the first specification in a multiple logical name definition. 7 GJ%ACC The JFN cannot be accessed by inferior processes. 8 GJ%DEL Ignore the file deleted bit in the FDB. 9-10 GJ%JFN Associate the JFN supplied in .GJJFN (word 10) of the argument block with the file specification. The value of this field is interpreted as follows: Value Meaning 0(.GJDNU) Ignore the JFN supplied. 2(.GJERR) Attempt to assign the JFN supplied and return an error if it is not available. 3(.GJALT) Attempt to assign the JFN supplied and, if it is not available, assign an alternate. 11 GJ%IFG The file specification can contain wildcard characters. 12 GJ%OFG Associate the JFN with the file specification string and not the file itself. This is termed a "parse-only JFN", and allows the syntax of a file name to be checked regardless of whether or not a file of that name actually exists. 13 GJ%FLG Return flags in AC1 on successful completion of the call. 14 GJ%PHY The physical device is to be used. 15 GJ%XTN The argument block contains more than 10 (octal) words. This bit must be set for the long form. 16 GJ%FNS This bit is ignored for the long form of the GTJFN call. 3-173
TOPS-20 MONITOR CALLS (GTJFN Long Form) 17 GJ%SHT This bit must be off for the long form of the GTJFN call. The generation number given in the right half of .GJGEN (word 0) of the argument block can be one of the following: 0(.GJDEF) to indicate that the next higher generation number is to be used if GJ%FOU is on, or to indicate that the highest existing generation number is to be used if GJ%FOU is off. -1(.GJNHG) to indicate that the next higher generation number is to be used if no generation number is supplied. -2(.GJLEG) to indicate that the lowest existing generation number is to be used if no generation number is supplied. -3(.GJALL) to indicate that all generation numbers are to be used and that the JFN is to be assigned to the first file in the group, if no generation number is supplied. (Bit GJ%IFG must be on.) 1-377777 to indicate that the specified number is to be used as the generation if no generation number is supplied. On a successful return, the following flags are returned in the left half of AC1 if flag bit GJ%IFG, GJ%OFG, or GJ%FLG was on in the call. Bits Returned on Successful GTJFN Call Bit Symbol Meaning 0 GJ%DEV The device field of the file specification contained wildcard characters. 1 GJ%UNT The unit field of the file specification contained wildcard characters. This bit will never be set because wildcard characters are not allowed in unit fields. 2 GJ%DIR The directory field of the file specification contained wildcard characters. 3 GJ%NAM The filename field of the file specification contained wildcard characters. 4 GJ%EXT The file type field of the file specification contained wildcard characters. 5 GJ%VER The generation number field of the file specification contained wildcard characters. 3-174
TOPS-20 MONITOR CALLS (GTJFN Long Form) 6 GJ%UHV The file used has the highest generation number because a generation number of 0 was given in the call. 7 GJ%NHV The file used has the next higher generation number because a generation number of 0 or -1 was given in the call. 8 GJ%ULV The file used has the lowest generation number because a generation number of -2 was given in the call. 9 GJ%PRO Protection field of file specification given 10 GJ%ACT The account field of the file specification was given. 11 GJ%TFS The file specification is for a temporary file. 12 GJ%GND Files marked for deletion were not considered when assigning JFNs. This bit is set if GJ%DEL was not set in the call. 13 GJ%NOD The node name field of the file specification was given. 17 GJ%GIV Invisible files were not considerd when assigning JFNs. This bit is set by the monitor if G1%IIN was not set by the user in the GTJFN call. See the short form of the GTJFN call for the possible error mnemonics. Returns the paging trap information for the specified process. ACCEPTS IN AC1: Process handle RETURNS +1: Always, with AC1 Containing number of pager traps (the number of times a trap has occurred to the pager) for designated process since the process was started 3-175
TOPS-20 MONITOR CALLS (GTRPI) AC2 Containing number of page faults (the number of times a trap has resulted in a page being swapped in) for designated process since the process was started AC3 Containing time spent (in milliseconds) in page routines by designated process since the process was started The number of pager traps will be greater than or equal to the number of page faults. Generates an illegal instruction interrupt on error conditions below. GTRPI ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle Returns the trap words. This monitor call allows a program to retrieve information about a previous read, write, or execute trap. ACCEPTS IN AC1: Process handle RETURNS +1: Always, with trap status word from last memory trap in AC1, and last monitor call that had an error in AC2. The following bits are defined in the status word: B0(PF%USR) page failure-user mode reference B5(PF%WRT) page failure-write reference B14(TSW%RD) trap status-read (always on) B15(TSW%WT) trap status-write (same setting as B5) B16(TSW%EX) trap status-execute (always on) B17(TSW%MN) trap status-monitor mode reference (complement of B0) B18-35 address of reference that caused the trap This information allows a program to determine the exact cause of a memory trap and/or the effective virtual address that caused the trap. This information is sufficient to enable the program to continue, if desired, when the cause of the trap has been removed. The contents of AC1 is 0 if there have been no memory traps. 3-176
TOPS-20 MONITOR CALLS (GTRPW) Generates an illegal instruction interrupt on error conditions below. GTRPW ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle Returns the status of a file associated with a JFN. ACCEPTS IN AC1: JFN in the right half RETURNS +1: Always, with status in AC2. If JFN is illegal in any way, B10 of AC2 will be 0. JFN STATUS WORD B0(GS%OPN) file is open B1(GS%RDF) if file is open (if bit 0 is on), it is open for read access B2(GS%WRF) if file is open, it is open for write access B3(GS%XCF) if file is open, it is open for execute access B4(GS%RND) if file is open, it is open for non-append access B7(GS%LNG) file is longer than 512 pages B8(GS%EOF) last read was past end of file B9(GS%ERR) file may be in error (a device or data error occurred) B10(GS%NAM) file specification is associated with this JFN B11(GS%AST) the JFN is parse-only (GJ%OFG was set in GTJFN call) B12(GS%ASG) JFN is currently being assigned B13(GS%HLT) I/O errors are considered terminating conditions B17 This is a restricted JFN (GJ%ACC was set in GJTFN call). Only the process that received this JFN may use it. Other processes may get another JFN for this file. B18(GS%PLN) if set, any line numbers present in the file are passed to the program during input (SIN, BIN, etc). If zero, line numbers are stripped from the data passed to the program. B32-35 data mode of the file. See Chapter 2. (GS%MOD) 3-177
TOPS-20 MONITOR CALLS (GTSTS) 0 .GSNRM normal data mode 1 .GSSMB small buffer mode 10 .GSIMG image mode 17 .GSDMP dump mode If B0(GS%OPN) is not set on return, the file is not opened, and the settings of bits 1 through 4 are indeterminate. The STSTS call can be used to set the status of a particular file. Returns the terminal type number for the specified terminal line. (See Section 2.4.9.4 for the terminal type numbers.) ACCEPTS IN AC1: Terminal designator RETURNS +1: Always, with terminal type number in AC2 and buffer allocation numbers (# of input buffers to be allocated in left half, and # of output buffers to be allocated in right half) in AC3. AC1 is unchanged. The STTYP monitor call can be used to set the terminal type number for a specified line. Generates an illegal instruction interrupt on error conditions below. GTTYP ERROR MNEMONICS: DESX1: Invalid source/destination designator TTYX01: Line is not active Halts the current process and any inferior processes of the current process. Sets the process's PC to the next after the call and saves it in the Process Storage Block (PSB) in case the process is continued. The user can continue the process by typing the CONTINUE command, which causes the process to start at the next instruction. 3-178
TOPS-20 MONITOR CALLS (HALTF) Sets bits 1-17(RF%STS) in the status word for this process to 2(.RFVPT). See the RFSTS monitor call for the format of the status word. If the top level process executes a HALTF call and does not have WHEEL or OPERATOR capability enabled, the job is logged out. If the top level process executes a HALTF call and does have WHEEL or OPERATOR capability enabled, control passes to mini-exec level. Halts one or more inferior processes. (See the HALTF monitor call description to halt the current process.) ACCEPTS IN AC1: Process handle (inferior processes only) RETURNS +1: Always Sets bits 1-17(RF%STS) in the status word(s) for addressed process(s) to 2(.RFVPT). See the RFSTS monitor call for the format of the status word. Generates an illegal instruction interrupt on error conditions below. HFORK ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process HFRHX1: Illegal to halt self with HFORK Returns the value of one of the high precision system clocks. Although the main time base from interrupts generated by the internal system clock is in units of 1 millisecond, the clock provides a time base in units of 10 microseconds. The HPTIM monitor call provides access to the variables kept in these high precision units. ACCEPTS IN AC1: Number of the clock to read (see below) 3-179
TOPS-20 MONITOR CALLS (HPTIM) RETURNS +1: Failure, error code in AC1 +2: Success, with AC1 containing the value of the specified clock The numbers for currently-defined clocks are: 0 .HPELP Elapsed time since system startup. (See the TIME call for obtaining the time in milliseconds.) 1 .HPRNT CPU runtime for this process. (See the RUNTM call for obtaining the time in milliseconds.) HPTIM ERROR MNEMONICS: HPTX1: Undefined clock number Initiates an orderly shutdown of the timesharing operation of the system. This call causes periodic notices of the impending shutdown to be issued to all terminals. It also causes any jobs still logged in at the designated shutdown to be logged out. RESTRICTIONS: Requires WHEEL, OPERATOR, or MAINTENANCE capability enabled. ACCEPTS IN AC1: Shutdown time with the date and time in the internal format. (See Section 2.9.2.) AC2: Date and time in internal format when system operation will resume (or 0 if unknown). Used for advisory messages only. RETURNS +1: Failure, error code in AC1 +2: Success, shutdown procedure initiated The shutdown notice is issued immediately to all terminals if the shutdown time is within two hours. The notice is also sent two hours, one hour, 30 minutes, 10 minutes, 5 minutes, and one minute before the shutdown. The time when the system is expected to be placed back into operation is not used directly by the monitor. It is entered into a GETAB table where it may be examined with the GETAB monitor call. 3-180
TOPS-20 MONITOR CALLS (HSYS) HSYS ERROR MNEMONICS: CAPX2: WHEEL, OPERATOR, or MAINTENANCE capability required TIMEX1: Time cannot be greater than 24 hours TIMEX2: Downtime cannot be more than 7 days in the future Converts separate numbers for the local year, month, day, and time into the internal date and time format. (See Section 2.9.2 for more information on the internal format.) ACCEPTS IN AC2: Year in the left half, and numerical month (0=January) in the right half AC3: Day of the month (0=first day) in the left half, and 0 in the right half AC4: B0(IC%DSA) Apply daylight savings according to the setting of B1(IC%ADS). If B0 is off, daylight savings is applied only if appropriate for the date. B1(IC%ADS) Apply daylight savings if B0(IC%DSA) is on. B2(IC%UTZ) Use time zone in B12-17. If this bit is off, the local time zone is used. B3(IC%JUD) Interpret the number in the right half of AC2 as being in Julian day format (Jan 1 is day 1). B12-17 Time zone to use if B2(IC%UTZ) is on. (IC%TMZ) (See Section 2.9.2 for the time zones.) B18-35 Local time in seconds since midnight. (IC%TIM) RETURNS +1: Failure, error code in AC1 +2: Success, AC2 contains the internal date and time, and AC3 contains B0 and B2 On for compatibility with the ODCNV call 3-181
TOPS-20 MONITOR CALLS (IDCNV) B1(IC%ADS) On if daylight savings was applied B12-17 Time zone used (IC%TMZ) IDCNV ERROR MNEMONICS: DATEX1: Year out of range DATEX2: Month is not less than 12 DATEX3: Day of month too large DATEX5: Date out of range DATEX7: Julian day is out of range TIMEX1: Time cannot be greater than 24 hours ZONEX1: Time zone out of range Inputs the date and time and converts them to the internal date and time format. (See Section 2.9.2.) The IDTIM monitor call does not permit either the date or the time to be entered separately and does not perform conversions for time zones other than the local one (unless the time zone is specified in the input string). See the IDTNC and IDCNV monitor calls descriptions for these functions. ACCEPTS IN AC1: Source designator AC2: Format option flags (see below), 0 is the normal case RETURNS +1: Failure, error code in AC2, updated string pointer in AC1, if pertinent +2: Success, updated string pointer, if pertinent, in AC1, and the internal format date and time in AC2 The format option flags in AC2 specify the interpretation to be used when a date or time specification is ambiguous. IDTIM Option Flags B1(IT%NNM) Do not allow the month to be numeric and ignore B2-3. B2(IT%SNM) Interpret the second number in the date as the month (for example, 6/2/76 is interpreted as Feb. 6, 1976). 3-182
TOPS-20 MONITOR CALLS (IDTIM) If this bit is off, the first number is interpreted as the month (for example, 2/6/76 is interpreted as Feb. 6, 1976). B3(IT%ERR) Return an error if the order of the day and month does not agree with the setting of B2(IT%SNM) even though the date can be successfully interpreted. If this bit is off, a date which can be interpreted by assuming the day and month are in the opposite order than that specified by the setting of B2(IT%SNM) will be considered valid. For example, if B2-3 are off, 30/5/76 will be considered as a valid date. B7(IT%NIS) Seconds cannot be included in a time specification. B8(IT%AIS) Seconds must be included in a time specification and must be preceded by a colon. If B7-8 are both off, seconds are optional in a time specification. If specified, seconds must be preceded by a colon. B9(IT%NAC) Colon cannot be used to separate hours and minutes. B10(IT%AAC) Colon must be used to separate hours and minutes. If B9-10 are both off, a colon is optional between hours and minutes. B11(IT%AMS) When B7-10 are off, always interpret a time specification containing one colon as hhmm:ss. B12(IT%AHM) When B7-10 are off, always interpret a time specification containing one colon as hh:mm and return an error if the first field is too large. This differs from B7(IT%NIS) in that seconds can be included if preceded by a second colon. If B7-12 are all off, a time specification containing one colon is interpreted as hh:mm if the first field is small enough. Otherwise it is interpreted as hhmm:ss. B14(IT%N24) Do not allow the time to be specified in 24-hour format (for example, 1520 for 3:20 in the afternoon) and make AM or PM specification mandatory. B15(IT%NTM) Do not allow the time specification to include AM, PM, NOON, or MIDNIGHT. B16(IT%NTZ) Do not allow a time zone to be specified. 3-183
TOPS-20 MONITOR CALLS (IDTIM) If AC2 is 0, the IDTIM call accepts the date and time in month/day/year or day/month/year format. Hyphens (-), slashes (/), and spaces ( ) are valid delimiters. In cases where pure numeric representation is used for the date (1/9/1967, for example), IDTIM checks the first number for being in the range: 0<n<13. If the test is successful, the first number is interpreted as the month. If the test is unsuccessful, the test is made on the second number and if successful, that number is interpreted as the month. Otherwise an error is generated. For example: 1. 5/6/1976 is interpreted as May 6, 1976 2. 6/5/1976 is interpreted as June 5, 1976 3. 13/5/1976 is interpreted as May 13, 1976 4. 13/13/1976 generates an error IDTIM ERROR MNEMONICS: DILFX1: Invalid date format TILFX1: Invalid time format DATEX1: Year out of range DATEX3: Day of month too large DATEX5: Date out of range All I/O errors are also possible. These errors cause software interrupts or process terminations as described under the BIN call. Inputs the date and/or the time and converts it into separate numbers for the local year, month, day, or time. The IDTNC call allows the date or time to be entered separately, which is not possible with the IDTIM JSYS because neither one can be converted to the internal format without converting the other. (See Section 2.9.2.) ACCEPTS IN AC1: Source designator AC2: Format option flags In addition to the flags described in the IDTIM call, the flags below can also be specified: B0(IT%NDA) Do not input the date and ignore B1-3. If IT%NDA is off, the date must be input. 3-184
TOPS-20 MONITOR CALLS (IDTNC) B6(IT%NTI) Do not input the time and ignore B7-16. If IT%NTI is off, the time must be input. RETURNS +1: Failure, error code in AC2, updated string pointer, if pertinent, in AC1 +2: Success, updated string pointer, if pertinent, in AC1 If the date was input, AC2 contains the year in the left half, and the month (0=January) in the right half. AC3 contains the day of the month (0=first day) in the left half, and the day of the week (0=Monday) in the right half. If the time was input, AC4 contains B0(IC%DSA) On if IT%NTI was set in AC2, or if IT%NDA was set in AC2 and a time zone was input (for compatibility with the ODCNV call). B1(IC%ADS) On if a daylight savings time zone was input, or if IT%NTI was set in AC2. B2(IC%UTZ) On if IT%NTI was set in AC2, or if IT%NDA was set in AC2 and a time zone was input (for compatibility with the ODCNV call). B3(IC%JUD) On if a number in Julian day format was input. B12-17 The time zone if one was input, or (IC%TMZ) The local time zone if none was input. (See Section 2.9.2 for the time zones.) B18-35 Time as seconds since midnight. (IC%TIM) A -1 returned in both AC2 and AC3 means the system date and time have not been set. IDTNC ERROR MNEMONICS: DILFX1: Invalid date format TILFX1: Invalid time format All I/O errors are also possible. These errors cause software interrupts or process terminations as described under the BIN call description. 3-185
TOPS-20 MONITOR CALLS (IDTNC) The IDTNC call does not detect certain errors in date input, such as day 31 of a 30-day month. These errors are detected by the IDCNV call. Initiates software interrupts on the specified channels in a process. (See Section 2.6.) ACCEPTS IN AC1: Process handle AC2: 36-bit word Bit n on means initiate a software interrupt on channel n. RETURNS +1: Always Generates an illegal instruction interrupt on error conditions below. IIC ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle FRKHX8: Illegal to manipulate an execute-only process Allows the user to obtain specific information on either the current system or any other system within a cluster. RESTRICTIONS: Requires WHEEL or OPERATOR capabilities enabled. ACCEPTS IN AC1: Address of argument block RETURNS +1: Always, with AC1: Address of argument block; or 1B0 - IN%RER to indicate a remote error, in which case, right half is remote error code. 3-186
TOPS-20 MONITOR CALLS (INFO%) CAUTION Upon successful return from INFO%, ACs 1-4 are not modified. This is due to the fact that INFO% preserves these ACs because it may perform internal monitor calls with the user's AC block. It is suggested that you do not attempt to have information returned by INFO% in ACs 1-4. The format of the argument block is as follows: NOTE The length of the argument block includes the .INFUN word. Argument block must be at least .INMIN words (.INMIN=3) long and no more than .INMAX(6). Left Half Right Half +----------------------+----------------------+ .INFUN | Function code | Length of arg. block | +----------------------+----------------------+ .INCID | CI node number (-1 for the local system) | +---------------------------------------------+ .INAC1 | INFO% Functions | +---------------------------------------------+ .INAC2 | INFO% Functions | +---------------------------------------------+ .INAC3 | INFO% Functions | +---------------------------------------------+ .INAC4 | See individual functions | +---------------------------------------------+ Code Symbol Meaning 0 .INCIN This function returns a maximum of 16 36-bit words. The CI node numbers of the systems responding to requests for remote information are returned in each word. Argument Block: .INAC1 Address of block to return CI node numbers. .INCIN Returns an argument block as the following diagram illustrates. 3-187
TOPS-20 MONITOR CALLS (INFO%) +-------------------------------------------+ 0 | Length of block returned | +-------------------------------------------+ 1 | CI node number of first (local) system | +-------------------------------------------+ 2 | CI node number of second system | +-------------------------------------------+ 3 | CI node number of third system | +-------------------------------------------+ \ \ n | CI node number of last system | +-------------------------------------------+ 1 .INCFG This function causes the CNFIG% monitor call to be executed on the specified system. See the CNFIG% monitor call for more information. Argument block: .INAC1 This word contains a function code for the CNFIG% on the specified system. (See CNFIG% - AC1) .INAC2 This contains the address of the argument block for CNFIG%. (See CNFIG% - AC2) 2 .INDST This function causes a DIRST% monitor call to be performed on the specified system. (See DIRST% for more information). Argument block: .INAC1 Destination designator .INAC2 User or directory number 3 .INGTB This function allows a GETAB% monitor call to be performed on the specified system. See GETAB% for more information. This function returns the 36-bit word from the table specified in .INAC1 in .INAC2 on success. Argument block: .INAC1 Index into table in left half, and table number in right half. (See Section 2.3.2 in the Monitor Calls Reference Manual.) See GETAB% for more information. 4 .INGJI This function performs a GETJI% monitor call. 3-188
TOPS-20 MONITOR CALLS (INFO%) Argument block: .INAC1 Job number or .TTDES+TTY number (-1 does not apply to this function) .INAC2 -<length of destination block>,,address of block. See GETJI% for a description of the block. .INAC3 Offset of first entry desired from job information table 5 .INGTY This function works like the GTTYP% monitor call and returns the information in the same manner that GTTYP% does. See the GTTYP% monitor call for more information. Argument Block: .INAC1 Terminal designator 6 .ININL This function does a INLNM% using only the .INSLY function. Argument Block: .INAC1 0 in the left half, and index into the table of logical names in the right half. (See AC1 for INLNM%.) .INAC2 Byte pointer to the string for storing the logical name. (See AC2 for INLNM%.) 7 .INLNS This function enables a LNMST% to be performed using only the .LNSSY function. Argument Block: .INAC1 .LNSSY .INAC2 Pointer to the logical name. The logical name must contain a colon. (See AC2 for LNMST%.) .INAC3 Pointer to the string where the original logical name definition is to be written. The name returned includes a terminating colon. (See AC3 for LNMST%.) 10 .INMSR Performs MSTR% functions as listed. Some functions require WHEEL or OPERATOR capability enabled. 3-189
TOPS-20 MONITOR CALLS (INFO%) Argument Block: .INAC1 Length of argument block in the left half and function code in right half (see below). .INAC2 Address of argument block (see MSTR% for format). Only the following MSTR% functions are valid for .INMSR (see MSTR% for more information): Function Symbol Privileged Meaning 0 .MSRNU Yes Return status of next disk unit 1 .MSRUS Yes Return status of given disk unit 4 .MSGSS No Return status of given structure 11 .MSGSU No Return the job numbers of the users on the given structure 11 .INMTO Performs MTOPR% functions as listed below. Argument Block: .INAC1 TTY device designator .INAC2 Function (see below) .INAC3 Address of argument block (if necessary) Only the following MTOPR% functions are available (see MTOPR% for more information): .MOPIH .MORSP .MORLW .MORLL .MORNT .MORBM .MORFW .MORXO .MORLC .MORLM .MOPCR .MORTF .MORTC .MOCTM 12 .INMUT Performs a MUTIL% monitor call on the given system. See MUTIL% for more information. Argument Block: .INAC1 Length of argument block .INAC2 Address of argument block 3-190
TOPS-20 MONITOR CALLS (INFO%) Only the following functions of the MUTIL% monitor call can be executed: .MUGTI .MUFOJ .MUFSQ .MUFFP .MUFPQ .MURSP .MUMPS 13 .INRCR Performs an RCUSR% on the specified system. This function returns the same information as RCUSR%. See RCUSR% for more information. Argument Block: .INAC1 Flag bits in the left half .INAC2 Byte pointer of ASCII string to be translated .INAC3 36-bit user number (given when stepping to the next user name in a group) 14 .INSKD Performs a SKED% on the specified system. See SKED% for more information. Argument Block: .INAC1 Function Code .INAC2 Address of argument block Only the following functions can be done. See SKED% for more information about them: .SKRBC .SKRCS .SKRJP .SKBCR .SKRCV 15 .INSNP Performs only 2 SNOOP% functions on the specified system. These functions are .SNPSY and .SNPAD. See SNOOP% for more information. Requires WHEEL, OPERATOR or MAINTENANCE capability enabled. Argument Block: .INAC1 Function code (.SNPSY or .SNPAD) .INAC2 Function-specific argument .INAC3 Function-specific argument 16 .INSGT Returns the table number, table length, and word 0 of the specified system table for the specified system. (See Section 2.3.2 of the Monitor Calls Reference Manual for the names of the system tables.) See SYSGT% for more information. 3-191
TOPS-20 MONITOR CALLS (INFO%) Argument Block: .INAC1 SIXBIT table name 17 .INTMN Performs a TMON%. See the TMON% monitor call for more information. Argument Block: .INAC1 Function code (see TMON%) 20 .INXPK Performs an XPEEK%. This function requires WHEEL or OPERATOR capability enabled. See XPEEK% for more information. Note that this function cannot return more than one page (512 36-bit words) of data. Argument Block: .INAC1 Address of argument block 21 .INDVC Performs a DVCHR% monitor call. See the DVCHR% monitor call for more information. Argument Block: .INAC1 Device designator 22 .INNTF Performs a NTINF% monitor call on the specified system. See NTINF% for more information. Argument Block: .INAC1 Address of argument block. Note that word .NWLIN of the argument block cannot contain -1. 23 .INSTV Performs a STDEV% monitor call. See STDEV% for more information. Argument Block: .INAC1 Byte pointer to the string to be translated. 24 .INDVT Performs a DEVST% monitor call. See DEVST% for more information. Argument Block: .INAC1 Destination designator .INAC2 Device designator 3-192
TOPS-20 MONITOR CALLS (INFO%) 25 .INSYS Returns SYSTAT string information. The argument block held in .INAC1 contains the byte pointers where the monitor is to return the information. Argument Block: .INAC1 Address of argument block to return information (see format of argument block below) .INAC2 Job number or .TTDES+TTY number +--------------------------------------------+ 0 .SYUSR | Byte pointer to store username | +--------------------------------------------+ 1 .SYDIR | Byte pointer to store connected directory | +--------------------------------------------+ 2 .SYPRG | SIXBIT program name | +--------------------------------------------+ 3 .SYORG | Byte pointer to job origin | +--------------------------------------------+ 4 .SYCJB | Controlling job number | +--------------------------------------------+ 5 .SYTTY | Controlling terminal number | +--------------------------------------------+ 6 .SYJOB | Job number | +--------------------------------------------+ 7 .SYSTT | 0 if state is TI, 1 if state is RUN | +--------------------------------------------+ 10 .SYTIM | Job runtime | +--------------------------------------------+ 11 .SYLIM | Job runtime limit | +--------------------------------------------+ 12 .SYCLS | Job Class (class scheduling) | +--------------------------------------------+ 13 .SYSHR | Job Share (class scheduling) | +--------------------------------------------+ 14 .SYUSE | Job Use (class scheduling) | | +--------------------------------------------+ | 15 .SYJCT | Job's connect time | | +--------------------------------------------+ 26 .INJOB This function returns a block of data containing the job numbers and terminal numbers for the given user. Argument Block: .INAC1 Byte pointer to username .INAC2 Address of argument block (see below) 3-193
TOPS-20 MONITOR CALLS (INFO%) This function returns information in the argument block specified in .INAC2 as follows: +-------------------------------------+ 0 .JOLEN | Count of words in this block | +-------------------------------------+ 1 | Job number | Terminal number | +-------------------------------------+ 2 | Job number | Terminal number | /-------------------------------------/ / / / / +-------------------------------------+ n | Job number | Terminal number | +-------------------------------------+ This function returns a slot in the argument block for each job that the specified user is logged into on the requested system. The count specified in the .JOLEN word includes the .JOLEN word. If the user is not logged into the specified node, this function returns an INFX07 error. 27 .INRCD Performs an RCDIR% JSYS call on the specified system. This function returns the same information as the RCDIR% monitor call. (See RCDIR% for more information.) Argument Block: .INAC1 Flag bits in the left half. .INAC2 Byte pointer of ASCII string to be translated. .INAC3 36-bit directory number (given when stepping to the next user name in a group). 30 .INTIM Performs a TIME% JSYS call on the specified system. This function returns the same information as the TIME% monitor call. (See TIME% for more information.) Argument Block: .INAC1 System uptime in milliseconds (returned). Generates an illegal instruction interrupt on error conditions below. 3-194
TOPS-20 MONITOR CALLS (INFO%) INFO% ERROR MNEMONICS INFX01: Invalid INFO% function INFX02: Invalid CI node number INFX03: WHEEL or OPERATOR capability required INFX04: CI node disconnected before information was returned INFX05: Remote node not supplying information INFX06: Insufficient system resources - no more swappable free space INFX07: User not logged in INFX08: Insufficient system resources on remote system INFX09: Unimplemented function on remote system INFX10: Insufficient SCA buffers to process request INFX11: Remote system not running CLUDGR SYSAP INFX12: Invalid argument block INFX13: Job not logged in INFX14: Remote node could not execute given function INFX15: Bad argument block length INFX16: Insufficient credit to send request to remote system INFX17: Remote XPEEK% can only return 512 words All I/O errors can occur also. Returns a logical name that is defined either for this job or for the system. (See Section 2.2.2 and CRLNM and LNMST monitor calls.) ACCEPTS IN AC1: Function code in the left half, and index into the table of defined logical names in the right half AC2: Byte pointer to the string for storing the logical name RETURNS +1: Failure, error code in AC1 +2: Success, updated string pointer in AC2 The available functions are: Code Symbol Meaning 0 .INLJB List the logical names defined for this job 1 .INLSY List the logical names defined for the system 3-195
TOPS-20 MONITOR CALLS (INLNM) INLNM ERROR MNEMONICS: INLNX1: Index is beyond end of logical name table INLNX2: Invalid function Performs Internet protocol network management operations. RESTRICTIONS: Requires NET WIZARD capability enabled. ACCEPTS IN AC1: Function code AC2: Function dependent argument AC3: Function dependent argument RETURNS +1: Always, with error code in AC1 on failure Function Codes: Code Symbol Meaning 0 .IPSNT Change network state. AC2 contains the Internet network number and AC3 contains the desired network state (zero to disable; nonzero to enable). 1 .IPRNT Read network state. AC2 contains the Internet network number. The network state is returned in AC3 (zero for disabled; nonzero for enabled). | | 2 .IPINI Reload Internet host and nameserver tables. 3 .IPGWY Reload Internet gateway routing table. 4 .IPRIB Read status of internet bypass. 5 .IPSIB Set status of internet bypass. 6 .IPNIP Enable/Disable NI IP protocol operations. 7 .IPNAP Enable/Disable NI ARPANET protocol operations. 10 .IPIGH Reload NI Internet Protocol. 3-196
TOPS-20 MONITOR CALLS (IPOPR%) 11 .IPRGH Return NI Internet Protocol GHT table. 12 .IPRIC Return NI Internet Protocol portal counters. | | 13 .IPRAC Return NI ARP protocol portal counters. | | 14 .IPDNS Reload Internet nameserver table. IPOPR% ERROR MNEMONICS: TCPX23: Invalid IPOPR function requested TCPX24: Wheel, Operator, or Network Wizard needed for special IPOPR function IPHCHK: Computed GHT checksum does not match IPHCNT: GHT entry count argument is not correct IPHNSP: Insufficient system resources (No free space for GHT) IPHEMX: Exceeded maximum number of GHT entries IPHSEQ: GHT Internet host numbers not in ascending order IPFLAD: Local Internet host number not in GHT ARPNSP: Insufficient system resources (No space for ARP buffers) IPARP1: Cannot start ARP until TCPNI service is running TCPX44: Monitor does not support TCP over Ethernet Returns the file specification currently associated with the JFN. ACCEPTS IN AC1: Destination designator where the ASCIZ string is to be written AC2: Indexable file handle (see GTJFN), or pointer to string AC3: Format control bits to be used when returning the string, or 0 AC4: Byte pointer to string containing prefix of file specification attribute RETURNS +1: Always, with updated string pointer, if pertinent, in AC1 AC2 can have one of two formats, depending on B26(JS%PTR) in AC3. The first format is a word with either 0 or the flag bits returned from GTJFN in the left half and the JFN in the right half. When the left 3-197
TOPS-20 MONITOR CALLS (JFNS) half is 0, the string returned is the exact specification associated with the JFN. If the given JFN is associated only with a file specification (it was obtained with B12(GJ%OFG) on in the GTJFN call), the string returned contains null fields for nonexistent fields or fields containing wildcards, and actual values for existent fields. When the left half is nonzero, the string returned contains wildcard characters for appropriate fields and 0, -1, or -2 as a generation number if the corresponding bit is on in the call. The second format (allowed only if B26(JS%PTR) of AC3 is on) is a pointer to the string to be returned. This string is one field of a file specification. The field is determined by the first nonzero 3-bit field in AC3 or by the setting of B27(JS%ATR) or B28(JS%AT1) in AC3. For example, if bits 6-8 (JS%NAM) of AC3 are nonzero, then the string is interpreted as a filename field. If B27(JS%ATR) is on, the string is interpreted as a file specification attribute. If B28(JS%AT1) is on, the string is concatenated to the string to which AC4 points, and a colon is inserted between the two strings. In all cases, the string is output to the destination designator, and the appropriate punctuation is added. AC3 contains control bits for formatting the string being returned. B0-20 are divided into fields corresponding to the fields in a file specification. The value of the control bits determines the output for that field of the file specification. The values are: 0 (.JSNOF) do not output this field 1 (.JSAOF) always output this field 2 (.JSSSD) suppress this field if it is the system default The bits that can be set in AC3 are as follows: B0(JS%NOD) Output for node field B1-2(JS%DEV) Output for device field B3-5(JS%DIR) Output for directory field B6-8(JS%NAM) Output for filename field (2 is illegal) B9-11(JS%TYP) Output for file type field (2 is illegal) B12-14(JS%GEN) Output for generation number field B0-14(JS%SPC) Output for all file specification fields named above. This field should have the same bits set as would be set in the fields above. (See B35(JS%PAF) below.) B15-17(JS%PRO) Output for protection field B18-20(JS%ACT) Output for account field B21(JS%TMP) Return ;T if appropriate B22(JS%SIZ) Return size of file in pages B23(JS%CDR) Return creation date B24(JS%LWR) Return date of last write B25(JS%LRD) Return date of last read B26(JS%PTR) AC2 contains pointer to the string being returned 3-198
TOPS-20 MONITOR CALLS (JFNS) B27(JS%ATR) Return file specification attributes if appropriate B28(JS%AT1) Return the specific specification attribute whose prefix is indicated by the string to which AC4 points. This bit is used when a program is processing attributes one at a time. If JS%ATR is also set, all attributes will be returned (WHEEL capabilities are required to receive the password). See the description of the long-form GTJFN for a list of file attributes. B29(JS%OFL) Return the "OFFLINE" attribute B32(JS%PSD) Punctuate the size and date fields B33(JS%TBR) Tab before all fields returned, except for first field B34(JS%TBP) Tab before all fields that may be returned (fields whose value is given as 1 or 2), except for first field B35(JS%PAF) Punctuate all fields from node through ;T If B32-35 are 0, punctuation between fields is not used. If AC3 is 0, the string is output in the format node::dev:<directory>name.typ.gen;T The temporary attribute (;T) is not returned if the JFN is a parse-only JFN (see GJ%OFG in the GTJFN description) or the file is not temporary. The punctuation used on each field is shown below. dev:<directory>name.typ.gen;attribute ,size,creation date,write date,read date The GTJFN or GNJFN monitor call is used to associate a JFN with a given file specification string. Generates an illegal instruction interrupt on error conditions below. JFNS ERROR MNEMONICS: DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer IOX11: Quota exceeded IOX34: Disk full IOX35: Unable to allocate disk - structure damaged 3-199
TOPS-20 MONITOR CALLS (KFORK) Kills one or more processes. When a process is killed, all private memory acquired by the process and its Process Storage Block are released. Also, any JFNs the process has created are released, and any terminal interrupt assignments that were acquired from another process are passed back. (Note that because the process is deleted asynchronously, a page of a file mapped into a lower process may not be unmapped before the KFORK call returns.) ACCEPTS IN AC1: Process handle RETURNS +1: Always, unless the current process attempts to kill itself The KFORK call will not release a process handle that identifies a process already killed by another process. In this case, the RFRKH call must be used to release the handle. The CFORK monitor call can be used to create an inferior process. Generates an illegal instruction interrupt on error conditions below. KFORK ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle KFRKX1: Illegal to kill top level process KFRKX2: Illegal to kill self Performs Local Area Transport (LAT) functions for TOPS-20. RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Address of argument block RETURNS +1: Always The possible LATOP% functions are as follows: 3-200
TOPS-20 MONITOR CALLS (LATOP%) Function Symbol Meaning 0 .LASET Set LAT parameters for local node. This function is used to set the dynamic parameters for the host in the local node. WHEEL or OPERATOR privileges are required. The argument block used to set the parameters is: Word Symbol Contents 0 .LAACT Length of the argument block, including this word. 1 .LAFCN .LASET 2 .LAPRM Parameter number for parameter being set. The following parameters can be set: Code Symbol Meaning 1 .LPMAC Maximum number of active circuits 2 .LPMCO Maximum number of simultaneous connects 3 .LPNUM Host number 4 .LPLAS LAT access state 5 .LPRLI Circuit retransmit limit 6 .LPTIM Circuit timer initial value 7 .LPMTI Multicast timer initial value 10 .LPCOD Group codes 11 .LPNNM Host node name 12 .LPNID Host node identification string 13 .LPSRV Service rating and description 3-201
TOPS-20 MONITOR CALLS (LATOP%) 3 .LAVAL Contents depend on the parameter code: Code Contents 1-7 New parameter value 10 Address of a bit mask representing codes to be set 11-13 ASCIZ string pointer to string representing parameters 4 .LAQUA Required for parameter 13 only. Contains the following: Bit Symbol Meaning 0 LA%RAT Set the rating as specified in the right half of this word. If all ones, the rating is set to DYNAMIC. 1 LA%DSC Set the service description as specified in the next word. If a particular bit is not set, the action taken depends on whether or not the service name previously existed: if previously existent, the parameter value is not changed. Otherwise the default for the parameter is set. 5 .LADSC An ASCIZ string pointer to the service description string to be set. If LA%DSC is set and this parameter is zero, the current service description is cleared. 1 .LACLR Clear local node's LAT parameters. This function is used to clear the dynamic parameters for the host in the local node. WHEEL or OPERATOR privileges are required. The format of the argument block is: 3-202
TOPS-20 MONITOR CALLS (LATOP%) Word Symbol Contents 0 .LAACT Length of the argument block, including this word. 1 .LAFCN .LACLR 2 .LAPRM Parameter number for parameter to clear. Parameter numbers are the same as those defined for the .LASET function. Parameters 4 and 11 cannot be cleared. To change them, the .LASET function must be used. 3 .LAVAL Depends on parameter code in .LAPRM. For parameter code 10, contains the address of the group code bit mask. For parameter 13, contains the ASCIZ pointer to service name to clear. This word is ignored for all other parameters. 2 .LASCH Show the local node's LAT parameters. This function is used to show the dynamic, static, and permanent parameters for the host in the local node. The format of the argument block is: Word Symbol Contents 0 .LAACT Length of the argument block, including this word. 1 .LAFCN .LASCH 2 .LABCT Number of words returned,,number of words reserved for returned information. 3 .LABFA Address of location where information is stored upon return (show buffer). The format of the buffer returned to the user follows the function descriptions. 3 .LASTC Show connects. This function is used to show all currently active LAT terminal connections at the local node. The format of the argument block is: 3-203
TOPS-20 MONITOR CALLS (LATOP%) Word Symbol Contents 0 .LAACT Length of the argument block, including this word. 1 .LAFCN .LASTC 2 .LABCT Flags,,number of words reserved for returned information. On return, number of words returned,,number of words reserved. The following flag can be set: Bit Symbol Meaning 0 LA%ECB Set to return information in Extended Connect Blocks. If not set, return standard Connect Blocks. 3 .LABFA Address where information is returned (show buffer). The format of the buffer returned to the user follows the function descriptions. 4 .LASAS Show Adjacent Servers. This function returns information about LAT servers that can access the local node. The format of the argument block is: Word Symbol Contents 0 .LAACT Length of the argument block, including this word. 1 .LAFCN .LASAS 2 .LABCT Number of words returned,,number of words reserved for returned information. 3 .LABFA Address where information is returned (show buffer). The format of the buffer returned to the user follows the function descriptions. 4 .LAQUA ASCIZ string pointer to server name if information about a specific server is requested (returns full format server block). If this word is 0 (default), a summary of all 3-204
TOPS-20 MONITOR CALLS (LATOP%) servers is returned (short form server block). 5 .LASCO Show Counters. Argument block format: Word Symbol Contents 0 .LAACT Length of the argument block, including this word. 1 .LAFCN .LASCO 2 .LABCT Number of words returned,,number of words reserved for returned information. 3 .LABFA Address where information is returned (show buffer). The format of the buffer returned to the user follows the function descriptions. 4 .LAQUA ASCIZ string pointer to server name if information about a specific server is requested (returns full format server block). If this word is 0 (default), a summary of all servers is returned (short form server block). 6 .LAZCO Zero Counters. WHEEL or OPERATOR privileges are required. The format of the argument block is: Word Symbol Contents 0 .LAACT Length of the argument block, including this word. 1 .LAFCN .LAZRO 2 .LABCT unused 3 .LABFA unused 4 .LAQUA ASCIZ string pointer to server name if information about a specific server is requested (returns full format server block). If this word is 0 (default), a summary of all servers is returned (short form server block). 7 .LARHC Request Host-Initiated Connect. This function requests a server to initiate a connection from an 3-205
TOPS-20 MONITOR CALLS (LATOP%) Application Terminal. If the connection completes successfully, the requesting process has an assigned TTY line to the Application Terminal. This function requires WHEEL or OPERATOR privileges. The format of the argument block is: Word Symbol Contents 0 .LAACT Length of the argument block, including this word. 1 .LAFCN .LARHC 2 .LAPRM Flags,,Connect-id. The following flags may be set: Bit Symbol Meaning 0 LA%PSI When set, the word .LAVAL should contain the PSI channel on which to interrupt the process when the connection is either made or rejected. If not set, the LATOP% JSYS block until either the connection is actually made, or the connection is rejected. If connection is made, the terminal designator can be obtained with the LATOP% function: .LASHC. A handle for use with the .LATHC and .LASHC functions is returned in LA%CID. NOTE When LA%PSI is set, you must have initialized the Software Interrupt 3-206
TOPS-20 MONITOR CALLS (LATOP%) System. (See Section 2.6 for more information on using Software Interrupts.) 1 LA%QUE If set, request is queued for access to application terminal. If not set, request is immediately accessed to application terminal. 3 LA%JOB Used by the .LASHC and .LATHC functions, and ignored by the .LARHC function. 4-17 Unused - Reserved for DEC. 18-35 LA%CID Connect-id returned for use with the .LATHC and .LASHC functions. 3 .LAVAL If the LA%PSI flag is clear, this location returns the terminal designator if the connection has been made, or this location returns a reject code if the connection has been rejected. (For possible reject codes see below.) If the LA%PSI flag is set, this location should be set to the PSI channel number on which you wish to be interrupted. 4 .LASVR Byte pointer to the Server Name (or zero). 5 .LASVC Byte pointer to the Service Name (or zero). 6 .LAPRT Byte pointer to the Port Name (or zero). 8 .LATHC Terminate Host-Initiated Connect. This function 3-207
TOPS-20 MONITOR CALLS (LATOP%) terminates connections from Application Terminals. The function requires WHEEL or OPERATOR privileges. The argument block for the .LATHC function has the same format as the one used by the .LARHC function. To cancel a particular pending connect, you can use the same argument block by changing word .LAFCN from .LARHC to .LATHC. The format of the argument block is: Word Symbol Contents 0 .LAACT Length of the argument block, including this word. 1 .LAFCN .LATHC 2 .LAPRM Flags,,Connect-id. The following flags may be set: Bit Symbol Meaning 3 LA%JOB If set, terminate all pending requests for this job. 4-17 Unused - reserved for DEC. 18-35 LA%CID If LA%JOB is not set, terminate the request associated with this Connect-id. 3 .LAVAL Ignored 4 .LASVR Ignored 5 .LASVC Ignored 6 .LAPRT Ignored 9 .LASHC Show Host-Initiated Connects. This function returns information about connections from Application Terminals. The function information returned is in the form of a "Status Block" (see .LASHC Status Block format below). The format of the argument block is: 3-208
TOPS-20 MONITOR CALLS (LATOP%) Word Symbol Contents 0 .LAACT Length of the argument block, including this word. On return, the left half contains the number of words returned. 1 .LAFCN .LASHC 2 .LABCT The number of words reserved for returned information. 3 .LABFA Address where information is returned (show buffer). 4 .LAQUA Flags,,Connect-id. If LA%SYS is set in this word, return information about all Application Terminal connections on the system. If LA%JOB is set in this word, return information about all application terminal connections for this job. Otherwise, LA%CID contains the Connect-id of the request to return information. Within the .LARHC function, the possible .LAVAL reject codes are: Code Symbol Meaning 0 .LAUNK Reason is unknown 1 .LAURD User requested disconnect 2 .LASSP System shutdown in progress 3 .LAISR Invalid slot received 4 .LAISC Invalid service class 5 .LAIRS Insufficient resources to satisfy request 6 .LASIU Service in use 7 .LANSS No such service 8 .LASDI Service is disabled 9 .LASNP Service is not offered by requested port 10 .LANSP No such port 11 .LAIPW Invalid password 12 .LAENQ Entry is not in the queue 13 .LAIAR Immediate access rejected 14 .LAACD Access denied 15 .LACSR Corrupted solicit request 16 .LACTI Command message type is illegal 17 .LASCS Start slot can not be sent 18 .LAQED Queue entry deleted by local node 19 .LAIRP Inconsistent or illegal request parameters 3-209
TOPS-20 MONITOR CALLS (LATOP%) With the .LARHC function, all combinations of Server Name, Service Name, and Port Name are defined as follows: Combination Definition Server Name only Not Allowed Service Name only Not Allowed Port Name only Not Allowed Service Name and Port Name Not Allowed Server Name and Port Name Request a connection to a particular port on a particular server. Server Name and Service Name Request a connection to a particular service on a particular server. Note that a service can be offered on more than one port. Server Name, Service Name, and Port Name Request a connection to a particular port on a particular server if that port offers the requested service. SHOW BLOCK FORMATS Several LATOP% functions return information in a buffer starting at the address stored in word .LABFA of the argument block. The functions and the format of the information returned are listed below. .LASCH (Show characteristics) Show buffer format is: 35 18 0 +-----------------------+-----------------------+ | MAX_ALLOC_CIRCUITS | N_ALLOC_CIRCUITS | +-----------------------+-----------------------+ | MAX_ACTIVE_CIRCUITS | N_ACTIVE_CIRCUITS | +-----------------------+-----------------------+ | MAX_CONNECTS | N_CONNECTS | +-----------------------+-----------------------+ | HOST_NUMBER |LAT_TERMINAL_ACCESS_STA| +-----------------------+-----------------------+ 3-210
TOPS-20 MONITOR CALLS (LATOP%) | HOST_RETRANSMIT_LIMIT | HOST_CIRCUIT_TIMER | +-----------------------+-----------------------+ | HOST_MULTICAST_TIMER | RESERVED | +-----------------------+-----------------------+ | HI_PROTOCOL_VERSION | LO_PROTOCOL_VERSION | +-----------------------+-----------------------+ | PROTOCOL_ECO | CUR_PROTOCOL_VERSION | +-----------------------+-----------------------+ | MAX_SLOT_SIZE | MAX_SLOTS | +-----------------------+-----------------------+ | FRAME_SIZE | MAX_SERVICES | +-----------------------+-----------------------+ | HOST_GROUP_CODES (8 words) | | | +-----------------------+-----------------------+ | HOST_NAME count | HOST_IDENT count | +-----------------------+-----------------------+ | HOST_NAME (2 words) | | | +-----------------------+-----------------------+ | HOST_IDENTIFICATION (13 words) | | | +-----------------------+-----------------------+ | Service Blocks (19 words/group name) | | | +-----------------------+-----------------------+ Service block format is: +-----------------------+-----------------------+ | HOST_SERVICE_NAME_RATING | +-----------------------+-----------------------+ | SERVICE_NAME count |SERVICE_DESCRIPTION cnt| +-----------------------+-----------------------+ | SERVICE_NAME (4 words) | | | +-----------------------+-----------------------+ | SERVICE_DESCRIPTION (13 words) | | | +-----------------------+-----------------------+ .LASTC (Show connects) There is one connect block returned for each LAT connection. The connect block format is: +-----------------------+-----------------------+ | Terminal Designator | +-----------------------+-----------------------+ 3-211
TOPS-20 MONITOR CALLS (LATOP%) | Server Name Count | Indeterminate | +-----------------------+-----------------------+ | Server Name (4 words) | | | +-----------------------+-----------------------+ The extended connect block format is: (LA%ECB is set) +-----------------------+-----------------------+ | Terminal Designator | +-----------------------+-----------------------+ | Server Name Count | Port Type | +-----------------------+-----------------------+ | Server Name (4 words) | | | +-----------------------+-----------------------+ | Port Name Count | Service Name Count | +-----------------------+-----------------------+ | Port Name (4 words) | | | +-----------------------+-----------------------+ | Service Name (4 words) | | | +-----------------------+-----------------------+ The Server Name, Port Name, and Service Name are 7-bit ASCIZ strings. The Count fields do not include terminating nulls. The following values are defined for the Port Type: Value Symbol Meaning 1 .LATTY This is a standard LAT terminal connection. 2 .LADLP This is a dialup LAT terminal connection. 3 .LAAPP This is a LAT application terminal. .LASAS (Show adjacent servers) A full format block is returned when the .LASAS request specifies a server name in argument .LAQUA. +-----------------------+-----------------------+ | Server Ethernet Address (2 words) | | | +-----------------------+-----------------------+ | FRAME_SIZE | SERVER_VERSION | +-----------------------+-----------------------+ | MAX_SLOTS | indeterminate | +-----------------------+-----------------------+ | CIRCUIT_TIMER | KEEP-ALIVE_TIMER | +-----------------------+-----------------------+ | PRODUCT_TYPE | STATE | 3-212
TOPS-20 MONITOR CALLS (LATOP%) +-----------------------+-----------------------+ | SERVER_NUMBER | SERVER_NAME count | +-----------------------+-----------------------+ | SERVER_LOCATION count | unused | +-----------------------+-----------------------+ | SERVER_NAME (4 words) | | | +-----------------------+-----------------------+ | SERVER LOCATION (4 words) | | | +-----------------------+-----------------------+ A short format block is returned when the .LASAS request specifies no server name. +-----------------------+-----------------------+ | SERVER_NUMBER | SERVER_NAME count | +-----------------------+-----------------------+ | SERVER_NAME (4 words) | | | +-----------------------+-----------------------+ | ETHERNET_ADDRESS (2 words) | | | +-----------------------+-----------------------+ .LASCO (Show counters) and .LAZCO (Zero counters) Counter Block Format: +------------------+------------------+ | Messages Received | +------------------+------------------+ | Messages Sent | +------------------+------------------+ | Messages Retransmitted | +------------------+------------------+ | Receive Sequence Errors | +------------------+------------------+ | Illegal Messages Received | +------------------+------------------+ | Resource Failures | +------------------+------------------+ .LASHC (Show Host-Initiated Connects) Status Block Status block format is: +-----------------------+-----------------------+ | Job Number | Connect ID | +-----------------------+-----------------------+ | Status | Queue Depth | 3-213
TOPS-20 MONITOR CALLS (LATOP%) +-----------------------+-----------------------+ | SERVER_NAME count | PORT_NAME count | +-----------------------+-----------------------+ | SERVER_NAME (4 words) | | | +-----------------------+-----------------------+ | PORT_NAME (4 words) | | | +-----------------------+-----------------------+ | SERVICE_NAME count | Indeterminate | +-----------------------+-----------------------+ | SERVICE_NAME (4 words) | | | +-----------------------+-----------------------+ Possible status values are: Value Symbol Meaning Terminal Designator Request was accepted. Reject Code Request was rejected. 377777 .LASOL Request is being solicited. 377776 .LAQUE Request is being queued. 377775 .LACAN Request has been canceled. 377774 .LATMO Request has timed out. Generates an illegal instruction trap on failure. LATOP% ERROR MNEMONICS: ARGX02: Invalid function ARGX04: Argument block too small ARGX05: Argument block too long CAPX1: WHEEL or OPERATOR capability required LATX01: Buffer size too small for available data LATX02: LAT parameter value out of range LATX03: LAT is not operational LATX04: Invalid or unknown LAT server name LATX05: Invalid LAT parameter LATX06: Invalid LAT parameter value LATX07: Invalid or unknown LAT service name LATX08: Insufficient LAT Resources LATX09: LAT Host name already set LATX10: Invalid or unknown LAT port name LATX11: Invalid or unknown connect id 3-214
TOPS-20 MONITOR CALLS (LGOUT) Kills the specified job and appends an accounting entry to the accounting data file. However, no entry is appended if the job was never logged in (that is, a CTRL/C was typed, but no login occurred). RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Number of the job to be logged out, or -1 for the current job RETURNS +1: Failure, error code in AC1 +2: Success When a specific job number is given in AC1, it must refer to either a PTY job controlled by the current job or a job logged in under the same user name as the current job. Otherwise, to give a specific job number, the process must have WHEEL or OPERATOR capability enabled. An argument of -1 must be given if the current job wishes to kill itself (that is, the job number given cannot be the same as the current job). Note that this monitor call does not return if the argument in AC1 is -1. The LGOUT monitor call outputs the time used (both CPU and console), the job number, the current date and time, and the name of the user who logged out the job if it is not the calling job. This information is output on the terminal to which the job being logged out is attached. LGOUT ERROR MNEMONICS: LOUTX1: Illegal to specify job number when logging out own job LOUTX2: Invalid job number LOUTX3: WHEEL or OPERATOR capability required LOUTX4: LOG capability required LOUTX5: Illegal to log out job 0 3-215
TOPS-20 MONITOR CALLS (LLMOP%) NOTE This JSYS is primarily intended for system use. The information returned may change in a future release. Provides access to Network Interconnect (NI) Remote Console Service and performs Ethernet loopback operations. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Function code AC2: Argument block RETURNS +1: Always Interface to NI Loopback Requestor/Server This interface provides three basic functions: checking the status of pending requests, initiating requests, and enabling to read unsolicited datagrams. The functions listed below perform the actual Ethernet loopback operations. All loopback operations are performed with padding enabled for the loopback protocol portal. Function Symbol Meaning 0 .ELDIR Builds an Ethernet loopback message from data supplied in the argument block, and transmits to the destination address. The argument block is: Word Symbol Meaning 0 .LMCID Channel ID. B34-35 (LM%CID) contain the value (from 0-3) of the Ethernet port to use. 1-2 .LMDST Destination address. 3 .LMREQ Request number, containing: Bit Symbol Meaning 0 LM%AIC Assigns interrupt channel specified in LM%ICH if this flag is set; if off, the LM%ICH field is 3-216
TOPS-20 MONITOR CALLS (LLMOP%) ignored and no interrupts are given. 12-17 LM%ICH Interrupt channel number. Contains number of PSI channel to interrupt when loopback reply message arrives from remote system. 18-35 LM%REQ Contains request number returned by LLMOP%. This value is used in function .ELRPY, .ELABT, .ELSTS. 4 .LMRBL Loopback request data buffer length. Bits 18-35 (LM%MBL) contain the length of the data protion of the loopback message. 5 .LMRBP Pointer to loopback request data buffer. 1 .ELAST Builds an Ethernet loopback message from data supplied in the argument block, and transmits it according to the type of assistance requested. Argument block words 0-5, .LMCID, .LMDST, .LMREQ, .LMRBL, and .LMRBP, are described in function .ELDIR. The remainder of the argument block is: Word Symbol Contents 6-7 .LMAST Address of the node used as the assistant in the loopback request. This cannot be a multicast address. 10 .LMHLP Assistance level Level Symbol Meaning 1 .LMXMT Transmit. Forwards the loopback message to destination and local nodes. 2 .LMRCV Receive. Forwards the loopback message to assistant and local nodes. 3-217
TOPS-20 MONITOR CALLS (LLMOP%) 3 .LMFUL Full. Forwards the loopback message to destination, assistant and local nodes. 2 .ELRPY Reads loopback reply. The format of the argument block is: Word Symbol Contents 0 .LMCID Channel ID. Bits 34 and 35 (LM%CID) contain the value of the Ethernet port to use. 1-2 .LMSRC Upon return, contains address of the remote system that satisfied the loop assisted operation. 3 .LMREQ Request number. Bits 18-35 (LM%REQ) contain the request number of the reply to be read. The caller is blocked until the reply arrives. 4 .LMRBL Loop response buffer length. Upon return, bits 0-17 (LM%RML) contain the length of the received loop reply message data. Bits 18-35 hold the maximum length of the loop response data buffer (supplied by user). 5 .LMRBP Pointer to loop reply buffer. 4 .ELABT Aborts Ethernet loop request. The format of the argument block is: Word Symbol Contents 0 .LMCID Channel ID. Bits 34-35 (LM%CID) contain the value of the Ethernet port to use. 3 .LMREQ Request number. Bits 18-35 (LM%REQ) contain the number of the request to be aborted. 5 .ELSTS Obtains the status of Ethernet loopback requests. The format of the argument block is: 3-218
TOPS-20 MONITOR CALLS (LLMOP%) Word Symbol Contents 0 .LMCID Channel ID. Bits 34-35 contain the value of the Ethernet port to use. 1 .LMSTF Upon return, contains status code for the request. Bits 18-35 (LM%RTC) contain one of the following status return codes: Code Symbol Meaning 0 .LMPND Request pending, not complete. 1 .LMSUC Request completed successfully. 3 .LMREQ Request number. Bits 18-35 (LM%REQ) contain the number of the request assigned by function .ELDIR or function .ELAST. Interface to NI Remote Console This interface provides four basic functions; gaining access to the NI Remote Console Service, initiating a request, checking the status of a pending request, and enabling to read unsolicited datagrams. LLMOP% provides the following remote console functions: Function Symbol Meaning 6 .RCRID Transmits a Read Identity protocol message to the destination address node on the Ethernet. Function .RCRPY must be used to read the system ID reply message. This function does not block the issuing process. The format of the argument block is: Word Symbol Contents 0 .LMCID Channel ID. Bits 34-35 contain the value of the Ethernet port to use. 1-2 .LMDST Destination address. 3 .LMREQ Request number, containing: 3-219
TOPS-20 MONITOR CALLS (LLMOP%) Bit Symbol Meaning 0 LM%AIC Assigns interrupt channel specified in LM%ICH if this flag is set; if off, the LM%ICH field is ignored and no interrupts are given. 12-17 LM%ICH Interrupt channel number. Contains number of PSI channel to interrupt when loopback reply message arrives from remote system. 18-35 LM%REQ Contains request number returned by LLMOP%. This value must be used in functions .RCRPY, .RCABT, and .RCSTS. 7 .RCRCT Transmits a Read Counters protocol message to the destination address node on the Ethernet. Use function .RCRPY to read the System ID reply message. The argument block is identical to that of function .RCRID. 11 .RCRBT Transmits a Boot protocol message to the destination address node on the Ethernet. This function blocks the issuing process until the transmit completes. The format of the argument block is: Word Symbol Contents 0 .LMCID Channel ID. Bits 34-35 (LM%CID) contain the value of the Ethernet port to use. 1-2 .LMDST Destination address. 3-4 .LMPWD 8-byte password verification code transmitted to the remote system for its use in deciding whether to allow the boot request. 5 .LMCIF Control information, in the form: 3-220
TOPS-20 MONITOR CALLS (LLMOP%) Bit Symbol Meaning 26 LM%BDV Boot device. 0 = system default; 1 = specified device. 27 LM%BSV Boot server. 0 = system default; 1 = requesting system. 28-35 LM%PRO Processor to boot. 0 = system processor; 1 = communication processor. 6 .LMDID Device ID in an 8-bit byte string. 7 .LMSID Software ID in an 8-bit byte string. 12 .RCRPY Reads the response to a .RCRID (request ID) or .RCRCT (request counters) function. The format of the argument block is: Word Symbol Contents 0 .LMCID Channel ID. If B0(LM%MRF) is set, there are more replies available for this request. Bits 34-35 contain the value of the Ethernet port to use. 1-2 .LMSRC Address of responding node. 3 .LMREQ Request number. Bits 18-35 (LM%REQ) contain the request number of the reply to be read. The caller is blocked until the reply arrives. 4 .LMRBL Console response buffer length. Upon return, bits 0-17 (LM%RML) contain the length of the received console reply message data. Bits 18-35 hold the maximum length of the remote console response data buffer (supplied by user). 5 .LMRBP Pointer to console reply buffer. 3-221
TOPS-20 MONITOR CALLS (LLMOP%) 13 .RCRSV Transmits a reserve remote console MOP message. The argument block contains words .lmCID, .lmDST, and .lmPWD, as described for function .RCRBT. 14 .RCREL Transmits a release remote console MOP message. The argument block contains words .lmCID and .lmDST, as described for function .RCRBT. 15 .RCSND Sends ASCII console command data to remote console and polls for response data. If no command data is included, this function only polls for response data. The format of the argument block is: Word Symbol Contents 0 .LMCID Channel ID Bit Symbol Meaning 34-35 LM%CID Channel ID. Value specifying Ethernet port to use. 1-2 .LMDST Destination address. 3 .LMREQ Request number, as described for function .RCRID. 4 .LMRBL Length of console request buffer. Bits 18-35 (LM%MBL) contain the maximum buffer length. 5 .LMRBP Pointer to remote console data buffer. 16 .RCPOL Polls for completion of function .RCSND (send console command). The format of the argument block is: Word Symbol Meaning 0 .LMCID Channel ID Bit Symbol Meaning 34-35 LM%CID Channel ID. 1-2 .LMSRC Address of node that sent this reply. 3 .LMREQ Request number. Bits 18-35 3-222
TOPS-20 MONITOR CALLS (LLMOP%) (LM%REQ) contain the request ID assigned by function .RCSND. 4 .LMRBL Length of console response buffer. Same as described for function .RCRPY. 5 .LMRBP Pointer to remote console data buffer. 17 .RCAIC Assigns software interrupt channel for Ethernet remote console message. The format of the argument block is: Word Symbol Contents 0 .LMCID Channel ID. Bits 34-35 (LM%CID) contain the value of the Ethernet channel to use. 1 .LMICF Interrupt channel flags. Bit Symbol Meaning 0 LM%AIC Assigns interrupt channel specified in LM%ICH if set; if off, the channel is deassigned. 12-17 LM%ICH Contains PSI channel to interrupt when remote console reply message arrives. This function returns an error for all but the first process to request it. 20 .RCABT Aborts an outstanding remote console request. The format of the argument block is the same as described for function .ELABT. 21 .RCSTS Obtains status of a remote console request. The format of the argument block is the same as described for function .ELSTS. 22 .RCADR Obtains a channel address. The format of the argument block is: 3-223
TOPS-20 MONITOR CALLS (LLMOP%) Word Symbol Contents 0 .LMCID Channel ID. Bits 34-35 (LM%CID) contain the value of the Ethernet port to use. 1-2 .LMHWA Hardware address. 3-4 .LMPYA Physical address. LLMOP% ERROR MNEMONICS: WHELX1: WHEEL or OPERATOR capability required ARGX02: Invalid function LLMX01: Transmit Datagram Failed LLMX02: LLMOP State is OFF LLMX03: Invalid byte pointer LLMX04: Nonexistent Request Number LLMX05: Invalid KLNI channel specified LLMX06: Configurator interrupts assigned to another process LLMX99: LLMOP Internal Error ARGX13: Invalid software interrupt channel number Translates a logical name to its original definition string. (See Section 2.2.2 and the CRLNM and INLNM monitor calls descriptions.) ACCEPTS IN AC1: Function code AC2: Pointer to the logical name. The logical name must not contain a terminating colon. AC3: Pointer to the string where the original logical name definition is to be written. The name returned includes a terminating colon. RETURNS +1: Failure, error code in AC1 +2: Success, updated string pointer in AC3 The codes for the functions are as follows: 0 .LNSJB Obtain the job-wide definition of the logical name. 1 .LNSSY Obtain the system definition of the logical name. 3-224
TOPS-20 MONITOR CALLS (LNMST) LNMST ERROR MNEMONICS: GJFX22: Insufficient system resources (Job Storage Block full) LNSTX1: No such logical name LNSTX2: Invalid function Logs a job into the system. Useful for logging in from an idle terminal on which a CTRL/C has been typed. RESTRICTIONS: When this call is used in any section other than section zero, one-word global byte pointers used as arguments must have a byte size of seven bits. ACCEPTS IN AC1: 36-bit user number under which user will log in AC2: Pointer to beginning of password string AC3: Account number in bits 3-35 if bits 0-2 are 5. Otherwise contains a pointer to an account string. If a null byte is not seen, the string is terminated after 39 characters are | | RETURNS: +1: Failure, error code in AC1 | | +2: Success with: | AC1: Date and time of last interactive login | AC2: Date and time of last non-interactive login | AC3: Password expiration date (0 if none, -1 if this | is the last time a user can login - that is, if the | password has expired) | AC4: Number of interactive login failures,,number of | non-interactive login failures | | The LOGIN% monitor call will allow 1 login after the user's password | has expired. It is the user's responsibility to then change the | password. The LOGIN monitor call does not require a password if the controlling terminal is a pseudo-terminal and the controlling job either has the WHEEL or OPERATOR capability enabled or is logged in as the same user being logged in for this job. 3-225
TOPS-20 MONITOR CALLS (LOGIN) If the call is successful, an accounting entry is appended to the accounting data file. If the account validation facility is enabled, the LOGIN call verifies either the account given or the default account of the user being logged in. LOGIN ERROR MNEMONICS: LGINX1: Invalid account identifier LGINX2: Directory is "files-only" and cannot be logged in to LGINX3: Internal format of directory is incorrect LGINX4: Invalid password LGINX5: Job is already logged in LGINX6: No more job slots available for logging in Loads the direct access Vertical Formatting Unit (VFU) or translation Random Access Memory (RAM) for the line printer. This call is executed at system startup by the program that configures the system. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: JFN of file containing VFU or RAM AC2: Status bits in the left half, and function code in the right half AC3: Unit number of line printer RETURNS +1: Always The following status bit is currently defined. B0(MO%LCP) Line printer is a lowercase printer. The available functions are as follows: Code Symbol Meaning 32 .MOLVF Load the VFU from the file indicated by the given JFN. 34 .MOLTR Load the translation RAM from the file indicated by the given JFN. 3-226
TOPS-20 MONITOR CALLS (LPINI) The line printer must not be opened by any process when this call is executed. If a condition occurs that prevents the VFU or RAM from being loaded (for example, the line printer is off line), the name of the file will be stored. The VFU or RAM will then be loaded automatically the next time a process performs output to the line printer. Generates an illegal instruction interrupt on error conditions below. LPINI ERROR MNEMONICS: LPINX1: Invalid unit number LPINX2: WHEEL or OPERATOR capability required LPINX3: Illegal to load RAM or VFU while device is OPEN Transfers control to the MDDT program while preserving the context of the process that issued the MDDT% JSYS. The terminal keyboard is activated and the user may enter commands to the MDDT program, or may return to TOPS-20 command level by typing CTRL/C, or may return to the issuing process by typing CTRL/Z. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. The MDDT% JSYS accepts no arguments. MDDT% ERROR MNEMONICS: WHELX1: WHEEL or OPERATOR capability required Returns the value of the execution accounting meter or the memory reference accounting meter. These values do not represent time as in "clock time"; rather, they represent the amount of time that the EBOX was busy and how many times the MBOX was referenced by the EBOX. 3-227
TOPS-20 MONITOR CALLS (METER%) ACCEPTS IN AC1: Function code RETURNS +1: Always, with 59-bit value in AC2 and AC3 Function Codes: Code Symbol Meaning 1 .MEREA Read process execution accounting meter doubleword. Value returned is EBOX busy time (number of EBOX ticks). 2 .MERMA Read process memory-reference accounting meter doubleword. Value returned is count of MBOX references (number of MBOX ticks). The accounting meters have bits that allow executive PI overhead and executive non-PI overhead to be included in the doubleword count. These are turned off by default (the monitor must be rebuilt to set them), so (by default) the EBOX count does not include the monitor overhead of paging, scheduling, or swapping. The EBOX count primarily includes only the EBOX time spent executing the instructions and JSYSs in the user's program. Interrupts caused by IO, paging, swapping, and so on, can cause instruction restarts or require pager refills, and these are included in the count. Because these interrupts depend on a variety of system variables, such as load average, subsequent timings of the same event will return varying count values. These fluctuations can be "smoothed" by timing the event repeatedly and taking the average of the values returned. The MBOX reference count has the same specifications as the EBOX count, and is subject to the same kind of fluctuations. Cache hit/no hit introduces an additional source of fluctuations. Again, timing the event repeatedly and taking the average of the values returned will "smooth" the counts. An event can be timed by an initial execution of METER%, a DMOVEM instruction to save the start value, and (after the event) a second execution of METER% followed by a DSUB instruction to find the elapsed number of ticks. For added accuracy, the average overhead for the timing sequence can be determined and subtracted from the average count value for the timed interval. The following diagram illustrates the format of the value returned: ! AC2 ! AC3 ! !=============================================================! ! High Order Part !0! Low Order Part ! Reserved ! !=============================================================! !0 35!0!1 23!24 35! 3-228
TOPS-20 MONITOR CALLS (METER%) Note that the following instruction changes the format of the values returned by the METER% call to form a right-justified doubleword value in AC2 and AC3. ASHC AC2,-^D12 METER% ERROR MNEMONICS: ARGX02: Invalid function code METRX1: METER% not implemented for this processor Retrieves an IPCF (Inter-Process Communication Facility) message from the process's input queue. See the Monitor Calls User's Guide for an overview and description of the Inter-Process Communication Facility. RESTRICTIONS: Some functions require WHEEL, OPERATOR or IPCF capability enabled. ACCEPTS IN AC1: Length of packet descriptor block AC2: Address of packet descriptor block RETURNS +1: Failure, error code in AC1 +2: Success. The packet is retrieved and placed into the block indicated by word .IPCFP of the packet descriptor block. AC1 contains the length of the next entry in the queue in the left half and the flags from the next packet in the right half. This returned word is called the associated variable of the next entry in the queue. If the queue is empty, AC1 contains 0. The format of the packet descriptor block is as follows: Word Symbol Meaning 0 .IPCFL Flags. (See the MSEND call description.) If bit IP%CFB is set in this word, MRECV does not block until a packet is read. 1 .IPCFS PID of sender. The caller does not supply this PID; the system fills it in when the packet is retrieved. 3-229
TOPS-20 MONITOR CALLS (MRECV) 2 .IPCFR PID of receiver. This PID can be one of three values: a specific PID, -1 to retrieve messages for any PID belonging to this process, or -2 to retrieve messages for any PID belonging to this job. When -1 or -2 is supplied, messages are not retrieved in any particular order except that messages from a specific PID are returned in the order in which they were received. 3 .IPCFP Pointer to block where message is to be placed (length of message in the left half and starting address of message in the right half). 4 .IPCFD User number of sender. Supplied by the monitor. 5 .IPCFC Enabled capabilities of sender. Supplied by the monitor. 6 .IPCSD Directory number of sender's connected directory. Supplied by the monitor. 7 .IPCAS Account string of sender. The caller supplies a pointer to the block where the account is to be placed. 10 .IPCLL Byte pointer to area to store logical location (node name) of sender. The caller (receiver) does not supply the information in words 4 through 7; the system fills in the words when the packet is retrieved. These words describe the sender at the time the message was sent and permit the receiver to validate messages. If a byte pointer is supplied in word .IPCLL, the monitor will use it to return the ASCIZ string for the logical location of the sender. See the MSEND call description for the flags that can be set in word .IPCFL of the packet descriptor block. MRECV ERROR MNEMONICS: IPCFX1: Length of packet descriptor block cannot be less than 4 IPCFX2: No message for this PID IPCFX3: Data too long for user's buffer IPCFX4: Receiver's PID invalid IPCFX5: Receiver's PID disabled IPCF11: WHEEL or IPCF capability required IPCF14: No PID's available to this job IPCF15: No PID's available to this process IPCF16: Receive and message data modes do not match IPCF24: Invalid message size 3-230
TOPS-20 MONITOR CALLS (MRECV) IPCF25: PID does not belong to this job IPCF26: PID does not belong to this process IPCF27: PID is not defined IPCF28: PID not accessible by this process IPCF29: PID already being used by another process IPCF31: Invalid page number IPCF32: Page is not private IPCF34: Cannot receive into an existing page IPCF36: PID not assigned on this LCS processor Sends an IPCF (Inter-Process Communication Facility) message. The message is in the form of a packet and can be sent to either the specified PID or the system process <SYSTEM>INFO. See the TOPS-20 Monitor Calls User's Guide for an overview and description of the Inter-Process Communication Facility. RESTRICTIONS: Some functions require WHEEL, OPERATOR, or IPCF capability enabled. ACCEPTS IN AC1: Length of packet descriptor block AC2: Address of packet descriptor block RETURNS +1: Failure, error code in AC1 +2: Success. The packet is sent to the receiver's input queue. Word .IPCFS of the packet descriptor block is updated with the sender's PID. This updating is done in case the PID was being defaulted or created by this call. The format of the packet descriptor block is as follows: Word Symbol Meaning 0 .IPCFL Flags. (See below.) 1 .IPCFS PID of sender; or address of PID if IP%CFS or IP%CFR is set in WORD .IPCFL; or 0 if no PID exists for sender. This word will be filled in by the monitor if the caller is creating a PID (flag bit IP%CPD is on). 3-231
TOPS-20 MONITOR CALLS (MSEND) 2 .IPCFR PID of receiver, or 0 if receiver is <SYSTEM>INFO. 3 .IPCFP Pointer to message block (length of message in the left half and starting address of message in the right half). When a packet is sent to <SYSTEM>INFO, the message block contains the request being made. (See below.) The following flags are defined in word .IPCFL of the packet descriptor block. These flags can be set on both the MSEND and MRECV calls. Flags Set By Caller B0(IP%CFB) Do not block process if there are no messages in the queue. If this bit is set, an error is given if there are no messages. B1(IP%CFS) Use, as the sender's PID, the PID obtained from the address specified in word .IPCFS. Setting bit IP%CFS notifies the monitor that word .IPCFS contains an address, and the sender's PID is located at that address. B2(IP%CFR) Use, as the receiver's PID, the PID obtained from the address specified in word .IPCFR. Setting bit IP%CFR notifies the monitor that word .IPCFR contains an address, and the receiver's PID is located at that address. B3(IP%CFO) Allow one send request above the quota. (The default send quota is 2.) B4(IP%TTL) Truncate the message, if it is larger than the space reserved. If this bit is not set, an error is given if the message is too large. B5(IP%CPD) Create a PID to use as the sender's PID and return it in word .IPCFS of the packet descriptor block. If flag IP%CFS is set, this function returns the created PID in the word to which the contents of .IPCFS points. B6(IP%JWP) Make the created PID be job wide (permanent until the job logs out). If this bit is not set, the PID is temporary until the process executes the RESET monitor call. If B5(IP%CPD) is not set, B6 is ignored. B7(IP%NOA) Do not allow other processes to use the created PID. If B5(IP%CPD) is not set, B7 is ignored. B8(IP%MON) Reserved for DIGITAL. 3-232
TOPS-20 MONITOR CALLS (MSEND) B18(IP%CFP) The packet is privileged. (This bit can be set only by a process with IPCF capability enabled.) When a privileged sender sets this bit, the MRECV and MUTIL calls return it set for any reply. An error is given if this bit is set by the sender and the receiver is not privileged. B19(IP%CFV) The packet is a page of data. Word .IPCFP of the packet descriptor block contains 1000 in the left half and the page number in the right half. The page the packet is being sent to must be private. B21(IP%INT) Reserved for DIGITAL. B22(IP%EPN) Page number in word .IPCFP of the packet descriptor block is 18 bits long. NOTE When a process sends a page of data with MSEND, that page is removed from the process's map. Flags Returned After Call B20(IP%CFZ) A zero-length message was sent, and the packet consists of only the packet descriptor block. B24-29(IP%CFE) Error code field for errors encountered by <SYSTEM>INFO during a send or receive request. Code Symbol Meaning 15 .IPCPI insufficient privileges 16 .IPCUF invalid function 67 .IPCSN <SYSTEM>INFO needs name 72 .IPCFF <SYSTEM>INFO free space exhausted 74 .IPCBP PID has no name or is invalid 75 .IPCDN duplicate name has been specified 76 .IPCNN unknown name has been specified 77 .IPCEN invalid name has been specified B30-32(IP%CFC) System and sender code. This code can be set only by a process with IPCF capability enabled. The system returns the code so that a nonprivileged user can examine it. Code Symbol Meaning 1 .IPCCC sent by <SYSTEM>IPCF 2 .IPCCF sent by system-wide <SYSTEM>INFO 3-233
TOPS-20 MONITOR CALLS (MSEND) 3 .IPCCP sent by receiver's <SYSTEM>INFO 4 .IPCCG sent by system for QUEUE% JSYS B33-35(IP%CFM) Field for return of special messages. This field can be set only by a process with WHEEL capability enabled. The system returns the information so that a nonprivileged user can examine it. Code Symbol Meaning 1 .IPCFN Process's input queue contains a packet that could not be delivered to intended PID. When the MSEND call is used to send a packet to <SYSTEM>INFO, the message portion of the packet (the first three words) contains the request. This request has the following format: Word Symbol Meaning 0 .IPCI0 User-defined code in the left half and the function (see below) <SYSTEM>INFO is to perform in the right half. The user-defined code is used to associate the response from <SYSTEM>INFO with the appropriate request. 1 .IPCI1 PID that is to receive a duplicate of the response from <SYSTEM>INFO. If this word is 0, the response is sent only to the originator of the request. 2 .IPCI2 Argument for the requested function. (See below.) The functions that can be requested of <SYSTEM>INFO, along with their arguments, are as follows: Function Argument Meaning .IPCIW name Return the PID associated with the specified name. The PID is returned in word .IPCI1. .IPCIG PID Return the name associated with the specified PID. The name is returned in word .IPCI1. .IPCII name in Assign the specified name to the PID ASCIZ belonging to the process making the request. The temporary or permanent status of the PID is specified by flag bit IP%JWP(B6) when the PID was originally created. .IPCIJ name in Identical to the .IPCII function. ASCIZ 3-234
TOPS-20 MONITOR CALLS (MSEND) .IPCIK PID Inform a PID when certain other PID's are deleted. The PID to be "watched" for deletion is placed in word .IPCI2. When that PID is deleted, SYSTEM INFO sends a message to the requesting PID with .IPCKM in the IP%CFE field, and the deleted PID in word .IPCI0 of the message. This function requires WHEEL or OPERATOR privileges. .IPCIS PID Disassociates all PIDs with names. However, the PID remains. To delete PID, use the .MUCHO and .MUDES functions of the MUTIL monitor call. This function (.IPCIS) requires WHEEL or OPERATOR capability enabled. MSEND ERROR MNEMONICS: IPCFX1: Length of packet descriptor block cannot be less than 4 IPCFX4: Receiver's PID invalid IPCFX5: Receiver's PID disabled IPCFX6: Send quota exceeded IPCFX7: Receiver quota exceeded IPCFX8: IPCF free space exhausted IPCFX9: Sender's PID invalid IPCF11: WHEEL or IPCF capability required IPCF12: No free PID's available IPCF13: PID quota exceeded IPCF14: No PID's available to this job IPCF15: No PID's available to this process IPCF19: No PID for [SYSTEM]INFO IPCF24: Invalid message size IPCF25: PID does not belong to this job IPCF26: PID does not belong to this process IPCF27: PID is not defined IPCF28: PID not accessible by this process IPCF29: PID already being used by another process IPCF31: Invalid page number IPCF32: Page is not private IPCF36: PID not assigned on this LCS processor Starts a process in monitor mode. This call allows job 0 to create multiple processes for handling various asynchronous monitor tasks. 3-235
TOPS-20 MONITOR CALLS (MSFRK) RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled, or execution from monitor mode. ACCEPTS IN AC1: Process handle AC2: 36-bit PC word, with user mode and other flags in the left half and the virtual address in the right half RETURNS +1: Always Because the starting context of the process is undefined, the process being started should execute the following sequence of instructions at its starting address: FBGN: MOVSI 1,UMODF ;fake user PC MOVEM 1,FPC ;simulate the JSYS call MCENTR ;establish usual top-level JSYS context Generates an illegal instruction interrupt on error conditions below. MSFRK ERROR MNEMONICS: FRKHX1: Invalid process handle FRKHX2: Illegal to manipulate a superior process FRKHX3: Invalid use of multiple process handle CAPX1: WHEEL or OPERATOR capability required Performs various structure-dependent functions. These functions include mounting and dismounting structures, incrementing and decrementing mount counts for structures, and setting and obtaining the status of structures. For regulated structures, the mount count must be incremented before access rights or JFNs can be given. All structures are regulated by default except the public structure or any structure declared non-regulated with the .MSSSS function of MSTR. Some functions require a structure device designator as an argument. Use the STDEV JSYS to obtain a device designator for a structure. RESTRICTIONS: Some functions require WHEEL, OPERATOR, or MAINTENANCE capability enabled. 3-236
TOPS-20 MONITOR CALLS (MSTR) ACCEPTS IN AC1: Length of the argument block in the left half and function code in the right half AC2: Address of the argument block RETURNS +1: Always, with some functions returning data in the argument block. (See individual function descriptions below.) The available functions are summarized below. Function Symbol Privileged Meaning 0 .MSRNU Yes Return the status of the next disk unit. 1 .MSRUS Yes Return the status of the given disk unit. 2 .MSMNT Yes Mount the given structure. 3 .MSDIS Yes Dismount the given structure. 4 .MSGSS No Return the status of the given structure. 5 .MSSSS Yes Change the status of the given structure. 6 .MSINI Yes Initialize the given structure. 7 .MSIMC No Increment the mount count for the given structure for the job. 10 .MSDMC No Decrement the mount count for the given structure for the job. 11 .MSGSU No Return the job numbers of the users of the given structure. 12 .MSHOM Yes Modify the home block of the given structure. 13 .MSICF No Increment the mount count for the given structure for the given fork. 3-237
TOPS-20 MONITOR CALLS (MSTR) 14 .MSDCF No Decrement the mount count for the given structure for the given fork. 15 .MSOFL Yes Receive interrupt when disk comes on-line. 16 .MSIIC Yes Ignore increment check for structure use 17 .MSCSM Yes Change structure mount attribute (CFS-20) Obtaining the Status of the Next Disk Unit - .MSRNU This function returns the status of the next disk unit on the system. The next disk unit is determined by searching the current channel and looking for the next physical unit on that channel. RESTRICTIONS: Requires WHEEL, OPERATOR, or MAINTENANCE capability enabled. The .MSRNU function accepts the channel, controller, and unit numbers in the first three words of the argument block. The time this function is executed, the value for each of these numbers is -1. After successful completion of this function, the channel, controller, and unit numbers are updated, and the software information about the disk drive is returned in the argument block. To locate all drives available for mounting structures, the channel, controller, and unit numbers returned from one .MSRNU function call are supplied on the next one until all units on all channels have been searched. When all units have been searched, the MSTR monitor call returns error MSTX18. The format of the argument block, whose length is .MSRLN, is as follows: Word Symbol Meaning 0 .MSRCH Channel number (0-7) 1 .MSRCT Controller number 2 .MSRUN Unit number (0-7) 3 .MSRST Returned software status of unit. The following status bits are defined: B0(MS%MNT) Unit is part of a mounted structure B2(MS%DIA) Unit is being used by an on-line diagnostic program B3(MS%OFL) Unit is off line 3-238
TOPS-20 MONITOR CALLS (MSTR) B4(MS%ERR) Unit has an error that was detected during reading B5(MS%BBB) Unit has a bad BAT block. If this bit is on, the data returned word .MSRSN (word 4) and in words .MSRNS through .MSRFI (words 6 through 20) is indeterminate. B6(MS%HBB) Unit has a bad HOME block B7(MS%WLK) Unit is write locked B8(MS%2PT) Unit is potentially dual-ported between systems B9-17 Type of disk unit (MS%TYP) 1 .MSRP4 RP04 5 .MSRP5 RP05 6 .MSRP6 RP06 7 .MSRP7 RP07 11 .MSRM3 RMO3 24 .MSR20 RP20 27 .MSR80 RA80 30 .MSR81 RA81 31 .MSR60 RA60 B18(MS%SVD) Unit is online (in use) by another system through the software MSCP disk server. B19(MS%IAC) Unit is temporarily inaccessible while the monitor checks the homeblocks to insure cluster integrity. 4 .MSRSN Byte pointer to ASCIZ string in which to store the structure name. This pointer is updated on return. 5 .MSRSA Byte pointer to ASCIZ string in which to store the structure alias. The alias is usually the same as the structure name. The alias is returned, and the pointer updated, only if the structure is on line. 6 .MSRNS Logical unit number within the structure of this unit in the left half, and number of units in the structure in the right half. 7 .MSRSW Number of pages for swapping on this structure. 10-12 .MSRUI Unit ID (3 words of 11-formatted ASCII) 13-15 .MSROI Owner ID (3 words of 11-formatted ASCII) 16-20 .MSRFI File system ID (3 words of 11-formatted ASCII) 3-239
TOPS-20 MONITOR CALLS (MSTR) 21 .MSRSP Number of sectors per page 22 .MSRSC Number of sectors per cylinder 23 .MSRPC Number of pages per cylinder 24 .MSRCU Number of cylinders per unit 25 .MSRSU Number of sectors per unit 26 .MSRBT Number of bit words in bit table per cylinder 27 .MSRSE Serial number of the CPU for which the structure is used in booting the system 30 .MSRLS Number of lost sectors per cylinder 31 .MSRSS Number of sectors per surface 32 .MSDSH High order serial number of disk drive 33 .MSDSN Low order serial number of disk drive 34 .MSTSP True number of sectors per page 35 .MSMID Disk pack maintenance identifier. This number is the same for all packs in a structure. The length of the argument block in words is given by symbol .MSRLN. The 11-formatted ASCII mentioned above is 7-bit ASCII stored four bytes to a 36-bit word in a format similar to that of a PDP-11: 0 1 9 10 17 20 28 29 35 =========================================================== !XX! CHAR 1 ! CHAR 0 !XX! CHAR 3 ! CHAR 2 ! ----------------------------------------------------------- !XX! CHAR 5 ! CHAR 4 !XX! CHAR 7 ! CHAR 6 ! ----------------------------------------------------------- !XX! CHAR 9 ! CHAR 8 !XX! CHAR 11 ! CHAR 10 ! =========================================================== The following errors are possible on the failure of this function. MSTRX2: WHEEL or OPERATOR capability required MSTRX3: Argument block too small MSTX14: Invalid channel number MSTX15: Invalid unit number MSTX16: Invalid controller number 3-240
TOPS-20 MONITOR CALLS (MSTR) MSTX18: No more units in system MSTX27: Specified unit is not a disk CAPX2: WHEEL, OPERATOR, or MAINTENANCE capability required Obtaining the Status of a Given Disk Unit - .MSRUS This function returns the status of the given disk unit. It accepts the channel, controller, and unit numbers in the first three words of the argument block. After successful completion of this function, the channel, controller, and unit numbers are unchanged, and the software information about the given disk unit is returned in the argument block. RESTRICTIONS: Requires WHEEL, OPERATOR, or MAINTENANCE capability enabled. The difference between this function and the .MSRNU function is that .MSRUS does not search for the next disk unit but rather returns the status for the given unit. The .MSRNU function searches for the next disk unit and returns the status for that unit. The format of the argument block is the same as described for the .MSRNU function. Mounting a Given Structure - .MSMNT This function brings the given structure on line and normally makes it available for general use. Any structure other than the public structure must be brought on line with this function. (The public structure is brought on line during the system startup procedure.) .MSMNT can also be used to limit access to structures mounted on a system running the Common File System, CFS-20. Depending upon the setting of the exclusive bit, MS%EXL, structure can be mounted as sharable or exclusive. Sharable structures can be accessed by any job running on any processor on the CI, as long as that processor has not excluded the specified structure. Exclusive structures can only be accessed by jobs running on the processor that has the structure mounted. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. It is recommended that the .MSRNU (Read Next Unit) function be given first to locate all units in the structure. Then the .MSMNT (Mount Structure) function can be given to read and verify the HOME blocks of each unit and to mount the structure. If one or more units of the structure are write-locked, the structure cannot be mounted and an error is given. The format of the argument block is as follows: 3-241
TOPS-20 MONITOR CALLS (MSTR) Word Symbol Meaning 0 .MSTNM Pointer to the ASCIZ string containing the name of the structure (colon not allowed). 1 .MSTAL Pointer to the ASCIZ string containing the alias of the structure. 2 .MSTFL Flag bits in the left half, and the number of units in the structure (.MSTNU) in the right half. The bits that can be set in the left half are: B0(MS%NFH) If one of the HOME blocks is incorrect, do not fix it, but do return an error. If one of the HOME blocks is incorrect and this bit is off, the correct block is copied into the bad HOME block, and the mounting procedure continues. B1(MS%NFB) If one of the BAT (Bad Allocation Table) blocks is incorrect, do not fix it and do return an error. If this bit is off and one of the BAT blocks is incorrect, the correct block is copied into the bad BAT block and the mounting procedure continues. B2(MS%XCL) Mount the structure for exclusive use by this job. This bit is set by a system program when it initializes or reconstructs a structure. If this bit if off, the structure is mounted for general use. B3(MS%IGN) Ignore correctable errors in the bit table and in the root directory on this structure. This bit is set by a system program when it reconstructs the root directory on a structure or rebuilds the bit table. If this bit is off and an error is detected, this function returns an error. B4(MS%EXL) Mount structure exclusive to this processor. If this bit is set, only jobs running on the processor on which the structure is mounted may access files on that structure. 3 .MSTUI Beginning of unit information for each unit in the 3-242
TOPS-20 MONITOR CALLS (MSTR) structure. The information is 3 words long per unit, and the symbol for this length is .MSTNO. The first 3-word block is for logical unit 0, and the last 3-word block is for the last logical unit (.MSTNU-1). The offsets into the 3-word block are: 0 .MSTCH Channel number of unit 1 .MSTCT Controller number of unit (currently must be -1) 2 .MSTUN Unit number of unit The number of argument words per unit is given by symbol .MSTNO (3). After successful completion of this function, the given structure is mounted and available for general use (unless bit MS%XCL was on in word .MSTFL of the argument block). The following errors are possible on the failure of this function. MSTRX2: WHEEL or OPERATOR capability required MSTRX3: Argument block too small MSTRX4: Insufficient system resources MSTRX5: Drive is not on line MSTRX6: Home blocks are bad MSTRX7: Invalid structure name MSTRX8: Could not get OFN for ROOT-DIRECTORY MSTRX9: Could not MAP ROOT-DIRECTORY MSTX10: ROOT-DIRECTORY bad MSTX11: Could not initialize Index Table MSTX12: Could not OPEN Bit Table File MSTX13: Backup copy of ROOT-DIRECTORY is bad MSTX14: Invalid channel number MSTX15: Invalid unit number MSTX16: Invalid controller number MSTX17: All units in a structure must be of the same type MSTX19: Unit is already part of a mounted structure MSTX20: Data error reading HOME blocks MSTX23: Could not write HOME blocks MSTX25: Invalid number of swapping pages MSTX27: Specified unit is not a disk MSTX30: Incorrect Bit Table counts on structure MSTX34: Unit is write-locked MSTX35: Too many units in structure MSTX44: Mount type refused by another CFS processor MSTX45: Structure naming or drive serial number conflict in CFS cluster MSTX47: Shared access denied; already set exclusive in CFS cluster MSTX48: Exclusive access denied; access conflict in CFS cluster 3-243
TOPS-20 MONITOR CALLS (MSTR) MSTX49: Structure naming conflict in CFS cluster MSTX50: Mount type refused by this CFS processor MSTX51: Insufficient system resources (structure limit exceeded) MONX01: Insufficient system resources Dismounting a Given Structure - .MSDIS This function indicates that the given structure can be removed from the system. Any mounted structure other than the public structure (usually called PS:) can be dismounted with this function. (The public structure is dismounted at system shutdown.) RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. Files that are open at the time this function is executed become inaccessible, and the jobs that had the files open receive an error if they reference them. Jobs that have mounted the structure or have connected to or accessed a directory on the structure receive an informational message on the terminal. This message is [STRUCTURE name: HAS BEEN DISMOUNTED] The format of the argument block is as follows: Word Symbol Meaning 0 .MSDNM Pointer to ASCIZ string containing the alias of the structure, or device designator of the structure. After successful completion of this function, the given structure is dismounted and can be physically removed from the system. The following errors are possible on the failure of this function. MSTRX2: WHEEL or OPERATOR capability required MSTRX3: Argument block too small MSTX21: Structure is not mounted MSTX24: Illegal to dismount the Public Structure Obtaining the Status of a Given Structure - .MSGSS This function returns the status of a mounted structure. The supplies the designators for the structure and for the storage of the structure's physical ID. After successful completion of the call, data is returned in the appropriate words in the argument block. The format of the argument block, whose length is .MSGLN, is as follows: 3-244
TOPS-20 MONITOR CALLS (MSTR) Word Symbol Meaning 0 .MSGSN Byte pointer to ASCIZ string containing the alias of the structure, or device designator of the structure. 1 .MSGST Returned status word. The status bits are: B0(MS%PS) This structure is the login structure. B1(MS%DIS) This structure is being dismounted and no further mount count increments are allowed. B2(MS%DOM) This structure is a domestic structure. B3(MS%PPS) This structure is a permanent, protected structure. B4(MS%INI) This structure is being initialized. B5(MS%LIM) Directories on this structure are limited to the size of a directory on a DECSYSTEM-2050 (30 pages). B6(MS%NRS) Structure is non-regulated. B7(MS%RWS) Read-after-write checking is being done in the swapping area. B8(MS%RWD) Read-after-write checking is being done in the data area. B9(MS%ASG) Disk assignments are prohibited because bit table is bad. B10(MS%MXB) Bit table is too large for the monitor address space. B11(MS%CRY) Password encryption is enabled. B12(MS%IDT) Enable password invalidation by date. B13(MS%IVS) Enable password invalidation by use. B14(MS%DMP) Structure is dumpable. B15(MS%EXC) Structure is mounted exclusive to this processor; if off, the structure may be shared by other systems on the CI. 3-245
TOPS-20 MONITOR CALLS (MSTR) B16(MS%IDX) Index table file for OFNs has been set up. B17(MS%CRD) The root directory is being created on this structure. B18(MS%OFS) This structure is offline. B19(MS%BS) This structure is the Boot structure. 2 .MSGNU Number of units in structure. 3 .MSGMC Mount count for this structure. This value is determined by the number of .MSIMC (Increment Mount Count) functions given for this structure by all users since the structure was mounted. 4 .MSGFC Open file count (number of open files) for this structure. 5 .MSGSI Pointer to ASCIZ string in which to store the structure's physical ID. The length of the argument block is given by symbol .MSGLN (6). After successful completion of this function, the status of the given structure is returned in the appropriate words of the argument block, and the pointer to the physical ID is updated to reflect the returned string. The following errors are possible on the failure of this function. MSTRX3: Argument block too small MSTX21: Structure is not mounted Changing the Status of a Given Structure - .MSSSS This function changes the status of a mounted structure. The caller can change four of the status bits in the structure's status word: the status of being dismounted, the status of being domestic, the status of having read-after-write checking done in the swapping area of the disk, and the status of having read-after-write checking done in the data area. RESTRICTIONS: Requires enabled WHEEL or OPERATOR capability. The format of the argument block, the length of which is .MSSLN, is: 3-246
TOPS-20 MONITOR CALLS (MSTR) Word Symbol Meaning 0 .MSSSN Byte pointer to ASCIZ string containing the alias of the structure, or device designator of the structure. 1 .MSSST Word containing the new values for the bits being changed. 2 .MSSMW Mask containing the bits being changed. The bits that can be changed are: B1(MS%DIS) Structure is being dismounted B2(MS%DOM) If set, structure is domestic; if not set, structure is foreign B6(MS%NRS) If set, structure is non-regulated; if not set, structure is regulated B7(MS%RWS) Read-after-write checking is being done in the swapping area B8(MS%RWD) Read-after-write checking is being done in the data area B14(MS%DMP) If set, structure is dumpable; if not set, structure cannot be dumped. The length of the argument block is given by symbol .MSSLN (3). After successful completion of this function, the status of the given structure is changed according to the data supplied in the argument block. The following errors are possible on the failure of this function. MSTRX2: WHEEL or OPERATOR capability required MSTRX3: Argument block too small MSTX21: Structure is not mounted MSTX22: Illegal to change specified bits Initializing a Given Structure - .MSINI This function creates a new structure or repairs an existing structure during normal system operation. The caller has the option of creating a new file system, reconstructing the root directory, writing a new set of HOME blocks on the structure, or rebuilding the index block. RESTRICTIONS: Requires enabled WHEEL or OPERATOR capability. 3-247
TOPS-20 MONITOR CALLS (MSTR) The format of the argument block is as follows: Word Symbol Meaning 0 .MSINM Byte pointer to ASCIZ string containing the name of the structure. 1 .MSIAL Byte pointer to ASCIZ string containing the alias of the structure. 2 .MSIFL Flag bits in B0-11, function value (MS%FCN) in B12-17, and number of units in structure (.MSINU) in B18-35. Flag Bits B0(MS%NFH) Do not fix HOME block if one is incorrect and do return an error. This bit can be on only with function .MSRRD. (See below.) B1(MS%NFB) Do not fix BAT block if one is incorrect and do return an error. B2(MS%XCL) Mount this structure for exclusive use by this job. If this bit is off, the structure is mounted for general use. B3(MS%IGN) Ignore errors in the bit table and in the root directory on this structure. If this bit is on, B2(MS%XCL) must also be on. B4(MS%EXL) Mount structure exclusive to this processor. If this bit is set, only jobs running on the processor on which the structure is mounted can access files on that structure. Function Values 1 .MSCRE Create a new file system 2 .MSRRD Reconstruct the root directory 3 .MSWHB Write a new set of HOME blocks 4 .MSRIX Rebuild the index table 3-5 .MSISU Beginning of unit information for each unit in the structure. The information is 3 words long per unit, and the symbol for this length is .MSINO. 3-248
TOPS-20 MONITOR CALLS (MSTR) The first 3-word block is for logical unit 0, and the last 3-word block is for the last logical unit (.MSINU-1). The offsets into the 3-word block are: 0 .MSICH Channel number of unit 1 .MSICT Controller number of unit (currently must be -1) 2 .MSIUN Unit number of unit The number of arguments per unit is given by symbol .MSINO (3). 6 .MSIST Status word (reserved for future use). 7 .MSISW Number of pages for swapping on this structure. 10 .MSIFE Number of pages for the front-end file system. 11-13 .MSIUI Unit ID (3 words of ASCII) 14-16 .MSIOI Owner ID (3 words of ASCII) 17-21 .MSIFI File system ID (3 words of ASCII) (reserved for future use) 22 .MSIFB Number of pages for the file BOOTSTRAP.BIN. 23 .MSISN Serial number of the CPU for which this structure is used in booting system. You must supply this word when creating a system structure that does not have the name PS:. Words 6 through 23 (.MSIST through .MSISN) of the argument block must be supplied when the MSTR call is being executed to create a new file system or to write a new set of HOME blocks. After successful completion of the .MSCRE function, the structure is initialized and the following directories are created: <ROOT-DIRECTORY> <SYSTEM> <SUBSYS> <ACCOUNTS> <SPOOL> <OPERATOR> <SYSTEM-ERROR> The following errors are possible on the failure of this function. MSTRX2: WHEEL or OPERATOR capability required 3-249
TOPS-20 MONITOR CALLS (MSTR) MSTRX3: Argument block too small MSTRX4: Insufficient system resources MSTRX5: Drive is not on line MSTRX6: Home blocks are bad MSTRX7: Invalid structure name MSTRX8: Could not get OFN for ROOT-DIRECTORY MSTRX9: Could not MAP ROOT-DIRECTORY MSTX10: ROOT-DIRECTORY bad MSTX11: Could not initialize Index Table MSTX12: Could not OPEN Bit Table File MSTX13: Backup copy of ROOT-DIRECTORY is bad MSTX14: Invalid channel number MSTX15: Invalid unit number MSTX16: Invalid controller number MSTX17: All units in a structure must be of the same type MSTX19: Unit is already part of a mounted structure MSTX20: Data error reading HOME blocks MSTX23: Could not write HOME blocks MSTX25: Invalid number of swapping pages MSTX26: Invalid number of Front-End-File system pages MSTX27: Specified unit is not a disk MSTX28: Could not initialize Bit Table for structure MSTX29: Could not reconstruct ROOT-DIRECTORY MSTX30: Incorrect Bit Table counts on structure MSTX50: Mount type refused by this CFS processor MSTX51: Insufficient system resources (structure limit exceeded) MONX01: Insufficient system resources Incrementing the Mount Count for the Job - .MSIMC Users indicate that they are actively using a structure by incrementing the structure's mount count. A nonzero mount count informs the operator that the structure should not be dismounted. Also, an IPCF message is sent to the Mountable Device Allocator to indicate that a user is using the structure. The .MSIMC function is used to increment a structure's mount count. Note that incrementing the mount count is a requirement for accessing files and directories on regulated structures. The job receives an error if the given structure is in the process of being dismounted (a job has given the .MSSSS function with the MS%DIS bit on), or if the job is not logged in. The format of the argument block is as follows: Word Symbol Meaning 0 .MSDEV Device designator, or byte pointer to ASCIZ string containing the alias of the structure. 3-250
TOPS-20 MONITOR CALLS (MSTR) 1 .MSJOB (Optional) Number of job (other than the current job) whose mount count is to be incremented. This requires WHEEL or OPERATOR capability to be enabled. After successful completion of this function, the mount count of the given structure has been incremented. The following errors are possible on the failure of this function. ARGX18: Invalid structure name CACTX2: Job is not logged in LOUTX2: Invalid job number MSTRX3: Argument block too small MSTX21: Structure is not mounted STRX10: Structure is offline MSTX31: Structure already mounted MSTX33: Structure is unavailable for mounting MONX01: Insufficient system resources STDVX1: No such device STRX01: Structure is not mounted STRX02: Insufficient system resources Decrementing the Mount Count for the Job - .MSDMC This function indicates that the given structure is no longer being used by the job executing the call. If the job executing the call has previously incremented the mount count for this structure via the .MSIMC (Increment Mount Count) function, the mount count is decremented. If the job has not incremented the mount count, the job receives an error. If the structure is regulated, and the user has any assigned JFNs on the structure, is accessing the structure or is connected to the structure, an error is returned. The format of the argument block is as follows: Word Symbol Meaning 0 .MSDEV Device designator, or byte pointer to ASCIZ string containing the alias of the structure. 1 .MSJOB (Optional) Number of job (other than the current job) whose mount count is to be decremented. This requires WHEEL or OPERATOR capability to be enabled. The resource allocator receives an IPCF packet when the mount count for a structure is decremented. The flag word (.IPCFL) of the packet descriptor block has a code of 1(.IPCCC) in the IP%CFC field (bits 30-32). This code indicates the message was sent by the monitor. The 3-251
TOPS-20 MONITOR CALLS (MSTR) first word of the packet data block contains the structure dismount code .IPCDS. The second word contains the number of header words and the number of the job decrementing the mount count. The third word contains the device designator of the structure. Thus, .IPCFL/<.IPCCC>B32 DATA/.IPCDS DATA+1/number of header words (2),, job number DATA+2/device designator of structure After successful completion of this function, the mount count of the structure has been decremented and the IPCF message has been sent. The following errors are possible on the failure of this function. MSTRX3: Argument block too small MSTX21: Structure is not mounted MSTX32: Structure was not mounted MSTX36: Illegal while JFNs assigned MSTX37: Illegal while accessing or connected to a directory ARGX18: Invalid structure name MONX01: Insufficient system resources STDVX1: No such device STRX01: Structure is not mounted STRX02: Insufficient system resources Obtaining the Users on a Given Structure - .MSGSU This function returns the job numbers of the users of the given structure. Users of a structure are divided into three classes: users who have incremented the mount count (MOUNT STRUCTURE command), users who are connected to the structure (CONNECT command), and users who have accessed the structure (ACCESS command). The caller specifies the classes of users for which information is to be returned by setting the appropriate bits in the argument block. The format of the argument block is as follows: Word Symbol Meaning 0 .MSUAL Byte pointer to ASCIZ string containing the alias of the structure, or device designator of the structure. 1 .MSUFL Flag bits in the left half and 0 in the right half. The bits that can be set are: B0(MS%GTA) Return users who have accessed the structure. 3-252
TOPS-20 MONITOR CALLS (MSTR) B1(MS%GTM) Return users who have incremented the mount count. B2(MS%GTC) Return users who are connected to the structure. After successful execution of this function, word 1 through word n+1 (where n is the number of items returned) are updated with the following information. Word Symbol Meaning 1 .MSUFL Right half contains the number of items (n) being returned. Left half is unchanged. 2 .MSUJ1 Flag bits for the job in the left half, and number of job in the right half. . . . . . . n + 1 Flag bits for the job in the left half, and number of job in the right half. The bits returned for each job are defined as: B0(MS%GTA) Job has accessed structure. B1(MS%GTM) Job has incremented the mount count for structure. B2(MS%GTC) Job has connected to structure. The following errors are possible on the failure of this function. MSTRX1: Invalid function MSTRX3: Argument block too small STRX01: Structure is not mounted STDVX1: No such device ARGX18: Invalid structure name MONX01: Insufficient system resources Specifying Word and Bits To Be Modified - .MSHOM This function allows an enabled WHEEL or OPERATOR program to modify a word of the homeblock of a mounted structure. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. 3-253
TOPS-20 MONITOR CALLS (MSTR) The format of the argument block is as follows: Word Symbol Meaning 0 .MSHNM Handle on alias such as pointer to string, or device designator. 1 .MSHOF Offset specifying which word should be changed. 2 .MSHVL Value for new bits. 3 .MSHMK Mask showing which bits should be changed. The following errors are possible on the failure of this function: MSTRX2: Insufficient privileges MSTRX3: Argument block too small MSTX21: Structure not mounted STRX10: Structure is offline Any errors "MODHOM" routine returns Incrementing the Mount Count for the Fork - .MSICF This function and the next (.MSDCF) allow job forks to independently mount and dismount structures without contending with one another for control of the structure. (This is primarily intended for SYSJOB.) Note that when either a job mount or fork mount is possible, the job mount is preferred as it incurs less overhead. This function indicates that a fork is actively using a structure. If the structure is being dismounted, the job receives an error. The format of the argument block is: Word Symbol Meaning 0 .MSDEV Pointer to ASCIZ string containing the alias of the structure, or device designator of the structure. The following errors are possible on the failure of this function. MSTRX3: Argument block too small MSTX21: Structure is not mounted MSTX33: Structure is unavailable for mounting ARGX18: Invalid structure name MONX01: Insufficient system resources STDVX1: No such device STRX01: Structure is not mounted STRX02: Insufficient system resources 3-254
TOPS-20 MONITOR CALLS (MSTR) Decrementing the Mount Count for the Fork - .MSDCF This function indicates that a fork is no longer using a structure. Note that if a job-wide increment has been done, the fork may still access the structure. The format of the argument block is: Word Symbol Meaning 0 .MSDEV Pointer to ASCIZ string containing the alias of the structure, or device designator of the structure. The following errors are possible on the failure of this function. MSTRX3: Argument block too small MSTX21: Structure is not mounted MSTX32: Structure was not mounted MSTX36: Illegal while JFNs assigned MSTX37: Illegal while accessing or connected to a directory ARGX18: Invalid structure name MONX01: Insufficient system resources STDVX1: No such device STRX01: Structure is not mounted STRX02: Insufficient system resources Receiving Interrupt when Disk Comes On-line - .MSOFL This function specifies who is to receive an interrupt when a disk comes on-line. It is provided for the Mountable Device Allocator in order to control the disks and inform the operator of structure status. Only one process on the system will receive the interrupts. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. The argument block has the following format: Word Symbol Meaning 0 .MSCHN Place this process on a software interrupt channel. An interrupt is then generated when a disk comes on-line. If the channel number is given as -1, a previously assigned interrupt channel will be deassigned. Ignoring Increment Check for Structure Use - .MSIIC Allows a process to use a regulated structure without previously incrementing the mount count. Entries are made to the accounting file only on structure decrements, so this function will enable bypassing of accounting. 3-255
TOPS-20 MONITOR CALLS (MSTR) RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. There is no argument block. The following errors are possible on the failure of this function. MSTRX2: WHEEL or OPERATOR capability required Converting the Structure Mount Attribute - .MSCSM This function may be used to change the mount attribute of a structure on a CFS-20 system. Under CFS-20, a structure may be mounted as sharable with other processors on the CI, or exclusive to a particular processor. Exclusive structures can only be accessed by jobs running on the owning processor. The structure may be mounted with MSTR% function .MSMNT with the exclusive bit on or off. This function, .MSCSM, may be used to change the setting of the exclusive bit while the structure is mounted. RESTRICTIONS: Requires enabled WHEEL or OPERATOR capability, and CFS-20 software. The format of the argument block is as follows: Word Symbol Meaning 0 .MSCDV Structure device designator 1 .MSCST New mount attribute B4(MS%EXL) 0 to set structure sharable 1 to set structure exclusive The following errors are possible on the failure of this function. MSTRX1: Invalid function MSTRX2: WHEEL or OPERATOR capability required MSTRX3: Argument block too small MSTX44: Mount type refused by another CFS processor MSTX46: Illegal to specify mount attribute MSTX47: Shared access denied; already set exclusive in CFS cluster MSTX48: Exclusive access denied; access conflict in CFS cluster MSTX50: Mount type refused by this CFS processor MSTX51: Insufficient system resources (structure limit exceeded) MONX02: Insufficient system resources (JSB full) STRX01: Structure is not mounted 3-256
TOPS-20 MONITOR CALLS (MTALN) Associates a given serial-numbered magnetic tape drive with the specified logical unit number. The MTALN call is a temporary call and may not be defined in future releases. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Slave type in left half; logical unit number of magtape in right half AC2: Decimal serial number of magnetic tape drive RETURNS +1: Always All units are searched for the specified serial number and slave type. When they are found, the drive is associated with the given logical unit number. The original unit is now associated with the logical unit number that the specified serial-numbered drive had before it was reassigned. The slaves recognized are .MTT45 TU45 (The system default) .MTT70 TU70 .MTT71 TU71 .MTT72 TU72 .MTT77 TU77 .MTT78 TU78 Generates an illegal instruction interrupt on error conditions below. MTALN ERROR MNEMONICS: WHELX1: WHEEL or OPERATOR capability required DEVX1: Invalid device designator OPNX7: Device already assigned to another job Performs various device-dependent control functions. This monitor call requires either that the JFN be opened or the device be assigned to the caller if the device is an assignable device. Because of the device dependencies of the MTOPR call, programs written 3-257
TOPS-20 MONITOR CALLS (MTOPR) with device-independent code should not use this call unless they first check for the type of device. RESTRICTIONS: Some functions require WHEEL or OPERATOR capability enabled. Some functions DECnet software. ACCEPTS IN AC1: JFN of the device AC2: Function code (see below) AC3: Function arguments or address of argument block (see descriptions of individual devices) RETURNS +1: Always The functions listed for each device apply only to that device. If a function applies to more than one device, its description is repeated for each applicable device. DECnet Functions DECnet-20 MTOPR functions are described below. For a complete description of their application, see the DECnet manual. Code Symbol Meaning 24 .MOACN Allow a network task to enable software interrupt channels for any combination of the following work types: o connect event pending o interrupt message available o data available This function requires that AC3 contain three 9-bit fields specifying the changes in the interrupt assignments for this link. These fields are: Field Symbol Used to Signal B0-8 MO%CDN Connect event pending B9-17 MO%INA Interrupt message available B18-26 MO%DAV Data available The contents of the fields are Value Meaning nnn The number of the channel to be enabled; 0-5 and 23-35 decimal 3-258
TOPS-20 MONITOR CALLS (MTOPR) .MOCIA Clear the interrupt .MONCI No change 25 .MORLS Read the link status and return a 36-bit word of information regarding the status of the logical link. AC3 contains flag bits in the left half and a disconnect code in the right half. The flag bits are Symbol Bit Meaning MO%CON B0 Link is connected MO%SRV B1 Link is a server MO%WFC B2 Link is waiting for a connection MO%WCC B3 Link is waiting for a connection confirmation MO%EOM B4 Link has an entire message to be read MO%ABT B5 Link has been aborted MO%SYN B6 Link has been closed normally MO%INT B7 Link has an interrupt message available MO%LWC B8 Link has been previously connected The disconnect/reject codes are as follows: Symbol Value Meaning .DCX0 0 Reject or disconnect by object .DCX1 1 Resource allocation failure .DCX2 2 Destination node does not exist .DCX3 3 Remote node shutting down .DCX4 4 Destination process does not exist .DCX5 5 Invalid process name field .DCX6 6 Object is busy .DCX7 7 Unspecified error .DCX8 8. Third party aborted link .DCX9 9. User abort (asynchronous disconnect) .DCX10 10. Invalid node name .DCX11 11. Local node shut down .DCX21 21. Connect initiate with illegal destination address .DCX22 22. Connect confirm with illegal destination address .DCX23 23. Connect initiate or connect confirm with zero source address 3-259
TOPS-20 MONITOR CALLS (MTOPR) .DCX24 24. Flow control violation .DCX32 32. Too many connections to node .DCX33 33. Too many connections to destination process .DCX34 34. Access not permitted .DCX35 35. Logical link services mismatch .DCX36 36. Invalid account .DCX37 37. Segment size too small .DCX38 38. No response from destination, process aborted .DCX39 39. No path to destination node .DCX40 40. Link aborted due to data loss .DCX41 41. Destination process does not exist .DCX42 42. Confirmation of disconnect initiate .DCX43 43. Image data field too long If a disconnect code does not apply to the current status of the link, the right half of AC3 will be zero. 26 .MORHN Return the ASCII name of the host node at the other end of the logical link. This function requires that AC3 contain a string pointer to the location where the host name is to be stored. (If the byte size exceeds eight bits, bytes are truncated to eight bits.) The monitor call returns with an updated pointer in AC3, and the host name stored as specified. This function is valid only for target tasks. 27 .MORTN Return the unique task name that is associated with your end of the logical link. If you had defaulted the task name in the network file specification, the call returns the monitor-supplied task name. In DECnet-20, the default task name is actually a unique number. This function requires that AC3 contain a string pointer to the location where the task name is to be stored. (If the byte size exceeds eight bits, bytes are truncated to eight bits.) The monitor call returns with an updated pointer in AC3 and the task name stored as specified. 30 .MORUS Return the source task user identification supplied in the connect initiate message. This 3-260
TOPS-20 MONITOR CALLS (MTOPR) function requires that AC3 contain a string pointer to the location where the user identification is to be stored. (If the byte size exceeds eight bits, bytes are truncated to eight bits.) The monitor call returns with an updated pointer in AC3 and the user identification stored as specified. If no user identification was supplied by the source task, AC3 continues to point to the beginning of the string, and a null is returned as the only character. 31 .MORPW Return the source task's password as supplied in the connect initiate message. This function requires that AC3 contain a string pointer to the location where the password is to be stored. (Passwords are binary; therefore, the string pointer should accomodate 8-bit bytes.) The monitor call returns with an updated pointer in AC3 and the source task's password stored as specified. AC4 contains the number of bytes in the string; a zero value indicates that no password was supplied by the source task. 32 .MORAC Returns the account string supplied by the source task in the connect initiate message. This function requires that AC3 contain a string pointer to the location where the account string is to be stored. (If the byte size exceeds eight bits, bytes are truncated to eight bits.) The monitor call return with an updated pointer in AC3 and the source task's account number stored as specified. If no account string was supplied by the source task, AC3 continues to point to the beginning of the string, and a null is returned as the only character. 33 .MORDA Return the optional data supplied in any of the connect or disconnect messages. This function requires that AC3 contain a string pointer to the location where the optional user data is to be stored. (This file is binary; the string pointer should specify 8-bit bytes.) The monitor call returns with an updated pointer in AC3 and the optional data stored as specified. AC4 contains the number of bytes in the data 3-261
TOPS-20 MONITOR CALLS (MTOPR) string; a zero value indicates that no optional data was supplied. 34 .MORCN Return the object type that was used by the source task to address this connection. The result indicates whether the local task was addressed by its generic type or its unique network task name. The monitor call returns with the object type in AC3. A zero object type indicates that the target task was addressed by its unique network task name; a nonzero value indicates that it was addressed by its generic object type. 35 .MORIM Read interrupt message. This function requires that AC3 contain a byte pointer to the receiving buffer. (If the byte size exceeds eight bits, bytes are truncated to eight bits.) The maximum message length is 16 bytes, and the buffer size should be at least 8 bits. The monitor call returns with an updated pointer in AC3, the message stored in the buffer, and the count of bytes received in AC4. 36 .MOSIM Send an interrupt message. This function requires that AC3 contain a byte pointer to the message (8-bit maximum) and that AC4 contain a count of the bytes in the interrupt message (16-byte maximum). 40 .MOCLZ Reject a connection either implicitly or explicitly. If the target task closes its JFN (via the CLOSF monitor call) before accepting the connection either implicitly or explicitly, the local NSP assumes that the connection is rejected and sends a connect reject message back to the source task. The reason given is process aborted (reject code 38, .DCX38). The target task must then reopen its JFN in order to receive subsequent connect initiate messages. In order to explicitly reject a connect and at the same time return a specific reject reason and set up 16 bytes of user data, the target task must use the .MOCLZ function of the MTOPR monitor call. The .MOLCZ function does not close the JFN. The function requires the following: 1. AC2 contain a reject code in the left half and .MOCLZ in the right half. The 3-262
TOPS-20 MONITOR CALLS (MTOPR) reject code is a 2-byte, NSP-defined decimal number indicating the reason that a target task is rejecting a connection. See the description of code 25, .MORLS, for a list of disconnect/reject codes. 2. AC3 contain a string pointer to any data to be returned. (If the byte size exceeds eight bits, bytes are truncated to eight bits.) 3. AC4 contain the count of bytes in the data string (maximum=16). A zero indicates no data. 41 .MOCC Accept a connection explicitly. Under certain conditions, the local NSP assumes that the connection is accepted and sends a connect confirm message back to the source task. These implicit conditions are the following: 1. The target task attempts to output to the logical link (issues a SOUT or SOUTR monitor call to the network). 2. The target task submits a read request to the logical link (issues a SIN or SINR monitor call to the network). In order to explicitly accept a connect and also return a limited amount of data, the target task must use the .MOCC function of the MTOPR monitor call. This function requires that AC3 contain a string pointer to any data to be returned. (If byte size exceeds eight bits, bytes are truncated to eight bits.) AC4 must contain the count of bytes in the data string to a maximum of 16 bytes. A zero indicates no data. 42 .MORSS Returns the maximum segment size that can be sent over this link. This value is the minimum of the maximum segment size supported by the remote NSP task, the segment size supported by the remote network task, and the segment size supported by the local NSP task. The local task can use this value to optimize the format of data being transmitted over the link. This function is illegal if the link is not in run state. The monitor call returns the maximum segment size, in bytes, in AC3. 3-263
TOPS-20 MONITOR CALLS (MTOPR) 44 .MOSNH Sets the network host. This function causes the terminal specified in the argument block to send data to and receive data from the DECnet logical link. The link connects the terminal on the local host to a job on a foreign host. The DECnet logical link to the foreign host must be established by the user process before this MTOPR function can be executed. This function requires the JFN of the logical link in AC1, and the address of the argument block in AC3. The argument block has the following format: Word Symbol Contents 0 The length of the argument block including this word. 1 .SHTTY Identifier of the terminal that is controlling the local job. 2 .SHESC Flags in the left half, ASCII escape character in the right half. The flags defined are: SH%LPM local page mode 45 .MOSLP Set link parameters. This function causes the link parameters specified in the argument block to be set. The process must have WHEEL or OPERATOR capability enabled to use this function. This function must be called before the link is established (before the OPENF call for an active link, or before the MTOPR call that accepts a link for a passive link). This function requires the address of the argument block be in AC3. The argument block has the following format: Word Symbol Contents 0 The length of the argument block, including this word. 1 .SLPSS The link segment size. The value actually used is the lowest of these 3 values: the segment size specified, the local node's maximum segment size, and the remote node's segment size. 3-264
TOPS-20 MONITOR CALLS (MTOPR) 2 .SLPFC The flow control option. The argument consists of two fields: B15-B17 MO%RFC Remote end flow control B33-B35 MO%LFC Local end flow control If a value for the remote end flow control is given, it is ignored. The possible values for the local end flow control are: Value Symbol Meaning 1 NSF.CO No flow control 2 NSF.CS Segment flow control 3 NSF.CM Message flow control 46 .MORLP Read link parameters. This function returns the link parameters. The arguments to this function are the same as those to .MOSLP (set link parameters) function. No capabilities are required for this function. Returned value of -1 means that the parameters for the link have not yet been decided. Note that the .MORSS MTOPR function can be used to retrieve the segment size. There is no difference between the value of segment size returned by the .MORSS function and the .MORLP function, once the link is established. 47 .MOSLQ Set link quotas. This function sets the parameters related to link quotas. This function requires the address of an argument block in AC3. The argument block has the following format: Word Symbol Contents 0 Length of the argument block, including this word. 1 .SLQIP Percent of link quota used for input. However, a minimum of one buffer is reserved for input and output. 3-265
TOPS-20 MONITOR CALLS (MTOPR) 2 .SLQLQ Link quota. This function sets the quota of buffers for this logical link. The number of buffers used depends on the job quota, and on the availability of buffers. If the process does not have WHEEL or OPERATOR capability enabled, the default value is used instead. 3 .SLQIG Input goal. This function sets the goal for the number of outstanding input data requests. If the process does not have WHEEL or OPERATOR capability enabled, the default value is used instead. 50 .MORLQ Read link quota. The arguments to this function are the same as those to the .MOSLQ (set link quota parameters) function, and the values are returned in the argument block. 51 .MORFT Return the format type of the source process name. The monitor call returns the format type in AC3. The following format types are defined: Value Symbol Meaning 0 .FMTT0 Type 0. The user has specified a nonzero object type; the other fields must be zero or have a zero length. 1 .FMTT1 Type 1. The user has not specified an object type; the PBOBJ field is zero. The user supplied a process name up to 16 bytes long in the PBNAM field. 2 .FMTT2 Type 2. The user has not specified an object type; the PBOBJ field is zero. The monitor has filled in the PBGRP and PBUID fields with the ford number and job number, respectively. The monitor supplies the user's LOGINID up to 12 bytes long in the PBNAM field. 3-266
TOPS-20 MONITOR CALLS (MTOPR) Front-End Functions Code Symbol Meaning 3 .MOEOF Causes TOPS-20 to flush its buffers and send all data to the front end. Optionally, it will notify the front end of the end-of-file condition. If AC3 is zero, the buffers are flushed and the end of file status is sent to the front end. If AC3 is nonzero, only the buffers are flushed. This function is used for synchronization between a program running on TOPS-20 and a program running on the front end. 4 .MODTE Assign the specified device to the DTE controller on the front end. This function, which must be performed before I/O is allowed to the device, requires AC3 to contain the device type. The process must have WHEEL or OPERATOR capability enabled. Unless otherwise noted, the JFN must be opened before the MTOPR function can be performed. MTA/MT Functions The functions available for physical magnetic tape drives (MTA) and logical magnetic tape drives (MT) are described below. Some of these functions accept arguments in AC3 (see the individual descriptions). In the following descriptions, a labeled tape is one acquired via a MOUNT command and has one of the following attributes: ANSI, TOPS20, or EBCDIC. Code Symbol Meaning 0 .MOCLE Clear any error flags from a previous MTOPR call. 1 .MOREW Rewind the tape. This function waits for activity to stop before winding the tape. If sequential data is being output, the last partial buffer is written before the tape is rewound. Control returns to caller when rewinding begins. For labeled tapes, this function causes the first volume in the set to be mounted and positioned to the first file in the file set. Since a volume switch may be required, this function could block for a considerable amount of time. Use function .MORVL to rewind the current volume. 3-267
TOPS-20 MONITOR CALLS (MTOPR) 2 .MOSDR Set the direction of the tape motions for read operations. This function requires AC3 to contain the desired direction. If AC3=0, the tape motion is forwards; if AC3=1, the tape motion is backwards. This function is not available for labeled tapes and will return an MTOX1 error if used for that purpose. 3 .MOEOF Write a tape mark. This function requires that the magnetic tape be opened for write access. If sequential data is being output, the last partial buffer is written before the tape mark. For labeled tapes, issuing this function will terminate the data portion of the file, write EOF trailer labels and leave the tape positioned to accept user trailer labels. It is possible at this point to write user trailer labels or close the file. A second .MOEOF function issued without positioning the tape backwards will "close" the file (subsequent writes will create a new file). 4 .MOSDM Set the hardware data mode to be used when transferring data to and from the tape. This function requires AC3 to contain the desired data mode: 0 .SJDDM default system data mode 1 .SJDMC dump mode (36-bit bytes) 2 .SJDM6 SIXBIT byte mode for 7-track drives 3 .SJDMA ANSI ASCII mode (7 bits in 8-bit bytes) 4 .SJDM8 industry compatible mode 5 .SJDMH High-density mode for TU70 and TU72 tape drives only (nine 8-bit bytes in two words). For labeled tapes, this function is allowed only if the file is opened in dump mode (.GSDMP). If this is not the case, an MTOX1 error is returned. 5 .MOSRS Set the size of the records. This function requires AC3 to contain the desired number of bytes in the records. This function is allowed only if no I/O has been done since the JFN was opened. This function is illegal for labeled tapes; an MTOX1 error is returned. 3-268
TOPS-20 MONITOR CALLS (MTOPR) The maximum size of the records (in bytes) is as follows: Hardware Maximum I/O Mode Record Size (bytes) System-default --- Dump 8192 (dump is usual default) SIXBIT 49152 ANSI ASCII 40960 Industry compatible 32768 High density 8192 The above values can be exceeded in the execution of .MOSRS; however, the first data transfer will fail. 6 .MOFWR Advance over one record in the direction away from the beginning of the tape. If sequential data is being read in the forward direction and not all of the record has been read, this function advances to the start of the next record. If sequential data is being read in the reverse direction and not all of the record has been read, this function positions the tape at the end of that record. For labeled tapes, forward space will position over a logical record. This implies that many physical records may be skipped (if S format is used) perhaps involving one or more volume switches. 7 .MOBKR Space backward over one record in the direction toward the beginning of the tape. If sequential data is being read in the forward direction and not all of the record has been read, this function positions the tape back to the start of that record. If sequential data is being read in the reverse direction and not all of the record has been read, this function positions the tape to the end of the record physically preceding that record. For labeled tapes, backward spacing will position over a logical record. This implies that many physical records may be skipped (if S format is used) perhaps involving one or more volume switches. 10 .MOEOT For unlabeled tapes, advance forward until two 3-269
TOPS-20 MONITOR CALLS (MTOPR) sequential tape marks are seen and position tape after the first tape mark. For labeled tapes, this function will position the volume set beyond the end of the last file in the set. This is useful for adding a new file to the end of an already existing volume set. This function may take some time to complete as one or more volumes switches may be required. 11 .MORUL Rewind and unload the tape. This function is identical to the .MOREW function and also unloads the tape if the hardware supports tape unloading. This function is illegal for any tape acquired via the MOUNT command. 12 .MORDN Return the current density setting. On a successful return, AC3 contains the current density. 13 .MOERS Erase three inches of tape (erase gap). This function requires that the magnetic tape be opened for write access. This function is illegal for labeled tapes. 14 .MORDM Return the hardware data mode currently being used in transfers to and from the tape. On a successful return, AC3 contains the current data mode. 15 .MORRS Return the size of the records. On a successful return, AC3 contains the number of bytes in the records. 16 .MOFWF Advance to the start of the next file. This function advances the tape in the direction away from the beginning of the tape until it passes over a tape mark. For labeled tapes, forward space will skip one logical file. This implies that many physical files may be skipped, involving perhaps one or more volume switches. 17 .MOBKF Space backward over one file. This function moves the tape in the direction toward the beginning of the tape until it passes over a tape mark or reaches the beginning of the tape, whichever occurs first. 3-270
TOPS-20 MONITOR CALLS (MTOPR) For labeled tapes, backspace file will back up one logical file. This implies that many physical files may be skipped, involving perhaps one or more volume switches. NOTE For labeled ANSI tapes, the monitor can compute the number of volume switches required to get to the first section of the file. Thus, if this function is issued for an ANSI tape, at most one volume switch will be required. This is not true for EBCDIC tapes. Issuing this function when the tape is already positioned at the first volume of the volume set will not produce an error. The program issuing this function must follow the .MOBKF with a GDSTS call to determine if the BOT was encountered during the backspacing operation. 20 .MOSPR Set the parity. This function requires AC3 to contain the desired parity: 0 .SJPRO odd parity 1 .SJPRE even parity 21 .MORPR Return the current parity. On a successful return, AC3 contains the current parity. 22 .MONRB Return number of bytes remaining in the current record. On a successful return, AC3 contains the number of bytes remaining. This function is only meaningful during sequential I/O. 23 .MOFOU Force any partial records to be written during sequential output. 24 .MOSDN Set the density. The function requires AC3 to contain the desired density. 0 .SJDDN default system density 1 .SJDN2 200 BPI (8 rows/mm) 2 .SJDN5 556 BPI (22 rows/mm) 3 .SJDN8 800 BPI (31 rows/mm) 4 .SJD16 1600 BPI (63 rows/mm) 5 .SJD62 6250 BPI (246 rows/mm) This function is illegal for labeled tapes. 3-271
TOPS-20 MONITOR CALLS (MTOPR) 25 .MOINF Return information about the tape. This function requires AC3 to contain the address of the argument block in which the information is to be returned. The format of the argument block is as follows: Word Symbol Contents 0 .MOICT Length of argument block to be returned (not including this word) 1 .MOITP MTA type code 2 .MOIID MTA reel ID 3 .MOISN Channel, controller, and unit in the left half and serial number in the right half. 4 .MOIRD Number of reads done 5 .MOIWT Number of writes done 6 .MOIRC Record number from beginning of tape 7 .MOIFC Number of files on tape 10 .MOISR Number of soft read errors 11 .MOISW Number of soft write errors 12 .MOIHR Number of hard read errors 13 .MOIHW Number of hard write errors 14 .MOIRF Number of frames read 15 .MOIWF Number of frames written 16 .MOICH Channel number 17 .MOICO Controller number 20 .MOIUN Unit number 21 .MOIDH High order serial number of drive 22 .MOIDN Low order serial number of drive The JFN need not be open for this function. 26 .MORDR Return the direction that the tape is moving during read operations. On a successful return, AC3=0 if the direction of the tape motion is forwards, or AC3=1 if the direction of the tape motion is backwards. 27 .MOSID Set the reel identification of the tape mounted. The process must have WHEEL or OPERATOR capability enabled. This function requires AC3 to contain the desired 36-bit reel ID. The JFN need not be open for this function. 30 .MOIEL Inhibit error logging for the tape. If AC3 is nonzero, error logging will be inhibited on subsequent operations on the tape drive. If AC3 is zero, error logging will be performed. The setting remains in effect until the JFN is closed. 3-272
TOPS-20 MONITOR CALLS (MTOPR) Error logging occurs by default if no setting is made with function .MOIEL. 31 .MONOP Wait for all activity to stop. 32 .MOLOC Specifies the first volume in a MOUNT request, or identifies the "next" volume for a volume switch. This function requires OPERATOR or WHEEL capability. AC3 contains a pointer to an argument block having the following format: Word Symbol Contents 0 .MOCNT count of words in the block 1 .MOMTN MT unit number to associate with this MTA 2 .MOLBT label type (.LTxxx) 3 .MODNS density 4 .MOAVL address of volume labels 5 .MONVL number of volume labels at .MOAVL 6 .MOCVN volume number in the volume set 7 .MOVSN SIXBIT file set identifier The JFN need not be open for this function. 37 .MOSTA Return current magtape status. Argument block has the following form and contents: Word Symbol Contents 0 .MOCNT Count of words in the block including this word (user-supplied) 1 .MODDN Density flags (returned) Bit Symbol Meaning B1 SJ%CP2 200 BPI B2 SJ%CP5 556 BPI B3 SJ%CP8 800 BPI B4 SJ%C16 1600 BPI B5 SJ%C62 6250 BPI 2 .MODDM Data mode flags (returned) Bit Symbol Meaning B1 SJ%CMC core dump B2 SJ%CM6 SIXBIT 3-273
TOPS-20 MONITOR CALLS (MTOPR) B3 SJ%CMA ANSI ASCII B4 SJ%CM8 industry compatible B5 SJ%CMH high density mode 3 .MOTRK Recording track flags (returned) Bit Symbol Meaning B1 SJ%7TR 7-track drive B2 SJ%9TR 9-track drive 4 .MOCST Tape status flags (returned) Bit Symbol Meaning B0 SJ%OFS off line B1 SJ%MAI maintenance mode enabled B2 SJ%MRQ maintenance mode requested B3 SJ%BOT beginning of tape B4 SJ%REW rewinding B5 SJ%WLK write locked 5 .MODVT Device type (returned) Code Symbol Meaning 3 .MTT45 TU45 (system default) 17 .MTT70 TU70 20 .MTT71 TU71 21 .MTT72 TU72 13 .MTT77 TU77 19 .MTT78 TU78 The JFN need not be open for this function. 40 .MOOFL Enable interrupts for online/offline transition. Allows a process to be interrupted if a magnetic tape drive's state changes from online to offline or vice-versa and when a rewind operation completes. This function must be performed once for each drive for which interrupts are to be enabled. If multiple drives are enabled for interrupts, then a .MOSTA function should be performed (for each drive) before interrupts for the drives are enabled. Then, when an interrupt occurs, .MOSTA can be performed for each drive and the current status of that drive can be compared against the previous status. Thus, it can be determined which drive (or drives) interrupted. 3-274
TOPS-20 MONITOR CALLS (MTOPR) This function rquires OPERATOR or WHEEL capability. The JFN need not be open for this function. 42 .MOPST Declares the software interrupt channel to be used by the monitor to indicate that the UTL labels at the end-of-volume or the UHL labels at the start of the new volume are available. If this MTOPR is not performed before an EOV label set is encountered, the user program will not be given the opportunity to process the UTL or UHL labels during the volume switch operation. AC3 contains the PSI channel number to set. The channel can be cleared by using -1 in AC3. This function is for labeled tapes only. 43 .MORVL Rewind current labeled tape volume. This function is for labeled tapes only. 44 .MOVLS Switch volumes for an unlabeled multi-volume set. If an unlabeled tape is mounted specifying multiple volumes in the volume set, the monitor will not automatically perform a volume switch at the end of each volume. The .MOVLS function may be issued in such a case to perform a volume switch. This function is legal only for unlabeled MT devices. AC3 contains the address of an argument block having the following format: Word Contents 0 count of words in block including this word 1 flags,,function code 2 argument (if required) Available functions are: Word Symbol Function 1 .VSMNV mount absolute volume number (volume number in word 2 of the argument block) 2 .VSFST mount first volume in set 3 .VSLST mount last volume in set 4 .VSMRV mount relative volume number (volume number in word 2 of the argument block). For 3-275
TOPS-20 MONITOR CALLS (MTOPR) .VSMRV, the argument in word 2 of the argument block is the volume number relative to the current mounted volume to mount. For example, if volume #2 is currently mounted and .VSMRV is performed with 2 in word 2 of the argument block, then volume 4 will be mounted. Specifying 1 in word 2 of the argument block will mount the next volume in the set. 5 .VSFLS force volume switch for labeled tape. This function is only for tapes for which .MOSDS has previously been set. 45 .MONTR Set no translate. Sets or clears the EBCDIC to ASCII translate flag. If the flag is set and the tape file being read is from an IBM EBCDIC volume, then all data delivered to the user program will be in its original EBCDIC form. If the flag is not set, and the file is from an IBM EBCDIC volume, then all data delivered to the user program will be in ASCII. In order to perform this translation, certain information may be lost (as the EBCDIC character set contains 256 codes while the ASCII character set contains only 128 codes - see Appendix A for ASCII-to-EBCDIC conversions). Note that the setting of this flag has no effect on the data delivered by the MTU% JSYS. This setting applies until explicitly changed or until the MT is dismounted. The default value of the flag is "clear" (translate). If AC3 is zero, the translate flag is cleared. If AC3 is negative, the translate flag is set. This function is for labeled tapes only. The JFN need not be open for this function. 46 .MORDL Read user header labels. Labels must be read immediately after the file is opened (and before the first input is requested) or after a volume switch has occurred and the volume switch PSI has been generated. .MORDL may be used to read either the UHL or UTL labels. User header labels may be read only if the file is opened for read or 3-276
TOPS-20 MONITOR CALLS (MTOPR) append. The labels may be a maximum of 76 characters long. User trailer labels may be read at any time. If the program requests to read user trailer labels, the tape will be positioned to the EOF trailer section. AC3 contains a byte pointer to the area for receiving the label. On a successful return, AC2 contains the user label identifier. This will be the ASCII character following the UHL or the UTL. AC3 will contain an updated byte pointer. This function is for labeled tapes only. 47 .MOWUL Write user header labels or user trailer labels. User header labels may be written only after the file is opened (and before the first write is performed) or when a PSI is generated, indicating that a volume switch has occurred. User header labels may be written only if the file is opened for write access. User trailer labels may be read or written at any time. If the program requests to write user trailer labels, the file will be terminated with an EOF trailer section. Once user trailer labels are written in this manner, no more data may be read or written. User trailer labels may also be written during a volume switch sequence. Once the PSI indicating EOV has been received, the user program may write a UTL label into the EOV trailer section. This operation must be performed at interrupt level. AC3 contains a byte pointer to the label contents. This string must contain 76 bytes of data (the monitor will use only the first 76 bytes). AC4 contains a label identifier code (any ASCII character). It is possible to encounter EOT while writing the first UTL in the EOF trailer set. This can occur if the last data write overwrote the EOT mark. In this instance, the user program will receive the EOV PSI from within the code writing the UTL labels for the file. It is not possible to 3-277
TOPS-20 MONITOR CALLS (MTOPR) receive an EOV PSI while writing the trailer labels in the EOV set. This function is for labeled tapes only. 50 .MORLI Reads the available fields from the standard volume and header labels. AC3 contains a pointer to an argument block of the form: Word Contents 0 count of words in block 1 word to store label type of this tape Value Symbol Label Type 1 .LTUNL Unlabeled 2 .LTANS ANSI 3 .LTEBC EBCDIC 4 .LTT20 TOPS-20 2 byte pointer to area for storing volume name string 3 byte pointer to area for storing owner name string 4 word to store tape format (ASCII character) 5 word to store record length 6 word to store block length 7 word to store creation date (in internal format) 10 word to store expiration date (in internal format). Returns a -1 in this word if the date is invalid. 11 byte pointer to area for storing file name string 12 word to store generation number 13 word to store version number 14 word to store mode value (form-control value). The possible modes are as follows: Mode Value Meaning space no line format characters are present A FORTRAN format control characters are present 3-278
TOPS-20 MONITOR CALLS (MTOPR) M All necessary line format characters are present X Data in stream mode The user specifies only the block count and the byte pointers; the remaining values are returned by the monitor. If a zero is substituted for any of the byte pointers, then the associated string is not returned. This function is normally issued when the JFN is open. If issued when the JFN is closed, only the first 3 words of the argument block are returned. If the tape is unlabeled, only the first word of the argument block is returned. For labeled tapes only. 51 .MOSMV Declares the value to be placed in the DEC-defined "form-control" field in the HDR2 label. This field is not defined in the ANSI standard but should be specified whenever the data file is meant to be read with DEC-supplied software. This function merely declares the value to be placed in the label. It is the user program's responsibility to produce records that conform to the declared mode. AC3 contains one of the following modes: Value Symbol Mode 0 .TPFST X - (stream mode) 1 .TPFCP M - (all formatting control present) 2 .TPFFC A - (FORTRAN control present) 3 .TPFNC space - (no controls present) This function is for labeled tapes only. 52 .MOSDS Set deferred volume switch. Inhibits the monitor from doing an automatic volume switch and allows a program to write its own trailer information beyond the physical end-of-tape mark. This function is intended for labeled MT devices open for writing in DUMP mode. 53 .MOIRB Return the block status of the DUMP mode operation. A 0 is returned if the request will not block, and a nonzero is returned if the request will block. 3-279
TOPS-20 MONITOR CALLS (MTOPR) PLPT Functions The functions available for physical line printers (PLPT) are described below. Some of these functions accept the address of an argument block in AC3. The first word of the argument block contains the length (including this word) of the block. Remaining words of the block contain arguments for the particular function. Code Symbol Meaning 27 .MOPSI Enable for a software interrupt on nonfatal device conditions. Examples of these conditions are: 1. Device changed from offline to online. 2. Device changed from online to offline. 3. Device's page counter has overflowed. Other device errors or software conditions are not handled by this function; instead they cause a software interrupt on channel 11 (.ICDAE). Argument Block: Word Contents 0 word count including this word 1 interrupt channel number 2 flags. The following flag is defined: B0(MO%MSG) Suppress standard CTY device messages. 31 .MONOP Wait for all activity to stop. This function blocks the process until all data has actually been sent to the printer and has been printed. Because this function is transferring data, it can return an IOX5 data error. 32 .MOLVF Load the line printer's VFU (Vertical Formatting Unit) from the file indicated in the argument block. Argument Block: Word Contents 0 word count including this word 1 JFN of the file containing the VFU 3-280
TOPS-20 MONITOR CALLS (MTOPR) The system opens the file for input with a byte size of 18 bits. It closes the file and releases the JFN when the loading of the VFU is complete. 33 .MORVF Read the name of the current VFU file stored in the monitor's data base. Argument Block: Word Contents 0 word count including this word 1 pointer to destination area for ASCIZ name string 2 number of bytes in destination area 34 .MOLTR Load the line printer's translation RAM (Random Access Memory) from the file indicated in the argument block. Argument Block: Word Contents 0 word count including this word 1 JFN of the file containing the translation RAM The system opens the file for input with a byte size of 18 bits. It closes the file and releases the JFN when the loading of the translation RAM is complete. 35 .MORTR Read the name of the current translation RAM file stored in the monitor's data base. Argument Block: Word Contents 0 word count including this word 1 pointer to destination area for ASCIZ name string 2 number of bytes in destination area 36 .MOSTS Set the status of the line printer. Argument Block: 3-281
TOPS-20 MONITOR CALLS (MTOPR) Word Contents 0 word count including this word 1 software status word, with the following status bits settable by the caller: B0(MO%LCP) Set line printer as a lowercase printer. B12(MO%EOF) Set bit MO%EOF in the printer status word when all data sent to printer has actually been printed. The status word can be obtained with the .MORST function. B14(MO%SER) Clear the software error condition on the line printer. This condition usually occurs on a character interrupt. Other status bits can be read with the .MORST function (see below) but cannot be set by the caller. 2 value for page counter register. The caller can indicate the number of pages to be printed by specifying a value of up to 12 bits (4096). Each time the printer reaches the top of a new page, it decrements the value by one. When the value becomes zero, the printer sets status bit MO%LPC and generates an interrupt if the .MOPSI function was given previously. If the caller specifies a value of 0 in the register, the system will maintain the page counter and will not generate an interrupt to the caller when the page counter becomes zero. If the caller specifies a value of -1 in the register, the value will be ignored. 37 .MORST Read the status of the line printer. The status is obtained from the front end, and the caller is blocked until it receives the status. Argument Block: Word Contents 0 word count including this word 3-282
TOPS-20 MONITOR CALLS (MTOPR) 1 status word. The following bits are defined: B0(MO%LCP) Line printer is a lower case printer. This bit is set only if a .MOSTS function declaring the printer lower case was executed previously. B1(MO%RLD) Front end has been reloaded. This bit is reset to zero the next time any I/O activity begins for the line printer. B10(MO%FER) A fatal hardware error occurred. This condition generates a software interrupt on channel 11 (.ICDAE). B12(MO%EOF) All data sent to printer has actually been printed. B13(MO%IOP) Output to the line printer is in progress. B14(MO%SER) A software error (for example, interrupt character, page counter overflow) occurred. B15(MO%HE) A hardware error occurred. This error generates a software interrupt on channel 11 (.ICDAE). This condition usually requires that the forms be realigned. B16(MO%OL) Line printer is offline. This bit is set on the occurrence of any hardware condition that requires operator intervention. B17(MO%FNX) Line printer does not exist. B30(MO%RPE) A RAM parity error occurred. B31(MO%LVU) The line printer has an optical (12-channel tape reader) VFU. B33(MO%LVF) A VFU error occurred. The paper has to be realigned. 3-283
TOPS-20 MONITOR CALLS (MTOPR) B34(MO%LCI) A character interrupt occurred. This generates a software interrupt on channel 11 (.ICDAE). B35(MO%LPC) The page counter register has overflowed. Bits 2-17 contain the software status word from the front end, and bits 20-35 contain the hardware status word. 2 value of page counter register. A value of -1 indicates the printer has no page counter value defined. 40 .MOFLO Flush any line printer output that has not yet been printed. PCDP Functions The functions available for physical card punches (PCDP) are described below. Like the PLPT functions, these functions accept the address of an argument block in AC3. The first word of the block contains the length (including this word) of the block. Remaining words in the block contain arguments for the particular function. Code Symbol Meaning 27 .MOPSI Enable for a software interrupt on nonfatal device conditions. Examples of these conditions are: 1. Device changed from offline to online. 2. Device changed from online to offline. Other device errors or software conditions are not handled by this function; instead they cause a software interrupt on channel 11 (.ICDAE). Argument Block: Word Contents 0 word count including this word 1 interrupt channel number 2 flags. The following flag is defined: B0(MO%MSG) Suppress standard CTY device messages. 3-284
TOPS-20 MONITOR CALLS (MTOPR) 37 .MORST Read the status of the card punch. The status is obtained from the front end, and the caller is blocked until it receives the status. Argument Block: Word Contents 0 word count including this word 1 status word. Bits 2-17 contain the software status word from the front end, and bits 20-35 contain the hardware status word. B10(MO%FER) Fatal error condition B12(MO%EOF) All pending output has been processed B13(MO%IOP) Output in progress B14(MO%SER) Software error has occurred (would generate an interrupt on an assigned channel) B15(MO%HE) Hardware error has occurred (would generate interrupt on channel .ICDAE) B16(MO%OL) Card punch is offline. This bit is set when operator intervention is required (card jam, hopper empty, or stacker full). B17(MO%FNX) Card punch doesn't exist B32(MO%HEM) Hopper is empty or stacker is full B33(MO%SCK) Stack check B34(MO%PCK) Pick check B35(MO%RCK) Read check PCDR Functions The functions available for physical card readers (PCDR) are described below. These functions accept the address of an argument block in AC3. The first word of the block contains the length (including this word) of the block. Remaining words in the block contain arguments for the particular function. Code Symbol Meaning 27 .MOPSI Enable for a software interrupt on nonfatal device conditions. Examples of these conditions are: 1. Device changed from offline to online. 3-285
TOPS-20 MONITOR CALLS (MTOPR) 2. Device changed from online to offline. Other device errors or software conditions are not handled by this function; instead they cause a software interrupt on channel 11 (.ICDAE). Argument Block: Word Contents 0 word count including this word 1 interrupt channel number 2 flags. The following flag is defined: B0(MO%MSG) Suppress standard CTY device messages. 37 .MORST Read the status of the card reader. The status is obtained from the front end, and the caller is blocked until it receives the status. Argument Block: Word Contents 0 word count including this word 1 status word. B2-17 contain the software status word from the front end, and B20-35 contain the hardware status word. B0(MO%COL) Card reader is on line. This bit is not obtained from the front end. B1(MO%RLD) Front end has been reloaded. This bit is reset to zero the next time I/O activity begins for the card reader. 10(MO%FER) A fatal hardware error occurred. This condition generates a software interrupt on channel 11 (.ICDAE). B12(MO%EOF) Card reader is at end of file. B13(MO%IOP) Input from the card reader is in progress. B14(MO%SER) A software error (for example, interrupt character) occurred. 3-286
TOPS-20 MONITOR CALLS (MTOPR) B15(MO%HE) A fatal hardware error occurred. This error generates a software interrupt on channel 11 (.ICDAE). B16(MO%OL) Card reader is off line. This bit is set on the occurrence of any hardware condition that requires operator intervention. B17(MO%FNX) Card reader does not exist. B31(MO%SFL) The output stacker is full. B32(MO%HEM) The input hopper is empty. B33(MO%SCK) A card did not stack correctly in the output stacker. B34(MO%PCK) The card reader failed to pick a card correctly from the input hopper. B35(MO%RCK) The card reader detected a read error when reading a card. PTY Functions The functions available for pseudo-terminals (PTY) are described below. Some of these functions accept arguments in AC3. (See the individual descriptions.) Code Symbol Meaning 24 .MOAPI Assign PTY interrupt channels. This function requires AC2 to contain: B0(MO%WFI) enable waiting-for-input interrupt B1(MO%OIR) enable output-is-ready interrupt B12-17(MO%SIC) software interrupt channel number for input to the PTY. The channel number used for output from the PTY is one greater than the channel number used for input to the PTY. B18-35 function code 25 .MOPIH Determine if PTY job needs input. On a successful return, AC2 contains 0(.MONWI) if PTY job is not waiting for input or contains -1(.MOWFI) if PTY job is waiting for input. 3-287
TOPS-20 MONITOR CALLS (MTOPR) 26 .MOBAT Set batch control bit. This function requires AC3 to contain 0(.MONCB) if the job is not to be controlled by batch or to contain 1(.MOJCB) if the job is to be controlled by batch. To obtain this value, the process can execute the GETJI JSYS, function .JIBAT. TTY Functions Code Symbol Meaning 25 .MOPIH Determine if TTY job needs input. On a successful return, AC2 contains 0(.MONWI) if TTY job is not waiting for input or contains -1(.MOWFI) if TTY job is waiting for input. 26 .MOSPD Set the terminal line speed. This function accepts in AC3 the desired line speed (input speed in the left half and output speed in the right half). The left half of AC2 contains flag bits indicating the type of line being set. If B0(MO%RMT) is on, the line is a remote (dataset) line. If B1(MO%AUT) is on, the line is a remote autobaud line (is automatically set at 300 baud, and the contents of AC3 are ignored. The process must have WHEEL or OPERATOR capability enabled to set B0(MO%RMT) and B1(MO%AUT). In addition, these bits can only be set at start-up time. They cannot be set during timesharing.) 27 .MORSP Return the terminal line speed. On a successful return, left half of AC2 contains flag bits indicating the type of line, and AC3 contains the speed (input speed in the left half and output speed in the right half). If B0(MO%RMT) of AC2 is on, the line is a remote line, and if B1(MO%AUT) is on, the line is a remote autobaud line. AC3 contains the speed or contains -1 if the speed is unknown or is not applicable. 30 .MORLW Return the terminal page width. On a successful return, AC3 contains the width. 31 .MOSLW Set the terminal page width. This function requires AC3 to contain the desired width. 3-288
TOPS-20 MONITOR CALLS (MTOPR) 32 .MORLL Return the terminal page length. On a successful return, AC3 contains the length. 33 .MOSLL Set the terminal page length. This function requires AC3 to contain the desired length. 34 .MOSNT Specify if terminal line given in AC1 is to receive system messages. This function requires AC3 to contain 0 (.MOSMY) to allow messages or 1 (.MOSMN) to suppress messages. 35 .MORNT Return a code indicating if terminal line given in AC1 is to receive system messages. On a successful return, AC3 contains 0 (.MOSMY) if messages are being sent to this line or 1 (.MOSMN) if messages are being suppressed to this line. 36 .MOSIG Specify if input on this terminal line is to be ignored when the line is inactive (is not assigned or opened). This function requires AC3 to contain 0 if characters on this line are are not to be ignored or 1 if characters on this line are to be ignored. When input is being ignored and characters are typed, no CTRL/G (bell) is sent, as is the normal case when characters are typed on an inactive line. 37 .MORBM Read the 128-character break mask. The argument block (filled in by monitor) is the same as for .MOSBM (below). 40 .MOSBM Set the 128-character break mask. Argument Block: E: 0,,4 E+1-E+4: character mask. The leftmost 32 bits of each consecutive word correspond to the ASCII character set in ascending order. For example, 1B0 in word E+1 (of the argument block) corresponds to ASCII code 000 (null), 1B1 in word E+1 corresponds to ASCII code 001 (SOH). Bits 32-35 of each word must be zero. 41 .MORFW Return the current value of the field width in AC3. Note that this may be less than the value last set by .MOSFW. If the field width is set to value X and two characters are read before the .MORFW is executed, the value returned will be X-2. A zero returned in AC3 indicates that no field width is now in effect. 3-289
TOPS-20 MONITOR CALLS (MTOPR) 42 .MOSFW Set the field width to the value in AC3. A zero indicates that no field width is in effect. 43 .MOXOF Enable/disable pause-at-end-of-page mode. This function controls the TOPS-20 feature that sends exactly n lines of data to the terminal and suspends data transmission (n is the terminal length parameter, set by function .MOSLL). The user may manually resume data transmission by typing ^Q. AC3 contains one of the following values: 0 .MOOFF Disable pause-at-end-of-page mode 1 .MOONX Enable pause-at-end-of-page mode Note that this feature operates independently of the pause-on-command mode implemented in the JFN mode word (see bit TT%PGM of the JFN mode word). 44 .MORXO Read the end-of-page mode. This function returns, in AC3, a one if PAUSE ON END-OF-PAGE is set for the terminal, a zero otherwise. 45 .MOSLC Set the terminal's line counter to value in AC3. This counter is incremented by the monitor everytime a linefeed is output to the terminal. The monitor clears this counter only when a line becomes active. 46 .MORLC Read the terminal's line counter and return with its value in AC3. 47 .MOSLM Set line maximum to the value in AC3. This function sets the maximum value of the line counter seen so far. The monitor compares the line counter with the maximum every time a linefeed is typed, and if the line counter value is larger, the monitor sets the line maximum to the value of the line counter. When TEXTI moves the cursor up on screen terminals, it decrements the line counter. 50 .MORLM Read the current value of the line maximum and return with its value in AC3. 51 .MOTPS Assign terminal interrupt channels. An interrupt will be generated if a character is input, or an output-buffer-empty condition occurs on output. AC3 contains the address of a two-word argument block. The first word of the block contains the 3-290
TOPS-20 MONITOR CALLS (MTOPR) number of words in the block (2), and the second word of the block contains the following: output PSI channel,,input PSI channel. All input or output PSI channels for the terminal are cleared by placing a -1 in the appropriate half, or both halves, of word 2 of the argument block. 52 .MOPCS Set the pause and unpause characters for the terminal. This function requires that AC3 contain the pause character in the left half, and the unpause (continue-after-pause) character in the right half. The characters can be the same, but should not be CTRL/Q or CTRL/S. 53 .MOPCR Read the terminal pause and unpause (continue-after-pause) characters. This function returns, in AC3, the pause character in the left half, and the unpause character in the right half. 54 .MORTF Read the setting of various terminal functions. This function returns the settings in AC3. B34(MO%NUM) All nonprivileged SENDs are refused. B35(MO%NTM) All messages are refused. 55 .MOSTF Set or clear the setting of various terminal functions. This function accepts the settings in AC3. B34(MO%NUM) Refuse all nonprivileged SENDs. B35(MO%NTM) Refuse all messages (SENDs, LINKs, nonprivileged ADVICE, privileged BOUTs and SOUTs). Implements the TERMINAL INHIBIT Command. 56 .MOTCE Set two-character escape sequence. This function requires that AC3 contain the 2-character escape sequence, right justified. Neither character can be a null, and the 2 characters cannot be the same. 57 .MORTC On return AC3 contains the 2-character escape sequence, right justified. 60 .MOCTM This function returns nonzero in AC3 if the terminal is a CTERM terminal: returns 1 if remote system supports full CTERM functionality returns 2 or greater if remote system supports limited CTERM functions 3-291
TOPS-20 MONITOR CALLS (MTOPR) 61 .MOTXT Set up for remote TEXTI% call (monitor only). Call with AC3 containing flags,,length, where flags have the same format as the .RDFLG word in the TEXTI% monitor call, and length is the maximum length of the read. The following flags are the only significant ones: RD%RIE return if input buffer is empty RD%RAI raise input RD%NED disable some editing characters AC4 contains a byte pointer to ctrl-R buffer; 0 if no reprompt text. 62 .MOHUP Hangup the terminal line specified. This function is used by a program to break the connection on a DECnet NRT, DECnet CTERM, TCP/IP TVT, or LAT terminal line. On a RSX20F terminal line configured as REMOTE, the DTR signal is lowered. Independent of this MTOPR function, when a program uses the CLOSF% JSYS to close the last JFN associated with a terminal line, DTR is lowered. The terminal line must not be the controlling terminal for any job and must be an RSX20F terminal which is configured as REMOTE in x-CONFIG.CMD. This feature provides an easy way for a program to control a dial out modem or other equipment connected to an RSX20F terminal line. 63 .MOUHU Raise DTR on the specified RSX20F terminal line. This function is used by a program to raise the DTR signal on a terminal line which is connected to RSX20F and configured as REMOTE in x-CONFIG.CMD. Independent of this MTOPR function, when a program uses the OPENF% JSYS to open a JFN on a terminal, DTR is raised. The terminal line must be an RSX20F terminal which is configured as REMOTE in x-CONFIG.CMD, and must not be the controlling terminal of a job. This feature provides an easy way for a program to raise DTR on an RSX20F terminal line to control a dial out modem or other equipment. Generates an illegal instruction interrupt on error conditions below. MTOPR ERROR MNEMONICS: ANTX01: No more network terminals available 3-292
TOPS-20 MONITOR CALLS (MTOPR) DCNX8: Invalid network operation DESX1: Invalid source/destination designator DESX2: Terminal is not available to this job DESX3: JFN is not assigned DESX4: Invalid use of terminal designator or string pointer DESX5: File is not open DESX9: Invalid operation for this device DEVX2: Device already assigned to another job IOX4: End of labels encountered IOX5: Device or data error MTOX1: Invalid function MTOX2: Record size was not set before I/O was done MTOX3: Function not legal in dump mode MTOX4: Invalid record size MTOX5: Invalid hardware data mode for magnetic tape MTOX6: Invalid magnetic tape density MTOX7: WHEEL or OPERATOR capability required MTOX8: Argument block too long MTOX9: Output still pending MTOX10: VFU or RAM file cannot be OPENed MTOX11: Data too large for buffers MTOX12: Input error or not all data read MTOX13: Argument block too small MTOX14: Invalid software interrupt channel number MTOX15: Device does not have Direct Access (programmable) VFU MTOX16: VFU or Translation RAM file must be on disk MTOX17: Device is not on line MTOX18: Invalid software interrupt channel number MTOX19: Invalid terminal line width MTOX20: Invalid terminal line length MTOX21: Illegal two-character escape sequence TTYX01: Line is not active Allows privileged programs to perform various utility functions for magnetic-tape MT: devices. This JSYS differs from the MTOPR JSYS in that the invoking program need not have a JFN on the MT nor need it even have access to the MT. It is used by MOUNTR to declare a volume switch error and by the access-control program (user supplied) to read file and volume labels. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Function code 3-293
TOPS-20 MONITOR CALLS (MTU%) AC2: MT unit number AC3: Address of argument block RETURNS +1: Always The functions and associated argument blocks are as follows: Code Symbol Function 1 .MTNVV Declare volume switch error Argument Block: Word Symbol Contents 0 .MTCNT count of words in block 1 .MTCOD error code to return to user 2 .MTPTR byte pointer to operator response 2 .MTRAL Read labels Argument Block: Word Symbol Contents 0 .MTCNT count of words in block 1 .MTVL1 byte pointer to area to hold VOL1 label 2 .MTVL2 byte pointer to area to hold VOL2 label 3 .MTHD1 byte pointer to area to hold HDR1 label 4 .MTHD2 byte pointer to area to hold HDR2 label If any of the byte pointers is zero, the associated string is not returned. The label values are always returned without translation. For example, if the tape is an EBCDIC labeled tape, the returned data will be EBCDIC data. 3 .MTASI Return assignment information Argument Block: Word Symbol Contents 0 .MTCNT count of words in block 3-294
TOPS-20 MONITOR CALLS (MTU%) 1 .MTPHU returned MTA number associated with the MT. If there is no association, .MTNUL is returned. This function is used by MOUNTR to determine if there are any existing MT to MTA associations. 4 .MTCVV Clear the volume ID for the specified MT unit. This request will fail if the MT is opened or if the volume belongs to a labeled volume set. Requires WHEEL or OPERATOR capability enabled. There is no argument block. MTU% ERROR MNEMONICS: ARGX04: Argument block too small ARGX05: Argument block too long CAPX1: WHEEL or OPERATOR capability required DESX1: Invalid source/destination designator DESX9: Invalid operation for this device IOX8: Monitor internal error OPNX1: File is already open OPNX8: Device is not on line Performs various IPCF (Inter-Process Communication Facility) functions, such as enabling and disabling PIDs, assigning PIDs, and setting quotas. See the TOPS-20 Monitor Calls User's Guide for an overview and description of the Inter-Process Communication Facility. RESTRICTIONS: Some functions require WHEEL, OPERATOR, or IPCF capability enabled. ACCEPTS IN AC1: Length of argument block AC2: Address of argument block RETURNS +1: Failure, error code in AC1 +2: Success. Responses from the requested function are returned in the argument block. The format of the argument block is as follows: 3-295
TOPS-20 MONITOR CALLS (MUTIL) Word Meaning 0 Code of desired function. (See below.) 1 through n Arguments for the desired function. The arguments, which depend on the function requested, begin in word 1 and are given in the order shown below. Responses from the requested function are returned in these words. The available functions, along with their arguments, are described below. Code Symbol Meaning 1 .MUENB Enable the specified PID to receive packets. The PID must have been created by the caller's job. Also, if the calling process was not the creator of the PID, the no-access bit (IP%NOA) must be off in the IPCF packet descriptor block. Argument PID 2 .MUDIS Disable the specified PID from receiving packets. The PID must have been created by the caller's job. Also, if the calling process was not the creator of the PID, the no-access bit (IP%NOA) must be off in the IPCF packet descriptor block. Argument PID 3 .MUGTI Return the PID associated with <SYSTEM>INFO. The PID is returned in word 2 of the argument block. Argument PID or job number 4 .MUCPI Create a private copy of <SYSTEM>INFO for the specified job. The caller must have IPCF capability enabled. Arguments PID to be assigned to <SYSTEM>INFO PID or number of job creating private copy 5 .MUDES Delete the specified PID. The caller must own the 3-296
TOPS-20 MONITOR CALLS (MUTIL) PID being deleted. To obtain ownership of the PID, the caller can first use the .MUCHO function to assign the PID to the caller's job. Argument PID 6 .MUCRE Creates a PID for the specified process or job. The flags that can be specified are B6(IP%JWP) to make the PID job wide and B7(IP%NOA) to prevent access to PID from other processes. The caller must have IPCF capability enabled if the job number given is not that of the caller. The PID created is returned in word 2 of the argument block. If a job number is specified, the created PID will belong to the top fork of the job. Argument flags,,process handle or job number 7 .MUSSQ Set send and receive quotas for the specified PID. The caller must have IPCF capability enabled. The new send quota is given in B18-26, and the new receive quota is given in B27-35. The receive quota applies to the specified PID, but the send quota applies to the job to which that PID belongs. Arguments PID new quotas 10 .MUCHO Change the job number associated with the specified PID. The caller must have WHEEL capability enabled. Arguments PID new job number or PID belonging to new job 11 .MUFOJ Return the job number associated with the specified PID. The job number is returned in word 2 of the argument block. Argument PID 3-297
TOPS-20 MONITOR CALLS (MUTIL) 12 .MUFJP Return all PIDs associated with the specified job. Two words are returned, starting in word 2 of the argument block, for each PID. The first word is the PID. The second word has B6(IP%JWP) set if the PID is job wide and B7(IP%NOA) set if the PID is not accessible by other processes. The list is terminated by a 0 PID. Argument job number or PID belonging to that job 13 .MUFSQ Return the send and receive quotas for the specified PID. The quotas are returned in word 2 of the argument block with the send quota in B18-26 and the receive quota in B27-35. The receive quota applies to the specified PID, but the send quota applies to the job to which that PID belongs. Argument PID 15 .MUFFP Return all PIDs associated with the same process as that of the specified PID. The list of PIDs returned is in the same format as the list returned for the .MUFJP function (12). Argument PID 16 .MUSPQ Set the maximum number of PIDs allowed for the specified job. The caller must have IPCF capability enabled. Arguments job number or PID PID quota 17 .MUFPQ Return the maximum number of PIDs allowed for the specified job. The PID quota is returned in word 2 of the argument block. Argument job number or PID 20 .MUQRY Return the Packet Descriptor Block for the next packet in the queue associated with the specified 3-298
TOPS-20 MONITOR CALLS (MUTIL) PID. An argument of -1 returns the next descriptor block for the process, and an argument of -2 returns the next descriptor block for the job. The descriptor block is returned starting in word 1 of the argument block. The calling process and the process that owns the specified PID must belong to the same job. Argument PID 21 .MUAPF Associate the PID with the specified process. The calling process and the process that owns the specified PID must belong to the same job. Arguments PID process handle 22 .MUPIC Place the specified PID on a software interrupt channel. An interrupt is then generated when: 1. The .MUPIC function is issued while the PID has one or more messages in its receive queue. 2. The PID's receive queue changes its state from empty to containing a message. Subsequent entries to a queue that is not empty do not cause an interrupt. If the channel number is given as -1, the PID is removed from its current channel. The calling process and the process that owns the specified PID must belong to the same job. Arguments PID channel number 23 .MUDFI Set the PID of <SYSTEM>INFO. An error is given if <SYSTEM>INFO already has a PID. The caller must have IPCF capability enabled. Argument PID of <SYSTEM>INFO 3-299
TOPS-20 MONITOR CALLS (MUTIL) 24 .MUSSP Place the specified PID into the system PID table at the given offset. The caller must have WHEEL, OPERATOR, or IPCF capability enabled. See .MURSP for a list of system PIDs. Arguments index into system PID table PID 25 .MURSP Return a PID from the system table. The PID is returned in word 2 of the argument block. The system PID table currently has the following entries: 0 .SPIPC Reserved for DEC 1 .SPINF PID of <SYSTEM>INFO 2 .SPQSR PID of QUASAR 3 .SPMDA PID of QSRMDA 4 .SPOPR PID of ORION 5 .SPNSR PID of NETSER 6 .SPCUS PID of CUSTOM APPLICATION (used by QUEUE%) 7 .SDIPC PID of DEBUG IPCC (used by QUEUE%) 10 .SDINF PID of DEBUG <SYSTEM>INFO (used by QUEUE%) 11 .SDQSR PID of DEBUG QUASAR (used by QUEUE%) 12 .SDMDA PID of DEBUG QSRMDA (used by QUEUE%) 13 .SDOPR PID of DEBUG ORION (used by QUEUE%) 14 .SDNSR PID of DEBUG NETSER (used by QUEUE%) 15 .SDCUSf PID of DEBUG CUSTOM APPLICATION (used by QUEUE%) Argument index into system PID table 26 .MUMPS Return the system-wide maximum packet size. The size is returned in word 1 of the argument block. 27 .MUSKP Set PID to receive deleted PID messages. Allows a controller task to be notified if one of its subordinate tasks crashes. After this function is performed, if the subordinate PID is ever deleted (via RESET or the .MUDES MUTIL function), the monitor will send an IPCF message to the controlling PID notifying it that the subordinate 3-300
TOPS-20 MONITOR CALLS (MUTIL) PID has been deleted. This message contains .IPCKP in word 0 and the deleted PID in word 1. Argument Source (subordinate) PID Object (controller) PID 30 .MURKP Return controlling PID for this subordinate PID. Argument Source (subordinate) PID Object (controller) PID (returned) MUTIL ERROR MNEMONICS: IPCFX2: No message for this PID IPCFX3: Data too long for user's buffer IPCFX4: Receiver's PID invalid IPCFX5: Receiver's PID disabled IPCFX6: Send quota exceeded IPCFX7: Receiver quota exceeded IPCFX8: IPCF free space exhausted IPCFX9: Sender's PID invalid IPCF10: WHEEL capability required IPCF11: WHEEL or IPCF capability required IPCF12: No free PID's available IPCF13: PID quota exceeded IPCF14: No PID's available to this job IPCF15: No PID's available to this process IPCF16: Receive and message data modes do not match IPCF17: Argument block too small IPCF18: Invalid MUTIL JSYS function IPCF19: No PID for [SYSTEM]INFO IPCF20: Invalid process handle IPCF21: Invalid job number IPCF22: Invalid software interrupt channel number IPCF23: [SYSTEM]INFO already exists IPCF24: Invalid message size IPCF25: PID does not belong to this job IPCF26: PID does not belong to this process IPCF27: PID is not defined IPCF28: PID not accessible by this process IPCF29: PID already being used by another process IPCF30: job is not logged in IPCF32: page is not private IPCF33: invalid index into system PID table IPCF35: Invalid IPCF quota IPCF36: PID not assigned on this LCS processor 3-301
TOPS-20 MONITOR CALLS (NI%) Provides the TOPS-20 user interface to the Ethernet. RESTRICTIONS: Requires WHEEL or OPERATOR capability enabled. ACCEPTS IN AC1: Address of argument block RETURNS +1: Always NI% JSYS OVERVIEW The NI% JSYS provides a mechanism for transmitting and receiving data over an Ethernet. A general description of the Ethernet, including the architectural structure, can be found in the Ethernet Specifications, Version 2. Portals Portals are the basic working entity of the NI% JSYS. A portal uniquely identifies a particular user of the Ethernet. In order to transmit and receive data, you must have a portal. There are two types of portals: 1. Regular (transmit and receive) 2. Information-only A regular portal includes the following information: 1. PSI channels 2. Ethernet channel number 3. Your protocol type 4. Your enabled multicast addresses 5. List of outstanding transmit and receive buffers 6. Counters Information-only portals only include PSI channels. They have no protocol type and cannot transmit or receive. Portal ID A portal ID is a half-word (18-bit) value that uniquely identifies a portal to the NI% JSYS. Portal IDs are fork-wide unique numbers that 3-302
TOPS-20 MONITOR CALLS (NI%) start at 1 and increase by 1 for every new portal that is opened. Portal IDs are assigned beginning with the lowest available portal ID. Protocol Types The protocol type field, EI%PRO, within word .EIPRO, can have several meanings depending on the value it contains. The possible values are: Value Meaning 0-177777 Normal Ethernet protocol types. -1 Information only. No protocol type is associated with this portal. The portal is able to perform any function except transmit or receive functions. -2 Promiscuous mode is enabled (receive all Ethernet traffic). No other protocol types can be enabled by any user on the system while promiscuous mode is enabled. -3 Unknown Protocol Type Queue is assigned to this portal. This queue receives messages that do not match any other enabled protocol types. Buffer Descriptor Block Both receive and transmit buffers are described by one type of block. This block is called a Buffer Descriptor Block. Each block contains all the information pertinent to a single buffer. Word Symbol Meaning 0 .BXLEN Length of block (including this word). 1 .BXNXT Pointer to next Buffer Descriptor Block. 2 .BXBSZ Length of buffer (byte count). (Returns: length of datagram.) 3 .BXBFA Byte pointer to beginning of buffer. (Returns: byte pointer to beginning of received data.) 5 .BXBID Buffer ID (36-bit value associated with the buffer). 6 .BXSTA B0(BX%VAL) This block is valid (return only). B18-35(BX%STA) Status mask (return only). 7 .BXDAD Destination Ethernet address. 3-303
TOPS-20 MONITOR CALLS (NI%) 11 .BXSAD Source Ethernet address (return only). 13 .BXPRO Protocol type. A number of receive buffers can be associated with each portal. Receive buffers are queued by the .EIRCV (post a receive buffer) function. When a datagram is received, the received buffer is put onto an internal monitor receive queue. If this receive queue makes a transition from empty to non-empty, an interrupt is generated on the "receive completion" channel. The .EIRRQ (read receive queue) function is used for reading the internal receive queue. This function takes a Buffer Descriptor Block chain as an argument. Each block in the chain is filled in with all the information specific to a received buffer. This includes a byte count, a byte pointer, and a buffer ID. Buffer Descriptor Blocks are chained by placing a pointer in .BXNXT. This capability allows for efficient manipulation of multiple datagram buffers with fewer monitor calls. Receive Buffer Pointer The location of a receive buffer is specified by a byte pointer (any format) stored in .BXBFA and .BXBFA+1. Receive Buffer Size The size of a receive buffer (in bytes) is specified in .BXBSZ. The size in .BXBSZ depends on whether or not padding is enabled. If padding is not being used with this portal, the buffer size must include room for: 1. User data field from the received datagram (46-1500 (decimal) bytes long). 2. Cyclic Redundancy Check (CRC) (four bytes long). For example, if the maximum message size for your protocol is 100 bytes, you must use receive buffers that are 104 bytes long. For portals that use padding, the buffer size must include room for: 1. Data Length Field (two bytes long). 2. User data field from the received datagram (44-1498 (decimal) bytes long). 3-304
TOPS-20 MONITOR CALLS (NI%) 3. Cyclic Redundancy Check (CRC) (four bytes long). For example, if your protocol specifies that padding should be used, and states that the maximum message size (excluding padding) is 200 bytes long, you must use receive buffers that are 206 bytes long. NOTE The minimum receive buffer size is 50 (decimal) bytes, and the maximum receive buffer size is 1504 (decimal) bytes. Received Datagram Pointer The byte pointer returned in .BXBFA is the same type that was specified when the buffer was originally queued. This byte pointer (any format) points to the first byte of user data. If padding is not in use, the byte pointer is identical to the one that was used to post the buffer. If padding is in use, the byte pointer is advanced past the data length field. Received Datagram Length .BXBSZ contains the length of only the data portion of the message (not including the CRC). If padding is in use, .BXBSZ contains the value in the data length field of the padded datagram. Receive Buffer Constraints There are a number of constraints on receive buffers: o They must be word-aligned. o Trailing bytes are indeterminate. Due to a hardware restriction, the buffer must be word aligned. Therefore, the byte pointer must indicate a word-aligned byte. As an example, byte pointers 441000,,ADDR and 011000,,ADDR-1 are both valid byte pointers to a word-aligned buffer at ADDR. Note that if the length of the received datagram is not a multiple of four, the trailing bytes, up to the end of the last word, are indeterminate after the buffer is filled. For example, if you specified a length of 41 (decimal) bytes, there is room for three more bytes within the last word of the buffer, and the contents of those bytes are indeterminate. Transmit Buffers Transmit buffers are queued to the channel by the .EIXMT (send a 3-305
TOPS-20 MONITOR CALLS (NI%) datagram) function. Any number of buffers can be queued at a given time. When the channel completes transmission of a buffer, an interrupt is signaled on the "Transmission Complete" interrupt channel. The list of transmitted buffers can be obtained via the .EIRTQ (read transmit queue) function. .BXBFA and .BXBFA+1 contain a byte pointer (any format) to a buffer, and .BXBSZ contains the length of that buffer (in bytes). Unlike receive buffers, transmit buffers do not need to be word aligned. The maximum and minimum data lengths depend on whether padding is in use. If padding is in use, the maximum data length is 1498 (decimal) bytes, and the minimum data length is zero. When padding is not in use, the maximum data length is 1500 (decimal) bytes, and the minimum data length is 46 (decimal) bytes. Channel States The Ethernet channel participates in a state machine that can be observed and partially controlled by the user. User Symbol Settable Meaning .EISVG No Virgin - has never run before .EISRE Yes Reload - reload requested .EISCR No Cannot reload - reload request timed out .EISIN No Init - waiting for response to first command .EISRN Yes Run - channel is running and can accept commands .EISDP Yes Dump - a dump was requested .EISDR Yes Dump and reload - dump followed by a reload request .EISBK No Broken - channel cannot be initialized .EISOF Yes Off - channel is off .EISRR Yes Reload requested - make KNILDR run The NI% JSYS also provides a number of other functions for obtaining information and controlling the Ethernet. These are described in the individual function descriptions on the following pages. All functions use the same general argument block format: 3-306
TOPS-20 MONITOR CALLS (NI%) Word Symbol Meaning 0 .EILEN B0-17 (EI%LEN) Length of argument block .EIFCN B18-35(EI%FCN) Function code (see below) 1 through n Arguments for the desired function. The arguments, which depend on the function requested, begin in word 1 and are described as part of the specific function descriptions. NOTE All fields that are not explicitly described in the description for a particular function are ignored by that function. The following errors are possible on failure from all functions: CAPX1: WHEEL or OPERATOR capability required NIEIFC: Illegal Function Code The available functions are: Function Code Symbol Meaning 1 .EIOPN Open a portal 2 .EICLO Close a portal 3 .EIRCV Post a receive buffer 4 .EIRRQ Read receive queue 5 .EIXMT Transmit datagram(s) 6 .EIRTQ Read transmit queue 7 .EIEMA Enable a multicast address 10 .EIDMA Disable a multicast address 11 .EIRPL Read portal list 12 .EIRCL Read channel list 13 .EIRPC Read portal counters 14 .EIRCC Read channel counters 15 .EIRCI Read channel information 3-307
TOPS-20 MONITOR CALLS (NI%) 16 .EISCS Set channel state 17 .EISCA Set channel address 20 .EIGET Obtain ownership of the channel 21 .EIREL Release ownership of the channel 22 .EIRPI Read portal information 22 .EIMAX Maximum function value The available functions, along with their arguments, are described below. Open a Portal - .EIOPN This function creates portals. It returns a portal ID in .EIPID. The same portal ID must be used in all subsequent calls that are associated with this portal. The portal is always created, even if the channel is not running (as indicated by .EISTA). This is done so the user can be notified of the channel coming online without having to poll. The format of the argument block is: Word Symbol Meaning 1 .EIFLG B4(EI%PAD) Enable padding feature with this portal .EIPID B18-35(EI%PID) Portal ID (return only) 2 .EICHN B0-17(EI%CHN) Ethernet channel number .EIPRO B18-35(EI%PRO) Protocol type 3 .EIPSI B0-11(EI%TCH) Software interrupt channel for notification of transmit complete B12-23(EI%RCH) Software interrupt channel for notification of receive complete B24-35(EI%SCH) Software interrupt channel for notification of status change 4 .EISTA Ethernet channel status (return only) The protocol type must not be associated with any other existing portals on the system. It is not possible to transmit or receive on a protocol type that is already assigned. Fields EI%TCH, EI%RCH, EI%SCH are used to indicate which software 3-308
TOPS-20 MONITOR CALLS (NI%) interrupt channels should be used to indicate the occurrence of certain events. If an interrupt is not desired for a particular event, -1 should be placed in the field corresponding to that event. The following errors are possible on failure of this function: MONX05: Insufficient system resources (no resident free space) MONX06: Insufficient system resources (no swappable free space) NIENSC: No such channel NIEIVP: Illegal value for protocol type field NIEPIU: Protocol type already in use Close a Portal - .EICLO This function closes portals and releases all resources associated with a portal. EI%PID indicates which portal will be closed. The format of the argument block is: Word Symbol Meaning 1 .EIPID B18-35(EI%PID) Portal ID The following error is possible on failure of this function: NIENSP: No such portal Post a Receive Buffer - .EIRCV This function supplies buffers to the channel driver for the asynchronous receipt of datagrams. The format of the argument block is: Word Symbol Meaning 1 .EIFLG B0(EI%BLK) Function should block B1(EI%TBA) Transmit buffer available