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The DEC PDP-10 Emulation Webpage

Last Updated: 2022-06-06

Latest News!

(2022-06-03) Announcing the Open SIMH project!
The SIMH Steering Group
Clem Cole
Richard Cornwell
Paul Koning
Timothe Litt
Seth Morabito
Bob Supnik
(2022-04-12) Richard Cornwell has added KS10 support to SIMH, with this addition, all of DEC's PDP-10 models are now supported in his release. His KS10 emulation is a cross between KLH10 and Bob Supnik's KS10 release in SIMH. It will run ITS with IMP and Chaosnet, and supports up to 1MW of memory.
Additionally build systems for many versions of TOPS-10 and TOPS-20 can be found at his website.
(2020-03-10) Richard Cornwell has added KL10 support to SIMH, with this addition, all of DEC's PDP-10 models are now supported!
(2019-07-10) Richard Cornwell has completed his KA10 and KI10 simulators!
(2019-03-14) Richard Cornwell notes that his KA10 simulator is getting close to release
to the main SIMH tree, and that the also supports the KI10. He will be adding support for the PDP-6.
(2019-03-14) Lars Brinkhoff is continuing his work on ITS, and he has a nearly complete
system running now that builds on Rich's KA10, KLH10 and Bob's KS10 simulator.
(2018-02-10) I'm in the process on putting notes on each link, to show that it's been verified, or that it's dead.
(2018-01-16) Richard Cornwell has made a KA10 emulator that can run TOPS-10 and ITS based on SIMH. It has not been merged with the SIMH codebase at this time. You have to boot from paper-tape to install ITS, currently Lars Brinkhoff is working on an automated install, which will be found at when complete. (Link verified - Feb 2018)
(2017-10-11) Starting to update the webpages after a decade long haitus, additionally the webpages just moved from the homedirectory at my old ISP, to a server of mine.
(2012-05-03) SIMH V3.9-0 released.
(2007-02-03) SIMH V3.7-0 released.
(2006-06-29) Mark Crispin's Panda distribution of TOPS-20 is now available for download. It includes klh10-2.0h, and a prebuilt image of TOPS-20 with many enhancements and third party software that can't be found anywhere else. (Link verified - Feb 2018)


This page is very out of date, but as of February 2018, I'm in the process of updating it.

The purpose of this web page is to aid people in finding all the bits and pieces that they'll need in order to set up the PDP-10 OS of their choice (if possible) running under an emulator. I started this webpage as a way that I could keep track of where everything is, and I'm trying to keep it as up to date as possible. I've broken the webpage down into the four main steps of obtaining an emulator, getting the installation documentation for the OS of your choice, getting the software, and then getting further documentation.

Please note that most of the links below are to data located at other peoples sites. I've tried to ensure that in all cases it's obvious who's site the data is located at.

If you're new to the PDP-10 and it's Operating Systems, I'd recommend starting with either TOPS-10 V7.03 or TOPS-20 V7.0.

Table of Contents

  1. Obtain an emulator
  2. Obtain Installation Documentation
  3. Obtain Software
  4. Obtain Further Documentation
  5. Adding Additional Software
  6. Mailing Lists
  7. Public Access Systems
  8. Other
  9. Related PDP-10 Links


Contacting Me

If you have any comments about this page I can be reached at healyzh AT avanthar DOT com. If you know of any software or documentation that isn't listed below I'd appreciate knowing about it so that I can provide links. Also, if anyone has scanned in PDP-10 documenation, and needs a server to host it, I've plenty of disk space.

System Requirements In Progress

Tips and Tricks A work in progress

Step 1. Obtain an emulator:

At this point the best choice for OS's other than Linux is simh, I'm not sure which is the best for Linux. In order to get an idea of the capabilities of the various emulators I've created a page comparing the various emulators. (Link verified - Feb 2018)

Step 2. Obtain Installation Documentation:

One of the temptations that has existed for people installing TOPS-10 is to use the documentation I wrote in March of 2001, when no documentation was available. Don't do this, use the correct Monitor Installation Guide (MIG) listed below.

There has been some concern expressed by people trying to figure out how to install TOPS-20 4.1 since there isn't a Monitor Installation Guide available for it. While it can be tricky, it is possible to install it using the procedure written up by Bob Supnik, and you will find useful information in the 7.0 Installation Guide. I'd never touched a TOPS-20 system in my life, and this is how I installed TOPS-20.

Step 3. Obtain Software:

Of the OS's that existed on the PDP-10 currently two versions of TOPS-10, two versions of TOPS-20, and ITS are available. With TOPS-10, V7.04 is the last version that was available, however V7.03 is the preferred on at least TS10 and SIMH (it looks like it should work just fine on KLH10). For TOPS-20 you can run V4.1 on the KS10 emulators, or V7.0 on the KL10B version of KLH10. As for ITS, I'm not really sure what version is available, it says it's ITS1633 and DDT 1546 when it boots. There are older versions of TOPS-10 and TOPS-20 available at Tim Shoppa's PDP-10 Software Archive, but at this time I don't think anyone has tried to get them to boot. (Link verified - Feb 2018)

  1. TOPS-10 7.03 Distribution Tim Shoppa's site
    1. The distribution Tape
    2. MPE - (CPNSER) - an unbundled product Johnny Eriksson's site
    3. DECnet-10 - an unbundled product Johnny Eriksson's site
    4. Bootable Media (KL10) (KS10) You'll need the KS10 tape for SIMH
    5. DEC-Supported CUSP Distribution (tape 1) (tape 2)
    6. Customer Supported Tape
    7. Tools Tape
  2. TOPS-10 7.03 Prebuilt system Paul Allen's site
    1. For SIMH
    2. A prebuilt 7.03 system with DSKB and DSKC structures and a monitor that supports printing and serial logins.
    3. At least the following tapes look to have already been added.
      TOPS-10 Integration Tools, V4, 10-Jan-1986 [1,2,EDT]
      BASIC-10 V17F [1,2,BASIC]
      Kermit [76,5,kermit]
      TOPS-10 Customer Supported CUSPs [1,2,140B]
  3. TOPS-10 7.03 Prebuilt System Bill Schaub's Site
    1. For SIMH
    2. Homepage
    3. Based on the image at Paul Allen's site. So far it adds APLSF V2 (435), BLISS-36 V4.2 (236), DBMS V5A, IQL3A V30, Message System V11CK , ALGOL-10 Version 10A, COBOL(68 and 74) and FORTRAN.
  4. TOPS-10 7.04 Distribution (I've heard that someone has now gotten this at least partially running) Primarily Tim Shoppa's site
    1. The distribution Tape
    2. MPE - (CPNSER) - an unbundled product Probably not usable
    3. DECnet-10 - an unbundled product (all that exists is a DECnet-10 Supplemental Tape which is unusable)
    4. DEC-Supported CUSP Distribution (tape 1) (tape 2)
    5. Customer Supported Tape
    6. Customer Supported Tools Tape
    7. RSX20F - DECtapes (KL10-D sites)
    8. RSX20F - Floppy diskettes (KL10-E/R sites) John Wilson's site
  5. TOPS-10 7.04 Prebuilt system Ken Harrenstein's site
    1. For KLH10 / KL10B
    2. A prebuild 7.04 system with DSKA and DSKB structures with the following prebuilt montiors
      1. 704NON.EXE - TOPS-10 V7.04 no network, won't try to load KLNI
      2. 704LAT.EXE - TOPS-10 V7.04 with just LAT
      3. 704DCN.EXE - TOPS-10 V7.04 with DECnet and LAT
      4. SYSTEM.EXE - TOPS-10 V7.04 for the KS
    3. Install done by Larry Sendlosky
    4. This is a very basic install. It doesn't contain things such as the HLP files, or Source to rebuild the monitor. As a result you'll still need to load a lot of stuff off of tape. However MX works on this system!
  6. TOPS-10 6.03a Richard Cornwell's site
    1. Automated Build (Link verified - April 2019)
    2. According to Rich:
      1. "This includes automated builds of the system and many of the layered
  7. TOPS-10 5.03 Richard Cornwell's site
    1. Automated Build (Link verified - April 2019)
    2. According to Rich:
      1. "This has many fixes from the version that was on the DECUS tape. It
        has slow output on console, but that is an issue with TOPS10 not the
        simulator. I believe there is some issue with how terminal I/O was
  8. TOPS-20 4.1 Distribution Tim Shoppa's site
    1. TOPS-20 V4.1 2020 Installation tape
    2. TOPS-20 V4.1 2020 Distribution (tape 1) of (tape 2)
    3. TOPS-20 V4.1 Tools tape
    4. TOPS-20 V4.1 TP#12 "Exec Src Mod"
    5. TOPS-20 V4.1 TP#12 "Monitor Sources"
  9. TOPS-20 7.0 Distribution Tim Shoppa's site
    1. TOPS-20 V7.0 Installation BB-H137F-BM
    2. TCP/IP-20 V4.0 Distribution BB-EV83B-BM
    3. TOPS-20 V7.0 Distribution Tape 1 of 2 BB-H138F-BM
    4. TOPS-20 V7.0 Distribution Tape 2 of 2 BB-LW55A-BM
    5. TOPS-20 V7.0 Monitor Source BB-M780D-SM
    6. TOPS-20 V7.0 EXEC Source BB-GS97B-SM
    7. TOPS-20 V7.0 #04 MON SRC MOD BB-M080Z-SM
    8. TOPS-20 V7.0 #04 EXEC SRC MOD BB-M081Z-SM
    9. TOPS-20 V7.0 TSU04 Tape 1 OF 2 BB-PENEA-BM
    10. TOPS-20 V7.0 TSU04 Tape 2 OF 2 BB-KL11M-BM
    11. TOPS-20 V7.0 Tools BB-M836D-BM
  10. TOPS-20 7.x Panda Distribution
    1. Panda Programming TOPS-10 Home Page Mark Crispin's site (Deceased Link)
    2. Panda TOPS-20 distribution at trailing-edge
  11. MIT ITS - The Incompatible Timesharing System (Requires simh 2.6b or 2.7beta4, it and the RP06 emulation don't seem to agree, I was able to install it on a RM03 disk). Mirian Crzig Lennox's site
    1. Alan Bawden has made sanitized (ie doesn't contain peoples personal projects and email) copies of AI and MC final backups available. Information about this can be found here.
  12. MIT ITS Prebuilt System
    1. For KLH10 / KS10
    2. Can be found at this site
  13. ITS for KA10, KL10, KS10 and KLH10 on Github.
  14. BBN TENEX Nothing Available
  15. Stanford WAITS - Westcoast Alternative to ITS
    1. A prebuilt system is now available to download.
  16. Tymshare TYCOM-X Nothing Available

Step 4. Obtain Further Documentation

As anyone that knows me is aware, I view documentation as the single most important thing, with the software coming in a close second. This is the case, both with systems I own such as my PDP-11's, and with systems I'm emulating.

The AI ITS documentation is just about the only local resource. The original files were made available by Alan Bawden, and I've built web indexes to the files to allow for easy access. I've also created links from this page to some of the more interesting documents.

  1. TOPS-10 Documentation
  2. Tim Shoppa's TOPS-10 V7.04 Doc Archive Tim Shoppa's site (Link verified - Feb 2018)
  3. TOPS-10 Software Notebooks (January 1989) Al Kossow's site
  4. TOPS-10 Monitor Internals Course Al Kossow's site
  5. TOPS-20 V3 Documentation Al Kossow's site
  6. TOPS-20 V5 Documentation Al Kossow's site
  7. TOPS-20 V6.1 Documentation Al Kossow's site
  8. TOPS-20 V7.0 Doc Archive local copies of the files found in TOAD:<DOCUMENTATION> to see what's missing check the TOPS-20 Software Notebook Set page. Warning: Unfortunatly it has come to my attention that the PDF and HTML conversions are less than perfect, as such the text versions are the ones to use. (Link verified - Feb 2018)
  9. TOPS-20 Documentation
  10. ITS Documentation
  11. BBN TENEX Al Kossow's site (BBN) (University of Hawaii)
  12. Stanford WAITS - Westcoast Alternative to ITS Nothing Available
  13. Tymshare TYCOM-X Nothing Available
  14. Applications Documentation
  15. Other Documentation

Step 5. Adding Additional Software

Once you've got your system up and running you'll most likely want to add some additional software. Obviously your first stop will be Tim Shoppa's PDP-10 Software Archive. What follows are some of the highlights of that archive and software that is available elsewhere. (Link verified - Feb 2018)


Mailing Lists

Mirian Crzig Lennox has created a mailing list for people interested in ITS with an emphasis on using it on the emulators. It is also for supporting people using her ITS Starter Kit. In order to subscribe send an empty email with "subscribe" in the subject line to The list is currently not archived on the web and if at a later date it is, peoples email addresses will be munged to prevent the harvesting of them. To prevent spam, you must be subscribed in order to post to the list.

Public Access Systems

There are a few publically accessable systems on the Internet. These systems are only listed here with thier owners permission. If you have such a system, and would like to have it listed, pleast let me know and I would be happy to add it to the list. I can be contacted at 'healyzh at aracnet dot com'.

If you access any of these systems please be considerate and avoid doing damage to them. Remember these systems are the work of fellow hobbyists, and they are providing a generous service by opening up thier systems to you.


I'm not really sure where to put this information, so am sticking it here temporarily. (30DEC02, I'm not sure where this stuff is, you'll want to poke around the FTP site to see if you can find it if you're interested) (Dead links)

Thu, 11 Oct 2001 13:52:41 
Johnny Eriksson <bygg at stacken,kth,se>
Newsgroups: alt.sys.pdp10
Tops10/Ethernet/IP, status is:
* A couple of updates to the DEUNA support in SIMH.
* An IP stack with UDP support, but not yet TCP.  Written under 7.04, but
  the changes to the DEC modules are fairly small and should be easily
  ported to other versions.  *.dif/*.mac files provided.
* A sligthly working tftp daemon.

As usual, regard this as beta quality, at best.

Related PDP-10 Links

Outdated Information

Prior to the discovery of the TOPS-10 7.03 MIG I'd written a Installation of TOPS-10 v7.03 document and Michael Thompson has done an updated version of this document.

DEC Emulation Website (Main Page) -- PDP-1 -- PDP-4 -- PDP-6 -- PDP-7 -- PDP-8 -- PDP-9 -- PDP-10 -- PDP-11 -- PDP-15 -- VAX -- Alpha -- MIPS -- FPGA -- Other: Honeywell DPS-6 -- Other: Honeywell DPS-8