New book about the PiDP-10 including ITS, TOPS-10 and TOPS-20

[Andrew Barron]

Hi everyone, I am pleased to announce that I have finished my book about the PiDP-10. When I finished building the kit, I was unsure how to make it do anything. The manual Lars Brinkhoff wrote was excellent and got me started. But I wonder how many completed kits never get much past running the 'Blinkin Lights' program. 

This is the link to the book on Amazon. https://www.amazon.com/dp/B0FNJC5PQ7. 

It will be available from Amazon in:

• USUKDEFRESITNLPLSEJPCAAU
  
  You can see what it looks like, check the Contents page, and read a sample on the Amazon website. The book is aimed at new users, not seasoned professionals. It will get you started on the ITS, TOPS-10, and TOPS-20 operating systems. There are small sample programs in Cobol, Fortran, Lisp, ALGOL, BASIC, FORTH, C, MacLisp, Interlisp, and a few others. Plus a little PDP-10 history and some of the specifications like disk sizes and blocks etc. It is aimed making the PiDP-10 and its operating systems interesting and fun!
  
  BTW you don't have to have a PiDP10 kit. The book is just as useful if you are just using the PDP-10 emulator software. 

This is a link to see my other books. https://www.qsl.net/zl3dw/Books.html 

The page about the PiDP-10 book is at https://www.qsl.net/zl3dw/PiDP-10.html but it just repeats what I have said here. 

This is the Amazon "sales pitch" for the book.

This book is about the PiDP-10 kit and the three operating systems that you can run on it. You can learn what it was like to operate a terminal, control the computer, write programs in computer languages such as LISP, FORTRAN, COBOL, ALGOL, or BASIC, and, of course, play some of the computer games that became the classics, which spawned the games we play today. The book is intended for beginners, like me. I went from looking at the Blinkin Lights display with no idea what to do next, to information overload from all of the available documents, websites, and videos. Nothing is stopping you from downloading the software to your trusty Raspberry Pi and using the software. It is fully functional without the PiDP-10 hardware.

Retro computing is driven by a sense of nostalgia and a strong desire to preserve the computing achievements that led to the technical world we live in today. Very few people have the room, the money, or the time to restore a full-size PDP-10. They were large installations that required a big climate-controlled room. However, due to the work by Richard Cornwell, the developer of the Simh emulator, we can run an accurate simulation of the DEC PDP-10 system.

I am standing on the shoulders of giants. All the hard work has been done by Oscar Vermeulen, the creator of the PiDP-10 kit, and Richard Cornwell, the developer of the PDP-10 KA10 emulator. Lars Brinkhoff has contributed a huge amount to the ITS reconstruction project and PDP-10 restoration projects. I am indebted to him and several members of the PiDP-10 forum who helped me when I was stuck.

[Bob Eager]

I ordered it 12 hours ago!

[Steven Hirsch]

Ordered my copy earlier today.

[Andy]

Just ordered it..... looking forward to the excellent read!

thanks

Andy

[Eric Freeman]

I need this book!  Just ordered from Amazon. Thanks Andy.

Eric

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[Phillip Porch, MD]

I just ordered a copy. Thank you. 

Phillip Porch, MD, FACS

On Aug 24, 2025, at 6:13 PM, Steven Hirsch <snhi...@gmail.com> wrote:

Ordered my copy earlier today.

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[Charley Jones]

I just did too, 

If you are shipping, could you sign? 

Sent from my iPhone 15pm!

Charley Jones, PMP

On Aug 24, 2025, at 7:01 PM, Phillip Porch, MD <ppp...@gmail.com> wrote:

I just ordered a copy. Thank you. 

To view this discussion visit https://groups.google.com/d/msgid/pidp-10/329CAF29-E21F-48C3-8A42-B723578F1D4B%40gmail.com.

[Andrew Barron]

Thanks, everyone! I will be interested to see your reviews. I hope you find the book interesting, helpful, and fun! Please spread the word to anyone who might be interested. I don't do any advertising, and I don't like to overload the forum with unwanted 'sales' spam.

Sorry, the books are printed and shipped from the country of the Amazon site you bought the book on. So it is not possible to sign copies. 

regards

Andrew B.

[Anthony Eros]

Just ordered a copy!

— Tony

To view this discussion visit https://groups.google.com/d/msgid/pidp-10/0d5b513c-dcf3-4e11-9053-a136e6a539a4n%40googlegroups.com.

[Whit Turner]

Ordered as well. Looking forward to it!

Whit

To view this discussion visit https://groups.google.com/d/msgid/pidp-10/CAABkpuoDfxmV8puUYM30V2hW96zKcwczRUDwxsY7cH7Uqy-aLg%40mail.gmail.com.

[Alexander Jacocks]

Indeed, thank you much. I ordered a copy as well.

- Alex

To view this discussion visit https://groups.google.com/d/msgid/pidp-10/CA%2BBYvdu%3Dhuh_JMAxzOHXf6cyyteGFWuAXuxpZ1dxUG-mFfQPyg%40mail.gmail.com.

[John Johnson]

This sounds great! I should get mine tomorrow. 

Looking forward to your books on the PiDP-11 and Altair-Duino!

(Hint)

John

On Aug 25, 2025, at 5:29 PM, Alexander Jacocks <jjac...@gmail.com> wrote:



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[R H]

Andrew, It looks very good on the sample, so ordered a copy straight away.

I too got in to computing on the TRS-80 back in 78/79 but as only just a teenager I could not afford one on my paper round wages so asked my local Tandy store if I could use their in-store Model I .. they said yes if I wrote some demo programs for them .. then I got a part-time job with Tandy and eventually bought my own Model I in ’81 (which still works) and computing has been core to my life ever since. I also have an understanding wife and too much retro kit .. and last year I branched out to computer control of model railways which is taking up more space, time and pension.

Cheers, Richard

[R Clark]

Order one up too. Thank you for putting this together.  Should be a good reference!

Now I am just waiting on word on the PDP-1 kit!

[Tim Radde]

Ordered my copy just now.

[Richard Cini]

Mine’s coming tomorrow as well. Can’t wait to read it. 

Rich

To view this discussion visit https://groups.google.com/d/msgid/pidp-10/38E297E9-84B3-4B83-B464-E784FAF1C259%40gmail.com.

[Thomas Niccum]

Mine arrived today!

[Peter Fall]

Yep - looks good. I ordered mine yesterday

[Steven Hirsch]

Received my copy yesterday and read it through.  A lot of work went into to compiling that and it should prove helpful for beginners.  That being said, there are a number of areas that could benefit from review.  In particular I almost never have a keyboard, mouse and display connected to my unit and have found remote access of various types to be quite doable.  For example, there's not a single mention of the official Raspberry Pi screen sharing!  It's far more responsive than VNC and lets you deal with both graphics displays and console prompts remotely with no sacrifice.

[Tim Radde]

My copy just arrived.

[Anthony Eros]

Just got my copy.  Looks great!

I did scratch my head a bit reading the introduction.  Lots of references to SIMH, but Bob Supnik isn’t mentioned at all.  In fact, the first reference to SIMH implied that Richard Cornwell had written it.

I’m looking forward to working my way through the book.  I think it will be an invaluable resource for getting the most out of my PiDP-10, once I finally get it up and running. 😀

— Tony

To view this discussion visit https://groups.google.com/d/msgid/pidp-10/a8d56289-5a09-4bfa-b2e4-5132a10390fan%40googlegroups.com.

[Tim Radde]

That part bothers me.  How could the author not know Simh was not created by Richard Cornwell?  The Github site for the pidp-10 stuff was created by him.  Yes.  But if he doesn't know about

Bob Supnik what else is not correct in this book?

[Andrew Barron]

I am sorry, I had never heard of Bob Supnik. https://simh.trailing-edge.com/ does not mention his name!  I will make an immediate change to the book to credit Bob.

I am now very confused.  Perhaps you can clarify the roles of Bob Supnik and Richard Cornwell so that I can improve the accuracy of my book.

Wikipedia says,  SIMH is a free and open source, multi-platform multi-system emulator. It is maintained by Bob Supnik, a former DEC engineer and DEC vice president, and has been in development in one form or another since the 1960s.  So that is clear. I will credit Bob Supnik with developing simh. 

But what did Richard Cornwell do? Should I credit him anywhere in the book, or remove him completely? 

https://github.com/obsolescence/pidp10 states "  @rcornwell wrote the PDP-10 KA10 simulator (the Engine), " Is the KA-10 simulator not part of Simh? Does it sit on top of the Simh platform? 

Regarding "Yes.  But if he doesn't know about Bob Supnik what else is not correct in this book?" I have said several times that I am only a beginner. I have done the best I can. I am fully aware that there will be errors, and I am happy to make changes when  mistakes are brought to my attention. If the whole book is a crock of sh--- I will remove it from sale and not attempt another book about retro computers.

Andrew Barron.

[terry-...@glaver.org]

On Thursday, August 28, 2025 at 12:14:24 AM UTC-4 zl...@outlook.co.nz wrote:

Regarding "Yes.  But if he doesn't know about Bob Supnik what else is not correct in this book?" I have said several times that I am only a beginner. I have done the best I can. I am fully aware that there will be errors, and I am happy to make changes when  mistakes are brought to my attention. If the whole book is a crock of sh--- I will remove it from sale and not attempt another book about retro computers.

Don't beat yourself up too badly. You tried to perform a service for other PiDP-10 users and you have some errors. If you revise the book, I suggest you do what O'Reilly did and publish a complete list of errata and corrections and make that list freely available.

I have one or two small subjects where I'm probably the leading US expert  in them. Yet when I write a book (or extensive online documentation) on those subjects I solicit other experts as reviewers before publishing / posting the final version. They usually don't find anything, but sometimes they do. I'd suggest you do the same in your future books.

[Charley Jones]

I also got my copy and enjoyed the history and programming examples very much.  As a longtime c programmer, might I suggest that you are missing #include <stdio.h>

That may be why you had warnings.  Not certain.

Sent from my iPhone 15pm!

Charley Jones, PMP

On Aug 27, 2025, at 10:43 PM, terry-...@glaver.org <terry-...@glaver.org> wrote:



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[Bob Eager]

Andrew, I suggest you start by looking at these papers:

 https://simh.trailing-edge.com/papers.html

Bob is a very helpful guy. I am currently in the throes of writing a new simulator, based on the SIMH code. Bob has been very helpful when I have had questions; he knows SIMH inside out, and he wrote many of the DEC simulators. He was also heavily involved with the design of at least some of the later VAXes.

[Ken Hansen]

See in-line comments below

On Aug 28, 2025, at 00:43, terry-...@glaver.org <terry-...@glaver.org> wrote:



On Thursday, August 28, 2025 at 12:14:24 AM UTC-4 zl...@outlook.co.nz wrote:

Regarding "Yes.  But if he doesn't know about Bob Supnik what else is not correct in this book?" I have said several times that I am only a beginner. I have done the best I can. I am fully aware that there will be errors, and I am happy to make changes when  mistakes are brought to my attention. If the whole book is a crock of sh--- I will remove it from sale and not attempt another book about retro computers.

It's not a "crock of sh--", don't beat yourself up. This was a non-trivial effort on your part and the community appreciates it. Really, we do.

Don't beat yourself up too badly. You tried to perform a service for other PiDP-10 users and you have some errors. If you revise the book, I suggest you do what O'Reilly did and publish a complete list of errata and corrections and make that list freely available.

The book is printed on-demand, revisions are easy and Andrew already said he'd make changes.

I have one or two small subjects where I'm probably the leading US expert  in them.

How modest of you.

Yet when I write a book (or extensive online documentation) on those subjects I solicit other experts as reviewers before publishing / posting the final version. They usually don't find anything, but sometimes they do. I'd suggest you do the same in your future books.

Do you not see how that comes across?

I concede you meant that to come across as constructive feedback, but...

Andrew has 25 other books published, as listed on the back of his latest book - this book was a departure from his typical topic (how-to on amateur radios), this wasn't his first attempt at writing.

Ken

[Andy]

Totally agree - you're living the life Andrew!

And yep an errata would be perfect. We've got some very sharp people here :-)

[Tim Radde]

I havre to admit I have (had) never herad of Richard Cornwell before now.  I've used Simh quite extensively over the years.  Then again I am more of a pdp-8 and pdp-11 person than a pdp-10 person.  Yes, I was an operator of the KA-10 at Penn State but until Oscar's kit came along

I never really used any of the pdp-10 simulators.  Never had a reason to until then.  But I would think that any research into Simh would pop up Bob Supnik's name.  I had to look up the name Richard Cornwell to see who he was.  I did not mean to come off so harsh to the book.

I have not had time to read it yet.  I like to finish the book I am currently reading before I pick up another.

[Steven Hirsch]

You've done a great job pulling that book together, but it could benefit greatly from community review and input/corrections.  Definitely not a "crock", but more a good work that needs iterative refinement.

It sounds like you may be unaware of two useful remote access methods:  X11 forwarding over ssh and Raspberry Pi desktop sharing.  X11 forwarding allows you to start the simulator remotely and have the Type 340 display window pop up on the remote host.  I've only done this from a Linux system, but it should be possible from Mac and Windows as well.  Desktop sharing behaves like VNC, giving you a complete rendering of the RPi screen in a large window.  In my setup RPi sharing is faster and smoother than VNC - YMMV.  There are instructions on the official RPi website to help you get it going.

Lastly, if you have been unable to get certain things working, it may be a good idea to raise them here.  Perhaps you have hit actual program bugs that should be logged or are missing a step somewhere?

If you are amenable to feedback, I'll make some notes during my next pass through the book as it differs from my experience.

On Thursday, August 28, 2025 at 12:14:24 AM UTC-4 zl...@outlook.co.nz wrote:

[Andy]

Fantastic book - just got mine this morning!

On Wednesday, August 27, 2025 at 10:16:44 AM UTC-4 peter...@gmail.com wrote:

[Clem Cole]

below...  and I guess I should put on my OpenSIMH SG hat here ...

On Thu, Aug 28, 2025 at 12:14 AM Andrew Barron <zl...@outlook.co.nz> wrote:

I am sorry, I had never heard of Bob Supnik. https://simh.trailing-edge.com/ does not mention his name!  I will make an immediate change to the book to credit Bob.

I am now very confused.  Perhaps you can clarify the roles of Bob Supnik and Richard Cornwell so that I can improve the accuracy of my book.

Please see https://opensimh.org/about/ and discussion below please. 

Wikipedia says,  SIMH is a free and open source, multi-platform multi-system emulator. It is maintained by Bob Supnik, a former DEC engineer and DEC vice president, and has been in development in one form or another since the 1960s.  So that is clear. I will credit Bob Supnik with developing simh. 

You might skip Wikipedia and got directly to the project website.. 

But what did Richard Cornwell do? Should I credit him anywhere in the book, or remove him completely? 

Remember https://opensimh.org is the >> official << website for the primary code base is: https://github.com/open-simh/simh

from the filehttps://github.com/open-simh/simh/README.md:

Open SIMH machine simulator

This is the codebase of SIMH, a framework and collection of computer system simulators.

SIMH was created by Bob Supnik, originally at Digital Equipment Corporation, and extended by contributions of many other people. It is now an open source project, licensed under an MIT open source license (see LICENSE.txt for the specific wording). The project gatekeepers are the members of the SIMH Steering Group. We welcome and encourage contributions from all. Contributions will be covered by the project license.

The Open SIMH code base was taken from a code base maintained by Mark Pizzolato as of 12 May 2022. From that point onward there is no connection between that source and the Open SIMH code base. A detailed listing of features as of that point may be found in SIMH-V4-status.

PLEASE NOTE

Do not contribute material taken from github.com/simh/simh unless you are the author of the material in question.

Please note the name open-simh -- I'll leave out the commentary of the core history, but take you to the end state. The Project is FOSS, and there are many derivatives, both open source and proprietary [as I type this Open SIMH V4.1-0 Current        git commit id: c064bb66 is the current].  It is noted that Bob works on an older version (V3) and releases independently of the OpenSIMH code base.   Bob is also a member of the OpenSIMH SG, and supports the position of OpenSIMH as the mainline.   Later versions of his code start to add a number of features, particularly WRT to UI) that Bob did want to track; he has continued to want to broaden the number of systems (ISPs) covered.  Thus, when Bob makes a change to his code base and it is known to be stable, companion changes are pushed to OpenSIMH ASAP. 

That said, Oscar forked his original work from https://retrocmp.com/, which was based on an older version of the simh v4 line, and had added a fork to all REALCONS as opposed to the built-in console to simh.  He has pulled from different versions, and indeed, the PiDP-10 simulator is based on the bloodline Richard maintains. Just so you know, Richard is also a member of the SG.  I have not rebuilt any of Oscar's versions in a while, but I believe there was some attempt to come closer to the mainline this spring as I know someone fixed and verified some pull requests in the space.  But I can not say, because I have not looked at the current PiDP-10 package Oscar has.  I do know that I run the OpenSIMH version of the PDP11, 8 and 10 versions on my Mac and use a number of the same virtual disks as those have my different flavor PiDPs, so I know that they are close enough alike in format to be compatible.

I will state that there is a desire at some point to have a set of hooks in OpenSIMH that are a tad more elegant than the original retrocmp changes, but that all of Oscar's and other people Blinkenlights can be made to work across all of the OpenSIMH simulators [which is essentially why it has been done imported yet = the changes are relatively profound and the test matrix is larger than th small group of people behind the scenes to check].  Speaking for myself, not the OpenSIMH team, I would love to see Oscar be able to pick up a simulator binary for the project for each system and go.  That his code was 100% on top of ours without modifications.

Back to your question. As for cudos and credit, of course, Bob's name should be on his work as it is the foundation and inspiration for it all and following the first paragraph from the project makes good sense.   Similarly, Richard was influential with the PDP-10 family specifically (as well as a number of the other simulators BTW), so including it seems reasonable, but a pointer to the entire project and the other simulators that run on platforms without Oscar's excellent piece of hardware, which seems appropriate also. 

https://github.com/obsolescence/pidp10 states "  @rcornwell wrote the PDP-10 KA10 simulator (the Engine), " Is the KA-10 simulator not part of Simh?

Yes...

The key point here is that several different PDP-10 simulators are available, and each has its own fan base, as they each excel in a specific area.  For a long time, the "klh" set for the PDP-10 was the cat's meow. However, I can think of a few others as well.  There are a number within the simh base, but the set that Richard maintains is the strongest in the SIMH suite.

 

Does it sit on top of the Simh platform? 

No, the KA/KI/KS 10 simulators are all an integral part of the entire platform.  There are other simulators for many other systems. Please go to the website for more details.

Regarding "Yes.  But if he doesn't know about Bob Supnik what else is not correct in this book?" I have said several times that I am only a beginner. I have done the best I can. I am fully aware that there will be errors, and I am happy to make changes when  mistakes are brought to my attention.

Great.  It might be a good idea to have someone from the OpenSIMH SG to review -- you can follow up off this list with an email directly cl...@ccc.com or the entire SG: SIMH Steering Group <s...@opensimh.org> 

Respectfully, 

Clem

[terry-...@glaver.org]

On Thursday, August 28, 2025 at 9:05:26 AM UTC-4 n2...@w5fc.org wrote:

See in-line comments below

On Aug 28, 2025, at 00:43, terry-...@glaver.org <terry-...@glaver.org> wrote:

Don't beat yourself up too badly. You tried to perform a service for other PiDP-10 users and you have some errors. If you revise the book, I suggest you do what O'Reilly did and publish a complete list of errata and corrections and make that list freely available.

The book is printed on-demand, revisions are easy and Andrew already said he'd make changes.

Paper books on technical subjects (other than histories) become out-of-date. Until the number of changes justifies a reprint (and even then, for people who don't want to purchase another copy to just get the fixes), which is why I suggested the O'Reilly method, for example: https://www.oreilly.com/catalog/errata.csp?isbn=9781491949467 

I have one or two small subjects where I'm probably the leading US expert  in them.

How modest of you.

Take it or leave it, I'm not justifying myself to you.

The comment was intended to convey that despite that, I still seek reviewers / feedback before "going to press" (either on paper or as downloadable books) to catch things I might have missed or under-explained because I'm so familiar with the material.  

Yet when I write a book (or extensive online documentation) on those subjects I solicit other experts as reviewers before publishing / posting the final version. They usually don't find anything, but sometimes they do. I'd suggest you do the same in your future books.

Do you not see how that comes across?

I concede you meant that to come across as constructive feedback, but...

Andrew has 25 other books published, as listed on the back of his latest book - this book was a departure from his typical topic (how-to on amateur radios), this wasn't his first attempt at writing.

How DOES it come across? I'm not saying that Andrew is an inexperienced author, just that it is better to have others (preferably subject experts) read and provide feedback on the book before proceeding to the publishing stage. In the case here, there are a number of PDP-10 experts, such as Lars, here that could have provided beneficial insights and prevented incorrect information from appearing.

I'm not talking about the level of commentary / criticism that you get when you submit a paper to a scientific journal where there is a mandatory review by other experts on the editorial review board (I've done that, it isn't fun), just some constructive feedback.

[Richard C]

Hi,

   In terms of contributes to this project. Bob Supnik wrote the original SimH framework. He also did a KS10 emulator. I started writing a KA10 emulator and it kind of grew into emulating all PDP10 models. With Lars's and Eric's help we were able to get ITS running on all models. I did much of the work to get Tops10 and Tops20 systems running. Lars's is also responsible for many of the ITS devices the emulator supports.

   For the PiDP10 I did extensions to my emulator to run the display. I started with Oscar's code and did a bunch of cleanup. I maintain a fork of his PiDP10 repo where I update the sources periodically. Oscar does a build for the various platforms he supports. Lars's and many many others contributed to build ITS. The Tops10 that Oscar provides was built by me for testing.

  If anyone is interested I can go over a more detailed history of the development of my PDP10 simulators.

Rich

[Andrew Barron]

Thanks to everyone who bought the book. I am sorry that some people resorted to abuse when they could have made a polite suggestion.  I got my copy today and I quite liked it. 

I have made the suggested change regarding crediting Bob Supnik. Ironic that that person had not heard of Richard Cornwell. But I didn't flame him for that. I have no intention of writing this book by committee. It was written by a beginner for beginners. If it lacks some feature you feel is important, please go ahead and write a better book. 

I am leaving this forum and going on holiday, so please don't expect any further comments from me. 

regards

Andrew Barron.

[Andrew O'Neill]

Thank you for all of your efforts Andrew. I look forward to receiving my copy shortly and enjoying it for its intended purpose. Please enjoy a well earned break.

Andrew

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[John Johnson]

No good deed goes unpunished. 

On Aug 29, 2025, at 12:48 AM, Andrew Barron <zl...@outlook.co.nz> wrote:

Thanks to everyone who bought the book. I am sorry that some people resorted to abuse when they could have made a polite suggestion.  I got my copy today and I quite liked it. 

--

[Ric Werme]

Minor math error on page 213/214.

My copy arrived yesterday, while thumbing through it, I noticed an error in describing some machine code.  If I don't log it now, I'll probably forget it.

The code is a lights program that looks like it moves a block of one bits around the data lights.  It has this delay loop:

MOVEI 2,60650 ;Decimal 25,000
LSH 2,4 ;Shift left four bits (multiply by 16)
SOJN 2,. ;Delay for a while

The description says "The MOVEI 2,60650 command puts ... and the 4 bit shift makes it 606500000."  You described a four octet (12 bit) shift.  A three bit shift makes it 606500, one more yields 1415200.  The delay loop executes decimal 400,000 times, not 102,400,000 times.

[Lawrence Fisher]

Just got my copy in yesterday. Revision 1.2. includes the changes to reference Bob Supnik. 

Gotta love Amazon publish on demand!

[Anthony Eros]

I just ordered an updated edition for my office.  

The first copy I bought is going on the shelf in the family room, next to my first edition of “Hunt for Red October” 😀

— Tony

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[Greg Taylor]

Andrew, I've been enjoying the book and was wondering if you'll also make a Kindle version available for those of us whose eyesight is not as good. Thanks for your consideration. 

-- Greg

[Francis King]

In the sample it says that the console doesn't work on ITS, but it works fine on my ITS system.