PiDP-1, or the rebirth of an old machine | Hacker News Reader

PiDP-1, or the rebirth of an old machine

hackaday.io

107 pointsozymandiax32 comments

As one of those guys in the photo I really hope everyone will have a lot of fun with this :)

The photos don't show it but you can also have your PiDP-1 in white instead of blue. It will come with both sets of front panels.

The blue is amazing though!

This looks fascinating! is there a link that would be a better intro to the project?

There was this link on the page https://hackaday.io/project/202541-replica-of-the-pdp-1-pidp...

Ah thanks. I didn't scroll down far enough

In case you didn't see, the hackaday project page has two more links on the side, but currently information is a bit sparse, sorry. We're currently on a sprint to finish and polish the software distribution.

Wow, one of these should be at a museum or public institution.

I have so much fun with my PiDP-11 that this will have to go on the list.

Does anyone know if MIDAS has been recreated for it or not?

A bit of the hint on the PPT reader, which would be awesome, the rp2xxx chips PIO can handle that with ease. As the PDP1 doesn't have take-up it is pretty trivial to make at 'historic' speeds. Obviously punching is much more difficult.

I looked into it for quite a bit, but not having access to tapes, puncher, supplies etc... I gave up on the idea as the PiDP-10 will scratch my personal nostalgia itch a bit more right now.

There are some versions of MIDAS around on bitsavers but I have to admit i haven't really looked into them much yet. Gotta leave something to the community, right? (or so i tell myself...). Another thing is that not all PDP-1s were the same and especially the PDP-1/X at MIT was a super hacked up version. Any code for that will not run my emulation (at least for now).

A real tape reader would be great and is something we are considering for the future, but without a punch it's not very satisfying. There will be a paper tape visualization though (currently writing the code for that).

Delighted by the resemblance of the HN title to Tracy Kidder's Pulitzer Prize-winning book, "The Soul of a New Machine."

https://en.wikipedia.org/wiki/The_Soul_of_a_New_Machine

That was probably intentional :)

I love that book

The PiDP-1 and PiDP-10 are both absolutely gorgeous; while I'm glad to have modern keyboard and monitors and processors, I envy the past its style.

I'd never heard of these things, but they really are beautiful.

I got into the game when my older brother was sysadmin for a PDP-11. I had the opportunity to look at tall the collected reference work going back to the PDP-1.

All very interesting reads.

I've got a PiDP-11 from the same group. It's a faithful replica, and it brings back memories from 50 years ago.

https://obsolescence.dev

I just built my PiDP-11 and would love to get one of these.

They want it to be an afforable kit. Indeed very nice to get your hands on one

Yes, with the PiDP-10 we did a huge injection mold and it nearly killed us. Well, no, but we still have not recovered the investment. And it became an expensive thing, which limits the amount of people who want to play with one.

So with the PiDP-1, we figured out how to make the entire case from FR4 panels. As there are no Iconic Curves in a PDP-1 case. Turns out this is the sturdiest PiDP yet!

We hope to get some interest from the democoder community. Writing games and demos for the PDP-1's Type 30 display is so much more fun than pushing pixels on a C64 :-)

Can't wait to see the PiDP-1! By the way, something I'm really looking forward to is the KA-10 FPGA implementation for the PiDP-10, rather than the less realistic SIMH simulator running on top of Linux/Raspberry Pi. It would be a true miniaturized PDP-10 CPU, not just a simulation. Do you know if this is still being worked on?

I have a bunch of KA10 verilog that worked on a DE10-nano in the past, but it's been quite a while and i think i have a bunch of uncommitted stuff lying around as well. The verilog is based on the original schematics and I successfully ran LISP and Spacewar on it. Unfortunately simulating peripherals is always a pain, so the project currently lies dormant. But i'd like to pick it up again at some point. I just really need to rethink my approach how to do this, qsys was maybe not the greatest way to wire up the system.

https://github.com/aap/fpdpga/tree/master/ka10

It’s exciting to hear that you’ve successfully run LISP and Spacewar on it, especially since the Verilog is based on the original schematics. That makes the PiDP-10 an actual KA-10 CPU, which is a big deal for authenticity.

I completely understand the difficulty with simulating peripherals. Perhaps the FPGA could focus on implementing the CPU, leaving the peripherals to a SIMH backend using a hybrid approach. A slightly longer PCB with space for both a DE10-nano and an RPi 0 might work out well.

Have you considered opening a discussion on VCFED or Google Groups to gather more ideas and see what others think? I’m sure many people would be excited to follow and contribute to that progress.

I'm looking forward to seeing how this develops.

I hadn't connected it to the pidp-10 panel yet actually, my stuff is older than that. but eventually i would like to. the approach i went with was to put some of the peripherals on the linux side of things but have the controller logic on the FPGA. it's all a bit fiddly with FPGAs...

Someone had a PiDP-10 set up at the last Hacker's Conference. Damn it's a gorgeous machine. Your heroic efforts to recreate it in such spectacular fidelity are greatly appreciated by many!

I have to say, the results were absolutely worth it in the kit. The PiDP-10 is a beautiful work of art and I am thrilled to have it!

Being an old DEC programmer (RSTS/E BASIC, VAX BASIC and C), this stuff is more than nostalgia. It’s literally the foundation of my technical soul.

Congratulations on getting the vector display working as well! Now we can have the world's most baroque Spacewar! mini arcade machine ever ;)

OK, after reading this site I want to know more about the PDP-1 demoscene.

This is a good start: https://www.masswerk.at/minskytron/

The pdp-1 "demoscene" has been rather inactive for ~6 decades now :) Our hope is to breathe some new life into it.

As an "old skool" demo coder, I'm impressed! I'm thinking with the vector display and the fall-off you could probably do some really fun stuff.

Would be interesting to get some modern demo coders onto it to see what was possible.

Regarding the display, it's a point plotting display, which is really the major performance bottleneck, as each dot has to be drawn individually and each dot takes 50 nanoseconds to display. (You can interleave computations and display operations in an asynchronous fashion, but this takes you only that far.) And you have to maintain the screen programatically, redrawing each dot periodically.

As there is no memory or frame buffer involved, the display resolution is pretty high, at 1024 × 1024 display locations (with a "visual resolution" of about 512 × 512, because dot size depends on the intensity and display locations may overlap), but drawing a line across the screen is pretty expensive in terms of runtime. Hence the complexity and fluency of a "display hack" depends largely on the number of dots drawn and maintained.

On the plus side, display commands are pretty simple and straight forward, put one coordinate in the accumulator and the other one in the IO register and off you go. Acording to Marvin Minsky computer graphics just went into decline after this.

Regarding modern and contemporary coders, there are really few tricks that haven't been explored with Spacewar! already. (Mind that Steve Russell was also the programmer, who gave us Lisp.) Spacewar! does all calculations in realtime, without referring to lookup tables, but, otherwise, this is pretty advanced, even featuring a JIT compiler (by Dan Edwards, who is important for the history of Lisp, as well) for the configurable spaceship outlines.

Having said that, the PDP-1 has a pretty fascinating while simple instruction set (including universal indirection), which lends itself especially well to assembler programming, and should be a source of previously unknown joy for any modern coder.

As for the current one, a few years ago (2016), I wrote a new game for the PDP-1, a Computer Space simulator for the machine that inspired this first coin-op arcade video game. (Hence, Ironic Computer Space Simulator or short ICSS.) It proves that the venerable PDP-1 is capable of running a video game at 60 fps!

https://www.masswerk.at/icss/

As this was a RetroChallenge project, there's also project blog: https://www.masswerk.at/rc2016/10/

See www.obsolescence.dev for more details

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