ozymandiax

Our informal group has been making replicas of ancient computers for years.

Of course, the learning curve for these machines is steep. The Agent-PDP1 github is our hope of now 'adding a replicant PDP-1 Hacker to sit with you on the replica machine'.

This has been fun, but there is a long way to go. Still, it really does feel like you are sitting next to the PDP-1 from Stephen Levy's "Hackers" with an old hacker. A little fuzzy in his old age, but with a phenomenal knowledge and skill set...

I do feel like such Hacker Replicants can add to our goal ("Making fully functional replicas, their historical software archive built in. We think of them as computer time capsules")

Whether a Hermes agent with PDP-1 skills is the best setup, I am frankly not sure. We arrived at that over the past year, but it won't be the end.

In fact: the end goal is to have a replica Arpanet network of replica IMPs, with the MIT/Stanford/UCLA/BBN nodes attached to it: https://github.com/obsolescence/arpanet

And THEN have such replicants roam the Arpanet, free to finger/chat for advice.

We'll see :-) But advice on making the next steps with these 'replicants' is welcome. We need to make them for the PDP-8/11/10 plus the Arpanet IMP as well.

It's bizarre that a 1960 computer can run a port of the Z machine, and run most of the Infocom adventures. All on primitive drum storage.

A page introducing Bill Ezell's pidp1-mods. Bill spent a year on building everything needed for the 'ultimate hacker's PDP-1'. That meant building all sorts of peripherals into the PDP-1 simulator. Developing a modern, gcc based development toolchain to suit modern-day hackers. And allowing people to build their own hardware for the P(i)DP-1. Be that virtual hardware in simulation, or real, modern day Maker hardware through an I2C port.

Then, staying within the hardware limits of this 1960 machine, he ported first Adventure from the PDP-10, then, the Z Machine. So you can now play Beyond Zork on a VT-100 terminal, through a faithfully simulated 64-serial port interface (Type 630) on a PDP-1, using drum storage to hold the data.

It might be esoteric, but if you care for ancient computer history, this is an amazing playground.

Note - no need to own the PiDP-1 hardware. This will run on any Linux with a virtual PDP-1 front panel included.

Thanks, Bill!

Incredible project! It would be amazing to have this machine up and running, I never thought that would even be possible. I wonder about your electricity bills though :-)

Apple might sue you though, like they did DRI :-)

Just discovered the videos (https://www.youtube.com/@NostalgiaPCTV) ...and the source code on github reads like a book.

Amazing.

This rewrites what-could-have-been history a bit... better get my IBM XT/286 out of storage! Is this for real?

From Computerphile - nice insight in the guts of Lisp from the IBM 704 and PDP-6 Lisp. Software archaeology can be insightful :-)

This famous 'hacker OS' was the birthplace of rather a lot - emacs, AI living in a 3D world, as well as the Open Source culture. A reconstruction project has brought it back to life. It's fun to experience what it was like circa 1973, having a heavyweight PDP-10 mainframe class machine hacked on for fun and exploration.

The software used in the Computerphile episode can run on any Pi - and, in fact, any Linux - without the replica hardware.

I hope this gets some attention to an OS right at the root of what we're living with day to day now!

A practical tip that works miracles on 5.25 diskettes: rub their edges against a table top or whatever, making them sit looser in their sleeves. Does miracles to disks that cause read errors - strange as it sounds.

Also, using an 80 track drive to read a 40 track disk works most of the time. But if you get any read errors, trying with a 40 track drive solves a lot of them!

Lastly, have multiple drives. A read error on one drive might not be a problem on another drive.

I recovered more than a thousand floppies some years ago. And learned that read errors in most cases are not irrecoverable. Try another drive, rub the diskette's edges - the two things that fixed most problems.

Wow! How did I manage to miss this treasure trove! Thank you.

But we'd need to backport emacs to the PDP-1 then :-)

I was wrong - it was not Peter Deutsch who ported Eliza to Lisp, it was Bernie Cossell at BBN (one of the famous IMP Guys a few years later!). And it is here:

https://github.com/jeffshrager/elizagen.org/tree/master/1966...

That makes a PDP-1 Lisp backport very tempting... amazing how ancient code comes back from presumed extinction.

Actually, https://github.com/cl-aip/eliza/ would be a great starting point for a backport to Lisp 1.5. Hmmm...

We already have it running on the PDP-10 reconstruction, and it is known that people around Deutsch at BBN ported it back to the PDP-1. But that version has been lost. From the link you gave, a backport would be feasible... especially because the PDP-1 simulator has the full memory upgrade to 64Kw!

I was born too late (not a bad thing necessarily) to have experienced that founding era. But I think that for later generations, there's a lot to learn still from what evolved in the earliest years. We've gained a lot since then, but we also lost a lot. Mean and lean programming, closeness to the hardware, inventiveness. And the liberating absence of 'software stacks'...

It's fascinating how on such a tiny computer, something like a comfortable interactive Lisp just emerged. Relatively comfortable.

When we visited some of the 1970s 'heros' of the MIT AI Lab, we were told the informal story behind SHRDLU, the AI living in a PDP-10 3D world. How this graphical AI triggered the first AI Summer --

https://www.youtube.com/watch?v=8ZGQcJVdjj8

-- and as it fell short of first impressions, perhaps the first winter too?

The PDP-1 Lisp page has 4 rather good books linked as PDFs. Oh - but all on the earliest history of Lisp as well! That is not what you're looking for I think.

Written by Peter Deutsch, then a then-high school student on a tiny 4K (admittedly, 4K 18-bit words) machine. Amazingly usable - and lives on in the Python REPL concept.

Our PiDP-1 simulator on github lets you try it out on any Linux machine (not just a Raspberry PI): https://github.com/obsolescence/pidp1

Posting this in the hope that someone will feel triggered to backport Eliza, it was done in the 1960s but it's been lost :-)

Simulator is on https://github.com/obsolescence/pidp1. It does not need a hardware front panel, runs with an on-screen virtual one too.

And pretty authentic development tools as well - I hear Michael Gardi used Macro1_1, which though a cross assembler, is pretty much the Macro on the PDP-1 itself.