Hacker News: ozymandiax

New comment by ozymandiax in "Exploring PDP-1 Lisp (1960)"

ozymandiax — Tue, 30 Jun 2026 10:09:22 +0000

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

New comment by ozymandiax in "Exploring PDP-1 Lisp (1960)"

ozymandiax — Tue, 30 Jun 2026 02:48:31 +0000

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

New comment by ozymandiax in "Exploring PDP-1 Lisp (1960)"

ozymandiax — Tue, 30 Jun 2026 02:22:34 +0000

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.

New comment by ozymandiax in "Exploring PDP-1 Lisp (1960)"

ozymandiax — Tue, 30 Jun 2026 02:04:01 +0000

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

New comment by ozymandiax in "Exploring PDP-1 Lisp (1960)"

ozymandiax — Tue, 30 Jun 2026 01:45:36 +0000

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!

New comment by ozymandiax in "Exploring PDP-1 Lisp (1960)"

ozymandiax — Tue, 30 Jun 2026 01:35:38 +0000

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.

New comment by ozymandiax in "Exploring PDP-1 Lisp (1960)"

ozymandiax — Tue, 30 Jun 2026 01:17:16 +0000

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?

New comment by ozymandiax in "Exploring PDP-1 Lisp (1960)"

ozymandiax — Tue, 30 Jun 2026 01:09:15 +0000

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.

New comment by ozymandiax in "Exploring PDP-1 Lisp (1960)"

ozymandiax — Tue, 30 Jun 2026 01:01:49 +0000

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 :-)

Exploring PDP-1 Lisp (1960)

ozymandiax — Tue, 30 Jun 2026 00:56:42 +0000

Article URL: https://obsolescence.dev/pdp1-lisp-introduction.html

Comments URL: https://news.ycombinator.com/item?id=48727323

Points: 105

# Comments: 23

New comment by ozymandiax in "Hacking on a PDP1 front panel replica [Computerphile video]"

ozymandiax — Fri, 08 May 2026 01:40:23 +0000

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

Hacking on a PDP1 front panel replica [Computerphile video]

ozymandiax — Wed, 06 May 2026 23:39:10 +0000

Article URL: https://www.youtube.com/watch?v=7WEewUVQabU

Comments URL: https://news.ycombinator.com/item?id=48043343

Points: 5

# Comments: 1

New comment by ozymandiax in "Lunar Lander ported to the PDP-1"

ozymandiax — Sat, 14 Mar 2026 02:26:39 +0000

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.

Lunar Lander ported to the PDP-1

ozymandiax — Sat, 14 Mar 2026 02:26:39 +0000

Article URL: https://hackaday.io/project/204632-lunar-lander-for-the-pdp-1

Comments URL: https://news.ycombinator.com/item?id=47372669

Points: 4

# Comments: 1

A 2025 manual to the DEC PDP-1

ozymandiax — Thu, 02 Oct 2025 01:33:26 +0000

Article URL: https://obsolescence.dev/pdp1-manual.html

Comments URL: https://news.ycombinator.com/item?id=45445551

Points: 20

# Comments: 0

New comment by ozymandiax in "Arpanet Reconstruction Project"

ozymandiax — Thu, 24 Jul 2025 05:22:32 +0000

Bringing up an interactive Arpanet so people can relive the 'Arpanet Scenarios' people could try at the 1972 ICCC convention.

Arpanet Reconstruction Project

ozymandiax — Thu, 24 Jul 2025 05:22:32 +0000

Article URL: https://obsolescence.dev/obsolescence-newsletter-dec-2024.html

Comments URL: https://news.ycombinator.com/item?id=44667211

Points: 2

# Comments: 1

New comment by ozymandiax in "Classic Computer Replicas"

ozymandiax — Wed, 23 Apr 2025 01:31:10 +0000

Thank you dbelson for the mention! It's the oxygen we need.

...but just now, our web server crashed on the Hacker News traffic. Of course...

New comment by ozymandiax in "An FPGA-based LGP-30 Replica"

ozymandiax — Tue, 08 Apr 2025 04:19:04 +0000

My favourite computer... timing instruction placement on the drum. Juergen is actually planning to make a batch of kits later this year!

New comment by ozymandiax in "PiDP-1, or the rebirth of an old machine"

ozymandiax — Mon, 07 Apr 2025 20:22:35 +0000

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 :-)