#pdp8 — Public Fediverse posts

I modified a VERY cheap and nasty display rack to fit my #PDP8 computer and monitor, almost perfectly.

This post
https://fosstodon.org/@deshipu/116510956431897662

tongue in cheek as it is, idly got me wondering if building a 5 bit computer would have ever made sense. The PDP-8/S was a *ONE* bit computer in the sense it reused the ALU one bit at a time cycling the bits through. It had also earned the nickname the PDP-8/Slow for this reason.
A University school mate of mine owned one!
The minimum 'byte' was 6 bits and it used RAD50 for this reason. So no a 5 bit computer would not have made sense, to save RAM as jokingly put, but we come close.

#PDP8 #PDP8S

Field Service Only. #dec #pdp8 #VCFe #VCFe25 #vintagecomputing

#RetroComputing Meetup @cbase
Freitag, 01.05. ab 20 Uhr
in der c-base, Rungestraße 20, 10179 Berlin

Offener #VintageComputing Stammtisch

Bei einem Getränk reden wir über Themen von #Zuse bis #Amiga, egal ob #Atari, #Commodore, #Apple oder #PDP8-#PDP11 - Hauptsache alte Rechner

[Перевод] RESISTORS: как подростки из 1960-х работали с компьютерами до эпохи ПК

В конце апреля 1968 года компьютерная конференция в Атлантик-Сити едва не сорвалась из-за забастовки телефонисток: терминалы крупных компаний стояли мёртвые. И вот посреди этой неразберихи в центре внимания оказалась небольшая группа подростков из окрестностей Принстона. Они раздобыли акустический модем, подсоединили его к ближайшему таксофону — и вышли на связь с удалённой мини-ЭВМ. Отраслевая газета Computerworld вывела их на первую полосу с заголовком в духе «Школьники украли шоу у профессионалов». Эти ребята называли себя RESISTORS — придуманная задним числом расшифровка аббревиатуры: «Radically Emphatic Students Interested in Science, Technology, Or Research Studies» — то есть «Радикально увлечённые ученики, интересующиеся наукой, техникой и исследованиями».

https://habr.com/ru/companies/cloud4y/articles/1029094/

#RESISTORS #история_компьютеров #Тед_Нельсон #гипертекст #PDP8 #Burroughs_Datatron_205 #Клод_Каган #Project_Xanadu #Computer_Lib #история_программирования

Well, I've now bypassed Tindie (that I've always wanted to support previously) and ordered a #PDP8 kit directly...

https://obsolescence.dev/pdp8.html

War schon 1982 klar, dass das mit dem Wal so kommen musste:

The Baltic See is getting warmer!
Gemessen und berechnet mit KSR4100 aus CZJ Jena, aka PDP-8

https://pflegende.wordpress.com/2025/08/23/pdp-8-revieval-2025/ #COCOM, #COMECON, #DDR, #DEC, #Emulation, #History, #PDP-8, #PDP8, #ROBOTRON #retrocomputing

#RetroComputing Meetup @cbase
Freitag, 06.03. ab 20 Uhr
in der c-base, Rungestraße 20, 10179 Berlin

Offener #VintageComputing Stammtisch

Bei einem Getränk reden wir über Themen von #Zuse bis #Amiga, egal ob #Atari, #Commodore, #Apple oder #PDP8-#PDP11 - Hauptsache alte Rechner

The next thing I've been tackling has been the verb/grammar code. The goal here is to represent the logic/data structures from this section of the #PunyInform library: https://github.com/johanberntsson/PunyInform/blob/master/lib/grammar.h#L7-L225

It looks like a combinatorial explosion of possible prepositions in a large space of possible sequences, along with placeholders for object search conditionals. It feels like the kind of thing that needs a lot of core just to map it all out. Sure, I have my input words compressed to single 12-bit integers, but there's a lot of repetition in the source there and it seems like a mess to represent.

I made a list of all the tokens in this thing, and came up with 32 values (including a null). Well, that's neat! I could decide that if the most significant bit of a tanner is `0`, it's a lookup into a table of 12-bit values. I have some space left in my compression scheme for ideas like "object in scope" or "object in inventory" (which can gobble multiple words), so I can handle common cases like `INVENTORY`, or `GET LAMP`, or `TURN ON LAMP`. I map the `TURN` verb into a pair of indices for `ON` and *noun*, pointing out to our equivalent of the Puny `SwitchOn` function in the #PDP8 game code.

Okay, but what about all that `'in'/'into'/'inside'/'on'/'onto'` stuff? Well, If the tanner's most significant bit is `1`, then I treat it as a sort of pointer into the second half of my grammar index. So that might look like this:

37. `IN`, `INTO`
38. `INSIDE`, *37*
39. `ON`, `ONTO`
40. *38*, *39*

So I might have `GET` mapping a grammar word of [*40*,*noun*] to the `ENTER` procedure, so that `GET INSIDE BICYCLE` and `GET ONTO BICYCLE` will both call the same code. The grammars use 3 words per mapping, and make use of a table of 64 words. This feels more comfortable for the type of system I'm writing here.

Yes, this is just #LISP cons cells, and I love that.

Now I just need to write all this...

Who wants to build a P(i)DP-8? ❤️

#raspberrypi #pdp8 #electronics

#RetroComputing Meetup @cbase
Freitag, 05.12. ab 20 Uhr
in der c-base, Rungestraße 20, 10179 Berlin

Offener #VintageComputing Stammtisch

Bei einem Getränk reden wir über Themen von #Zuse bis #Amiga, egal ob #Atari, #Commodore, #Apple oder #PDP8-#PDP11 - Hauptsache alte Rechner

Forgot I even had this! #pdp8 #pdp-8 #intersil #6100

#RetroComputing Meetup @cbase
Freitag, 07.11. ab 20 Uhr
in der c-base, Rungestraße 20, 10179 Berlin

Offener #VintageComputing Stammtisch

Bei einem Getränk reden wir über Themen von #Zuse bis #Amiga, egal ob #Atari, #Commodore, #Apple oder #PDP8-#PDP11 - Hauptsache alte Rechner

Why does booting a #PDP8 straight eight take 20 minutes? The #Teletype isn't any faster reading the paperstrip...

#datArena

„Die leistungsfähige Arbeitsmethode für Ingenieure“

Es ist eine Werbebroschüre für eine PDP-8/e. #vintagecomputing #retrocomputing #classiccomputing2025 #classiccomputing #pdp #pdp8

Programming a PDP-8 with a Teletype Writer. Please note the coordinated color scheme of the PDP with the programmers shirt. #vintagecomputing #retrocomputing #classiccomputing2025 #classiccomputing #pdp #pdp8

#RetroComputing Meetup @cbase
Freitag, 04.07. ab 20 Uhr
in der c-base, Rungestraße 20, 10179 Berlin

Offener #VintageComputing Stammtisch

Bei einem Getränk reden wir über Themen von #Zuse bis #Amiga, egal ob #Atari, #Commodore, #Apple oder #PDP8-#PDP11 - Hauptsache alte Rechner

Finally found lunarlander.foc again!

Running Lunar Lander on the PDP-8 Using Paper Tape FOCAL - Computer History Wiki

https://gunkies.org/wiki/Running_Lunar_Lander_on_the_PDP-8_Using_Paper_Tape_FOCAL

(Edit this is actually a different version!)

#Retrocomputing #focal #LunarLander #PDP8

My student, Zach, got the famous Whetstone floating-point benchmark running in FORTRAN IV on our PDP-12 (results had never been recorded for a '12 without an FPP). He also implemented the Dhrystone integer benchmark in PDP-8 assembly, which (as far as we know) has never been done before. You can read more about it here, and if you have a PDP-8 compatible machine (with or without EAE), you should be able to run his code to benchmark your system! Way to go, Zach! https://forum.vcfed.org/index.php?threads/pdp-8-and-pdp-12-and-dhrystone-and-whetstone.1253367/ #pdp12 #pdp #retrocomputing #umdpdp12 #pdp8

#RetroComputing Meetup @cbase
Freitag, 06.06. ab 20 Uhr
in der c-base, Rungestraße 20, 10179 Berlin

Offener #VintageComputing Stammtisch

Bei einem Getränk reden wir über Themen von #Zuse bis #Amiga, egal ob #Atari, #Commodore, #Apple oder #PDP8-#PDP11 - Hauptsache alte Rechner

#RetroComputing Meetup @cbase
Freitag, 06.06. ab 20 Uhr
in der c-base, Rungestraße 20, 10179 Berlin

Offener #VintageComputing Stammtisch

Bei einem Getränk reden wir über Themen von #Zuse bis #Amiga, egal ob #Atari, #Commodore, #Apple oder #PDP8-#PDP11 - Hauptsache alte Rechner

Perfect colours...

#pdp8 #RetroComputing

#RetroComputing Meetup @cbase
Freitag, 02.05. ab 19 Uhr
in der c-base, Rungestraße 20, 10179 Berlin

Offener #VintageComputing Stammtisch

Bei einem Getränk reden wir über Themen von #Zuse bis #Amiga, egal ob #Atari, #Commodore, #Apple oder #PDP8-#PDP11 - Hauptsache alte Rechner

#RetroComputing Meetup @cbase
Freitag, 04.04. ab 19 Uhr
in der c-base, Rungestraße 20, 10179 Berlin

Offener #VintageComputing Stammtisch

Bei einem Getränk reden wir über Themen von #Zuse bis #Amiga, egal ob #Atari, #Commodore, #Apple oder #PDP8-#PDP11 - Hauptsache alte Rechner

Everything else has FTPed over to the Minitel/PiDP8i evening stereo without any trouble apart from Floral Shoppe. A problem with the Japanese characters? I've moved a tonne of City Pop over without any issues.

Finally moved it physically with a USB drive. We might have expected this from Vektroid.

#vaporwave #MacintoshPlus #FloralShoppe #vektroid #minitel #pidp8i #pdp8

Makes no difference to how it looks, but I upgraded the microSD that the PiDP8/i runs on from 32GB to 256GB, which gives it some decent storage capacity in its main role as the evening stereo system.

FTPing music from my main desk PC seems to work pretty well. It's almost like a feasible solution.
#minitel #pdp8 #pidp8i #retrocomputing #MusicForLeisure

For its latest trick, the Minitel 1 can now act as an interface for playing music on the PiDP-8/i (which is really a Raspberry Pi in disguise).

This is what the kids describe as "neat".
#minitel #minitel1 #pdp8 #pidp8i #raspberrypi #retrocomputing #RM #kpop

Okay, the Minitel 1 is connecting to the PiDP8-i as a terminal. That wasn't something I was expecting to figure out before lunchtime.
#pdp8 #pidp8i #raspberrypi #minitel #retrocomputing

My brother got me a #pidp8i kit, assuming I knew how to solder it together. It makes a #RaspberryPi look and work like a #PDP8 minicomputer. Took me a while to put together, but it works! And it has tactile switches! Thanks Adam for the gift, and thanks @rehana for giving me the confidence and the documentation to re-learn how to solder after 25+ years.

Dear #RetroComputing #PDP8 enthusiasts, do any of you have a neglected #PiDP8 that you no longer use? Was it a fun lockdown toy that you no longer interact with? Are you within postal distance of #London? If so, get in touch: I'm working on a project in PAL assembler and would love to have the front switches and lights, but not enough to order and assemble the thing.

I can replace the #SBC inside, if you already scavenged it for something else! I just wonder if anyone has one taking up space that they'd rather use for something else these days.

@kenshirriff @rzbrk Ohhh, thanks so much for answering, Master Ken! Made my day! 🤩🙏 So, the PDP-8/e is still there in the exhibition? Cool! Wouldn‘t that be a nice project with #CuriousMarc, making it run again? 😉 #pdp8 #pdp8e

@rzbrk Mein Informatik LK Lehrer (damals, Mitte der 80er) war der Knaller und wir hatten sowohl eine PDP 8/e, als auch eine PDP 11/23 in der Schule! 🤩 Damals war ich allerdings eher auf dem Turbo Pascal Trip (BGI Treiber für EGA Grafik! 😂) und konnte mit diesen geschichtsträchtigen Maschinen von #DEC nicht viel anfangen. 🤷‍♂️ Würde er noch leben, hätte er *sicher* auch eine #PiDP8 und/oder #PiDP11 zuhause! #computerhistory #digital #pdp8 #pdp8e #pdp11

@rzbrk Yeah! 🤩 I‘d say „welcome to the club“ but I was late to the party and built my own #PiDP8 kit just a few weeks ago. Love programming it via the front switches in octal machine code! 🤓
The 3D printed stand (designed by Dan Novak) can be downloaded from my account at #MakerWorld here 👉 https://makerworld.com/en/models/561418#profileId-480815
#3dprinting #pdp8

@rzbrk No glue necessary, I just inserted the palm rest bar into the side pieces.
Uploaded the model here: https://makerworld.com/en/models/561418#profileId-480815
Do you own a PiDP-8, too? #3dprinting #electronic #pdp8 #pidp8 #bambulab

Best moments when two hobbies come together. Here I added a 3D printed, very solid stand to my self-assembled PiDP-8 replica of a #PDP8. The hand rest barely fit diagonally onto the print bed, phew! Together with four silicone bumpers the whole thing doesn’t move a bit on the desk. 👌 #3dprinting #computerhistory #decpdp8 #digitalpdp8 #bambulab #x1carbon #PiDP8

Finished & working! ✅ #PiDP8 #PDP8 #raspberrypi #ComputerHistory #electronics
Only thing left to do now: Design and 3d-print a stand for it to have a good viewing and operating angle when sitting at the desk. #3DPrinting Anyone any idea or already made a stand for a steep angle? 😳
(I wonder whether Global Thermonuclear War from #WarGames runs on the PDP-8, too. 😂) #WOPR

Almost finished the #PiDP8 kit today! Loads of soldering! Just one bad LED had to be fixed by replacing it. It works pretty well and it’s awesome! The #RaspberryPiZero2W does all the emulation. Can’t wait to write programs via the front switches – and play SpaceWar! later on. But before that I have to finish the casing! #ComputerHistory #electronics #decpdp #decpdp8 #pdp8 #SpaceWar 👉 http://www2.rdrop.com/~paulmck/projects/spacewar/

Over a week ago I received my happily expected #PiDP8 kit – but haven’t found the time yet to solder and assemble it! 🙈 The #RaspberryPi Zero 2, however, already runs the emulator. 😊 That’s a LOAD of LEDs to solder accurately. 😅 #decpdp8 #pdp8 #electronics #computerhistory

#PDP12 - #HELLORLD

https://www.youtube.com/watch?v=zcP_Dfgvuo8

#Programming #MachineCode #MachineProgramming #VintageProgramming #VintageComputing #Computing #PDP #PDP8 #UsagiElectric #PeterPeterson #2001 #HAL #HAL9000

One day down, maybe two more days to go on a #PDP8 numerical simulation run. So far, its accuracy is pretty close to modern IEEE double precision.

I'm so glad that the #PiDP8 runs roughly 23× faster than the real thing. I'd have had to budget nearly 10 weeks (at roughly 750 W) on real DEC hardware.

#fortran

The Universe has been restored to order 😃 I carefully flipped the Deposit switch in my beloved PiDP-8, so it is now operating the same way as a real PDP-8. How I hate cutting PCB traces 😬 but it was for a good cause.

#12bit #RetroComputing #pdp8 #pidp8i

OK, so where did all of this #LINC and #pdp8 stuff from this whoooole thread end up? Well, Dick Clayton from #dec explains in this short interjection at the DigiBarn event:

https://youtu.be/xT_5PcrVI9Q?t=5810

Basically Digital made a weird hybrid LINC/pdp8 system called the LINC-8, but it wasn't that great. So while he was on jury duty, he sketched out the Right Way to do it so that the system could switch between "8 mode" and "LINC mode" *in software*. The result was the #pdp12, which sold more units than all the previous LINC systems combined.

And that takes us to tonight's thread from @tastytronic, where the #umdpdp12 has just had its first successful verification tests of some of its 60-year-old flipchip cards: https://teh.entar.net/@tastytronic/109644812161500698