#computer #DEC #DigitalEquipmentCorporation #PDP8 #vintage #SpaceWar

Digital Equipment Corporation PDP-8/I running Space War by David Gesswein at VCF East XVII

#computer #DEC #DigitalEquipmentCorporation #PDP8 #vintage #SpaceWar

Digital Equipment Corporation PDP-8/I running Space War by David Gesswein at VCF East XVII

The SBC6120 PDP-8 clone was complaining that its IDE connection had fallen out. It's right as rain now. (And hey, who knew that minicom could talk DEC's weird Mark parity?)

Running on actual silicon with the original SBC6120 distro makes me really appreciate:

1) the work that Warren Young et al have done on the PiDP-8/I OS/8 software distribution after the SBC6120 came out: https://tangentsoft.com/pidp8i/wiki?name=Home

2) how much faster emulation can be

#RetroComputing #pdp8

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

Why yes I did recreate period-correct FORTRAN code for plotting the Mandelbrot set before it was known as the Mandelbrot set ... even got it running on a PDP-8

https://math.stackexchange.com/a/4674800/578897

#mandelbrot #RetroComputing #FORTRAN #pdp8

Picked up a little restoration project from a local: A PDP-8A/420, complete with 20-slot OMNIBUS backplane, PSU, CPU, serial, and 16KB of core memory. The story is that it had been used with a CNC machine at some point, and it is quite filthy. #PDP8 #RetroComputing #DEC #digital

KYMPUTER 6100 with flat cables
6.7.1980
dia18x24-006
Kamera Kleffel
Objektiv Euryscop 4,5/280
4s (+15 dunk.) Blende 32 Ektachrome 64 Prof.
#Fotografie #Großformat #largeformatphotography #photography #rm53 #believeinfilm #filmisnotdead #homebrew #computer #minicomputer #pdp8-compatible #microcomputer

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

Just tried ChatGPT for the first time and wanted to see how well it fares off the beaten path and asked if it can write PDP-8 assembly.

Well, the general info looks good, but the assembly it so confidently presents as an example is unfortunately not PDP-8 assembly… In fact only HLT is a genuine PDP-8 instruction, also the apparently octal 12 bit addresses would be a good match. LDA and STA look more like 6502 instructions.

#ChatGPT #PDP8 #retrocomputing #assembly

But like, where else will I get Gordon Bell telling the story of Chalk River and the #pdp5 and #pdp8?

Anyway, eff that dude.

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

I highly recommend watching the video above. Wilkes wrote an OS for the scope that provided a full-screen text editor at a time when most luxury OSes only had teletype-oriented line editors at best. The interviewers are kind of pushy, and seem to be getting her to give her talk to the camera when she wants to ensure they get certain documents, but she's game and gives a lot of good history about the machine's operational lifetime.

In particular, she worked first on a LINC simulator on the TX-2, but they kept changing the architecture so that's partly why they had to ship her a LINC in Baltimore while they all set up shop in St. Louis.

Note that she also stressed the behaviour of system sounds as an indication of smooth operation, much like the technicians who preferred Hamilton's code for SAGE.

Anyway, LINC showed that you could build a small inexpensive computer from #dec flipchips. So what did Digital themselves do?

Well, they tried to make their own, and that was the #PDP5. This ultimately became the #pdp8
But they did something clever: they made a change to the #LINCTape format that let it read data backwards as well as forwards.

And they called it #DECTape. In one of the videos I pasted above, Wes Clark mentions that he specifically asked that they take all LINC branding off of this, because he didn't want to get called doing support requests for Ken's customers!

Ward Cunningham once wrote a #PDP8 emulator on a CDC 6500 so that he could assemble PAL code more quickly on a second-hand 8/e. As is typical for him, the Web page is really well made: http://c2.com/ward/pdp8sim/

Sometimes in museums you'll find later #ls8 models using #pdp8/a units and floppy drives instead of paper tape to hold the cues:
https://www.computerhistory.org/collections/catalog/X1060.91

https://youtu.be/o7PgUXOKqJ8?t=205

A Chorus Line was the first stage show to have computer-controlled lighting, and they used a #dec #pdp8 to drive it all in #BASIC. #VintageComputing

I've been pasting lots of random #pdp8 stuff into an ephemeral chat with some friends, and one has asked me to save all my #VintageComputing discoveries here so there's at least a thread to find them. I'll do the Lincoln Labs/DEC general stuff elsewhere, but here to start off there's a pretty neat PDP8 hardware simulation online at https://pdp8.app

Every holiday season I seem to pick #PDP8 #VintageComputing back up, and every year I am reminded that if you have an EAE you totally get an OR instruction via MQA if you just remember to use it.

Didn't know that there was a Pascal compiler and runtime for the PDP-8 running OS/8.
Got it working, and it compiles and runs my Mandelbrot program perfectly 😃
#12bit #RetroComputing #pdp8

::1

OpSec Fail, but what the heck.
(At least it's old shite not worth nicking)

#BattleStation #Lemmy #DSHIELD #ISCTV #TuxedoComputers #LittleBobbyTables #PDP8 #Digital #DEC

Yet another great xmas gift for me! If I had known how effective and quick this is, I should've had one many years ago - better late than never 😃
#8bit #RetroComputing #Z80 #pdp8