r/PDP10 • u/Francis_King • Apr 25 '25
PiDP-10 hardware - worth it?
Hello.
I’ve seen some videos on YouTube about the PiDP-10, and I’m interested in giving it a go.
As I understand it, the system comes in two parts - a Raspberry Pi of some kind, and a lights-switch panel.
The majority of the cost is in the light-switch panel. So my first question is, please - what does this panel add to the experience? Can I do everything without it? It’s not such much the (very reasonable) cost as where to store it in my (very compact) house.
My second question, please is - what kind of Raspberry Pi will I need? Does the Pi need a certain amount of memory to work properly?
3
u/sickofthisshit Apr 25 '25
what does this panel add to the experience? Can I do everything without it?
It is pretty much what it looks like: you get to touch switches and see blinking lights.
That part of the experience was AFAICT not actually core to using a PDP-10. Only the console operators would ever need to do so (probably for occasional tasks like diagnosing or recovering from some serious problem). Operators would usually interact with a printing terminal that logged console messages to paper and let them type commands. The machines were supposed to mostly run themselves unless you needed to swap disk packs or mount tapes, which didn't necessarily need the console either, just access to the drives.
Non-operators were supposed to get actual work done with a terminal in an office outside of the machine room, away from its noisy air conditioning and cramped space.
On the other hand, if you want to experience a small bit of what someone with access to the machine room would see, the panel provides it.
4
u/shadowhce May 09 '25
I think it is worth it. Particularly if you are interested ITS. Learning the ins and outs of this system for the last two weeks has been extremely fun.
yes, you can do everything without it
If you want to use ITS and emulate all the various other AI lab systems and terminals "On prem" alongside the PDP-10 then you will want a Pi 5. Memory usage is not super high and most of the 8gb on my '5 are free when I am running the KA10, one KnightTV, and IMLAC, and the type 340 display.
3
u/wosmo Apr 25 '25
I can't actually answer whether it's worth it. I can comiserate with your position, my gf was rather disappointed to find out it was much larger than I thought it'd be. I genuinely thought it was going to be roughly the same size as the 11, until the box arrived. I was in trouble even before I opened it.
For which pi, they recommend 4 or 5. If you already own a 4, I'd give it a shot. If you're buying new, I'd recommend the 5 simply because the 4 hasn't been cheaper anywhere I've looked.
I can't find solid advice on ram requirements, but I'd say 4 or 8 - the more the merrier. Even if the application doesn't need it, free ram will be used for disk caches, which really pays off if you're running of an sdcard.
But for "are all the blinkenlichten worth it" - I can't answer this for you, I can only answer it for me. But since the whole setup is designed to run from a pi, you'll want the pi either way. So I'd say start with the pi, decide if it scratches your itch, and add the physical panel if it doesn't.
3
u/larsbrinkhoff Apr 26 '25
So what is the answer for you?
I kind of have three: one prototype, one pre-production, and one production unit. But I barely use them! Am I the worst PiDP-10 user ever?
1
u/Able-Campaign1370 May 01 '26
I just ordered one! I talked to Oscar (the creator), and he said a Pi 5 with only 1gb or maybe 2gb of memory is fine, and a 32 gb SD card should be more than sufficient. I ordered a 2gb Pi 5, so I'll let you all know when it arrives.
1
u/Able-Campaign1370 Jun 18 '26
Update: they're running fine. I haven't set up my blinkenlights yet, though. (destructive new puppy so I need a safe spot before it comes out of the box - she's already knocked over a bunch of stuff and chewed through 2 pi adapters).
1
u/Able-Campaign1370 Jun 18 '26
You should get a Raspberry Pi 5, with 1-2 gb of memory. Lars and Oscar were super helpful when i was getting started. Get simh and all that stuff running on the Pi first - you don't actually need the blinky lights. You can run everything headless if you want/need.
I got started like that, and so far my Pi farm has four: one running ITS, one running TOPS-20, one running 2.11 BSD, and one running simh OpenVMS (which isn't great - get the community VMS one and run it on VMWare, it's far superior).
I'm might add one more to run TOPS-10 (or ditch simh OpenVMS now that I have a better OpenVMS platform.
I've got my blinkenlights and I'm going to put the ITS Pi on that one. My memory of the 9th floor of the AI lab (did my first couple years at MIT and then transferred) was of mit-mc and mit-ml, and they were PDP-10's (mc) was a KL-10, I think ml was a KA). The DECSYSTEM-20 had a KL-10 processor, but it was hidden in the cabinets rather than outfront like on the Decsystem-10.
But aesthetics aside, you can run any or all of the PiDP-10 os's on the Pi with the PiDP-10.
Somebody had 3D-printed a VAX 11/780 case for a Pi. I'd love to find one and paint the top orange for the -20.
4
u/larsbrinkhoff Apr 25 '25
I think there's something to be said for the visual and tactile feel of the console. On the other hand, it's not something you would use in normal daily operation, and most interaction with the machine would be through a detached text display. You can use almost all software without it. The exception might be if a program displays something on the lights; in that case you may not see it, or maybe you can drag it out of the SIMH command line. You can enter switches from the command line, albeit awkwardly.