Nov 042013

I recently learned of a computer collector up in Santa Clara, CA who was moving to a new location, and who needed to get rid of a lot of his vintage computer equipment that he had in storage. He had already moved the good stuff that he was keeping, but he offered up piles of gear for free to anybody who would haul it away on some specific days. I didn’t want to drive up there myself at the time, but one of my friends at work suggested that one of his daughters and her boyfriend lived nearby in Tracy, and they might be willing to grab a truckload of equipment and bring it down south next time they drove back to visit him.

Everything all came together, and we met at a restaurant near my home on Saturday to transfer the loot. The haul consisted of four PDP-11/44 chassis and on ASR-33 teletype!

There are slightly less than two computers’ worth of boards between the four chassis, and the ASR-33 is missing some bits… after all, these are the dregs that were destined for the scrap heap. I couldn’t be happier, though, because there should be enough pieces to build up one PDP-11/44 with some spares and trade fodder left over when I’m done, and the price was right!

I’m told that one of the power supplies is bad, and another is believed to be good. I don’t know which one is which, but I’ll figure it out. One of the four chassis has a larger expansion backplane than the other three. One has its rack slides with tilt mechanism, though it’s missing the read slide supports. One CPU has the floating point option card; one CPU is missing its datapath card. There are I/O cards including an interface for the RL01/RL02 removable pack hard drives, some serial port cards, and a couple others that I haven’t identified yet. I have a lot of debugging ahead of me, but I should have a nicely-configured computer once I’m done swapping pieces around and fixing whatever’s broken. I’ll still need to add more equipment such as disk drives and a rack cabinet, but this is a great start to get my feet wet in restoring old DEC computers.

  11 Responses to “My New DEC PDP-11/44 Project”

  1. Mark,

    You might ask Kees Stravers for tips on getting things back to working order. I know he’s been there, done that!

    Or start out on his home page, there are some illustrative VAX links here and you get to know him a bit.

    For other historical software, you might try


  2. Oh – almost forgot:
    (but I don’t personally know this guy)


  3. A very cool project! If you get a good copy of “spacewars” working, you’ll hit the top of my personal nastalgia meter!

    • Hi! I do want to get the old Star Trek game running on it, as well as the classic Adventure game. Spacewar would be cool, but I don’t have any graphical display in the plans right now. It gives me something to think about, though…

      There’s an old Amiga game called Gravity War that I used to like to play. I recently found it again and got it working on an Amiga 3000 that I acquired, and I still like to play it! It has some similarities to Spacewar as it’s described on Wikipedia. The two ships ar stationary and are surrounded by planets, black holes, and so forth. One looks like the Enterprise, and the other looks like a Klingon ship. Players take turns specifying the angle and launch velocity of a missile. The missiles are affected strongly by the gravitational fields of the masses around the ships.

  4. Sounds like fun! Still, Spacewar was the very first, wasn’t it?

  5. I have a 11/44. 2xrl drives. And misc extras. It is going in the dump in 2 weeks… do you know anyone who wants it FREE? schematics and rsx 11 mnuals and a few unix things…
    must pick up san antonio texas
    pick up by 12-24-2016

  6. Very nice. What’s the current status of your project to get them up and running? I also have a couple of 11/44s which are on my project list. Just need to make them a priority and get to work.