SPACEWAR! Switch Boxes for a PDP-12

Date: Mon, 24 Sep 2018 12:26:57 -0600 From: Eric Smith <spacewar at gmail.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: SPACEWAR! Switch Boxes for a PDP-12 Message-ID: <CAFrGgTS=XdctKw6G_FjddnLc6H=gpgf5JizV9zRXY4C0qhoYyg at mail.gmail.com> Content-Type: text/plain; charset="UTF-8" On Mon, Sep 24, 2018 at 11:23 AM, Robert Feldman via cctalk < cctalk at classiccmp.org> wrote: Ken Sumrall built the Spacewar control boxes used at the museum, with some suggestions from me. We originally intended these to be temporary, and to build nicer control boxes later. Since they were intended to be used by restoration team members, and possibly museum guests, we wanted them to be reliable rather than authentic, and specifically did NOT want these temporary boxes to themselves become historical artifacts. We chose inexpensive but robust arcade pushbuttons. They can take a beating, and in the event that the microswitch does break or wear out, it can easily be replaced, though the complete button assembly with microswitch is not expensive. The boxes are particle board. We used DE-9 connectors. On the PDP-1, hyperspace is invoked by the CW and CCW rotate controls being activated simultaneously, so the hyperspace button is wired via series diodes to both rotate buttons. After we built them, Steve Russell pointed out to us that although these boxes don't look like at all like the originals, they actually are authentic, in the sense that like the originals, these boxes were quickly knocked together rather than carefully planned, and are functional rather than pretty. We positioned the individual buttons based on the layout used on one of the Atari coinop games, "Space Duel" IIRC, on the because Atari had done a good job of laying them out to be easy to use. I'm not trying to discourage anyone from trying to make replicas of the original Spacewar control boxes, but aside from some grainy photos and a brief description, not much detail about them is actually known. We do not know what controls were used when PDP-1 Spacewar was demonstrated at the Computer Museum in Boston. We don't think they had the original control boxes. Possibly they might have just used the PDP-1 console switches, which is quite inconvenient and increases wear on those switches. When we restored the PDP-1, we discovered that some of the console switches were flaky, and upon inspection, that they appeared to have been replaced multiple times, with suboptimal craftsmanship.