PDP-9 Spacewar

[larsbrinkhoff]

There was a version of Spacewar for the PDP-9 with Graphic-II display. I believe the Bell Labs people said they had a version of Spacewar, so maybe it was that one?

I have two files: source code, and an assember listing. I can't share them now, but they will go public.

[larsbrinkhoff]

The question is, would this program be appropriate for this project? We can speculate that this is indeed the Spacewar that was running on the Unix PDP-7. After all, how many Graphic-II Spacewar versions could there be?

[sebras]

I found an old alt.folklore.computers usenet posting that mentions Spacewar for PDP-9 and has a partial source code listing. I don't see any GRAPHIC-2 instructions there, but there might be in the other parts.

[larsbrinkhoff]

https://www.bell-labs.com/usr/dmr/www/spacetravel.html says:

Later we fixed Space Travel so it would run under (PDP-7) Unix instead
of standalone, and did also a very faithful copy of the Spacewar game
originally done (I think) at MIT on the PDP-1, but that was a
different game.

The copy I have runs standalone, and it's written in MACRO-9. So I guess there were (at least) two different Graphic-II Spacewar versions.

[larsbrinkhoff]

I started this Spacewar on SIMH. It wasn't an immediate success, because the G-2 instruction words didn't make much sense. The display list is generated dynamically, so some debugging will be needed.

Possibly my translation from listing to binary was bad, or else this software is using some other version of the G-2 hardware.

[larsbrinkhoff]

Here is the code:

https://github.com/chriswalker-ge635/PDP9-SPACEWAR