Ah, computer history. Been that, done there. I happened to be an undergrad at MIT when
Spacewar was created. I was in that room, and got to play several times. It was a new monitor, on a PDP-1 computer, in the same room as the original TX-0. Next door was a teletype machine somebody had taught to play tic-tac-toe. Enjoyed the living daylights out of it.
I hadn't programmed it, I'm sorry to say. But when I went to grad school at the University of Minnesota, I ended up in the same lab as a CDC-3100 computer, and programmed it for Spacewar. Even made joysticks for it, as if such things were available they were probably reserved for jet planes.