That is the first mention of a Challenger 1 I’ve seen in quite a long time. My parents bought my older brother a Challenger 1p around 1978 and I learned to program on it. That thing was literally a tank. My brother had soldered on a joystick controller and hooked up our Sears pong paddle controller to it and showed me how to PEEK at the right address to read the value. It felt like magic to a 7 year old.
I still have it in my lab, right next to a PDP-11/05. I don't think I have a composite input monitor or NTSC TV around anymore to use as a display. I could rig something up.
