CASIO fx-4000P scientific calculator from 1986

[gning]

I still have an FX-4000P, though I haven't put fresh batteries in it for years. I used it a lot back in the eighties... and I even coded games on it.

The first game I coded was just a proof of concept to see how far I could push it. I taught it to play tic tac toe. I had routines to evaluate moves, and it had a strategy to counter the human move with a tree lookahead. A fully exhaustive tree lookahead. When you put in your opening move, it took about eight hours to respond! But the second response was only like one hour, and the third and fourth were quick. It filled the program space with just a few bytes to spare.

The second one I coded was Lunar Lander. I had parameters so you could play on the moon, or Mars, or Earth, but they had to be hardcoded in. There was some room to spare so I added different texts to indicate the severity of how hard you hit the ground, like "(bump)" or ">thump<" or "Thud!" or "*CRUNCH*" or ">>CRASH!<<". It was actually kind of fun to play, but certainly a pain to manually enter all the keystrokes.

I also did things like plot graph values for the response curves of theoretical loudspeakers. That required faking complex arithmetic.

If I dig enough I might still be able to find a notebook with those programs.