In my school, I was part of a group of students who hand-programmed games on TI-81 or TI-82 calculators using TI-BASIC. No cable transfers. Games included: Hangman, Missile Command, Minesweeper, and R-Type. Looking back, it was really amazingly impressive. Both what those calculators could do and how much free time we had to make them do it.

I programmed a Mandelbrot generator on my TI-81 (if I remember the model correctly) when I should have been paying attention in class. Entering the code was slow and painful - fortunately the algorithm is fairly simple. The batteries lasted forever, until one day I set the bailout to a ridiculously high value, given the limited resolution, and walked away.