My first computer. Played Blast-O!, Hunt The Wumpus, Chisolm Trail, A-MAZE-ING, and a couple other games. Learned the crummy programming language of TI-BASIC, gave up on software and stuck with hardware ever since.

Funny enough, now as part of my job, I advise TI on various upcoming power ranges for various lighting types, and they do on occasion make an IC based on my specs for general production.