I used to have a fare few of the older retro desktop chess computers, sold a few over last two years and had many fun hours playing them, be interested in hearing your stories!? I now only have 3 remaining: Novag Citrine in mint condition, a Fidelity Challenger and The Great game Machine Module with the Sargon2.5 program ... boxed, sargon is rare as its boxed in mint so would never sell, first commercial chess program to play a decent game! these old chess computers are part of history and hold memories dear!