1) Chess engine 
Microchess, by Peter R. Jennings, was originally a microcomputer chess program for the MOS Technology KIM-1 microcomputer, first released on December 18, 1976. Microchess, as small as it was in terms of program size, could still play passable chess on the KIM-1 with its 6502 microprocessor, 1 kilobyte of memory, simple hex keyboard, and seven-segm...