In 1981 Synertek released a new version of their popular SYM-1 single board microcomputer. SYM-2 which offered a choice of 6502, 6809 or 6802 CPUs was software-compatible to its predecessor had new hardware features: on-board power supply, eight toggle switches for input, eight LEDs to display binary output and on-board cassette interface with audio input and output jacks. Hardware compatibily between both SYMs ensured that RAM and disk drive interface devices worked with both models.