High Quality Content by WIKIPEDIA articles! The SS-50 bus was an early computer bus designed as a part of the SWTPC 6800 Computer System that used the Motorola 6800 CPU. The SS-50 motherboard would have around seven 50-pin connectors for CPU and memory boards plus eight 30-pin connectors for I/O boards. The I/O section was sometimes called the SS-30 bus. Southwest Technical Products Corporation introduced this bus in November 1975 and soon other companies were selling add-in boards. Some of the early boards were floppy disk systems from Midwest Scientific Instruments, Smoke Signal Broadcasting, and PerCom Data; an EPROM programmer from the Micro Works; video display boards from Gimix; memory boards from Seals. By 1978 there were a dozen SS-50 board suppliers and several compatible SS-50 computers.