Before revision: The S-100 bus is based on Intel 8080 signals, the STD Bus around Z80 signals, the SS-50 bus around the Motorola 6800, and the G64 bus around 68000 signals.
After revision: The S-100 bus is based on Intel 8080 signals, the STD Bus around Z80 signals, the SS-50 bus around the Motorola 6800, and the G64 bus around 6809 signals.