C Z80 Control Logic
This section describes the generation of three control inputs to the Z80 CLOCK , RESET-, and WAIT-. The control input Bus Request BUSRQ- may be wired on some boards, but it is never used. The Clock Circuit provides the Z80 Controller Board with a stable source of timing, thus insuring, among other things, that all audio sounds remain in tune. Composed of U24, U29, Yl, and other discrete parts, the Clock Circuit consists of an oscillator and several dividers and drivers. The oscillator is...