Donn Stewart
13917 Deviar Dr
Centreville, VA 20120
dstew@cpuville.com
13917 Deviar Dr
Centreville, VA 20120
dstew@cpuville.com
Since I had in-hand a Z80 based microcomputer kit, I decided to use that system with my new processor. So, like the Z80, my new processor would have an 8-bit data word size, and a 16-bit address space. I would have to make the processor accept varying instructions sizes, from one to three bytes. Also, it would need to have separate input-output and memory access instructions, to appropriately access the various ports in a system that was designed for the Z80. However, I did not need need the interrupt system, or the direct memory access system, or the dynamic memory refresh system, or wait states (the Z80 kit system did not use these features). I would make an adapter that would plug the new processor into the Z80 socket, and that should be all that was needed. Here is a comparison of the Z80 and the 8-bit processor pinouts:
The new processor with the signals as shown above should be able to operate the CPUville Z80 computer system in the place of the Z80.
8-bit processor links:
