It is nice to see this kind of thing still going on. I've been doing something similar with a Z80 recently; currently I have a Z80 hooked up to an arduino-mega, which is faking port-based I/O and RAM read/writes.
When I started my goal was to write some simple code, hosted on the arduino, then put together a "real" system with EPROM for ROM and proper RAM chips.
Instead I got distracted porting BASIC, FORTH, and similar things to the working processor. I should get back to it!
I think the Z80 is simpler to get started with than the 6502, when it comes to physical circuits, as it needs fewer components. (Having RAM refresh built-in, for example.)
When I started with the 6502 it took a while to get a working, stable system due to a couple of weird circuit issues (like forgetting to qualify R/W by PHI2) which wouldn't have been the case if I was using a Z80
Do you know if there is a forum for Z80 homebrew systems?
http://www.z80.info/ has a lot of information, but it's not a forum as such. I've found a couple of groups on reddit, for retro building and z80 systems, but nothing really large.
FWIW this is the high-level overview I've put together:
When I started my goal was to write some simple code, hosted on the arduino, then put together a "real" system with EPROM for ROM and proper RAM chips.
Instead I got distracted porting BASIC, FORTH, and similar things to the working processor. I should get back to it!
I think the Z80 is simpler to get started with than the 6502, when it comes to physical circuits, as it needs fewer components. (Having RAM refresh built-in, for example.)