fachat wrote:
The z80 sets /mreq and /iosel only when Ax are valid and /wr only when Dx are valid to accommodate for transparent latch type devices. So, those type of devices would only work with further qualification of the select and r/-w lines.
Yeah, that's what was niggling me about this. The core of it I think is that unlike R/W, /RD and /WR include timing information, so there's really no way to go back and forth without conversion.
I suppose one for RC6502 leave the /RD and /WR signals as they are, put R/W elsewhere, and then ask CPU boards to generate both. But that seems like a bunch of extra work (and uses up a valuable signal line!) for dubious gain, when I think the same thing could be done anyway with a separate bus adapter that would sit on the RC6502 bus and generate RC2014 bus signals on its other side.