Wow. This sounds very cool! I've never actually run CP/M, and I'm not sure that running it on Model-T is super exciting (probably just because I haven't tried it) but the capabilities of the REXCPM sound awesome.
I'm fine with a 3-wire install. Hell, any number of wires to the mobo would not be a turn-off for me using it; basically as long as trace-cutting isn't involved it won't bother me. I'm assuming the CPLD and SRAM are on the other side? Man, that board is gonna be crammed! :) -Josh