rc2014-compat

A respin of the RC2014 ecosystem. I don't have any opposition to building things out of SMD parts (in some ways, I find it easier to work with), so some boards might go that way to the extent that parts availability allows. Also, I'd like to keep all board sizes within the 100x100mm limit within which PCB fabs offer their cheapest rates (like $2 double-sided at JLCPCB, for instance).

z80-cpu

Basically the same as the RC2014 Z80 module, but with a 10-MHz LQFP-44 CPU and a crystal oscillator to run it at that speed.