A few years ago I bought a "retroshield", which is the same kinda idea:<p><a href="http://www.8bitforce.com/projects/retroshield/" rel="nofollow">http://www.8bitforce.com/projects/retroshield/</a><p>There were (are?) boards for driving a Z80, 8085, and a couple of other processors all via an Arduino-Mega.<p>It was a fun project which later lead to me working on a simple single-board Z80-based system, and that lead to me playing around with CP/M and similar things.
Some years ago there was Pinguino (penguin in spanish). Pinguino is an Arduino-like board based on a PIC Microcontroller.<p>But it is dead: <a href="https://web.archive.org/web/20180512095336/http://www.hackinglab.org/" rel="nofollow">https://web.archive.org/web/20180512095336/http://www.hackin...</a>