In the 80s I was young and owned and used 6502 machines and not Z80, so had a builtin bias about the Z80. But looking back now, it really is a nifty processor, I wish I'd had a chance to spend more time with it. Not as cycle efficient as the '02, but looks nicer to write code for.
I had a single sheet double sided plastic reference card for the 6502. Had everything needed to dig deep into the Apple ][+ / ][e computers we had at school. My most productive use of that was to hack Lode Runner to start on arbitrary levels so we could get to the higher levels of the game during lunch break. Such fun!
