"learn Z80 Assembly" There was a series of disassembled and commented ROM and OS series named "Journey to the center of the ROM" for the TRS80 family and that

"learn Z80 Assembly" There was a series of disassembled and commented ROM and OS series named "Journey to the center of the ROM" for the TRS80 family and that was very instructive for me. Sort of like "Lions Commentary on UNIX" but a decade later for Z80 rather than unix v6. Something to realize is back in the old days even the old timers only had like two years of experience writing Z80 code. And you were limited by memory enough that scalability problems were not an issue. And people with more than 2 years of experience perhaps writing IBM360 assembler were making so much money they had little interest in these Z80 6809 6502 things.