While the 8080 started the personal computer revolution, the Z80 was quickly a winner because it was easier to use and had more capabilities. [Noel] found out though that the Z80 OUT instruction is a little odd and, in fact, some of the period documentation was incorrect.
This is a companion discussion topic for the original entry at https://hackaday.com/2024/01/19/z80-i-o-madness/