I do some retro work, and in order to debug a system (this was at a time when I knew less about this type of system) I once plugged in a Raspberry Pi Pico into a Z80 socket (not directly of course) and ran commands to read/write from/to memory/IO/ROM to see if I could find the problem. Makes you feel quite omnipotent :)
Course, my setup didn't really emulate the Z80 to run code, it just emulated its signals for a handful of instructions, which I instructed the Pico to do on demand via its UART. (Pictures and some code: https://blog.qiqitori.com/2023/02/two-raspberry-pi-picos-pre...)
Course, my setup didn't really emulate the Z80 to run code, it just emulated its signals for a handful of instructions, which I instructed the Pico to do on demand via its UART. (Pictures and some code: https://blog.qiqitori.com/2023/02/two-raspberry-pi-picos-pre...)