Arduino Nano as CP/M-Compatible Computer – Arduino Project Hub

https://www.hackster.io/FoxyLab/arduino-nano-as-cp-m-compatible-computer-c09d4e?use_route=project
cpm4nano – CP/M-compatible computer based on Arduino Nano.

This looks interesting but maybe not very practical. I remember using and CP/M in early 1980s and even remember writing some code to it.