This is an emulator I wrote which turns an Arduino DUE into an old Z80 CP/M machine. Who those willing to run dBase II or Wordstar 4 again.
It just needs an Arduino DUE with a SD Card shield, format the SD card with hat filesystem, load yout cpm apps onto it and off you go.
This is a fork of my RunCPM project (https://github.com/MockbaTheBorg/RunCPM/).
I have added the source code to https://github.com/MockbaTheBorg/CPMduino/
Feel free to download the sketch and give it a try.
Right now everything seems to be working other than directory based functions.
Basically the SearchFirst and SearchNext functions are utterly broken.
So far I have been able to run mbasic and UCD Mumps with perfect results. Didn't have the chance to test with other applications.
It may be possible to adapt it to run on other Arduinos as well, as long as there's enough Flash and RAM. My next step is to port it to the Teensy 3.1 (with external SD card and SPI SRAM).