This is a CP/M v2.2 computer. It uses a Z80 emulator, and runs on an Arduino Due.
Building the application is easy. Simply get a copy of CPM_Due, open the .ino file in the Arduino IDE, compile it, and load it on your Arduino Due or Digistump DigiX HW. Note that in order to build applications you'll need Arduino 1.5 or higher to support the ARM processor on the Due/DigiX. I've been using 1.5.6-r2.
To create the disk image you'll need to follow the directions in the tools/avrcpm/z80 directory to create a floppy disk onto an SD card.