Greetings to all lovers of Arduino and old school computing! Nostalgia for the eight-bit computers of my youth led me to this project :-) - CP/M 2.2 computer from ... what would you think? ... Arduino Nano 3.0!
For weeks two or three I made the i8080 processor emulator for Arduino Nano (it passes the test from MICROCOSM) and adapted the CP / M. The main problem - Arduino has only 2 (!) KB of RAM. But we also have an SD card - I made a 4-line cache (32 bytes) to this card, and the card itself emulated all 64 KB of RAM. Although I applied the most primitive cache management algorithm, the speed of work is not so bad. At the same time, this card also emulates four floppy disks.
Here's the quick-and-dirty prototype of my work:
Yes, I did not use the adapter for the card, I inserted it into the connector of the cable from the five-inch drive. :-)
To communicate with a computer, I use a terminal program (in the future I plan a PS/2 keyboard and an LCD screen or connect to a TV).
Here is a screenshot of the memory check:
My first program in BASIC for the past twenty (!)))) years: (I launched TinyBASIC).
Are you interested in such a project?