I have a Quay 900, which is an obscure Z80-based system from 1979. It has two MPI (CDC) eight-inch double-sided floppy drives, and uses a Quay MPS-90F single-board computer rather than the then-common S-100 bus, though it has two daughterboards for additional parallel and serial I/O. I received it with no documentation or software. I heard about it back in the day, but I’m not sure where, as there don’t even seem to have been many advertisements for it. The Internet doesn’t know much about it.
I recently reverse-engineered the boot EPROM, which only contained code to read track 00 from drive 0 in double density. In particular, it didn’t initialize the console serial port or output any messages to it. I used a continuity checker to figure out the port and bit assignments of the console UART, and wrote a simple monitor ROM that lets me dump memory, download programs in Intel hex records, and execute them. I also wrote a floppy disk formatter.
For RC2014SC, I plan to get write or port more software to the Quay. This will likely be some subset of:
- Upgrade my floppy formatter
- Add double-density support
- Add error recovery
- Write a program to upload and download entire floppy disk images
- Write a CBIOS and get CP/M 2.2 running
- Get FIG-Forth running on the bare metal (Z80 version here) (or maybe CamelForth under CP/M)
- Write an I2L interpreter and run XPL0 programs (once upon a time Pickles & Trout sold XPL0 for the 8080, but I haven’t been able to track down a copy)
And perhaps other stuff I haven’t thought of yet.