This is the Kyber Minus from Kyber Calcolatori, it's a CP/M clone thing.
The owner has provided a boot floppy image for it but am having trouble getting it to even attempt to boot, a ready signal from the floppy drive should generate an interrupt to trigger the boot process. I have a schematic so may submit as is in case anyone else can make more sense of it.
BBC Model B, ATPL Sidewise, Acorn Speech, 2xWatford Floppy Drives, AMX Mouse, Viglen case, etc.