Microcom S-64 8085 Eurocard System

I know absolutely nothing about this system. Found them in a box at a swapmeet years ago.

The CPU board has a dual baud rate generator which can be jumpered to RST 6.5 and RST 7.5. I expect the 8085 Serial I/O goes to the backplane.

There's also a jumper "F000/F800" which I guess sets the ROM location for RESET -- at this stage I don't know the mechanism of how the ROM is mapped to 0000 at RESET.

The CPU board also makes -12V with a DC/DC converter and puts that on the backplane.

The RAM boards have jumpers for low byte (selected) and high byte. So the bus accommodates 16 bits data. The CPU board connects to the low byte (makes sense) but the RAM boards obviously can work in a 16-bit system.

There are two banks of 8k, which can be mapped to a "page", and then also selected / deselected in 1k blocks.

Another jumper "Port 40/C0" tells me maybe there's some kind of software paging support too.

These are the jumpers on the other two boards.

The RAM/ROM board has 8k in 2114s and another 8k in 2716 or 6116. This one is jumpered for 6116 and there's a wire mod to accommodate the 2716. From the switches, the 2114s are at 0xC000 and the 6116s and 2716 are at 0xE000.

I am no CP/M expert but a question on the Classic Computer mailing list taught me that CP/M needs RAM at 0000 and therefore this box most likely ran CP/M. Which, given the 1981 date and the presence of an FDC makes sense.