GM 853


Using the same PCB as the GM863 Battery-backed static RAM card, Gemini appears to have got a 2-for-1 deal here! All the components for supporting the static ram are omitted and instead of soldered-in RAM chips there are sockets.

This has 8 “Bytewide” EPROM sockets. These would be mapped into the memory space using the DIP switches along the top edge.

The sockets are arranged in 2 banks, A & B.

Credit to Daniel for this picture. 🙂

I would appreciate a manual and circuit for this and the GM863 if anyone has them.