I’ve designed a board that allows replacement of the 8 x 4116 on the Model 1 or System 80 (aka Video Genie) with a single static RAM.
It also allows an upgrade to 48k with no extra parts. A similar board for the Model 3 and Model 4 will follow, with support for up to 128k.
I’m finishing up the board design now. The System 80 has weird spacing on the DRAMs, so I have to adjust the board to accomodate.
I’m trying very hard to get the gerbers out to PCBWay this week. Finger crossed!