This is my own design. Based on neatSRAM schematic by Pasi Lassila.
I wanted to create a drop in modern memory replacement for C64 long boards that use eight memory chips. Gaps between memory chips on 250407 and 250425 motherboards is different. My board can be used with both. Pin headers need to be soldered according to which motherboard the memory is installed.
This will also fix VSP bug.
I have red and blue PCBs available. Boards are the same except the color. You can also buy boards without pin headers installed. If you want to solder pin headers yourself note that you need round pin headers. Square ones don’t fit.