Last weekend I’ve finished my first CPLD experiment, which (of course) was an project for the C64. This small extension is a GeoRAM compatible RAM extension or a EasyFlash like extension. It’s possible to switch between them via software. In other words you can use it as pure ram or load cartridges in the ram and play (instead of burning eprom modules).

This is only thought as an experiment for me to learn to deal with CPLD. So far it’s working as it should and I’m happy ;-)

The used Parts:

• an CPLD: Xilinx XC9572
• 512KiB RAM
• 74hc365 hex buffer/line driver
• a led (with a 1k5 resistor)
• sockets, circuit board and wire