Today I hooked up an 8k FRAM chip using SPI. I found these FRAM chips on Adafruit. They are pretty sweet being fast, cheap, and most importantly non-volatite. To use SPI I am bit banging Port B on the 6522 VIA. Based on multiple recommendations I have found around the internet, I put the clock on bit 0, and the two serial lines on bits 6 and 7. With this configuration only 10 or so lines of assembly code are needed for the serialization function!

The goal for these FRAM chips is to support swappable game cartridges. I can copy executable code from the chip over SPI and place it in RAM and then execute it. Before this can happen I need to take the IO functions I have and turn them into a BIOS by making sure they are in a predictable place in memory so that they can be called by programs that are compiled independently.

The other option is just to use one for saving high score data.