Looks like I need to take a look at the connections. Some observations
- V2.7, V3.1 and V4.6 all don't work
- Adding the line to V2.7 just makes the LED go dark whereas without the line it is blue. There's no blinking
- In V4.6 the LED blinks when writing the save to the cart but goes dark when verifying the written data. So I assume writing to eeprom may still work but reading it doesn't
- Reading the N64 ROM still works
- Reading flash memory still works (Paper Mario)
- I added some print statements and commented out noInterrupt and it looks like it gets stuck on the call to readData() so I assume this is a data line issue? Since the other functionality I mentioned above still works could it still be a clock issue?
Testing the data line connections I can see continuity between everything other than the middle pin of the eeprom switch and the GBA cart pin. When I test those points I see my multimeter go to 1400. The connection between the middle pin and the 1K resister is also fine as I hear a beep. So is the issue here likely to do with the connection between the switch and the data lines? I'm not sure if I should hear a beep or if it should go to 1400 between those connections.