One suggestion was to use a setup like follows:
- Bit 0 as SDA
- Bit 1 as SCL
- Map EEPROM somewhere in $A130xx (gotta pick an address)
The other issue is that we need to settle on an EEPROM size, since different sizes have different ways to select the address (the smallest ones only have one address byte, larger ones have two address bytes, even larger ones have three). I suppose 32KB or 64KB would work but would be nice to settle on one.
And finally, include this in the ROM header (probably where the SRAM information would usually go, that gives us 12 bytes). Ideally, it should include the EEPROM size, just in case we insist on having room to go for different ones. This way emulators can be updated to detect this setup without resorting to databases (and have homebrew built against this spec).
Anyway, discuss, I want to have people settle on something so I can document EEPROM on Plutiedev :v
EDIT: assembled a list of $A130xx address ranges that I know are used up