Disch wrote:
Anyway... I'm a little confused. Is it really that MMC3 can't access 1MB? Or is it just that no boards have that much PRG on them? Like... does the MMC3 just not have enough pinouts?
MMC3 has enough PRG ROM address pins to switch 64 banks, each of 8 KiB.
Quote:
I'm not really very knowledgable when it comes to hardware. I tried making sense of the pinout on
kevtris' page, and it looks like it has pins going up to PRG A18... but wouldn't that make the cap 256K?
There are a total of 19 pins, numbered A0, A1, A2, ..., A18, going into the PRG ROM's address bus. A0 through A12 come from the NES PRG bus, and A13 through A18 come from the MMC3. If you have 19 address pins and 8 data pins, you can address 2^19 octets = 512 KiB.