The ROM is Megaman 2.
Mapper is MMC5.
The total size is 1.25 MB (1,281 KB)
PRG banks: 16 x 16kb
CHR banks: 128 x 8kb
8 x 8 sprites (not 8 x 16)
CHR-ROM size was maxed out, where-as PRG-ROM was not expanded at all.
I am currently converting Megaman 2 to CHR-ROM. This project depends on me being able to swap 2K CHR banks. If I can't do it, I'm screwed.
I messed with register $5130 so many times. And I tried all variations of $5130 in conjuction with the chr bank numbers, adding two $5130s, omitting them completely, putting the chr bank numbers in $5130 instead, and making the chr bank addresses 0, etc. NOTHING WORKS.
The game doesn't want to do 2K CHR switches. It will only do 8K or 4K. And I followed the wiki.nesdev article, and I have had nothing but success up until now. There is no reason why my code shouldn't be working. But it doesn't.
I'm actually stuck on this. I wouldn't ask for help if I didn't need it.
Okay, apparently you can't load two 2K CHR banks on the left side of the PPU, and then switch the mode to 4K, and load the 4K bank on the right side of the PPU. I don't know why you can't, but you can't. So, I'll just deal with it.