techniques for animated background tiles?

qbradq · Post by **qbradq** » Wed Jun 22, 2011 5:15 pm

Do most emulators support CHR-RAM banking in MMC3? I did a test ROM but can't remember the results and I've lost the code in a HDD crash.

tokumaru · Post by **tokumaru** » Wed Jun 22, 2011 5:40 pm

I did a quick Mega Man 4 hack (I messed up the code that initializes the CHR banks) and indeed graphics got screwed up in all emulators I tested (FCEUX, Nestopia and Nintendulator), so it's safe to say that at least these support this feature.

Bregalad · Post by **Bregalad** » Thu Jun 23, 2011 3:46 am

I guess the emus will switch the banks if you write something to the banking registers, but they will default to the regular "0,1,2,3,4,5" bank switching if you do nothing, while the real MMC1 will default to "0,0,0,0,0". So if yo actually want to use the CHR-RAM like a plain 8KB RAM, you should first do some bank switching at startup so that it is set up correctly.

It was Banshaku if I remember well who had this problem, his program worked fine in all emus, but failed on a real cart because of that.

tokumaru · Post by **tokumaru** » Thu Jun 23, 2011 10:38 am

Yup, you have to initialize the mapping with sequential numbers if you want to use the memory contiguously.