Mapper 17 bug with mmc4-like chr banking
Closed this issue · 6 comments
as stated, mmc4-like banking mode is broken
mapper_017.zip
see rom file SM6003 and sm6015
2nd chr bank should be from chr bank 4, instead of bank 1 aka
bank[4] = m006.chr.reg[4 | m006.chr.mmc4[1]] & 0xFC;
instead of
bank[4] = m006.chr.reg[1 | m006.chr.mmc4[1]] & 0xFC;
this breaks mmc4-type chr banking, including most of mapper 12-sub1 rom files. inital prg banking for mapper 12 is also incorrect for some types.
see: "Initial PRG register content" section
https://www.nesdev.org/wiki/INES_Mapper_012
on a related note, you may be interested to add mapper 562 which is similar mapper to 0006/561
mapper562.zip
(this are just some because of file size limit)
Hi negativeExponent,
as stated, mmc4-like banking mode is broken
Fixed in my personal branch.
on a related note, you may be interested to add mapper 562 which is similar mapper to 0006/561
Thanks for the roms, I hadn't implemented it because I didn't have any.
inital prg banking for mapper 12 is also incorrect for some types.
Can you send me some roms with mapper 012? I only have two.
mapper_012.zip
@punesemu
Many thx.
i assume this is done., so im closing it.
I intended to close it after implementing the 562 mapper but it's fine anyway. Thx for the support.