Blaster Master: Blaster Master MMC1 to MMC3 Hack

Here is a patch that converts the mapper in Blaster Master from MMC1 to MMC3. Documentation is also included.

7/28/13
infidelity

Converting Blaster Master MMC1 to MMC3

Found these 2 right off the bat!

$D4 = Sprite PPU 00-FF ;$1EC4A - A5D4 2064E6
$D5 = BG PPU 00-FF ;$1EC4F - A5D5 2050E6

This is strange, at bootup, $1E69C does A980 8DFFFF60??

$1E635 does = A5DB 203CE6, which is the MMC1 bankswap routine

BAH-ZING! This rom has some major free space in bank 06 from $1BC40-$1BFFF (3C0 bytes!)

MMC3 bankswap routine will be located at $1FED0 '20A8FE'

MMC3 setup
$1BF10 = A900 8D0080 8D0180 8D00A0 8D01A0 8D00C0 8D01C0 8D00E0 8D01E0 A205 8E0080 BD29BF 8D0180 CA 10F4 60 00 02 04 05 06 07
$1FEAD = A906 20A8FE 2000BF 4CF4FF
$2000C = 9DFE

CHANGE JSR BANKSWAPS
$1E637 = 20A8FE
$1E69E = 20A8FE
$1EC63 = 20A8FE
$1EC6B = 20A8FE

MMC3 CHR ROUTINE (WITHOUT USING RAM REGISTERS, A NEW METHOD I CAME UP WITH)
$1E674 = A906 20A8FE 2030BF 60 00000000000000000000
$1BF40 = A900 8D0080 A4D4 B9B0BF 8D0180 A901 8D0080 B9B0BF 38 6901 8D0180 60
$1E660 = A906 20A8FE 204CBF 60 00000000000000000000
$1BF59 = A902 8D0080 A4D5 B9B0BF 8D0180 A903 8D0080 B9B0BF 38 6900 8D0180 A904 8D0080 B9B0BF 38 6901 8D0180 A905 8D0080 B9B0BF 38 6902 8D0180 60
$1BFC0 = 0004080C1014181C2024282C3034383C4044484C5054585C6064686C7074787C

DONE! Blaster Master is now MMC3! :-D
-infidelity




Blaster Master (USA).nes - NOINTRO
CRC32: 52BCF64A
MD5: 9C96408F7A7AA0DA2C3B723759699506
SHA-1: ADB89B4923BB34805A39C141BAF227849A27CE41
SHA-256: CE7B1CC6BA10E3163781BBFD2F00A8E50FA68529B915C7818E04B126EED862FD