Metroid: Metroid MMC1 to MMC3 Hack

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

7/18/13
infidelity

Converting Metroid from MMC1 to MMC3

MMC1 Bankswap for Metroid is at $1C50A

MMC3 Bankswap at $1FFE8 = 0A48A9068D0080688D0180090148A9078D0080688D018060
20D8FF is new jsr bankswap routine

$1FFD6 = A205 8E0080 BD0AC5 8D0180 CA 10F4($8001 chr setup) 4C1AC0
$1FFEA = 0A48A9068D0080688D0180090148A9078D0080688D018060(mmc3 bsr)
$1C50A = 20D8FF(jsr to bsr) A500 60
$1C4F1 = 1D (changed BEQ's branch to the rts located above for $1C50A, default was 2D)
$1C510 = 000000000000000000
$1C51A = 00 02 04 05 06 07($8001 chr setup table)
$1C4D5 = 8D00A0(mirroring) 60 00000000000000000000000000000000

Game boots, displays correctly, viewing ppu while game runs, and things change properly, mirroring is correct as well. Plays on all emulators and on nes. Made sure JUSTIN BAILEY worked as well, and it does.

Metroid is now converted from MMC1 to MMC3! :-D
END


Metroid (USA).nes - NOINTRO
CRC32: A2C89CB9
MD5: D77C8053168DA14B360BF5CAECCC5964
SHA-1: ECF39EC5A33E6A6F832F03E8FFC61C5D53F4F90B
SHA-256: E6E6B7014685ADAE447EBB3833242815747BC1E5DF83ADE79F693FB67CF565B6