INES Mapper 025: Difference between revisions
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* [[INES Mapper 021]] / [[VRC4]] | * [[INES Mapper 021]] / [[VRC4]] | ||
* [[INES Mapper 022]] / [[VRC2]] | * [[INES Mapper 022]] / [[VRC2]] | ||
Note that the VRC4d variant uses different address lines to select registers than '''351948''' and the VRC4b variants. Your emulator implementation must either combine address lines (like FCEUX; bitwise OR is good enough), use checksums, or NES 2.0 submappers. |
Revision as of 19:08, 29 July 2016
iNES Mapper 025 is used to represent the VRC4b (PCB 351406) and VRC4d (PCB 352400) variants of Konami's VRC4 mapper, as well as the VRC2-using board 351948 used for Ganbare Goemon Gaiden: Keita Ougon Kiseru. The last has 8kB RAM (like VRC4) and doesn't divide the CHR bank numbers by two (unlike mapper 22).
For details see the following:
Note that the VRC4d variant uses different address lines to select registers than 351948 and the VRC4b variants. Your emulator implementation must either combine address lines (like FCEUX; bitwise OR is good enough), use checksums, or NES 2.0 submappers.