INES Mapper 187
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iNES Mapper 187 is used for the 卡聖 (Kǎshèng) A98402 and similar boards, an MMC3-clone-bearing board with an NROM-like PRG-ROM register that can override the MMC3 clone's PRG-ROM bank. Used by:
- Street Fighter Zero 2 (Kǎshèng/Hummer Team, not Street Fighter Zero 2 '97)
- The King of Fighters '96 (Kǎshèng/Hummer Team)
- 餓狼伝説 Special (Garō Densetsu Special, Kǎshèng re-release, originally released by 哥德 (Gouder) on INES Mapper 116)
Registers
NROM Override Register ($5000, $6000)
Mask: Unknown; FCEUX basically uses $FFFF D~7654 3210 --------- MSN. BBBb ||| ++++- Select 16 KiB PRG-ROM bank at CPU ||| $8000-$BFFF and $C000-$FFFF ||+------- 0: Do not replace bit 0 (NROM-128) || 1: Replace bit 0 with CPU A14 (NROM-256) |+-------- 0: Do not shift BBBb to the right by one bit | 1: Shift BBBb to the right by one bit (*) +--------- 0: Use PRG bank from MMC3; ignore $6000 bits 0-3/5 1: Ignore PRG bank from MMC3; apply $6000 bits 0-3/5
(*) This seems to be more of a heuristic by FCEUX to differentiate two different boards rather than actual hardware behavior.
Protection Read ($5000-$5FFF)
Mask: Unknown
The actual values that are returned are unknown; The King of Fighters '96 reads from here and only expects bit 7 of the value being returned to be set.
CHR A18 Control ($8000-$9FFF, even)
Mask: $E001 D~7654 3210 --------- M... .... +--------- Select CHR A18 Mode 0: CHR A18=inverted PPU A12 1: CHR A18=PPU A12
Basically, either sprites or background tiles will come from the the second 256 KiB of CHR-ROM. Note that setting bit 7 will still also activate the MMC3 clone's CHR A12 inversion.
MMC3-compatible registers ($8000-$FFFF)
Mask: $E001, see MMC3.
Errata
- GoodNES 3.23b has several INES Mapper 121 and INES Mapper 189 images erroneously set to 187.