INES Mapper 116

iNES Mapper 116 is used for the SOMARI-P board bearing the Huang-1 or Huang-2 ASICs and a PAL, used by releases from Gouder, also known as 哥德 (Gēdé):

• Huang-1 chip:
  • A.V. 美少女戰士 Girl Fighting (A.V. Měi Shàonǚ Zhànshì)
  • 餓狼伝説 Special (Garō Densetsu Special, original Gouder release only)
  • Kart Fighter
  • Somari the Adventurer (original Gouder and Kǎshèng releases)
• Huang-2 chip:
  • A.V. 究極麻將 II (A.V. Jiūjí Májiàng, original Gouder release only)

This mapper can simulate three different ASICs: the Nintendo MMC1, MMC3 and Konami VRC2 (A0/A1, i.e. VRC2b). All three simulated chips have their separate registers, so that when switching between modes using the supervisor register, the entire mapper state changes including PRG/CHR ROM switchable and fixed banks as well as IRQ state.

Supervisor Register ($4100, write)

Mask: $C100

D~7654 3210
  ---------
  .... .CMM
        |++- Mapper mode
        |     0: VRC2
        |     1: MMC3
        |     2: MMC1
        |     3: same as 2
        +--- Outer 256 KiB CHR-ROM bank (CHR A18)

Notes

• The Huang-2 chip differs from the Huang-1 chip in that the MMC1 PRG-ROM bank registers are shifted by one bit to the left compared to what one would write to a normal MMC1, or to the Huang-1 in MMC1 mode. No submapper has been proposed yet for this behavior. In the meantime, the one game relying on this can be heuristically detected by having a PRG-ROM size of only 128 KiB, which is the maximum size available with said bit shift.
• When switching to MMC1 mode, the serial shift register is reset. Garō Densetsu Special relies on this. Supposedly, only the -W configuration of the PAL actually does this, though no game seems to be adversely affected by always emulating this behavior.
• The VRC2 CHR-ROM registers are initialized on power-up to $FF. The original release of Somari the Adventurer relies on this.
• Garō Densetsu Special relies on being able to write to mirrors of $8xxx, $9xxx, and $Axxx in VRC2 mode.
• The Kǎshèng rerelease of Garō Densetsu Special uses INES Mapper 187 instead.

Similar mappers

• INES Mapper 014 and INES Mapper 238 uses the same ASIC but with the PAL programmed differently to respond in other ways to other addresses.