INES Mapper 116: Difference between revisions

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(add mapper 116 docs based on inspection of cah4e3's sources and experimentation)
 
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These boards appear to have been researched by Cah4e3. They're used for some chinese games and bootlegs. He has described them in fceu-mm sources as:
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)


* SL12 Protected 3-in-1 mapper hardware (VRC2, MMC3, MMC1)
* the same as 603-5052 board (TODO: add reading registers, merge)
* SL1632 2-in-1 protected board, similar to SL12 (TODO: find difference)


The following PCBs are listed as examples:
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.


* Garou Densetsu Special (G0904.PCB, Huang-1, GAL dip: W conf.)
==Supervisor Register ($4100, write)==
  * Kart Fighter (008, Huang-1, GAL dip: W conf.)
  Mask: $E100
  * Somari (008, C5052-13, GAL dip: P conf., GK2-P/GK2-V maskroms)
* Somari (008, Huang-1, GAL dip: W conf., GK1-P/GK1-V maskroms)
  D~7654 3210
* AV Mei Shao Nv Zhan Shi ()
  ---------
* Samurai Spirits (Full version) (Huang-1, GAL dip: unk conf. GS-2A/GS-4A maskroms)
  .... .CMM
* Contra Fighter (603-5052 board, C5052-3, GAL dip: unk conf. SC603-A/SCB603-B maskroms)
        |++- Mapper mode
        |    0: VRC2
        |    1: MMC3
        |    2: MMC1
        |    3: same as 2
        +--- Outer 256 KiB CHR-ROM bank (CHR A18)


These documents were verified by implementation into bizhawk based solely on the fceu-mm sources. FCEUX also possesses fceu-mm's sources for this mapper.
==Notes==
* The '''Huang-2''' chip differs from the '''Huang-1''' chip in that the MMC1 PRG-ROM bank register is 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 PRG-ROM and CHR-ROM sizes each of only 128 KiB.
* 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 [[Mirroring#Memory Mirroring|mirror]]s of $8xxx, $9xxx, and $Axxx in VRC2 mode.
* The Kǎshèng rerelease of ''Garō Densetsu Special'' uses [[INES Mapper 115]] instead.
* The Kǎshèng rerelease of ''A.V. 究極麻將 II'' uses [[INES Mapper 115]] instead.
{{DEFAULTSORT:116}}[[Category:iNES Mappers]][[Category:MMC3-like mappers]][[Category:Mappers using $4020-$5FFF]][[Category:Mappers with scanline IRQs]][[Category:Mappers with cycle IRQs]][[Category:Multi-ASIC mappers]]


This equipment is much simpler to operate than you might expect, considering that it is a combination of VRC2 + MMC3 + MMC1. There is a register:
With a iNES 2.0 Header Sub Mapper 3 sets Mapper 116 as a Reset Based Mapper that will switch games on a Hard Reset this however is current only used for one known 5-in-1 Multi-Cart that has 5 MMC3 based Mario Hacks. (SL-FC5-1) Mario 5-in-1


  Range,Mask:  $4000-7FFF, $4100
==Similar mappers==
    $4100:  [.... .CMM]
* [[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.
      MM = Mapper mode
          %00 = VRC2
          %01 = MMC3
          %02, %03 = MMC1
      C = 256K CHR ROM base (AV Girl Fighting uses this)
 
This control register supposedly occupies the WRAM address range, so there can be no WRAM. However, it only answers to $41xx.
 
The Mapper mode bits control which of the mapper circuits are connected to the NES. All of the PRG-based registers and IRQ signals are connected or disconnected accordingly. This means that in order to configure one of the mapper circuits, it must be connected. 
 
The VRC2 acts somewhat differently from a stock VRC2. Fundamentally, the VRC2 registers are mapped as documented elsewhere as VRC2b, not suffering from any of the PCB address signal rewiring complexities as most of the VRC-based boards. However, it seems important that the $8xxx, $9xxx, $Axxx regs be mapped to the entire $1000 region (unlike stock VRC2 which is supposedly strictly answering to $8000-$8003, etc.) This is important for "Garou Densetsu Special". Additionally, the PRG registers are 5 bits instead of 4. Finally, the CHR regs must be initialized specially: the first four to $FF, at least. (SOMARI-W depends on this). There is no evidence for what the subsequent 4 CHR regs must be initialized to.
 
The MMC3 acts exactly as a stock TxROM. It has not been determined which MMC3 variant this MMC3 is acting as. Fceu-mm makes it seem as if the mmc3 CHR regs must be initialized at power-on in a certain pattern; it is unknown why this would be important.
 
The MMC1 acts exactly as a stock SxROM. Fceu-mm contained "hacky hacky" logic to do a reset of sorts on the MMC1 whenever the low bit of $41xx's address was set, claiming it was necessary for SOMARI-W.
 
The C bit of the m116's control reg simply provides a CHR ROM base offset for the VRC2 and MMC3 modes. After running the VRC2 or MMC3 logic, toss this extra signal onto the output CHR ROM address bus. One might speculate that this applies to MMC1 as well, but there is no evidence.

Latest revision as of 14:53, 7 July 2023

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: $E100

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 register is 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 PRG-ROM and CHR-ROM sizes each of only 128 KiB.
  • 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 115 instead.
  • The Kǎshèng rerelease of A.V. 究極麻將 II uses INES Mapper 115 instead.

With a iNES 2.0 Header Sub Mapper 3 sets Mapper 116 as a Reset Based Mapper that will switch games on a Hard Reset this however is current only used for one known 5-in-1 Multi-Cart that has 5 MMC3 based Mario Hacks. (SL-FC5-1) Mario 5-in-1

Similar mappers

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