INES Mapper 197: Difference between revisions

From NESdev Wiki
Jump to navigationJump to search
(Created page with "{{DEFAULTSORT:197}}Category:NES 2.0 mappers with submappersCategory:MMC3-like mappersCategory:Mappers with scanline IRQs iNES Mapper 197 denotes an MMC3 clone...")
 
(Forgot one submapper that Nestopia Plus! had assigned in July 2018)
 
Line 1: Line 1:
{{DEFAULTSORT:197}}[[Category:NES 2.0 mappers with submappers]][[Category:MMC3-like mappers]][[Category:Mappers with scanline IRQs]]
{{DEFAULTSORT:197}}[[Category:NES 2.0 mappers with submappers]][[Category:MMC3-like mappers]][[Category:Mappers with scanline IRQs]][[Category:NES 2.0 mappers with submappers]]
iNES Mapper 197 denotes an [[MMC3]] clone wired to support 512 KiB of CHR-ROM by increasing CHR banking granularity from 1/2 KiB to 2/4 KiB.
iNES Mapper 197 denotes an [[MMC3]] clone wired to support 512 KiB of CHR-ROM by increasing CHR banking granularity from 1/2 KiB to 2/4 KiB.
All of its games are mapper hacks, usually by 卡聖 (Kǎshèng, NT-xxx cartridge codes), of games originally released on mappers [[iNES Mapper 090|90]] and [[iNES Mapper 091|91]].
All of its games are mapper hacks, usually by 卡聖 (Kǎshèng, NT-xxx cartridge codes), of games originally released on mappers [[iNES Mapper 090|90]] and [[iNES Mapper 091|91]].
Line 89: Line 89:
  4              unused
  4              unused
  5              2 KiB CHR-ROM bank at PPU $1800-$1FFF
  5              2 KiB CHR-ROM bank at PPU $1800-$1FFF
==Submapper 3==
* ''1995 Super 2-in-1 (2B20)''
Like Submapper 0, but with an additional outer bank register at $6000-$7FFF:
Mask: $E000
D~7654 3210
  ---------
  .... S..P
        |  +- PRG A17 if S=1
        +---- PRG A17 mode
              0: PRG A17=MMC3 PRG A17 (256 KiB)
              1: PRG A17=P (128 KiB)
As the outer bank register uses the MMC3 clone's WRAM interface, writes only have an effect if WRAM is enabled and not write-protected via $A001.

Latest revision as of 12:03, 9 November 2019

iNES Mapper 197 denotes an MMC3 clone wired to support 512 KiB of CHR-ROM by increasing CHR banking granularity from 1/2 KiB to 2/4 KiB. All of its games are mapper hacks, usually by 卡聖 (Kǎshèng, NT-xxx cartridge codes), of games originally released on mappers 90 and 91. Submappers, assigned by Nestopia Plus!, denote three different wiring variants. PRG-ROM, nametable mirroring and IRQs function as in mapper 4.

Submapper 0

  • Super Fighter III (PRG-ROM CRC32 0xC333F621), originally for Mapper 91.1.
Pin            Connected to
PPU A10        CHR-ROM A10
PPU A11        MMC3 PA10
GND            MMC3 PA11
PPU A12        MMC3 PA12
MMC3 CHR A10   CHR-ROM A11
    :             :
MMC3 CHR A17   CHR-ROM A18

So that the MMC3 sees the followings addresses:

Real PPU Addr  MMC3 PPU Addr
$0000          $0000 -> reg 0 AND $FE
$0400          $0000 -> reg 0 AND $FE
$0800          $0400 -> reg 0 OR $01
$0C00          $0400 -> reg 0 OR $01
$1000          $1000 -> reg 2
$1400          $1000 -> reg 2
$1800          $1400 -> reg 3
$1C00          $1400 -> reg 3

This results in the following CHR banks:

MMC3 reg#      Meaning
0              4 KiB CHR-ROM bank at PPU $0000-$0FFF
1              unused
2              2 KiB CHR-ROM bank at PPU $1000-$17FF
3              2 KiB CHR-ROM bank at PPU $1800-$1FFF
4              unused
5              unused

Submapper 1

  • Super Fighter III (PRG-ROM CRC32 0x2091BEB2), UNIF board name UNL-FC-28-5027, originally for Mapper 91.1.
Pin            Connected to
PPU A10        CHR-ROM A10
PPU A11        MMC3 PA10
Vcc            MMC3 PA11
PPU A12        MMC3 PA12
MMC3 CHR A10   CHR-ROM A11
    :             :
MMC3 CHR A17   CHR-ROM A18

So that the MMC3 sees the followings addresses:

Real PPU Addr  MMC3 PPU Addr
$0000          $0800 -> reg 1 AND $FE
$0400          $0800 -> reg 1 AND $FE
$0800          $0C00 -> reg 1 OR $01
$0C00          $0C00 -> reg 1 OR $01
$1000          $1800 -> reg 4
$1400          $1800 -> reg 4
$1800          $1C00 -> reg 5
$1C00          $1C00 -> reg 5

This results in the following CHR banks:

MMC3 reg#      Meaning
0              unused
1              4 KiB CHR-ROM bank at PPU $0000-$0FFF
2              unused
3              unused
4              2 KiB CHR-ROM bank at PPU $1000-$17FF
5              2 KiB CHR-ROM bank at PPU $1800-$1FFF

Submapper 2

  • Mortal Kombat III Special (NT-328/YY-030) (PRG-ROM CRC32 0x60815A7D), originally for Mapper 90.
Pin            Connected to
PPU A10        CHR-ROM A10
PPU A11        MMC3 PA10 and MMC3 PA11
PPU A12        MMC3 PA12
MMC3 CHR A10   CHR-ROM A11
    :             :
MMC3 CHR A17   CHR-ROM A18

So that the MMC3 sees the followings addresses:

Real PPU Addr  MMC3 PPU Addr
$0000          $0000 -> reg 0 AND $FE
$0400          $0000 -> reg 0 AND $FE
$0800          $0C00 -> reg 1 OR $01
$0C00          $0C00 -> reg 1 OR $01
$1000          $1000 -> reg 2
$1400          $1000 -> reg 2
$1800          $1C00 -> reg 5
$1C00          $1C00 -> reg 5

This results in the following CHR banks:

MMC3 reg#      Meaning
0 (AND $FE)    2 KiB CHR-ROM bank at PPU $0000-$07FF
1 (OR $01)     2 KiB CHR-ROM bank at PPU $0800-$0FFF
2              2 KiB CHR-ROM bank at PPU $1000-$17FF
3              unused
4              unused
5              2 KiB CHR-ROM bank at PPU $1800-$1FFF

Submapper 3

  • 1995 Super 2-in-1 (2B20)

Like Submapper 0, but with an additional outer bank register at $6000-$7FFF:

Mask: $E000

D~7654 3210
  ---------
  .... S..P
       |  +- PRG A17 if S=1
       +---- PRG A17 mode
              0: PRG A17=MMC3 PRG A17 (256 KiB)
              1: PRG A17=P (128 KiB)

As the outer bank register uses the MMC3 clone's WRAM interface, writes only have an effect if WRAM is enabled and not write-protected via $A001.