INES Mapper 200: Difference between revisions

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m (iNES category sorting)
(Finally add submapper for mirroring-challenged files using the same mapper number.)
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[[Category:iNES Mappers|200]][[Category:Multicart mappers|200]]
{{DEFAULTSORT:200}}[[Category:iNES Mappers]][[Category:Multicart mappers]]
  Here are Disch's original notes: 
'''iNES Mapper 200''' denotes the circuit boards of simple address-latch-based NROM-128 multicarts, i.e. CPU $8000-$BFFF is always a mirror of CPU $C000-$FFFF. The mapper number is used for two variants that differ in the bit that selects nametable mirroring.
  ========================
 
  =  Mapper 200         =
=Address Latch ($8000-$FFFF, write)=
  ========================
==Submapper 0==
 
  A~[1... .... .... bBBB]
  Example Games:
                  |+++- PRG A16..A14, CHR A15..A13
  --------------------------
                  +---- PRG A17, CHR A16, Mirroring:
  1200-in-1
                          0: Vertical
  36-in-1
                          1: Horizontal
 
 
 
==Submapper 1==
  Registers:
A~[1... .... .... .bBB]
  ---------------------------
                    |++- PRG A15..A14, CHR A14..A13
 
                    +--- PRG A16, CHR A15, Mirroring:
 
                          0: Vertical
    $8000-FFFF: A~[.... ....  .... MRRR]
                          1: Horizontal
      M = Mirroring (0=Vert, 1=Horz)
=Notes=
      R = PRG/CHR Reg
* Some menus select bank numbers beyond the PRG ROM size, expecting to read back a solder pad value to select one of several displayed game counts.
 
* [[NES 2.0 Mapper 338]] flips the meaning of the mirroring bit.
 
  CHR Setup:
  ---------------------------
 
        $0000  $0400  $0800  $0C00  $1000  $1400  $1800  $1C00
      +---------------------------------------------------------------+
      |                            $8000                            |
      +---------------------------------------------------------------+
 
 
  PRG Setup:
  ---------------------------
 
      $8000  $A000  $C000  $E000 
      +---------------+---------------+
      |    $8000    |    $8000    |
      +---------------+---------------+

Revision as of 13:19, 16 January 2023

iNES Mapper 200 denotes the circuit boards of simple address-latch-based NROM-128 multicarts, i.e. CPU $8000-$BFFF is always a mirror of CPU $C000-$FFFF. The mapper number is used for two variants that differ in the bit that selects nametable mirroring.

Address Latch ($8000-$FFFF, write)

Submapper 0

A~[1... .... .... bBBB]
                  |+++- PRG A16..A14, CHR A15..A13
                  +---- PRG A17, CHR A16, Mirroring:
                         0: Vertical
                         1: Horizontal

Submapper 1

A~[1... .... .... .bBB]
                   |++- PRG A15..A14, CHR A14..A13
                   +--- PRG A16, CHR A15, Mirroring:
                         0: Vertical
                         1: Horizontal

Notes

  • Some menus select bank numbers beyond the PRG ROM size, expecting to read back a solder pad value to select one of several displayed game counts.
  • NES 2.0 Mapper 338 flips the meaning of the mirroring bit.
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