User:PostNES

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Mappers


Top 10 mappers used (NesCartDB)

by usage
Mfr icon Nintendo.png 001
Mfr icon Nintendo.png 004
Mfr icon Nintendo.png 002
Mfr icon Nintendo.png 000
Mfr icon Nintendo.png 003
Mfr icon Rare.png 007
Mfr icon Namco.png 206
Mfr icon Color Dreams.png 011
Mfr icon Nintendo.png 005
Mfr icon Namco.png 019
ascending
Mfr icon Nintendo.png 000
Mfr icon Nintendo.png 001
Mfr icon Nintendo.png 002
Mfr icon Nintendo.png 003
Mfr icon Nintendo.png 004
Mfr icon Nintendo.png 005
Mfr icon Rare.png 007
Mfr icon Color Dreams.png 011
Mfr icon Namco.png 019
Mfr icon Namco.png 206

Mapper ideas

  • CHR hardware scrolling unit
    • Scrolls portions of pattern table with wrapping for hardware accelerated parallax effects
      • implementation: two CHR ROMs with alternately stored tiles (VRAM address %0AAAAA AAAcBBBB -> ROM %c, address in ROM %AAAAAAAABBBB) for parallel fetching of pixel rows
  • CHR color remapping unit
    • ExGraphix-like, with each byte in ExRAM storing a color index (0-3) to be remapped to in a character, for every source color index (0-3). This would allow to conserve some palette/CHR-ROM space in some cases.
      Example:
ExRAM byte = %01010000, or 1100 in quaternary system: remap 0 to 0, 1 to 0, 2 to 1, 3 to 1

Original character:
.defchr $00000000,
        $02233200,
        $02100120,
        $03000030,
        $03333310,
        $03000030,
        $03000030,
        $03222210

Remapped:
.defchr $00000000,
        $01111100,
        $01000010,
        $01000010,
        $01111100,
        $01000010,
        $01000010,
        $01111100
  • DPCM converter
    • Converts any on-cartridge audio to DPCM and returns it to CPU on sample reads so that there's audio expansion on NES!
      • DMC rate control would coarsely alter pitch if the conversion rate is constant
  • DPCM hardware mixer
    • Plays back (by returning to CPU on sample read) multiple samples at different speeds