FxROM: Difference between revisions

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[[Category:Nintendo licensed mappers]]
The generic designation '''FxROM''' refers to cartridge boards made by Nintendo that use the [[MMC4|Nintendo MMC4]] mapper.
The generic designation '''FxROM''' refers to cartridge boards made by Nintendo that use the [[MMC4|Nintendo MMC4]] mapper.
== Board Types ==


The following FxROM boards are known to exist:
The following FxROM boards are known to exist:
{| border="1"
{| class="tabular"
! Board || PRG ROM || PRG RAM || CHR
! Board || PRG ROM || PRG RAM || CHR
|-
|-
|FJROM || 128, 256 KB || 8 KB || 16, 32, 64 KB ROM
|FJROM || 128 / 256 KB || 8 KB || 16 / 32 / 64 KB ROM
|-
|-
|FKROM || 128, 256 KB || 8 KB || 128 KB ROM
|FKROM || 128 / 256 KB || 8 KB || 128 KB ROM
|}
|}


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* PRG RAM without data retention : 'SL' connected, D1, D2, R1, R2, R3 not present.
* PRG RAM without data retention : 'SL' connected, D1, D2, R1, R2, R3 not present.


On the FKROM board, battery backup appears to be compulsary unless there is a hidden solder pad below the MM1026 chip.
On the FKROM board, battery backup appears to be compulsory unless there is a hidden solder pad below the MM1026 chip.


== Hardware ==
== Hardware ==

Latest revision as of 06:23, 7 April 2021

The generic designation FxROM refers to cartridge boards made by Nintendo that use the Nintendo MMC4 mapper.

Board Types

The following FxROM boards are known to exist:

Board PRG ROM PRG RAM CHR
FJROM 128 / 256 KB 8 KB 16 / 32 / 64 KB ROM
FKROM 128 / 256 KB 8 KB 128 KB ROM

Overview

  • PRG ROM size: up to 256 KB
  • PRG ROM bank size: 16 KB
  • PRG RAM: 8 KB plus optional battery
  • CHR capacity: up to 128 KB ROM
  • CHR bank size: 4 KB
  • Nametable mirroring: Controlled by mapper
  • Subject to bus conflicts: No

Solder Pad config

Battery backup

  • PRG RAM with data retention : 'SL' disconnected, D1, D2, R1, R2, R3 present.
  • PRG RAM without data retention : 'SL' connected, D1, D2, R1, R2, R3 not present.

On the FKROM board, battery backup appears to be compulsory unless there is a hidden solder pad below the MM1026 chip.

Hardware

The FKROM board uses a Mitsumi MM1026 chip dedicated to safe battery backup. It's the only Nintendo board to use a specific chip dedicated to safe battery backup.

See also