PxROM

The designation PxROM covers all boards that use the Nintendo MMC2 mapper. The iNES format assigns mapper 9 to these boards.

The following PxROM boards are known to exist:

Board	PRG ROM	CHR
PNROM	128 KB	128 KB ROM
PEEOROM	128 KB	128 KB ROM

Overview

• PRG ROM size: up to 128 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

Notes

The PEEOROM board is used in the re-issue of Mike Tyson's Punch-Out!!. Unlike PNROM, and unlike most other boards used in NES Game Paks sold to the public, it can be configured to support EPROM memory through jumpers on the board.