DxROM

The generic designation DxROM refers to cartridge boards made by Nintendo that use the seemingly-identical Namco 108, 109, 118 or 119 mappers. Nintendo did not manufacture the Famicom counterparts. The iNES format assigns Mapper 206 to DxROM.

The following DxROM boards are known to exist:

Board	PRG ROM	CHR ROM	Comments
DEROM	64 KiB	32,64 KiB ROM	Nintendo's clone of 3413 and 3414
DE1ROM	128 KiB	64 KiB	Nintendo's clone of 3406
DRROM	128 KiB	64 KiB	Four-screen mirroring

The Famicom counterparts:

Board	PRG ROM	CHR ROM
3401, 3417, 3451	32 KiB	32 KiB
3405, 3415	128 KiB	32 KiB
3406, 3416	128 KiB	64 KiB
3407	32 KiB	16,32 KiB
3413	64 KiB	32 KiB
3414	64 KiB	64 KiB
3425	128 KiB	32 KiB
3433, 3443	128 KiB	128 KiB
3446	128 KiB	128 KiB
3453	128 KiB	128 KiB

Otherwise, the Namco 108 family is just a subset of MMC3