National CF-2131
This page was last modified 11:57, 22 December 2021 by Mars2000you. Based on work by Gdx and Rderooy.


The cartridge CF-2131 is an expansion of 16kB RAM made and sold by National in Japan.

Its RAM is placed on page 2 (8000h~BFFFh). This allows you to upgrade an MSX from 16kB to 32kB. It is mainly useful for BASIC programs since you will be able to run the largest programs. System base memory and expansion will be in different locations but this causes few compatibility issues with software which blindly assumes all memory is in one location on MSXs with 16kB.

If you are looking for a memory expansion nowaday we recommend to buy another standard expansion of 64kB or even better a Memory Mapper cartridge MSX1 compatible that initializes its segments itself.


National CF-2131 box
National CF-2131
National CF-2131
National CF-2131 PCB
CF-2131 underside
National CF-2131 box and content

Minimum System Requirements

  • MSX1 computer with 16kB RAM, one free slot cartridge