Yamaha URM-01
This page was last modified 11:18, 13 April 2019 by Mars2000you. Based on work by Gdx and Rderooy.


The cartridge URM-01 is an expansion of 32kB RAM made and sold by Yamaha.

Its RAM is placed on pages 0 and 1 (0000h~7FFFh). As such it is only useful to upgrade a 32kB MSX to 64kB. However the systems base memory and the expansion will be in different slots which can cause compatibility problems with some software that blindly assumes all memory to be in a single slot.

If you are looking for a memory expansion we recommend to buy another standard expansion. A 64kB RAM expansion, or even better a Memory Mapper cartridge that initializes its segments itself at start up is the best choice.


Yamaha URM-01
Yamaha URM-01 back

Minimum System Requirements

  • MSX1 computer with 32kB, one free slot cartridge