This new cartridge is a 1 Mega byte memory expansion, it is compatible with MSX1, MSX2, MSX2+ and Turbo-R computers.
The 1MB expansion is the ideal complement to the Rookie drive cartridge, if you are using it in an MSX1 and want to use the Nextor operating system, or if you have a Japanese MSX2 with only 64KB, since the Nextor operating system requires at least 128KB.
It is also very useful for those MSX2, like the HB-F9S that only have 128KB, with this RAM expansion and a mass storage cartridge you can use the wonderful SofaRun software, which allows loading games in .ROM format into RAM. .