Files with the extension .M$S are 'Firmware Update' files utilised by
the 'MindStor' portable storage device.

Firmware is a computer program that is embedded within a hardware device, it acts like a software computer program i.e. being executed via a microprocessor, however it is specific to a particular piece of hardware, and is useless without it.

The .M$S firmware file is specific to the MindStor 'portable wallet' and is used for downloading updates to the devices firmware.

* MindStor is essentially a mobile hard-drive.