M series (computer)


M-20, M-220 and M222 were a range of general-purpose computers designed and manufactured in the USSR.
These computers were developed by the Scientific Research Institute of Electronic Machines and built
at Moscow Plant of Calculating and Analyzing Machines and
the Kazan Plant of Computing Machines.

Operating systems

The operating system provided batch processing and simultaneous execution, subsequently enhanced to provide a multitasking mode.