Not only the M21 but a whole line of proprietary
machines sold to
government and small businesses. The os was called MOS and written in
a proprietary language Pascal+ with synchronization primitives like
monitors, semaphores etc. I never used it personally but heard quite
a bit about MOS while workinh in the Unix group of Olivetti. Apparently
MOS was only segmented.
When I think of MOS, I think of a multi-user MS-DOS clone.
We had a server running it on a small (less than a dozen systems)
network in the late 80's. I no longer remember the protocal or NIC
type used but we had a bunch of Z-248's connected to this machine,
which I believe was a '386, using coax cable. It replaced a single
CP/M system for keeping our troublecall database.
Jeff
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