UNOS is a derivative of UNIX by Charles River Information Systems.

Google and Wikipedia doesn't have much information on it.

Is there any version of it still in use?


1 Answer 1


UNOS was written by a group of former AT&T employees around Jeff Goldberg.

UNOS was written at Charles River Data Systems in 1980 and sold since 1981.

It was the first UNIX look alike but it had a much better kernel concept. It offered a fully preemptive kernel based on eventcounts and real time support. It was used in rocket control units and thus had a limited number of customers as you needed to get an approval from the US government to buy the source code. It did however offer many interesting and innovative features that UNIX added 15 years later.

H.Berthold AG in Berlin bought a source license in 1982 and in 1983/1984, we created a kernel rewrite that offered demanded page load support based on the papers from UCB for UNIX. In 1985 H.Berthold AG decided to switch to SunOS, since there was no networking support.

Around 1995, Charles River Data Systems did shut down and UNOS was sold to a long term support company. So UNOS is de-facto dead since 1995.

The last time I did see it was IIRC in 1994 at the CeBIT and it seemed that they did not really enhance it.

  • The editor still dumped core if you typed ^E (go to end of line) at the last line that did not end in a newline

  • When I tried to become root using the ps command, they pulled the plug ;-)

The last user I am aware of was Krone AG in Berlin in 1994, but I know of noone who still uses it.


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