UNOS (operating system)
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Intel 80486 | |
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Kernel type | Monolithic |
UNOS is the first, now discontinued,
History
Jeff Goldberg created an experimental OS using only eventcounts for synchronization, that allowed a preemptive kernel, for a Charles River Data Systems (CRDS)
UNOS was written for the
UNOS has a cleaner kernel interface than UNIX in 1981.[citation needed] There was e.g., a system call to obtain ps information instead of reading /dev/kmem.[citation needed]
UNOS required memory protection, with the 68000 using an MMU developed by CRDS;[citation needed] and only used Motorola MMUs after UNOS 7 on the 68020 (CRDS System CP20)[citation needed] (using the MC68851 PMMU).
UNOS was written in the programming languages C and assembly language, and supported Fortran, COBOL, Pascal, and Business Basic.[citation needed]
Limits
UNOS from CRDS never supported paged virtual memory[citation needed] and multiprocessor support had not been built in from the start,[citation needed] so the kernel remained mostly single-threaded on the few multiprocessor systems built.[citation needed] A UNOS variant enhanced by
References
- ^ "Multics Significance". Retrieved August 15, 2015.
- ^ Fiedler, Ryan (October 1983). "The Unix Tutorial / Part 3: Unix in the Microcomputer Marketplace". Byte. p. 132. Retrieved 30 January 2015.