UNOS (operating system)
Template:Short description Template:Ou Template:Refimprove Script error: No such module "Unsubst".Script error: No such module "Check for unknown parameters". UNOS is a discontinued real-time operating system (RTOS); it was the first 32-bit Unix-like system with real-time extensions.Script error: No such module "Unsubst". It was developed by Jeffery Goldberg, MS. who left Bell Labs after using Unix and became VP of engineering for Charles River Data Systems (CRDS), now defunct. UNOS was written to capitalize on the first 32-bit microprocessor, the Motorola 68k central processing unit (CPU).Script error: No such module "Unsubst". CRDS sold a UNOS based 68K system, and sold porting services and licenses to other manufacturers who had embedded CPUs.[1]
History
Jeff Goldberg created an experimental OS using only eventcounts for synchronization, that allowed a preemptive kernel, for a Charles River Data Systems (CRDS) PDP-11. CRDS hired Goldberg to create UNOS and began selling it in 1981.[2]Template:Better source
UNOS was written for the Motorola 68000 series processors. While compatible with Version 7 Unix, it is also an RTOS.Script error: No such module "Unsubst". CRDS supported it on the company's Universe 68 computers, as did Motorola's Versabus systems.[3] CRDS's primary market was OEMs embedding the CRDS unit within a larger pile of hardware, often requiring better real-time response than Unix could deliver.Script error: No such module "Unsubst".
UNOS has a cleaner kernel interface than UNIX in 1981.Script error: No such module "Unsubst". There was e.g., a system call to obtain ps information instead of reading /dev/kmem.Script error: No such module "Unsubst".
UNOS required memory protection, with the 68000 using an MMU developed by CRDS;Script error: No such module "Unsubst". and only used Motorola MMUs after UNOS 7 on the 68020 (CRDS System CP20)Script error: No such module "Unsubst". (using the MC68851 PMMU).
UNOS was written in the programming languages C and assembly language, and supported Fortran, COBOL, Pascal, and Business Basic.Script error: No such module "Unsubst".
Limits
UNOS from CRDS never supported paged virtual memory[2] and multiprocessor support had not been built in from the start,[2] so the kernel remained mostly single-threaded on the few multiprocessor systems built.[2] A UNOS variant enhanced by H. Berthold AG under the name vBertOS added demanded page loading and paged processes in 1984,Script error: No such module "Unsubst". but was given up in favor of SunOS because of the missing GUI and the missing networking code in Spring 1985,Script error: No such module "Unsubst". when Berthold imported the first Sun to Europe.Script error: No such module "Unsubst".
References
Template:Real-time operating systems Script error: No such module "Navbox".