Editing UNICOS

{{More citations needed|date=September 2010}}
{{Infobox OS
| name = UNICOS
| logo = <!-- Filename only: no wikilink, Image: or File: -->
| logo caption = 
| logo alt = 
| screenshot = <!-- Filename only: no wikilink, Image: or File: -->
| caption = 
| screenshot alt = 
| developer = [[Cray]] Research
| family = [[Unix]] and [[Linux]]
| working state = Discontinued
| source model = [[Closed source]] and [[Open source]]
| released = {{Start date and age|1984}}<!-- If known, add |mm|dd|df=yes -->
| discontinued = Yes
| latest release version = 
| latest release date = {{Start date and age|2007}}<!-- If known, add |mm|dd|df=yes -->
| marketing target = [[Supercomputer]]s
| programmed in = [[Assembly language|Assembly]], [[C (programming language)|C]]
| language = English
| update model = 
| supported platforms = [[Monolithic kernel]]: [[Cray-1]], [[Cray-2|2]], [[Cray X-MP|X-MP]], [[Cray X1|X1]], [[Cray XT3|XT3]], [[Cray XT4|XT4]], [[Cray XT5|XT5]]<br/>[[Microkernel]]: [[Cray Y-MP|Y-MP]], [[Cray C90|C90]], [[Cray T3D|T3D]], [[Cray T3E|T3E]]
| kernel type = [[Monolithic kernel|Monolithic]] (some)<br/>[[Microkernel]] (some)
| userland = 
| ui = [[Command line interface]]
| license = [[Proprietary software|Proprietary]]
| preceded by = CX-OS<br/>[[Cray Operating System]] (COS)
| succeeded by = Cray Linux Environment
| website = {{URL|www.cray.com}}
| other articles = 
}}
'''UNICOS''' is a range of [[Unix]] and later [[Linux]] [[operating system]] (OS) variants developed by [[Cray]] for its [[supercomputer]]s. UNICOS is the successor of the [[Cray Operating System]] (COS). It provides network [[Cluster (computing)|clustering]] and source code [[compatibility layer]]s for some other Unixes. UNICOS was originally introduced in 1985 with the [[Cray-2]] system and later ported to other Cray models. The original UNICOS was based on [[UNIX System V]] Release 2, and had many [[Berkeley Software Distribution]] (BSD) features (e.g., [[computer networking]] and [[file system]] enhancements) added to it.

==Development==
CX-OS was the original name given to what is now UNICOS. This was a prototype system which ran on a [[Cray X-MP]] in 1984 before the Cray-2 port. It was used to demonstrate the feasibility of using [[Unix]] on a supercomputer system, before Cray-2 hardware was available.

The operating system revamp was part of a larger movement inside Cray Research to modernize their corporate software: including rewriting their most important [[Fortran]] compiler (cft to cft77) in a higher-level language ([[Pascal (programming language)|Pascal]]) with more modern optimizations and vectorizations.

As a migration path for existing COS customers wishing to transition to UNICOS, a Guest Operating System (GOS) capability was introduced into COS. The only guest OS that was ever supported was UNICOS. A COS batch job would be submitted to start up UNICOS, which would then run as a subsystem under COS, using a subset of the systems CPUs, memory, and peripheral devices. The UNICOS that ran under GOS was exactly the same as when it ran stand-alone: the difference was that the [[Kernel (operating system)|kernel]] would make certain low-level hardware requests through the COS GOS hook, rather than directly to the hardware.

One of the sites that ran very early versions of UNICOS was [[Bell Labs]], where Unix pioneers including [[Dennis Ritchie]] ported parts of their [[Research Unix|Eighth Edition Unix]] (including [[STREAMS]] [[input/output]] (I/O)) to UNICOS. They also experimented with a guest facility within UNICOS, allowing the stand-alone version of the OS to host itself.

== Releases ==
Cray released several different OSs under the name UNICOS, including:
#''UNICOS'': the original Cray Unix, based on System V. Used on the [[Cray-1]], [[Cray-2]], [[Cray X-MP|X-MP]], [[Cray Y-MP|Y-MP]], [[Cray C90|C90]], etc.
#''UNICOS MAX'': a [[Mach kernel|Mach]]-based [[microkernel]] used on the [[Cray T3D|T3D]]'s processing elements, together with UNICOS on the host Y-MP or C90 system.
#''UNICOS/mk'': a ''serverized'' version of UNICOS using the [[ChorusOS|Chorus]] [[microkernel]] to make a [[distributed operating system]]. Used on the [[Cray T3E|T3E]]. This was the last Cray OS really based on UNICOS sources, as the following products were based on different sources and simply used the "UNICOS" name.
#''UNICOS/mp'': not derived from UNICOS, but based on [[IRIX]] 6.5. Used on the [[Cray X1|X1]].
#''UNICOS/lc'': not derived from UNICOS, but based on [[SUSE Linux]]. Used on the [[Cray XT3|XT3]], [[Cray XT4|XT4]] and [[Cray XT5|XT5]]. UNICOS/lc 1.x comprises a combination of
##the compute elements run the [[Catamount (operating system)|Catamount]] microkernel (which itself is based on [[Cougaar]])
##the service elements run SUSE Linux
#''Cray Linux Environment'' (CLE): from release 2.1 onward, UNICOS/lc is now called Cray Linux Environment
##the compute elements run [[Compute Node Linux]] (CNL) (which is a customized [[Linux kernel]]<ref>{{cite web|url=https://cug.org/5-publications/proceedings_attendee_lists/2007CD/S07_Proceedings/pages/Authors/Wallace-7C/Wallace-7C-paper.pdf |archive-url=https://web.archive.org/web/20160305014832/http://cug.org/5-publications/proceedings_attendee_lists/2007cd/s07_proceedings/pages/authors/wallace-7c/wallace-7c-paper.pdf |archive-date=2016-03-05 |url-status=live|title=Cray XT3/XT4 Software: Status and Plans|last=Wallace|first=David|date=2007-05-05|work=CUG 2007 Proceedings|publisher=Cray User Group|access-date=2012-12-18}}</ref>)
##the service elements run [[SUSE Linux Enterprise Server]]

== See also ==
{{Portal|Science|Free and open-source software|Linux}}
* [[Scientific Linux]], a [[Linux distribution]] by [[Fermilab]] and [[CERN]]
* [[Rocks Cluster Distribution]], a Linux distribution for supercomputers

==References==
{{Reflist}}
* {{cite web
| url = http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-5000-10011
| title = UNICOS 10.0.1.1 Release Overview
| publisher = [[Cray Inc]]
| access-date = 2009-02-12
| archive-date = 2020-01-07
| archive-url = https://web.archive.org/web/20200107154424/http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-5000-10011
| url-status = dead
}}
* {{cite web
| url = http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-2600-206
| title = UNICOS/mk 2.0.6 Release Overview
| publisher = Cray Inc
| access-date = 2009-02-12
| archive-date = 2020-01-07
| archive-url = https://web.archive.org/web/20200107154425/http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-2600-206
| url-status = dead
}}
* {{cite web
| url = http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-2336-31
| title = UNICOS/mp 3.1 Release Overview
| publisher = Cray Inc
| access-date = 2009-02-12
| archive-date = 2020-01-07
| archive-url = https://web.archive.org/web/20200107154425/http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-2336-31
| url-status = dead
}}
* {{cite web
| url = http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-2425-21
| title = Cray XT System Software Release Overview
| publisher = Cray Inc
| access-date = 2009-02-12
| archive-date = 2020-01-07
| archive-url = https://web.archive.org/web/20200107154437/http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-2425-21
| url-status = dead
}}
* {{cite web
| url = http://www.0x07bell.net/WWWMASTER/CrayWWWStuff/index.html
| title = Cray Supercomputer FAQ and other documents
| last=Gannett |first=Fred
| date = 2007-10-25}}
* {{cite web
 |url = http://cm.bell-labs.com/cm/cs/who/dmr/cray.html
 |title = Experiences with the Cray X/MP
 |last=Ritchie |first=Dennis
 |author-link = Dennis Ritchie
 |date = September 2000
 |url-status = dead
 |archive-url = https://web.archive.org/web/20130317154318/http://cm.bell-labs.com/cm/cs/who/dmr/cray.html
 |archive-date = 2013-03-17
}}
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{{Supercomputer operating systems}}
{{Unix}}
{{Microkernel}}

[[Category:1984 software]]
[[Category:Cray software]]
[[Category:Linux distributions]]
[[Category:Microkernel-based operating systems]]
[[Category:Microkernels]]
[[Category:Supercomputer operating systems]]
[[Category:Unix distributions]]
[[Category:UNIX System V]]