Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
UNICOS
open-in-new
<h2 id="development">Development</h2> <p>CX-OS was the original name given to what is now UNICOS. This was a prototype system which ran on a <a href="/facts/Cray_X-MP/BmPqwbta">Cray X-MP</a> in 1984 before the Cray-2 port. It was used to demonstrate the feasibility of using <a href="/facts/Unix/0pNL2seI">Unix</a> on a supercomputer system, before Cray-2 hardware was available. </p><p>The operating system revamp was part of a larger movement inside Cray Research to modernize their corporate software: including rewriting their most important <a href="/facts/Fortran/m1KqjcMU">Fortran</a> compiler (cft to cft77) in a higher-level language (<a href="/facts/Pascal_(programming_language)/b3yvp8bF">Pascal</a>) with more modern optimizations and vectorizations. </p><p>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 <a href="/facts/Kernel_(operating_system)/uEj4U3Rz">kernel</a> would make certain low-level hardware requests through the COS GOS hook, rather than directly to the hardware. </p><p>One of the sites that ran very early versions of UNICOS was <a href="/facts/Bell_Labs/fKP5Gk0H">Bell Labs</a>, where Unix pioneers including <a href="/facts/Dennis_Ritchie/I1yu1UWU">Dennis Ritchie</a> ported parts of their <a href="/facts/Research_Unix/5oWmUdwo">Eighth Edition Unix</a> (including <a href="/facts/STREAMS/MWSDgwBL">STREAMS</a> <a href="/facts/Input%2foutput/WQTE8Jas">input/output</a> (I/O)) to UNICOS. They also experimented with a guest facility within UNICOS, allowing the stand-alone version of the OS to host itself. </p> <h2 id="releases">Releases</h2> <p>Cray released several different OSs under the name UNICOS, including: </p> <ol><li><i>UNICOS</i>: the original Cray Unix, based on System V. Used on the <a href="/facts/Cray-1/4afuzp0D">Cray-1</a>, <a href="/facts/Cray-2/bljhxYCT">Cray-2</a>, <a href="/facts/Cray_X-MP/BmPqwbta">X-MP</a>, <a href="/facts/Cray_Y-MP/CrAr81uB">Y-MP</a>, <a href="/facts/Cray_C90/9pwsywMx">C90</a>, etc.</li> <li><i>UNICOS MAX</i>: a <a href="/facts/Mach_kernel/rqK8DES2">Mach</a>-based <a href="/facts/Microkernel/wsaWtYCU">microkernel</a> used on the <a href="/facts/Cray_T3D/VDFNMbMW">T3D</a>'s processing elements, together with UNICOS on the host Y-MP or C90 system.</li> <li><i>UNICOS/mk</i>: a <i>serverized</i> version of UNICOS using the <a href="/facts/ChorusOS/pKfjxP7q">Chorus</a> <a href="/facts/Microkernel/wsaWtYCU">microkernel</a> to make a <a href="/facts/Distributed_operating_system/Vm9Eu6Q4">distributed operating system</a>. Used on the <a href="/facts/Cray_T3E/AU1PrgsU">T3E</a>. 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.</li> <li><i>UNICOS/mp</i>: not derived from UNICOS, but based on <a href="/facts/IRIX/vK9rSatM">IRIX</a> 6.5. Used on the <a href="/facts/Cray_X1/D1SwcKq8">X1</a>.</li> <li><i>UNICOS/lc</i>: not derived from UNICOS, but based on <a href="/facts/SUSE_Linux/TAEDo44B">SUSE Linux</a>. Used on the <a href="/facts/Cray_XT3/g56R5w2h">XT3</a>, <a href="/facts/Cray_XT4/vQrL0hh1">XT4</a> and <a href="/facts/Cray_XT5/hy3bFPxJ">XT5</a>. UNICOS/lc 1.x comprises a combination of <ol><li>the compute elements run the <a href="/facts/Catamount_(operating_system)/nGX3sXI2">Catamount</a> microkernel (which itself is based on <a href="/facts/Cougaar/mk0UfxDX">Cougaar</a>)</li> <li>the service elements run SUSE Linux</li></ol></li> <li><i>Cray Linux Environment</i> (CLE): from release 2.1 onward, UNICOS/lc is now called Cray Linux Environment <ol><li>the compute elements run <a href="/facts/Compute_Node_Linux/h1QUWAUy">Compute Node Linux</a> (CNL) (which is a customized <a href="/facts/Linux_kernel/dlkduHuA">Linux kernel</a><a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a>)</li> <li>the service elements run <a href="/facts/SUSE_Linux_Enterprise_Server/Fqf31h9R">SUSE Linux Enterprise Server</a></li></ol></li></ol> <h2 id="see-also">See also</h2> <ul> <li>Science portal</li><li>Free and open-source software portal</li><li>Linux portal</li></ul> <ul><li><a href="/facts/Scientific_Linux/HqNBSblf">Scientific Linux</a>, a <a href="/facts/Linux_distribution/0vVl4N4f">Linux distribution</a> by <a href="/facts/Fermilab/8yyTx3oj">Fermilab</a> and <a href="/facts/CERN/y1gwRchm">CERN</a></li> <li><a href="/facts/Rocks_Cluster_Distribution/mu4EuGbr">Rocks Cluster Distribution</a>, a Linux distribution for supercomputers</li></ul> <ul><li><a href="https://web.archive.org/web/20200107154424/http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-5000-10011">"UNICOS 10.0.1.1 Release Overview"</a>. <a href="/facts/Cray_Inc/coAlupuy">Cray Inc</a>. Archived from <a href="http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-5000-10011">the original</a> on 2020-01-07. Retrieved 2009-02-12.</li> <li><a href="https://web.archive.org/web/20200107154425/http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-2600-206">"UNICOS/mk 2.0.6 Release Overview"</a>. Cray Inc. Archived from <a href="http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-2600-206">the original</a> on 2020-01-07. Retrieved 2009-02-12.</li> <li><a href="https://web.archive.org/web/20200107154425/http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-2336-31">"UNICOS/mp 3.1 Release Overview"</a>. Cray Inc. Archived from <a href="http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-2336-31">the original</a> on 2020-01-07. Retrieved 2009-02-12.</li> <li><a href="https://web.archive.org/web/20200107154437/http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-2425-21">"Cray XT System Software Release Overview"</a>. Cray Inc. Archived from <a href="http://docs.cray.com/cgi-bin/craydoc.cgi?mode=View;id=S-2425-21">the original</a> on 2020-01-07. Retrieved 2009-02-12.</li> <li>Gannett, Fred (2007-10-25). <a href="http://www.0x07bell.net/WWWMASTER/CrayWWWStuff/index.html">"Cray Supercomputer FAQ and other documents"</a>.</li> <li><a href="/facts/Dennis_Ritchie/I1yu1UWU">Ritchie, Dennis</a> (September 2000). <a href="https://web.archive.org/web/20130317154318/http://cm.bell-labs.com/cm/cs/who/dmr/cray.html">"Experiences with the Cray X/MP"</a>. Archived from <a href="http://cm.bell-labs.com/cm/cs/who/dmr/cray.html">the original</a> on 2013-03-17.</li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Wallace, David (2007-05-05). "Cray XT3/XT4 Software: Status and Plans" (PDF). CUG 2007 Proceedings. Cray User Group. Archived (PDF) from the original on 2016-03-05. Retrieved 2012-12-18. <a href="https://cug.org/5-publications/proceedings_attendee_lists/2007CD/S07_Proceedings/pages/Authors/Wallace-7C/Wallace-7C-paper.pdf" target="_blank">https://cug.org/5-publications/proceedings_attendee_lists/2007CD/S07_Proceedings/pages/Authors/Wallace-7C/Wallace-7C-paper.pdf</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> </ol>