Sequent Computer Systems

<h2 id="history">History</h2>

Originally named Sequel,<a class="footnote-ref" id="fnref:13" href="#fn:13">13</a> Sequent was formed in 1983<a class="footnote-ref" id="fnref:14" href="#fn:14">14</a> when a group of seventeen engineers and executives left <a href="/facts/Intel/SMF0gJJX">Intel</a> after the failed <a href="/facts/Intel_iAPX_432/z0xPqFQf">iAPX 432</a> "mainframe on a chip" project was cancelled; they were joined by one non-<a href="/facts/Intel/SMF0gJJX">Intel</a> employee. They started Sequent to develop a line of SMP computers,<a class="footnote-ref" id="fnref:15" href="#fn:15">15</a> then considered one of the up-and-coming fields in computer design.<a class="footnote-ref" id="fnref:16" href="#fn:16">16</a><a class="footnote-ref" id="fnref:17" href="#fn:17">17</a><a class="footnote-ref" id="fnref:18" href="#fn:18">18</a>

<h3>Balance</h3>
Sequent's first computer systems were the Balance 8000 (released in 1984) and Balance 21000 (released in 1986).<a class="footnote-ref" id="fnref:19" href="#fn:19">19</a> Both models were based on 10 MHz <a href="/facts/National_Semiconductor/xeAD8doA">National Semiconductor</a> <a href="/facts/NS32000/zCXoyxzh">NS32032</a> processors, each with a small write-through cache connected to a common memory to form a <a href="/facts/Shared_memory_architecture/zmpH7WuV">shared memory</a> system. The Balance 8000 supported up to 6 dual-processor boards for a total maximum of 12 processors.<a class="footnote-ref" id="fnref:20" href="#fn:20">20</a><a class="footnote-ref" id="fnref:21" href="#fn:21">21</a><a class="footnote-ref" id="fnref:22" href="#fn:22">22</a> The Balance 21000 supported up to 15 dual-processor boards for a total maximum of 30 processors.<a class="footnote-ref" id="fnref:23" href="#fn:23">23</a><a class="footnote-ref" id="fnref:24" href="#fn:24">24</a>
The systems ran a modified version of <a href="/facts/Berkeley_Software_Distribution/XQKcURrh">4.2BSD</a> <a href="/facts/Unix/0pNL2seI">Unix</a> the company called <a href="/facts/DYNIX/hrGXKYQ8">DYNIX</a>, for DYNamic unIX. The machines were designed to compete with the <a href="/facts/Digital_Equipment_Corporation/ztxs6keA">DEC</a> <a href="/facts/VAX-11%2f780/prkm7jvA">VAX-11/780</a>, with all of their inexpensive processors available to run any process. In addition the system included a series of libraries that could be used by programmers to develop applications that could use more than one processor at a time.

<h3>Symmetry</h3>
Their next series was the <a href="/facts/Intel_80386/ag5eSgWv">Intel 80386</a>-based Symmetry, released in 1987. Various models supported between 2 and 30 processors, using a new <a href="/facts/Write-back_cache/gmJYN8wm">copy-back cache</a> and a wider <a href="/facts/64-bit/AgvkQHkM">64-bit</a> <a href="/facts/Front_side_bus/LgYSB7Wl">memory bus</a>. 1991's Symmetry 2000 models added multiple <a href="/facts/SCSI/pxXulrBr">SCSI</a> boards, and were offered in versions with from one to six <a href="/facts/Intel_80486/2zfEAXAw">Intel 80486</a> processors. The next year they added the <a href="/facts/VMEbus/wbApkELJ">VMEbus</a> based Symmetry 2000/x50 with faster CPUs.

The late 1980s and early 1990s saw big changes on the software side for Sequent. DYNIX was replaced by DYNIX/ptx, which was based on a merger of <a href="/facts/AT%2526T_Corporation/BfsX7eX2">AT&T Corporation</a>'s <a href="/facts/UNIX_System_V/Epm6GEY4">UNIX System V</a> and <a href="/facts/Berkeley_Software_Distribution/XQKcURrh">4.2BSD</a>. And this was during a period when Sequent's high-end systems became particularly successful due to a close working relationship with <a href="/facts/Oracle_Corporation/0z14FygH">Oracle</a>, specifically <a href="/facts/Oracle_database/FHv5g732">their high-end database servers</a>. In 1993 they added the Symmetry 2000/x90 along with their ptx/Cluster software, which added various <a href="/facts/High-availability_cluster/MNWwE5RX">high availability</a> features and introduced custom support for Oracle Parallel Server.
In 1994 Sequent introduced the Symmetry 5000 series models SE20, SE60 and SE90, which used 66 MHz <a href="/facts/Pentium_(original)/dqChAmxz">Pentium</a> CPUs in systems from 2 to 30 processors.<a class="footnote-ref" id="fnref:25" href="#fn:25">25</a> The next year they expanded that with the SE30/70/100 lineup using 100 MHz Pentiums,<a class="footnote-ref" id="fnref:26" href="#fn:26">26</a> and then in 1996 with the SE40/80/120 with 166 MHz Pentiums. A variant of the Symmetry 5000, the WinServer 5000 series, ran <a href="/facts/Windows_NT/EtccWvxQ">Windows NT</a> instead of DYNIX/ptx.<a class="footnote-ref" id="fnref:27" href="#fn:27">27</a>

<h3>NUMA</h3>
Recognizing the increase in competition for SMP systems after having been early adopters of the architecture, and the increasing integration of SMP technology into microprocessors, Sequent sought its next source of differentiation. They began investing in the development of a system based on a cache-coherent non-uniform memory architecture (<a href="/facts/CcNUMA/MpmN5mN0">ccNUMA</a>) and leveraging <a href="/facts/Scalable_Coherent_Interconnect/QvMJHpge">Scalable Coherent Interconnect</a>. NUMA distributes memory among the processors, avoiding the bottleneck that occurs with a single monolithic memory. Using NUMA would allow their multiprocessor machines to generally outperform SMP systems, at least when the tasks can be executed close to their memory — as is the case for <a href="/facts/Server_(computing)/dEaYFD7r">servers</a>, where tasks typically do not share large amounts of data.
In 1996 they released the first of a new series of machines based on this new architecture. Known internally as STiNG, an <a href="/facts/Abbreviation/VxBQfhII">abbreviation</a> for Sequent: The Next Generation (with Intel inside), it was productized as NUMA-Q<a class="footnote-ref" id="fnref:28" href="#fn:28">28</a> and was the last of the systems released before the company was purchased by IBM for over $800 million.
IBM then started <a href="/facts/Project_Monterey/u2LLat0U">Project Monterey</a> with <a href="/facts/Santa_Cruz_Operation/jLoYByEf">Santa Cruz Operation</a>, intending to produce a NUMA-capable standardized <a href="/facts/Unix/0pNL2seI">Unix</a> running on <a href="/facts/IA-32/7yTv1aHH">IA-32</a>, <a href="/facts/IA-64/m6egpGno">IA-64</a> and <a href="/facts/IBM_Power_microprocessors/twCjzqAx">POWER</a> and <a href="/facts/PowerPC/DqmM9y50">PowerPC</a> platforms. This project later fell through as both IBM and SCO turned to the <a href="/facts/Linux/9FvCKSTq">Linux</a> market, but is the basis for "the new SCO"'s <a href="/facts/SCO_v._IBM/va9dEpQ1">SCO v. IBM</a> Linux lawsuit.

<h3>IBM purchase and disappearance</h3>
With their future product strategy in tatters, it appeared Sequent had little future standing alone, and was purchased by IBM in 1999 for $810 million.<a class="footnote-ref" id="fnref:29" href="#fn:29">29</a> IBM released several x86 servers with a NUMA architecture. The first was the x440 in August, 2002 with a follow-on x445 in 2003. In 2004, an Itanium-based x455 was added to the NUMA family. During this period, NUMA technology became the basis for IBM's <a href="/facts/IBM_System_x/xMvfkbLV">extended X-Architecture</a> (eXA, which could also stand for enterprise X-Architecture). As of 2011, this chipset is now on its fifth generation, known as eX5 technology.<a class="footnote-ref" id="fnref:30" href="#fn:30">30</a><a class="footnote-ref" id="fnref:31" href="#fn:31">31</a> It now falls under the brand <a href="/facts/IBM_System_x/xMvfkbLV">IBM System x</a>.
According to a May 30, 2002 article in the <a href="/facts/Wall_Street_Journal/9Pkf2cYK">Wall Street Journal</a> (WSJ) entitled "Sequent Deal Serves Hard Lesson for IBM":

When IBM bought Sequent, ...it [Sequent] lacked the size and resources to compete with <a href="/facts/Sun_Microsystems/VJ9EzEFd">Sun</a> and <a href="/facts/Hewlett-Packard/abuNSYNu">Hewlett-Packard Co.</a> in the Unix server market....
In 1999, IBM had problems of its own with an aged and high-priced line of <a href="/facts/Server_(computing)/dEaYFD7r">servers</a>, particularly for its version of Unix known as <a href="/facts/AIX_operating_system/cRWERua2">AIX</a>. It also faced huge losses in <a href="/facts/Personal_computer/koaYfNce">personal computers</a> and declining sales in its cash-cow <a href="/facts/Mainframe_computer/nrBR6rWa">mainframe line</a>.
<h2 id="detailed-model-descriptions">Detailed model descriptions</h2>
The following is a more detailed description<a class="footnote-ref" id="fnref:32" href="#fn:32">32</a> of the first two generations of Symmetry products, released between 1987 and 1990.

<h3>Symmetry S-series</h3>
Symmetry S3
The S3 was the low-end platform based on commodity PC components running a fully compatible version of DYNIX 3. It featured a single 33 <a href="/facts/Megahertz/6Wshj5qm">MHz</a> <a href="/facts/Intel_80386/ag5eSgWv">Intel 80386</a> processor, up to 40 <a href="/facts/Megabyte/RBF4XpWb">megabytes</a> of RAM, up to 1.8 <a href="/facts/Gigabyte/s2hb2SEg">gigabytes</a> of <a href="/facts/SCSI/pxXulrBr">SCSI</a>-based disk storage, and up to 32 direct-connected <a href="/facts/Serial_port/VpcrH530">serial ports</a>.<a class="footnote-ref" id="fnref:33" href="#fn:33">33</a>
Symmetry S16
The S16 was the entry-level multiprocessing model, which ran DYNIX/ptx. It featured up to six 20 MHz Intel 80386 processors, each with a 128 <a href="/facts/Kilobyte/jIe6t4yv">kilobyte</a> <a href="/facts/CPU_cache/x8BYFcdv">cache</a>. It also supported up to 80 MB of RAM, up to 2.5 GB of SCSI-based disk storage, and up to 80 direct-connected serial ports.
Symmetry S27
The S27 ran either DYNIX/ptx or DYNIX 3. It featured up to ten 20 MHz Intel 80386 processors, each with a 128 KB cache. It also supported up to 128 MB of RAM, up to 12.5 GB of disk storage, and up to 144 direct-connected serial ports.<a class="footnote-ref" id="fnref:34" href="#fn:34">34</a>
Symmetry S81
The S81 ran either DYNIX/ptx or DYNIX 3. It featured up to 30 20 MHz Intel 80386 processors, each with a 128 KB cache. It also supported up to 384 MB of RAM, up to 84.8 GB of disk storage, and up to 256 direct-connected serial ports.<a class="footnote-ref" id="fnref:35" href="#fn:35">35</a>
<h3>Symmetry 2000 series</h3>
Symmetry 2000/40
The S2000/40 was the low-end platform based on commodity PC components running a fully compatible version of DYNIX/ptx. It featured a single 33 <a href="/facts/Megahertz/6Wshj5qm">MHz</a> <a href="/facts/Intel_80486/2zfEAXAw">Intel 80486</a> processor, up to 64 <a href="/facts/Megabyte/RBF4XpWb">megabytes</a> of RAM, up to 2.4 <a href="/facts/Gigabyte/s2hb2SEg">gigabytes</a> of <a href="/facts/SCSI/pxXulrBr">SCSI</a>-based disk storage, and up to 32 direct-connected <a href="/facts/Serial_port/VpcrH530">serial ports</a>.
Symmetry 2000/200
The S2000/200 was the entry-level multiprocessing model, which ran DYNIX/ptx. It featured up to six 25 MHz Intel 80486 processors, each with a 512 <a href="/facts/Kilobyte/jIe6t4yv">kilobyte</a> <a href="/facts/CPU_cache/x8BYFcdv">cache</a>. It also supported up to 128 MB of RAM, up to 2.5 GB of SCSI-based disk storage, and up to 80 direct-connected serial ports.
Symmetry 2000/400
The S2000/400 ran either DYNIX/ptx or DYNIX 3. It featured up to ten 25 MHz Intel 80486 processors, each with a 512 KB cache. It also supported up to 128 MB of RAM, up to 14.0 GB of disk storage, and up to 144 direct-connected serial ports.
Symmetry 2000/700
The S2000/700 ran either DYNIX/ptx or DYNIX 3. It featured up to 30 25 MHz Intel 80486 processors, each with a 512 KB cache. It also supported up to 384 MB of RAM, up to 85.4 GB of disk storage, and up to 256 direct-connected serial ports.
<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/NCR_Voyager/68oGqcdm">NCR Voyager</a> (early 486/Pentium SMP systems)</li></ul>

<h2 id="external-links">External links</h2>
<ul><li><a href="https://web.archive.org/web/19980203152329/http://www.sequent.com/">Official website</a> at the <a href="/facts/Wayback_Machine/nmQ3a6JC">Wayback Machine</a> (archived 1998-02-03)</li></ul>
 Media related to Sequent Computer Systems at Wikimedia Commons

<h2 id="references">References</h2>

<ol>
<li id="fn:1">Sequent was overmatched, CEO says, a July 1999 article from CNET Networks <a href="http://news.cnet.com/Sequent+was+overmatched,+CEO+says/2100-1001_3-228478.html" target="_blank">http://news.cnet.com/Sequent+was+overmatched,+CEO+says/2100-1001_3-228478.html</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">Sequent Computer Systems To Be Acquired by I.B.M., a July 13, 1999 article from The New York Times <a href="https://query.nytimes.com/gst/fullpage.html?res=950DE2DB113CF930A25754C0A96F958260" target="_blank">https://query.nytimes.com/gst/fullpage.html?res=950DE2DB113CF930A25754C0A96F958260</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">Sequent was overmatched, CEO says, a July 1999 article from CNET Networks <a href="http://news.cnet.com/Sequent+was+overmatched,+CEO+says/2100-1001_3-228478.html" target="_blank">http://news.cnet.com/Sequent+was+overmatched,+CEO+says/2100-1001_3-228478.html</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">Sequent Computer Systems To Be Acquired by I.B.M., a July 13, 1999 article from The New York Times <a href="https://query.nytimes.com/gst/fullpage.html?res=950DE2DB113CF930A25754C0A96F958260" target="_blank">https://query.nytimes.com/gst/fullpage.html?res=950DE2DB113CF930A25754C0A96F958260</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">IBM lays off 250 in Beaverton, a May 2002 article from Portland Business Journal, one of the American City Business Journals <a href="http://www.bizjournals.com/portland/stories/2002/05/20/daily45.html" target="_blank">http://www.bizjournals.com/portland/stories/2002/05/20/daily45.html</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">"HP pays for PolyServe while IBM and Dell watch". The Register. February 27, 2007. <a href="https://www.theregister.co.uk/2007/02/27/hp_buys_polyserve" target="_blank">https://www.theregister.co.uk/2007/02/27/hp_buys_polyserve</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">"Hewlett-Packard to buy PolyServe". March 2007. <a href="https://www.infoworld.com/article/2635806/hewlett-packard-to-buy-polyserve.html" target="_blank">https://www.infoworld.com/article/2635806/hewlett-packard-to-buy-polyserve.html</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">"SCO Falls Downstairs, Hitting its Head on Every Step — Updated: SCOsource is Born". Groklaw. 17 May 2003. Retrieved 27 September 2023. <a href="http://www.groklaw.net/article.php?story=6" target="_blank">http://www.groklaw.net/article.php?story=6</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
<li id="fn:9">"Oh, That is Why They Are Saying That". Groklaw. 17 June 2003. Retrieved 27 September 2023. <a href="http://www.groklaw.net/article.php?story=59" target="_blank">http://www.groklaw.net/article.php?story=59</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></li>
<li id="fn:10">"And They Call Linus Careless". Groklaw. 18 June 2003. Retrieved 27 September 2023. <a href="http://www.groklaw.net/article.php?story=66" target="_blank">http://www.groklaw.net/article.php?story=66</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></li>
<li id="fn:11">"Why Cringley Says SCO Will Lose". Groklaw. 20 June 2003. Retrieved 27 September 2023. <a href="http://www.groklaw.net/article.php?story=72" target="_blank">http://www.groklaw.net/article.php?story=72</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></li>
<li id="fn:12">Aliza Earnshaw (28 February 2007). "PolyServe to join HP division". Portland Business Journal. Retrieved 27 September 2023. <a href="http://www.bizjournals.com/portland/stories/2007/02/26/daily23.html" target="_blank">http://www.bizjournals.com/portland/stories/2007/02/26/daily23.html</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></li>
<li id="fn:13">Advanced Architecture Computers and Part Two, Argonne National Labs, Technical Report No. 57, Jack J. Dongarra and Iain S. Duff <a href="http://www.netlib.org/papers/advarch" target="_blank">http://www.netlib.org/papers/advarch</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></li>
<li id="fn:14">"Sequent Symmetry 5000". <a href="http://www.ricomputermuseum.org/Home/equipment/sequent-5000" target="_blank">http://www.ricomputermuseum.org/Home/equipment/sequent-5000</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></li>
<li id="fn:15">with some of their names included 
here [1] <a href="https://en.wikipedia.org/w/index.php?title=Sequent_Computer_Systems&diff=902882568&oldid=896743436" target="_blank">https://en.wikipedia.org/w/index.php?title=Sequent_Computer_Systems&diff=902882568&oldid=896743436</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></li>
<li id="fn:16">"DEC 1077 and SMP". <a href="http://www.ultimate.com/phil/pdp10/10periphs" target="_blank">http://www.ultimate.com/phil/pdp10/10periphs</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></li>
<li id="fn:17">VAX 8820/8830/8840 System Hardware User's Guide: by 1988 the VAX operating system was SMP <a href="http://www.bitsavers.org/pdf/dec/vax/8800/EK-8840H-UG-001_88xx_System_Hardware_Users_Guide_Mar88.pdf" target="_blank">http://www.bitsavers.org/pdf/dec/vax/8800/EK-8840H-UG-001_88xx_System_Hardware_Users_Guide_Mar88.pdf</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></li>
<li id="fn:18">was up & coming @ 1077, already came by VMS <a href="#fnref:18" class="footnote-back-ref">↩</a></li>
<li id="fn:19">R. W. Hockney; C. R. Jesshope (1988). Parallel Computers 2: Architecture, Programming and Algorithms. Taylor & Francis. p. 46. ISBN 0-85274-811-6. <a href="0-85274-811-6" target="_blank">0-85274-811-6</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></li>
<li id="fn:20">"Archived copy". Archived from the original on 2016-04-12. Retrieved 2022-07-17.{{cite web}}: CS1 maint: archived copy as title (link) <a href="https://web.archive.org/web/20160412082437/http://homepages.inf.ed.ac.uk/cgi/rni/comp-arch.pl?Shmem%2Fsb.html%2CShmem%2Fsb-f.html%2CShmem%2Fmenu-seq.html" target="_blank">https://web.archive.org/web/20160412082437/http://homepages.inf.ed.ac.uk/cgi/rni/comp-arch.pl?Shmem%2Fsb.html%2CShmem%2Fsb-f.html%2CShmem%2Fmenu-seq.html</a> <a href="#fnref:20" class="footnote-back-ref">↩</a></li>
<li id="fn:21">Foster, Richard; Kaplan, Sarah (2011-04-20). Creative Destruction: Why Companies That Are Built to Last Underperform the Market--And How to Success fully Transform Them. Crown. ISBN 9780307779311. <a href="9780307779311" target="_blank">9780307779311</a> <a href="#fnref:21" class="footnote-back-ref">↩</a></li>
<li id="fn:22">Machines. Sequent cs.berkeley.edu <a href="http://www.cs.berkeley.edu/~culler/machines/sequent.ps" target="_blank">http://www.cs.berkeley.edu/~culler/machines/sequent.ps</a> <a href="#fnref:22" class="footnote-back-ref">↩</a></li>
<li id="fn:23">Machines. Sequent cs.berkeley.edu <a href="http://www.cs.berkeley.edu/~culler/machines/sequent.ps" target="_blank">http://www.cs.berkeley.edu/~culler/machines/sequent.ps</a> <a href="#fnref:23" class="footnote-back-ref">↩</a></li>
<li id="fn:24">"Growth in Balance". UNIX Review. April 1986. pp. 79–80. Retrieved 24 June 2022. <a href="https://archive.org/details/sim_unix-review_1986-04_4_4/page/79/mode/1up" target="_blank">https://archive.org/details/sim_unix-review_1986-04_4_4/page/79/mode/1up</a> <a href="#fnref:24" class="footnote-back-ref">↩</a></li>
<li id="fn:25">"Sequent Symmetry 5000". <a href="http://www.ricomputermuseum.org/Home/equipment/sequent-5000" target="_blank">http://www.ricomputermuseum.org/Home/equipment/sequent-5000</a> <a href="#fnref:25" class="footnote-back-ref">↩</a></li>
<li id="fn:26">"Sequent Symmetry 5000". <a href="http://www.ricomputermuseum.org/Home/equipment/sequent-5000" target="_blank">http://www.ricomputermuseum.org/Home/equipment/sequent-5000</a> <a href="#fnref:26" class="footnote-back-ref">↩</a></li>
<li id="fn:27">"Sequent Unveils New High-End Systems for Windows NT; Based on Industry-Leading Platform Symmetry Platform". Business Wire. 1995-05-23. Retrieved 2009-03-23. <a href="http://www.allbusiness.com/technology/software-services-applications-computer/7126055-1.html" target="_blank">http://www.allbusiness.com/technology/software-services-applications-computer/7126055-1.html</a> <a href="#fnref:27" class="footnote-back-ref">↩</a></li>
<li id="fn:28">"IT news, careers, business technology, reviews". Archived from the original on 2019-06-23. <a href="https://web.archive.org/web/20190623084303/https://www.computerworld.co.nz/article/518203/auckland_university_first_buy_sequent_numa-q_box" target="_blank">https://web.archive.org/web/20190623084303/https://www.computerworld.co.nz/article/518203/auckland_university_first_buy_sequent_numa-q_box</a> <a href="#fnref:28" class="footnote-back-ref">↩</a></li>
<li id="fn:29">"IBM drops Intel high-end server". Computerworld. May 13, 2002. <a href="https://www.computerworld.com/article/2576139/network-servers/ibm-drops-intel-high-end-server.html" target="_blank">https://www.computerworld.com/article/2576139/network-servers/ibm-drops-intel-high-end-server.html</a> <a href="#fnref:29" class="footnote-back-ref">↩</a></li>
<li id="fn:30">"IBM eX5 flexible enterprise systems: EX5 systems overview". www.ibm.com. Archived from the original on 25 January 2013. Retrieved 22 May 2022. <a href="https://archive.today/20130125221915/http://www.ibm.com/systems/info/x86servers/ex5/" target="_blank">https://archive.today/20130125221915/http://www.ibm.com/systems/info/x86servers/ex5/</a> <a href="#fnref:30" class="footnote-back-ref">↩</a></li>
<li id="fn:31">"XREF: System x Reference | IBM Redbooks". <a href="http://www.redbooks.ibm.com/Redbooks.nsf/pages/xref?Open" target="_blank">http://www.redbooks.ibm.com/Redbooks.nsf/pages/xref?Open</a> <a href="#fnref:31" class="footnote-back-ref">↩</a></li>
<li id="fn:32">Sequent Computer Systems (1991). Symmetry Multiprocessor Architecture Overview. Company publication number 1003-50113-01 <a href="#fnref:32" class="footnote-back-ref">↩</a></li>
<li id="fn:33">"The Sequent Symmetry". February 24, 1994. <a href="http://www.cs.uoregon.edu/research/paraducks/papers/sc93.d/subsubsection3_3_2_3.html" target="_blank">http://www.cs.uoregon.edu/research/paraducks/papers/sc93.d/subsubsection3_3_2_3.html</a> <a href="#fnref:33" class="footnote-back-ref">↩</a></li>
<li id="fn:34">"Sequent Symmetry S27 and Symmetry S81 Parallel Bus Architecture". <a href="https://people.eecs.berkeley.edu/~culler/machines/sequent2.ps" target="_blank">https://people.eecs.berkeley.edu/~culler/machines/sequent2.ps</a> <a href="#fnref:34" class="footnote-back-ref">↩</a></li>
<li id="fn:35">"Sequent Symmetry S27 and Symmetry S81 Parallel Bus Architecture". <a href="https://people.eecs.berkeley.edu/~culler/machines/sequent2.ps" target="_blank">https://people.eecs.berkeley.edu/~culler/machines/sequent2.ps</a> <a href="#fnref:35" class="footnote-back-ref">↩</a></li>
</ol>

Sequent Computer Systems open-in-new

Sequent Computer Systems