Editing Burroughs Large Systems (section)

=={{anchor|B6500|B7500|B6700|B7700|B6500 and successors}}B6500, B6700/B7700, and successors==

{{See also|Burroughs B6x00-7x00 instruction set}}

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The B6500<ref name=B1043676>{{cite manual
 |  publisher = Burroughs
 |      title = Burroughs B6500 Information Processing System Reference Manual
 |         id = 1043676
 |       date = September 1969
 |        url = http://www.bitsavers.org/pdf/burroughs/LargeSystems/B6500_6700/1043676_B6500_RefMan_Sep69.pdf
 |       mode = cs2
 }}
</ref> (delivery in 1969<ref name="antitrust" /><ref>Archived at [https://ghostarchive.org/varchive/youtube/20211211/KOElQuCqj0Y Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20190918222303/https://www.youtube.com/watch?v=KOElQuCqj0Y&gl=US&hl=en Wayback Machine]{{cbignore}}: {{Citation|last=Burroughs Corporation|title=Burroughs B6500 Status Report|date=1969|url=https://www.youtube.com/watch?v=KOElQuCqj0Y|publication-date=2015-08-08|type=film|at=Timecode: 1969 status - 0:00-0:52, 6:04-7:01, 8:14; date - 3:40, 4:21|publisher=Nigel Williams|access-date=2019-03-04}}{{cbignore}}

* Shipments rate, first 16 computers: {{Cite book|url=http://archive.org/details/bitsavers_burroughsB0StatusApr70_1684164|title=burroughs :: B6500 6700 :: CUBE XVI B6500 Status Apr70|date=Apr 1970|pages=1–2}}</ref>) and B7500{{cn|date=April 2023}} were the first computers in the only line of Burroughs systems to survive to the present day. While they were inspired by the B5000, they had a totally new architecture. Among the most important differences were
*The B6500 had variable length instructions with an [[8-bit syllable]] instead of fixed length instructions with a [[12-bit syllable]].
*The B6500 had a 51-bit<ref group=NB>Not counting error controls</ref> instead of a 48-bit word, and used 3 bits as a [[Tagged architecture|tag]]<ref>{{cite book |title=Computer Architecture and Organization |last1=Hayes |first1=John P. |isbn=0-07-027363-4 |year=1978 |publisher= |pages=148–149}}</ref>
*The B6500 had [[Symmetric multiprocessing|Symmetric Multiprocessing (SMP)]]
*The B6500 had a [[Spaghetti stack|Saguaro stack]]
*The B6500 had paged arrays
*The B6500 had ''Display Registers, D1 thru D32'' to allow nested subroutines to access variables in outer blocks.
*The B6500 used monolithic [[integrated circuit]]s with magnetic [[thin-film memory]].<ref name="antitrust">{{cite web|url=https://archive.org/details/bitsavers_charlesRivit14971part2Jul80_43225678/page/n408|title=Historical Narrative The 1960s; US vs IBM, Exhibit 14971, Part 2|date=July 22, 1980|website=ed-thelen.org|publisher=US Government|page=648 (409)|access-date=February 21, 2019}} [http://ed-thelen.org/comp-hist/US_vs_IBM_Exhibit_14971_part_2_Jul80.pdf Alt URL]</ref>
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Among other customers of the B6700 and B7700 were all five New Zealand universities in 1971.<ref>{{cite web |title=Computing History Displays: Fourth Floor |url=https://www.cs.auckland.ac.nz/historydisplays/FourthFloor/MainFrameComputers/BurroughsB6700.php |publisher=University of Auckland |access-date=18 May 2020}}</ref>