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class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Decryption processes</span> </div> </a> <ul id="toc-Decryption_processes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Design_and_construction" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Design_and_construction"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Design and construction</span> </div> </a> <ul id="toc-Design_and_construction-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Operation" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Operation"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Operation</span> </div> </a> <ul id="toc-Operation-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Programming" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Programming"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Programming</span> </div> </a> <ul id="toc-Programming-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Influence_and_fate" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Influence_and_fate"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Influence and fate</span> </div> </a> <ul id="toc-Influence_and_fate-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Reconstruction" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Reconstruction"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>Reconstruction</span> </div> </a> <ul id="toc-Reconstruction-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Other_meanings" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Other_meanings"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>Other meanings</span> </div> </a> <ul id="toc-Other_meanings-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Footnotes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Footnotes"> <div class="vector-toc-text"> <span class="vector-toc-numb">10</span> <span>Footnotes</span> </div> </a> <ul id="toc-Footnotes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">11</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Further_reading" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Further_reading"> <div class="vector-toc-text"> <span class="vector-toc-numb">12</span> <span>Further reading</span> </div> </a> <ul id="toc-Further_reading-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">13</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Colossus computer</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 33 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-33" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">33 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D9%83%D9%88%D9%84%D9%88%D8%B3%D8%B3" title="كولوسس – Arabic" lang="ar" hreflang="ar" data-title="كولوسس" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/Colossus_Mark_I" title="Colossus Mark I – Bulgarian" lang="bg" hreflang="bg" data-title="Colossus Mark I" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Colossus" title="Colossus – Catalan" lang="ca" hreflang="ca" data-title="Colossus" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Colossus_(po%C4%8D%C3%ADta%C4%8D)" title="Colossus (počítač) – Czech" lang="cs" hreflang="cs" data-title="Colossus (počítač)" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Colossus" title="Colossus – Danish" lang="da" hreflang="da" data-title="Colossus" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Colossus" title="Colossus – German" lang="de" hreflang="de" data-title="Colossus" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Colossus" title="Colossus – Estonian" lang="et" hreflang="et" data-title="Colossus" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Colossus" title="Colossus – Spanish" lang="es" hreflang="es" data-title="Colossus" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%B1%D8%A7%DB%8C%D8%A7%D9%86%D9%87_%DA%A9%D9%84%D9%88%D8%B3%D9%88%D8%B3" title="رایانه کلوسوس – Persian" lang="fa" hreflang="fa" data-title="رایانه کلوسوس" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Colossus_(ordinateur)" title="Colossus (ordinateur) – French" lang="fr" hreflang="fr" data-title="Colossus (ordinateur)" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EC%BD%9C%EB%A1%9C%EC%84%9C%EC%8A%A4_(%EC%BB%B4%ED%93%A8%ED%84%B0)" title="콜로서스 (컴퓨터) – Korean" lang="ko" hreflang="ko" data-title="콜로서스 (컴퓨터)" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Colossus_(ra%C4%8Dunalo)" title="Colossus (računalo) – Croatian" lang="hr" hreflang="hr" data-title="Colossus (računalo)" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Komputer_Colossus" title="Komputer Colossus – Indonesian" lang="id" hreflang="id" data-title="Komputer Colossus" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Colossus" title="Colossus – Italian" lang="it" hreflang="it" data-title="Colossus" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%A7%D7%95%D7%9C%D7%95%D7%A1%D7%95%D7%A1_(%D7%9E%D7%97%D7%A9%D7%91)" title="קולוסוס (מחשב) – Hebrew" lang="he" hreflang="he" data-title="קולוסוס (מחשב)" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/Colossus" title="Colossus – Lithuanian" lang="lt" hreflang="lt" data-title="Colossus" data-language-autonym="Lietuvių" data-language-local-name="Lithuanian" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Colossus_(sz%C3%A1m%C3%ADt%C3%B3g%C3%A9p)" title="Colossus (számítógép) – Hungarian" lang="hu" hreflang="hu" data-title="Colossus (számítógép)" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Colossus_(computer)" title="Colossus (computer) – Dutch" lang="nl" hreflang="nl" data-title="Colossus (computer)" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/Colossus" title="Colossus – Japanese" lang="ja" hreflang="ja" data-title="Colossus" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Colossus" title="Colossus – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Colossus" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Colossus" title="Colossus – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Colossus" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Colossus" title="Colossus – Polish" lang="pl" hreflang="pl" data-title="Colossus" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Colossus_(computador)" title="Colossus (computador) – Portuguese" lang="pt" hreflang="pt" data-title="Colossus (computador)" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Colossus_(calculator)" title="Colossus (calculator) – Romanian" lang="ro" hreflang="ro" data-title="Colossus (calculator)" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/Colossus_(%D0%BA%D0%BE%D0%BC%D0%BF%D1%8C%D1%8E%D1%82%D0%B5%D1%80)" title="Colossus (компьютер) – Russian" lang="ru" hreflang="ru" data-title="Colossus (компьютер)" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Colossus_computer" title="Colossus computer – Simple English" lang="en-simple" hreflang="en-simple" data-title="Colossus computer" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/Kolos_(ra%C4%8Dunar)" title="Kolos (računar) – Serbian" lang="sr" hreflang="sr" data-title="Kolos (računar)" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Colossus_(tietokone)" title="Colossus (tietokone) – Finnish" lang="fi" hreflang="fi" data-title="Colossus (tietokone)" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Colossus" title="Colossus – Swedish" lang="sv" hreflang="sv" data-title="Colossus" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/Colossus_bilgisayar%C4%B1" title="Colossus bilgisayarı – Turkish" lang="tr" hreflang="tr" data-title="Colossus bilgisayarı" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9A%D0%BE%D0%BB%D0%BE%D1%81_(%D0%BA%D0%BE%D0%BC%D0%BF%27%D1%8E%D1%82%D0%B5%D1%80)" title="Колос (комп'ютер) – Ukrainian" lang="uk" hreflang="uk" data-title="Колос (комп'ютер)" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-yi mw-list-item"><a href="https://yi.wikipedia.org/wiki/%D7%A7%D7%90%D7%9C%D7%90%D7%A1%D7%95%D7%A1_%D7%A7%D7%90%D7%9E%D7%A4%D7%99%D7%95%D7%98%D7%A2%D7%A8" title="קאלאסוס קאמפיוטער – Yiddish" lang="yi" hreflang="yi" data-title="קאלאסוס קאמפיוטער" data-language-autonym="ייִדיש" data-language-local-name="Yiddish" class="interlanguage-link-target"><span>ייִדיש</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E5%B7%A8%E4%BA%BA%E8%AE%A1%E7%AE%97%E6%9C%BA" title="巨人计算机 – Chinese" lang="zh" hreflang="zh" data-title="巨人计算机" 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<div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Early British cryptanalysis computer</div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">Not to be confused with the fictional computer of the same name in the movie <a href="/wiki/Colossus:_The_Forbin_Project" title="Colossus: The Forbin Project">Colossus: The Forbin Project</a>.</div> <p class="mw-empty-elt"> </p> <style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox hproduct vevent"><caption class="infobox-title fn summary">Colossus computer</caption><tbody><tr><td colspan="2" class="infobox-image"><span typeof="mw:File"><a href="/wiki/File:Colossus.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4b/Colossus.jpg/300px-Colossus.jpg" decoding="async" width="300" height="200" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4b/Colossus.jpg/450px-Colossus.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4b/Colossus.jpg/600px-Colossus.jpg 2x" data-file-width="3504" data-file-height="2337" /></a></span><div class="infobox-caption">A Colossus Mark 2 computer being operated by <a href="/wiki/Women%27s_Royal_Naval_Service" title="Women's Royal Naval Service">Wrens</a>.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>a<span class="cite-bracket">]</span></a></sup> The slanted control panel on the left was used to set the "pin" (or "cam") patterns of the Lorenz. The "bedstead" paper tape transport is on the right.</div></td></tr><tr><th scope="row" class="infobox-label">Developer</th><td class="infobox-data"><a href="/wiki/Tommy_Flowers" title="Tommy Flowers">Tommy Flowers</a>, assisted by Sidney Broadhurst, William Chandler and for the Mark 2 machines, <a href="/wiki/Allen_Coombs" title="Allen Coombs">Allen Coombs</a></td></tr><tr><th scope="row" class="infobox-label">Manufacturer</th><td class="infobox-data"><a href="/wiki/Post_Office_Research_Station" title="Post Office Research Station">Post Office Research Station</a></td></tr><tr><th scope="row" class="infobox-label">Type</th><td class="infobox-data">Special-purpose electronic digital programmable computer</td></tr><tr><th scope="row" class="infobox-label">Generation</th><td class="infobox-data">First-generation computer</td></tr><tr><th scope="row" class="infobox-label">Release date</th><td class="infobox-data"><style data-mw-deduplicate="TemplateStyles:r1126788409">.mw-parser-output .plainlist ol,.mw-parser-output .plainlist ul{line-height:inherit;list-style:none;margin:0;padding:0}.mw-parser-output .plainlist ol li,.mw-parser-output .plainlist ul li{margin-bottom:0}</style><div class="plainlist"> <ul><li>Mk 1: December 1943<span style="display:none"> (<span class="bday dtstart published updated itvstart">1943-12</span>)</span></li> <li>Mk 2: 1 June 1944<span style="display:none"> (<span class="bday dtstart published updated itvstart">1944-06-01</span>)</span></li></ul> </div></td></tr><tr><th scope="row" class="infobox-label">Discontinued</th><td class="infobox-data">1960</td></tr><tr><th scope="row" class="infobox-label">Units shipped</th><td class="infobox-data">12</td></tr><tr><th scope="row" class="infobox-label">Media</th><td class="infobox-data"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"><div class="plainlist"> <ul><li><a href="/wiki/Typewriter#Electric_designs" title="Typewriter">Electric typewriter</a> output</li> <li><a href="/wiki/Computer_programming" title="Computer programming">Programmed</a> using switches and plug panels</li></ul> </div></td></tr><tr><th scope="row" class="infobox-label"><a href="/wiki/Central_processing_unit" title="Central processing unit">CPU</a></th><td class="infobox-data">Custom circuits using thermionic <a href="/wiki/Vacuum_tube" title="Vacuum tube">valves</a> and <a href="/wiki/Thyratron" title="Thyratron">thyratrons</a>. A total of 1,600 in Mk 1 and 2,400 in Mk 2. Also <a href="/wiki/Relay" title="Relay">relays</a> and <a href="/wiki/Stepping_switch" title="Stepping switch">stepping switches</a></td></tr><tr><th scope="row" class="infobox-label">Memory</th><td class="infobox-data">None (no <a href="/wiki/Random-access_memory" title="Random-access memory">RAM</a>)</td></tr><tr><th scope="row" class="infobox-label">Display</th><td class="infobox-data">Indicator lamp panel</td></tr><tr><th scope="row" class="infobox-label">Input</th><td class="infobox-data"><a href="/wiki/Punched_tape" title="Punched tape">Paper tape</a> of up to 20,000 × 5-bit characters in a continuous loop</td></tr><tr><th scope="row" class="infobox-label">Power</th><td class="infobox-data">8.5 kW<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>b<span class="cite-bracket">]</span></a></sup></td></tr></tbody></table> <p><b>Colossus</b> was a set of <a href="/wiki/Computer" title="Computer">computers</a> developed by British <a href="/wiki/Cryptanalysis" title="Cryptanalysis">codebreakers</a> in the years 1943–1945<sup id="cite_ref-tnmoc_3-0" class="reference"><a href="#cite_note-tnmoc-3"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> to help in the <a href="/wiki/Cryptanalysis_of_the_Lorenz_cipher" title="Cryptanalysis of the Lorenz cipher">cryptanalysis of the Lorenz cipher</a>. Colossus used <a href="/wiki/Vacuum_tube" title="Vacuum tube">thermionic valves (vacuum tubes)</a> to perform <a href="/wiki/Boolean_algebra_(logic)" class="mw-redirect" title="Boolean algebra (logic)">Boolean</a> and counting operations. Colossus is thus regarded<sup id="cite_ref-FOOTNOTECopeland_"Introduction"20062_4-0" class="reference"><a href="#cite_note-FOOTNOTECopeland_"Introduction"20062-4"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> as the world's first <a href="/wiki/Computer_programming" title="Computer programming">programmable</a>, <a href="/wiki/Electronics" title="Electronics">electronic</a>, <a href="/wiki/Digital_electronics" title="Digital electronics">digital</a> computer, although it was programmed by switches and plugs and not by a <a href="/wiki/Stored-program_computer" title="Stored-program computer">stored program</a>.<sup id="cite_ref-FOOTNOTESale2000_5-0" class="reference"><a href="#cite_note-FOOTNOTESale2000-5"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p><p>Colossus was designed by <a href="/wiki/General_Post_Office" title="General Post Office">General Post Office</a> (GPO) research telephone engineer <a href="/wiki/Tommy_Flowers" title="Tommy Flowers">Tommy Flowers</a><sup id="cite_ref-tnmoc_3-1" class="reference"><a href="#cite_note-tnmoc-3"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> based on plans developed by mathematician <a href="/wiki/Max_Newman" title="Max Newman">Max Newman</a> at the <a href="/wiki/Government_Communications_Headquarters#Government_Code_and_Cypher_School_(GC&CS)" class="mw-redirect" title="Government Communications Headquarters">Government Code and Cypher School</a> (GC&CS) at <a href="/wiki/Bletchley_Park" title="Bletchley Park">Bletchley Park</a>. </p><p><a href="/wiki/Alan_Turing" title="Alan Turing">Alan Turing</a>'s use of probability in cryptanalysis (see <a href="/wiki/Banburismus" title="Banburismus">Banburismus</a>) contributed to its design. It has sometimes been erroneously stated that Turing designed Colossus to aid the <a href="/wiki/Cryptanalysis_of_the_Enigma" title="Cryptanalysis of the Enigma">cryptanalysis of the Enigma</a>.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> (Turing's machine that helped decode <a href="/wiki/Enigma_machine" title="Enigma machine">Enigma</a> was the electromechanical <a href="/wiki/Bombe" title="Bombe">Bombe</a>, not Colossus.)<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p><p>The prototype, <b>Colossus Mark 1</b>, was shown to be working in December 1943 and was in use at Bletchley Park by early 1944.<sup id="cite_ref-tnmoc_3-2" class="reference"><a href="#cite_note-tnmoc-3"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> An improved <b>Colossus Mark 2</b> that used <a href="/wiki/Shift_register" title="Shift register">shift registers</a> to run five times faster first worked on 1 June 1944, just in time for the <a href="/wiki/Normandy_landings" title="Normandy landings">Normandy landings</a> on D-Day.<sup id="cite_ref-FOOTNOTEFlowers1983246_8-0" class="reference"><a href="#cite_note-FOOTNOTEFlowers1983246-8"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> Ten Colossi were in use by the end of the war and an eleventh was being commissioned.<sup id="cite_ref-FOOTNOTEFlowers1983246_8-1" class="reference"><a href="#cite_note-FOOTNOTEFlowers1983246-8"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> Bletchley Park's use of these machines allowed the <a href="/wiki/Allies_of_World_War_II" title="Allies of World War II">Allies</a> to obtain a vast amount of high-level <a href="/wiki/Military_intelligence" title="Military intelligence">military intelligence</a> from intercepted <a href="/wiki/Wireless_telegraphy" title="Wireless telegraphy">radiotelegraphy</a> messages between the <a href="/wiki/Oberkommando_der_Wehrmacht" title="Oberkommando der Wehrmacht">German High Command</a> (<i>OKW</i>) and their <a href="/wiki/Wehrmacht" title="Wehrmacht">army</a> commands throughout occupied Europe. </p><p>The existence of the Colossus machines was kept secret until the mid-1970s.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-lorenz_10-0" class="reference"><a href="#cite_note-lorenz-10"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> All but two machines were dismantled into such small parts that their use could not be inferred. The two retained machines were eventually dismantled in the 1960s. In January 2024, new photos were released by GCHQ that showed re-engineered Colossus in a very different environment from the Bletchley Park buildings, presumably at GCHQ Cheltenham.<sup id="cite_ref-FOOTNOTEGCHQ2024_11-0" class="reference"><a href="#cite_note-FOOTNOTEGCHQ2024-11"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> A functioning reconstruction of a Mark 2 Colossus was completed in 2008 by <a href="/wiki/Tony_Sale" title="Tony Sale">Tony Sale</a> and a team of volunteers; it is on display in <a href="/wiki/The_National_Museum_of_Computing" title="The National Museum of Computing">The National Museum of Computing</a> at Bletchley Park.<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-auto_13-0" class="reference"><a href="#cite_note-auto-13"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-The_Colossus_Computer_14-0" class="reference"><a href="#cite_note-The_Colossus_Computer-14"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Purpose_and_origins">Purpose and origins</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=1" title="Edit section: Purpose and origins"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Cryptanalysis_of_the_Lorenz_cipher" title="Cryptanalysis of the Lorenz cipher">Cryptanalysis of the Lorenz cipher</a></div> <figure class="mw-default-size mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:LorenzSZ42at_TNMOC.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f8/LorenzSZ42at_TNMOC.jpg/330px-LorenzSZ42at_TNMOC.jpg" decoding="async" width="330" height="248" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/f8/LorenzSZ42at_TNMOC.jpg/495px-LorenzSZ42at_TNMOC.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/f8/LorenzSZ42at_TNMOC.jpg/660px-LorenzSZ42at_TNMOC.jpg 2x" data-file-width="3648" data-file-height="2736" /></a><figcaption>A Lorenz SZ42 cipher machine with its covers removed at <a href="/wiki/The_National_Museum_of_Computing" title="The National Museum of Computing">The National Museum of Computing</a> on <a href="/wiki/Bletchley_Park" title="Bletchley Park">Bletchley Park</a></figcaption></figure> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:SZ42-6-wheels-lightened.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/3/39/SZ42-6-wheels-lightened.jpg/400px-SZ42-6-wheels-lightened.jpg" decoding="async" width="400" height="300" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/39/SZ42-6-wheels-lightened.jpg/600px-SZ42-6-wheels-lightened.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/39/SZ42-6-wheels-lightened.jpg/800px-SZ42-6-wheels-lightened.jpg 2x" data-file-width="2304" data-file-height="1728" /></a><figcaption>The <a href="/wiki/Lorenz_cipher" title="Lorenz cipher">Lorenz SZ machines</a> had 12 wheels, each with a different number of <a href="/wiki/Cam_(mechanism)" title="Cam (mechanism)">cams</a> (or "pins"). <table class="wikitable" style="margin: auto auto auto auto"> <tbody><tr> <th>Wheel number </th> <td>1</td> <td>2</td> <td>3</td> <td>4</td> <td>5</td> <td>6</td> <td>7</td> <td>8</td> <td>9</td> <td>10</td> <td>11</td> <td>12 </td></tr> <tr> <th>BP wheel name<sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11B_The_Tunny_Cipher_Machine,_p._6_15-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11B_The_Tunny_Cipher_Machine,_p._6-15"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> </th> <td style="text-align:center;"><i>ψ</i><sub>1</sub> </td> <td style="text-align:center;"><i>ψ</i><sub>2</sub> </td> <td style="text-align:center;"><i>ψ</i><sub>3</sub> </td> <td style="text-align:center;"><i>ψ</i><sub>4</sub> </td> <td style="text-align:center;"><i>ψ</i><sub>5</sub> </td> <td style="text-align:center;"><i>μ</i><sub>37</sub> </td> <td style="text-align:center;"><i>μ</i><sub>61</sub> </td> <td style="text-align:center;"><i>χ</i><sub>1</sub> </td> <td style="text-align:center;"><i>χ</i><sub>2</sub> </td> <td style="text-align:center;"><i>χ</i><sub>3</sub> </td> <td style="text-align:center;"><i>χ</i><sub>4</sub> </td> <td style="text-align:center;"><i>χ</i><sub>5</sub> </td></tr> <tr> <th>Number of cams (pins) </th> <td>43</td> <td>47</td> <td>51</td> <td>53</td> <td>59</td> <td>37</td> <td>61</td> <td>41</td> <td>31</td> <td>29</td> <td>26</td> <td>23 </td></tr></tbody></table> </figcaption></figure> <p>The Colossus computers were used to help decipher intercepted radio <a href="/wiki/Teleprinter" title="Teleprinter">teleprinter</a> messages that had been <a href="/wiki/Encryption" title="Encryption">encrypted</a> using an unknown device. Intelligence information revealed that the Germans called the wireless teleprinter transmission systems <i>"Sägefisch"</i> (sawfish). This led the British to call encrypted German teleprinter traffic "<a href="/wiki/Fish_(cryptography)" title="Fish (cryptography)">Fish</a>",<sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11A_Fish_Machines,_(c)_The_German_Ciphered_Teleprinter,_p._4_16-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11A_Fish_Machines,_(c)_The_German_Ciphered_Teleprinter,_p._4-16"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> and the unknown machine and its intercepted messages "<a href="/wiki/Lorenz_cipher" title="Lorenz cipher">Tunny</a>" (tunafish).<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </p><p>Before the Germans increased the security of their operating procedures, British cryptanalysts <a href="/wiki/Cryptanalysis_of_the_Lorenz_cipher#Diagnosis" title="Cryptanalysis of the Lorenz cipher">diagnosed</a> how the unseen machine functioned and built an imitation of it called "<a href="/wiki/Cryptanalysis_of_the_Lorenz_cipher#British_Tunny" title="Cryptanalysis of the Lorenz cipher">British Tunny</a>". </p><p>It was deduced that the machine had twelve wheels and used a <a href="/wiki/Vernam_cipher" class="mw-redirect" title="Vernam cipher">Vernam ciphering</a> technique on message characters in the standard 5-bit <a href="/wiki/ITA2" class="mw-redirect" title="ITA2">ITA2</a> telegraph code. It did this by combining the <a href="/wiki/Plaintext" title="Plaintext">plaintext</a> characters with a stream of <a href="/wiki/Key_(cryptography)" title="Key (cryptography)">key</a> characters using the <a href="/wiki/XOR" class="mw-redirect" title="XOR">XOR</a> <a href="/wiki/Boolean_function" title="Boolean function">Boolean function</a> to produce the <a href="/wiki/Ciphertext" title="Ciphertext">ciphertext</a>. </p><p>In August 1941, a blunder by German operators led to the transmission of two versions of the same message with identical machine settings. These were intercepted and worked on at Bletchley Park. First, <a href="/wiki/John_Tiltman" title="John Tiltman">John Tiltman</a>, a very talented GC&CS cryptanalyst, derived a <a href="/wiki/Keystream" title="Keystream">keystream</a> of almost 4000 characters.<sup id="cite_ref-FOOTNOTEBudiansky200655–56_18-0" class="reference"><a href="#cite_note-FOOTNOTEBudiansky200655–56-18"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> Then <a href="/wiki/Bill_Tutte" class="mw-redirect" title="Bill Tutte">Bill Tutte</a>, a newly arrived member of the Research Section, used this keystream to work out the logical structure of the Lorenz machine. He deduced that the twelve wheels consisted of two groups of five, which he named the χ (<i><a href="/wiki/Chi_(letter)" title="Chi (letter)">chi</a></i>) and ψ (<i><a href="/wiki/Psi_(letter)" class="mw-redirect" title="Psi (letter)">psi</a></i>) wheels, the remaining two he called μ (<i><a href="/wiki/Mu_(letter)" title="Mu (letter)">mu</a></i>) or "motor" wheels. The <i>chi</i> wheels stepped regularly with each letter that was encrypted, while the <i>psi</i> wheels stepped irregularly, under the control of the motor wheels.<sup id="cite_ref-FOOTNOTETutte2006357_19-0" class="reference"><a href="#cite_note-FOOTNOTETutte2006357-19"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> </p> <figure class="mw-default-size mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:Lorenz_Cams.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/56/Lorenz_Cams.jpg/330px-Lorenz_Cams.jpg" decoding="async" width="330" height="279" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/56/Lorenz_Cams.jpg/495px-Lorenz_Cams.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/56/Lorenz_Cams.jpg/660px-Lorenz_Cams.jpg 2x" data-file-width="2484" data-file-height="2098" /></a><figcaption>Cams on wheels 9 and 10 showing their raised (active) and lowered (inactive) positions. An active cam reversed the value of a bit (0→1 and 1→0).</figcaption></figure> <p>With a sufficiently random keystream, a Vernam cipher removes the natural language property of a plaintext message of having an uneven <a href="/wiki/Frequency_distribution" class="mw-redirect" title="Frequency distribution">frequency distribution</a> of the different characters, to produce a uniform distribution in the ciphertext. The Tunny machine did this well. However, the cryptanalysts worked out that by examining the frequency distribution of the character-to-character changes in the ciphertext, instead of the plain characters, there was a departure from uniformity which provided a way into the system. This was achieved by <a href="/wiki/Cryptanalysis_of_the_Lorenz_cipher#Differencing" title="Cryptanalysis of the Lorenz cipher">"differencing"</a> in which each bit or character was XOR-ed with its successor.<sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11C_Wheel_Patterns,_(b)_Differenced_and_Undifferenced_Wheels,_p._11_20-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11C_Wheel_Patterns,_(b)_Differenced_and_Undifferenced_Wheels,_p._11-20"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> After Germany surrendered, allied forces captured a Tunny machine and discovered that it was the <a href="/wiki/Electromechanical" class="mw-redirect" title="Electromechanical">electromechanical</a> <a href="/wiki/Lorenz_cipher" title="Lorenz cipher">Lorenz SZ</a> (<i>Schlüsselzusatzgerät</i>, cipher attachment) in-line cipher machine.<sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11A_Fish_Machines,_(c)_The_German_Ciphered_Teleprinter,_p._4_16-1" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11A_Fish_Machines,_(c)_The_German_Ciphered_Teleprinter,_p._4-16"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> </p><p>In order to decrypt the transmitted messages, two tasks had to be performed. The first was "wheel breaking", which was the discovery of the cam patterns for all the wheels. These patterns were set up on the Lorenz machine and then used for a fixed period of time for a succession of different messages. Each transmission, which often contained more than one message, was enciphered with a different start position of the wheels. Alan Turing invented a method of wheel-breaking that became known as <a href="/wiki/Turingery" title="Turingery">Turingery</a>.<sup id="cite_ref-FOOTNOTECopeland_"Turingery"2006378–385_21-0" class="reference"><a href="#cite_note-FOOTNOTECopeland_"Turingery"2006378–385-21"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> Turing's technique was further developed into "Rectangling", for which Colossus could produce tables for manual analysis. Colossi 2, 4, 6, 7 and 9 had a "gadget" to aid this process.<sup id="cite_ref-FOOTNOTEGoodMichieTimms194524_–_Rectangling:_24B_Making_and_Entering_Rectangles_pp._114–115,_119–120_22-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms194524_–_Rectangling:_24B_Making_and_Entering_Rectangles_pp._114–115,_119–120-22"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> </p><p>The second task was <a href="/wiki/Cryptanalysis_of_the_Lorenz_cipher#Steps_in_Wheel_Setting" title="Cryptanalysis of the Lorenz cipher">"wheel setting"</a>, which worked out the start positions of the wheels for a particular message and could only be attempted once the cam patterns were known.<sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11E_The_Tunny_Network,_(b)_Wheel-breaking_and_Setting,_p._15_23-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11E_The_Tunny_Network,_(b)_Wheel-breaking_and_Setting,_p._15-23"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> It was this task for which Colossus was initially designed. To discover the start position of the <i>chi</i> wheels for a message, Colossus compared two character streams, counting statistics from the evaluation of programmable Boolean functions. The two streams were the ciphertext, which was read at high speed from a paper tape, and the keystream, which was generated internally, in a simulation of the unknown German machine. After a succession of different Colossus runs to discover the likely <i>chi</i>-wheel settings, they were checked by examining the frequency distribution of the characters in the processed ciphertext.<sup id="cite_ref-FOOTNOTESmall194415_24-0" class="reference"><a href="#cite_note-FOOTNOTESmall194415-24"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> Colossus produced these frequency counts. </p> <div class="mw-heading mw-heading2"><h2 id="Decryption_processes">Decryption processes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=2" title="Edit section: Decryption processes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <table class="wikitable floatright"> <caption>Notation <sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_12_Cryptographic_Aspects,_12A_The_Problem,_(a)_Formulae_and_Notation,_p._16_25-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_12_Cryptographic_Aspects,_12A_The_Problem,_(a)_Formulae_and_Notation,_p._16-25"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> </caption> <tbody><tr> <td><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>P</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle P}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b4dc73bf40314945ff376bd363916a738548d40a" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.745ex; height:2.176ex;" alt="{\displaystyle P}"></span></td> <td>plaintext </td></tr> <tr> <td><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle K}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>K</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle K}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/2b76fce82a62ed5461908f0dc8f037de4e3686b0" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:2.066ex; height:2.176ex;" alt="{\displaystyle K}"></span></td> <td>key – the sequence of characters used in binary <a href="/wiki/XOR" class="mw-redirect" title="XOR">XOR</a> with <br /> the plaintext to give the ciphertext </td></tr> <tr> <td><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \chi }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>χ</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \chi }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/656111758322ace96d80a9371771aa6d3de25437" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.455ex; height:2.009ex;" alt="{\displaystyle \chi }"></span></td> <td><i>chi</i> component of key </td></tr> <tr> <td><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \psi }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>ψ</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \psi }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/45e5789e5d9c8f7c79744f43ecaaf8ba42a8553a" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.513ex; height:2.509ex;" alt="{\displaystyle \psi }"></span></td> <td><i>psi</i> component of key </td></tr> <tr> <td><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \psi '}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msup> <mi>ψ</mi> <mo>′</mo> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \psi '}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/3e4792d3361b67c2f3eb7a3394932d28a6ef2e7b" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.198ex; height:2.843ex;" alt="{\displaystyle \psi '}"></span></td> <td>extended <i>psi</i> – the actual sequence of characters added by <br /> the <i>psi</i> wheels, including those when they do not advance <sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11B_The_Tunny_Cipher_Machine,_(e)_Psi-key,_p._7_26-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11B_The_Tunny_Cipher_Machine,_(e)_Psi-key,_p._7-26"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle Z}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>Z</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle Z}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/1cc6b75e09a8aa3f04d8584b11db534f88fb56bd" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.68ex; height:2.176ex;" alt="{\displaystyle Z}"></span></td> <td>ciphertext </td></tr> <tr> <td><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle D}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>D</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle D}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/f34a0c600395e5d4345287e21fb26efd386990e6" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.924ex; height:2.176ex;" alt="{\displaystyle D}"></span></td> <td>de-<i>chi</i>—the ciphertext with the <i>chi</i> component of the key removed<sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_12_Cryptographic_Aspects,_12A_The_Problem,_(a)_Formulae_and_Notation,_p._16_25-1" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_12_Cryptographic_Aspects,_12A_The_Problem,_(a)_Formulae_and_Notation,_p._16-25"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \Delta }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi mathvariant="normal">Δ</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \Delta }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/32769037c408874e1890f77554c65f39c523ebe2" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.936ex; height:2.176ex;" alt="{\displaystyle \Delta }"></span></td> <td>any of the above XOR'ed with its successor character or bit<sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11C_Wheel_Patterns,_(b)_Differenced_and_Undifferenced_Wheels,_p._11_20-1" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11C_Wheel_Patterns,_(b)_Differenced_and_Undifferenced_Wheels,_p._11-20"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \oplus }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo>⊕</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \oplus }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/8b16e2bdaefee9eed86d866e6eba3ac47c710f60" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.505ex; width:1.808ex; height:2.176ex;" alt="{\displaystyle \oplus }"></span></td> <td>the XOR operation<sup id="cite_ref-27" class="reference"><a href="#cite_note-27"><span class="cite-bracket">[</span>c<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11B_The_Tunny_Cipher_Machine,_(a)_Addition,_p._5_28-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11B_The_Tunny_Cipher_Machine,_(a)_Addition,_p._5-28"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \bullet }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo>∙</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \bullet }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/3576c2406959ee194a6fc55c34b5ee9f6ffbb715" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: 0.125ex; margin-bottom: -0.297ex; width:1.162ex; height:1.509ex;" alt="{\displaystyle \bullet }"></span></td> <td>Bletchley Park shorthand for telegraphy code <i>space</i> (zero) </td></tr> <tr> <td><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \mathbf {x} }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="bold">x</mi> </mrow> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \mathbf {x} }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/32adf004df5eb0a8c7fd8c0b6b7405183c5a5ef2" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.411ex; height:1.676ex;" alt="{\displaystyle \mathbf {x} }"></span></td> <td>Bletchley Park shorthand for telegraphy code <i>mark</i> (one) </td></tr> </tbody></table> <p>By using differencing and knowing that the <i>psi</i> wheels did not advance with each character, Tutte worked out that trying just two differenced bits (impulses) of the <i>chi</i>-stream against the differenced ciphertext would produce a statistic that was non-random. This became known as <a href="/wiki/Cryptanalysis_of_the_Lorenz_cipher#The_"1+2_break_in"" title="Cryptanalysis of the Lorenz cipher">Tutte's "1+2 break in"</a>.<sup id="cite_ref-FOOTNOTEBudiansky200658–59_29-0" class="reference"><a href="#cite_note-FOOTNOTEBudiansky200658–59-29"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> It involved calculating the following Boolean function: </p> <dl><dd><dl><dd><dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \Delta Z_{1}\oplus \Delta Z_{2}\oplus \Delta \chi _{1}\oplus \Delta \chi _{2}=\bullet }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi mathvariant="normal">Δ</mi> <msub> <mi>Z</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo>⊕</mo> <mi mathvariant="normal">Δ</mi> <msub> <mi>Z</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mo>⊕</mo> <mi mathvariant="normal">Δ</mi> <msub> <mi>χ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo>⊕</mo> <mi mathvariant="normal">Δ</mi> <msub> <mi>χ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mo>∙</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \Delta Z_{1}\oplus \Delta Z_{2}\oplus \Delta \chi _{1}\oplus \Delta \chi _{2}=\bullet }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/078a4ac96da29678a71dc48d3359db3d795e3a1a" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:30.828ex; height:2.509ex;" alt="{\displaystyle \Delta Z_{1}\oplus \Delta Z_{2}\oplus \Delta \chi _{1}\oplus \Delta \chi _{2}=\bullet }"></span></dd></dl></dd></dl></dd></dl> <p>and counting the number of times it yielded "false" (zero). If this number exceeded a pre-defined threshold value known as the "set total", it was printed out. The cryptanalyst would examine the printout to determine which of the putative start positions was most likely to be the correct one for the <i>chi</i>-1 and <i>chi</i>-2 wheels.<sup id="cite_ref-FOOTNOTECarter200818–19_30-0" class="reference"><a href="#cite_note-FOOTNOTECarter200818–19-30"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> </p><p>This technique would then be applied to other pairs of, or single, impulses to determine the likely start position of all five <i>chi</i> wheels. From this, the de-<i>chi</i> (D) of a ciphertext could be obtained, from which the <i>psi</i> component could be removed by manual methods.<sup id="cite_ref-FOOTNOTESmall194465_31-0" class="reference"><a href="#cite_note-FOOTNOTESmall194465-31"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup> If the frequency distribution of characters in the de-<i>chi</i> version of the ciphertext was within certain bounds, "wheel setting" of the <i>chi</i> wheels was considered to have been achieved,<sup id="cite_ref-FOOTNOTESmall194415_24-1" class="reference"><a href="#cite_note-FOOTNOTESmall194415-24"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> and the message settings and de-<i>chi</i> were passed to the "<a href="/wiki/Testery" title="Testery">Testery</a>". This was the section at Bletchley Park led by Major <a href="/wiki/Ralph_Tester" title="Ralph Tester">Ralph Tester</a> where the bulk of the decrypting work was done by manual and linguistic methods.<sup id="cite_ref-32" class="reference"><a href="#cite_note-32"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> </p><p>Colossus could also derive the start position of the <i>psi</i> and motor wheels. The feasibility of utilizing this additional capability regularly was made possible in the last few months of the war when there were plenty of Colossi available and the number of Tunny messages had declined.<sup id="cite_ref-FOOTNOTECopeland200677_33-0" class="reference"><a href="#cite_note-FOOTNOTECopeland200677-33"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Design_and_construction">Design and construction</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=3" title="Edit section: Design and construction"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:GB-ENG_-_Bletchley_-_Computers_-_Buckinghamshire_-_Milton_Keynes_-_Bletchly_-_Bletchley_Park_(4890148011).jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/cb/GB-ENG_-_Bletchley_-_Computers_-_Buckinghamshire_-_Milton_Keynes_-_Bletchly_-_Bletchley_Park_%284890148011%29.jpg/220px-GB-ENG_-_Bletchley_-_Computers_-_Buckinghamshire_-_Milton_Keynes_-_Bletchly_-_Bletchley_Park_%284890148011%29.jpg" decoding="async" width="220" height="176" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/cb/GB-ENG_-_Bletchley_-_Computers_-_Buckinghamshire_-_Milton_Keynes_-_Bletchly_-_Bletchley_Park_%284890148011%29.jpg/330px-GB-ENG_-_Bletchley_-_Computers_-_Buckinghamshire_-_Milton_Keynes_-_Bletchly_-_Bletchley_Park_%284890148011%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/cb/GB-ENG_-_Bletchley_-_Computers_-_Buckinghamshire_-_Milton_Keynes_-_Bletchly_-_Bletchley_Park_%284890148011%29.jpg/440px-GB-ENG_-_Bletchley_-_Computers_-_Buckinghamshire_-_Milton_Keynes_-_Bletchly_-_Bletchley_Park_%284890148011%29.jpg 2x" data-file-width="2545" data-file-height="2032" /></a><figcaption>Valves (vacuum tubes) seen on end in a recreation of the Colossus computer</figcaption></figure> <p>Colossus was developed for the "<a href="/wiki/Newmanry" title="Newmanry">Newmanry</a>",<sup id="cite_ref-FOOTNOTEGoodMichieTimms19453_Organisation:_31_Mr_Newman's_section,_p._276_34-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19453_Organisation:_31_Mr_Newman's_section,_p._276-34"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup> the section headed by the mathematician <a href="/wiki/Max_Newman" title="Max Newman">Max Newman</a> that was responsible for machine methods against the twelve-rotor <a href="/wiki/Lorenz_cipher" title="Lorenz cipher">Lorenz SZ40/42 on-line teleprinter cipher machine</a> (code-named Tunny, for tunafish). The Colossus design arose out of a parallel project that produced a less-ambitious counting machine dubbed "<a href="/wiki/Heath_Robinson_(codebreaking_machine)" title="Heath Robinson (codebreaking machine)">Heath Robinson</a>".<sup id="cite_ref-FOOTNOTEGCHQ2024_11-1" class="reference"><a href="#cite_note-FOOTNOTEGCHQ2024-11"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> Although the Heath Robinson machine proved the concept of machine analysis for this part of the process, it had serious limitations. The electro-mechanical parts were relatively slow and it was difficult to synchronise two looped <a href="/wiki/Punched_tape" title="Punched tape">paper tapes</a>, one containing the enciphered message, and the other representing part of the keystream of the Lorenz machine.<sup id="cite_ref-FOOTNOTEAnderson20078_35-0" class="reference"><a href="#cite_note-FOOTNOTEAnderson20078-35"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> Also the tapes tended to stretch and break when being read at up to 2000 characters per second. </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:COLOSSUS,_part_of_the_machine,_presented_by_Director_GCHQ_to_Director_NSA_in_1986_-_National_Cryptologic_Museum_-_DSC07890.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4e/COLOSSUS%2C_part_of_the_machine%2C_presented_by_Director_GCHQ_to_Director_NSA_in_1986_-_National_Cryptologic_Museum_-_DSC07890.JPG/220px-COLOSSUS%2C_part_of_the_machine%2C_presented_by_Director_GCHQ_to_Director_NSA_in_1986_-_National_Cryptologic_Museum_-_DSC07890.JPG" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4e/COLOSSUS%2C_part_of_the_machine%2C_presented_by_Director_GCHQ_to_Director_NSA_in_1986_-_National_Cryptologic_Museum_-_DSC07890.JPG/330px-COLOSSUS%2C_part_of_the_machine%2C_presented_by_Director_GCHQ_to_Director_NSA_in_1986_-_National_Cryptologic_Museum_-_DSC07890.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4e/COLOSSUS%2C_part_of_the_machine%2C_presented_by_Director_GCHQ_to_Director_NSA_in_1986_-_National_Cryptologic_Museum_-_DSC07890.JPG/440px-COLOSSUS%2C_part_of_the_machine%2C_presented_by_Director_GCHQ_to_Director_NSA_in_1986_-_National_Cryptologic_Museum_-_DSC07890.JPG 2x" data-file-width="4320" data-file-height="3240" /></a><figcaption><a href="/wiki/Stepping_switch" title="Stepping switch">Stepping switch</a> said to be from an original Colossus, presented by the Director of <a href="/wiki/Government_Communications_Headquarters" class="mw-redirect" title="Government Communications Headquarters">GCHQ</a> to the Director of the <a href="/wiki/National_Security_Agency" title="National Security Agency">NSA</a> to mark the 40th anniversary of the <a href="/wiki/UKUSA_Agreement" title="UKUSA Agreement">UKUSA Agreement</a> in 1986<sup id="cite_ref-36" class="reference"><a href="#cite_note-36"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup></figcaption></figure> <p><a href="/wiki/Tommy_Flowers" title="Tommy Flowers">Tommy Flowers</a> <a href="/wiki/Order_of_the_British_Empire" title="Order of the British Empire">MBE</a><sup id="cite_ref-37" class="reference"><a href="#cite_note-37"><span class="cite-bracket">[</span>d<span class="cite-bracket">]</span></a></sup> was a senior electrical engineer and Head of the Switching Group at the <a href="/wiki/Post_Office_Research_Station" title="Post Office Research Station">Post Office Research Station</a> at <a href="/wiki/Dollis_Hill" title="Dollis Hill">Dollis Hill</a>. Prior to his work on Colossus, he had been involved with GC&CS at Bletchley Park from February 1941 in an attempt to improve the <a href="/wiki/Bombe" title="Bombe">Bombes</a> that were used in the cryptanalysis of the German Enigma cipher machine.<sup id="cite_ref-FOOTNOTERandell19809_38-0" class="reference"><a href="#cite_note-FOOTNOTERandell19809-38"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup> He was recommended to Max Newman by Alan Turing, who had been impressed by his work on the Bombes.<sup id="cite_ref-FOOTNOTEBudiansky2000314_39-0" class="reference"><a href="#cite_note-FOOTNOTEBudiansky2000314-39"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup> The main components of the Heath Robinson machine were as follows. </p> <ul><li>A tape transport and reading mechanism that ran the looped key and message tapes at between 1000 and 2000 characters per second.</li> <li>A combining unit that implemented the logic of <a href="/wiki/Cryptanalysis_of_the_Lorenz_cipher#Tutte's_"1+2_break_in"" title="Cryptanalysis of the Lorenz cipher">Tutte's method</a>.</li> <li>A counting unit that had been designed by <a href="/wiki/C._E._Wynn-Williams" title="C. E. Wynn-Williams">C. E. Wynn-Williams</a> of the <a href="/wiki/Telecommunications_Research_Establishment" title="Telecommunications Research Establishment">Telecommunications Research Establishment</a> (TRE) at Malvern, which counted the number of times the logical function returned a specified <a href="/wiki/Truth_value" title="Truth value">truth value</a>.</li></ul> <p>Flowers had been brought in to design the Heath Robinson's combining unit.<sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_15_Some_Historical_Notes,_15A_First_Stages_in_Machine_Development,_(c)_Heath_Robinson,_p._33_40-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_15_Some_Historical_Notes,_15A_First_Stages_in_Machine_Development,_(c)_Heath_Robinson,_p._33-40"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> He was not impressed by the system of a key tape that had to be kept synchronised with the message tape and, on his own initiative, he designed an electronic machine which eliminated the need for the key tape by having an electronic analogue of the Lorenz (Tunny) machine.<sup id="cite_ref-FOOTNOTEFlowers200696_41-0" class="reference"><a href="#cite_note-FOOTNOTEFlowers200696-41"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup> He presented this design to Max Newman in February 1943, but the idea that the one to two thousand thermionic valves (<a href="/wiki/Vacuum_tube" title="Vacuum tube">vacuum tubes</a> and <a href="/wiki/Thyratron" title="Thyratron">thyratrons</a>) proposed, could work together reliably, was greeted with great scepticism,<sup id="cite_ref-FOOTNOTEFlowers1983244_42-0" class="reference"><a href="#cite_note-FOOTNOTEFlowers1983244-42"><span class="cite-bracket">[</span>38<span class="cite-bracket">]</span></a></sup> so more Robinsons were ordered from Dollis Hill. Flowers, however, knew from his pre-war work that most thermionic valve failures occurred as a result of the thermal stresses at power-up, so not powering a machine down reduced failure rates to very low levels.<sup id="cite_ref-FOOTNOTECopeland_"Machine_against_Machine"200672_43-0" class="reference"><a href="#cite_note-FOOTNOTECopeland_"Machine_against_Machine"200672-43"><span class="cite-bracket">[</span>39<span class="cite-bracket">]</span></a></sup> Additionally, if the heaters were started at a low voltage then slowly brought up to full voltage, thermal stress was reduced. The valves themselves could be soldered-in to avoid problems with plug-in bases, which could be unreliable.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="There is no mention of these newly added points in Copeland (2006) (January 2018)">citation needed</span></a></i>]</sup> Flowers persisted with the idea and obtained support from the Director of the Research Station, W Gordon Radley.<sup id="cite_ref-FOOTNOTECopeland_"Machine_against_Machine"200674_44-0" class="reference"><a href="#cite_note-FOOTNOTECopeland_"Machine_against_Machine"200674-44"><span class="cite-bracket">[</span>40<span class="cite-bracket">]</span></a></sup> </p><p>Flowers and his team of some fifty people in the switching group<sup id="cite_ref-FOOTNOTEFlowers200680_45-0" class="reference"><a href="#cite_note-FOOTNOTEFlowers200680-45"><span class="cite-bracket">[</span>41<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-FOOTNOTERandell2006143_46-0" class="reference"><a href="#cite_note-FOOTNOTERandell2006143-46"><span class="cite-bracket">[</span>42<span class="cite-bracket">]</span></a></sup> spent eleven months from early February 1943 designing and building a machine that dispensed with the second tape of the Heath Robinson, by generating the wheel patterns electronically. Flowers used some of his own money for the project.<sup id="cite_ref-47" class="reference"><a href="#cite_note-47"><span class="cite-bracket">[</span>43<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-48" class="reference"><a href="#cite_note-48"><span class="cite-bracket">[</span>44<span class="cite-bracket">]</span></a></sup> This prototype, Mark 1 Colossus, contained 1,600 thermionic valves (tubes).<sup id="cite_ref-FOOTNOTEFlowers200680_45-1" class="reference"><a href="#cite_note-FOOTNOTEFlowers200680-45"><span class="cite-bracket">[</span>41<span class="cite-bracket">]</span></a></sup> It performed satisfactorily at Dollis Hill on 8 December 1943<sup id="cite_ref-FOOTNOTECopeland2010_49-0" class="reference"><a href="#cite_note-FOOTNOTECopeland2010-49"><span class="cite-bracket">[</span>45<span class="cite-bracket">]</span></a></sup> and was dismantled and shipped to Bletchley Park, where it was delivered on 18 January and re-assembled by <a href="/wiki/Harry_Fensom" title="Harry Fensom">Harry Fensom</a> and Don Horwood.<sup id="cite_ref-The_Colossus_Computer_14-1" class="reference"><a href="#cite_note-The_Colossus_Computer-14"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-50" class="reference"><a href="#cite_note-50"><span class="cite-bracket">[</span>46<span class="cite-bracket">]</span></a></sup> It was operational in January<sup id="cite_ref-51" class="reference"><a href="#cite_note-51"><span class="cite-bracket">[</span>47<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-lorenz_10-1" class="reference"><a href="#cite_note-lorenz-10"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> and it successfully attacked its first message on 5 February 1944.<sup id="cite_ref-FOOTNOTECopeland_"Machine_against_Machine"200675_52-0" class="reference"><a href="#cite_note-FOOTNOTECopeland_"Machine_against_Machine"200675-52"><span class="cite-bracket">[</span>48<span class="cite-bracket">]</span></a></sup> It was a large structure and was dubbed 'Colossus'. A memo held in the National Archives written by Max Newman on 18 January 1944 records that "Colossus arrives today".<sup id="cite_ref-FOOTNOTEGannon2007283_53-0" class="reference"><a href="#cite_note-FOOTNOTEGannon2007283-53"><span class="cite-bracket">[</span>49<span class="cite-bracket">]</span></a></sup> </p><p>During the development of the prototype, an improved design had been developed – the Mark 2 Colossus. Four of these were ordered in March 1944 and by the end of April the number on order had been increased to twelve. Dollis Hill was put under pressure to have the first of these working by 1 June.<sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_15_–_Some_Historical_Notes,_15C_Period_of_Expansion,_(b)_Colossus,_p._35_54-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_15_–_Some_Historical_Notes,_15C_Period_of_Expansion,_(b)_Colossus,_p._35-54"><span class="cite-bracket">[</span>50<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Allen_Coombs" title="Allen Coombs">Allen Coombs</a> took over leadership of the production Mark 2 Colossi, the first of which – containing 2,400 valves – became operational at 08:00 on 1 June 1944, just in time for the Allied <a href="/wiki/Invasion_of_Normandy" class="mw-redirect" title="Invasion of Normandy">Invasion of Normandy</a> on <a href="/wiki/Normandy_landings" title="Normandy landings">D-Day</a>.<sup id="cite_ref-55" class="reference"><a href="#cite_note-55"><span class="cite-bracket">[</span>51<span class="cite-bracket">]</span></a></sup> Subsequently, Colossi were delivered at the rate of about one a month. By the time of <a href="/wiki/Victory_in_Europe_Day" title="Victory in Europe Day">V-E Day</a> there were ten Colossi working at Bletchley Park and a start had been made on assembling an eleventh.<sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_15_–_Some_Historical_Notes,_15C_Period_of_Expansion,_(b)_Colossus,_p._35_54-1" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_15_–_Some_Historical_Notes,_15C_Period_of_Expansion,_(b)_Colossus,_p._35-54"><span class="cite-bracket">[</span>50<span class="cite-bracket">]</span></a></sup> Seven of the Colossi were used for 'wheel setting' and three for 'wheel breaking'.<sup id="cite_ref-FOOTNOTEKenyon201960_56-0" class="reference"><a href="#cite_note-FOOTNOTEKenyon201960-56"><span class="cite-bracket">[</span>52<span class="cite-bracket">]</span></a></sup> </p> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Wartime_photo_of_Colossus_10.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/0/08/Wartime_photo_of_Colossus_10.png/300px-Wartime_photo_of_Colossus_10.png" decoding="async" width="300" height="210" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/08/Wartime_photo_of_Colossus_10.png/450px-Wartime_photo_of_Colossus_10.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/08/Wartime_photo_of_Colossus_10.png/600px-Wartime_photo_of_Colossus_10.png 2x" data-file-width="1233" data-file-height="865" /></a><figcaption>Colossus 10 with its extended bedstead in Block H at <a href="/wiki/Bletchley_Park" title="Bletchley Park">Bletchley Park</a> in the space now containing the Tunny gallery of <a href="/wiki/The_National_Museum_of_Computing" title="The National Museum of Computing">The National Museum of Computing</a> </figcaption></figure> <p>The main units of the Mark 2 design were as follows.<sup id="cite_ref-FOOTNOTEFlowers200696_41-1" class="reference"><a href="#cite_note-FOOTNOTEFlowers200696-41"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-FOOTNOTEFlowers1983249–252_57-0" class="reference"><a href="#cite_note-FOOTNOTEFlowers1983249–252-57"><span class="cite-bracket">[</span>53<span class="cite-bracket">]</span></a></sup> </p> <ul><li>A tape transport with an 8-photocell reading mechanism.</li> <li>A six character <a href="/wiki/FIFO_(computing_and_electronics)" title="FIFO (computing and electronics)">FIFO</a> <a href="/wiki/Shift_register" title="Shift register">shift register</a>.</li> <li>Twelve thyratron ring stores that simulated the Lorenz machine generating a bit-stream for each wheel.</li> <li>Panels of switches for specifying the program and the "set total".</li> <li>A set of functional units that performed <a href="/wiki/Boolean_algebra" title="Boolean algebra">Boolean</a> operations.</li> <li>A "span counter" that could suspend counting for part of the tape.</li> <li>A master control that handled clocking, start and stop signals, counter readout and printing.</li> <li>Five electronic counters.</li> <li>An electric typewriter.</li></ul> <p>Most of the design of the electronics was the work of Tommy Flowers, assisted by William Chandler, Sidney Broadhurst and Allen Coombs; with Erie Speight and <a href="/wiki/Arnold_Lynch" title="Arnold Lynch">Arnold Lynch</a> developing the photoelectric reading mechanism.<sup id="cite_ref-FOOTNOTEFlowers1983243,_245_58-0" class="reference"><a href="#cite_note-FOOTNOTEFlowers1983243,_245-58"><span class="cite-bracket">[</span>54<span class="cite-bracket">]</span></a></sup> Coombs remembered Flowers, having produced a rough draft of his design, tearing it into pieces that he handed out to his colleagues for them to do the detailed design and get their team to manufacture it.<sup id="cite_ref-FOOTNOTECoombs1983_59-0" class="reference"><a href="#cite_note-FOOTNOTECoombs1983-59"><span class="cite-bracket">[</span>55<span class="cite-bracket">]</span></a></sup> The Mark 2 Colossi were both five times faster and were simpler to operate than the prototype.<sup id="cite_ref-61" class="reference"><a href="#cite_note-61"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup> </p><p>Data input to Colossus was by <a href="/wiki/Photoelectric_sensor" title="Photoelectric sensor">photoelectric</a> reading of a paper tape transcription of the enciphered intercepted message. This was arranged in a continuous loop so that it could be read and re-read multiple times – there being no internal storage for the data. The design overcame the problem of synchronizing the electronics with the speed of the message tape by generating a <a href="/wiki/Clock_signal" title="Clock signal">clock signal</a> from reading its sprocket holes. The speed of operation was thus limited by the mechanics of reading the tape. During development, the tape reader was tested up to 9700 characters per second (53 mph) before the tape disintegrated. So 5000 characters/second (40 ft/s (12.2 m/s; 27.3 mph)) was settled on as the speed for regular use. Flowers designed a 6-character shift register, which was used both for computing the delta function (ΔZ) and for testing five different possible starting points of Tunny's wheels in the five processors.<sup id="cite_ref-FOOTNOTEFlowers1983_62-0" class="reference"><a href="#cite_note-FOOTNOTEFlowers1983-62"><span class="cite-bracket">[</span>57<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-FOOTNOTEFlowers2006100_63-0" class="reference"><a href="#cite_note-FOOTNOTEFlowers2006100-63"><span class="cite-bracket">[</span>58<span class="cite-bracket">]</span></a></sup> This five-way parallelism<sup id="cite_ref-64" class="reference"><a href="#cite_note-64"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> enabled five simultaneous tests and counts to be performed giving an effective processing speed of 25,000 characters per second.<sup id="cite_ref-FOOTNOTEFlowers2006100_63-1" class="reference"><a href="#cite_note-FOOTNOTEFlowers2006100-63"><span class="cite-bracket">[</span>58<span class="cite-bracket">]</span></a></sup> The computation used algorithms devised by <a href="/wiki/W._T._Tutte" title="W. T. Tutte">W. T. Tutte</a> and colleagues to decrypt a Tunny message.<sup id="cite_ref-FOOTNOTECopeland2011_65-0" class="reference"><a href="#cite_note-FOOTNOTECopeland2011-65"><span class="cite-bracket">[</span>59<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-66" class="reference"><a href="#cite_note-66"><span class="cite-bracket">[</span>60<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Operation">Operation</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=4" title="Edit section: Operation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Colossus_computer_selection_panel.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/c2/Colossus_computer_selection_panel.png/300px-Colossus_computer_selection_panel.png" decoding="async" width="300" height="310" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/c2/Colossus_computer_selection_panel.png/450px-Colossus_computer_selection_panel.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/c2/Colossus_computer_selection_panel.png/600px-Colossus_computer_selection_panel.png 2x" data-file-width="923" data-file-height="953" /></a><figcaption>Colossus selection panel showing selections amongst others, of the far tape on the bedstead, and for input to the algorithm: Δ<b>Z</b>, Δ<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \chi }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>χ</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \chi }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/656111758322ace96d80a9371771aa6d3de25437" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.455ex; height:2.009ex;" alt="{\displaystyle \chi }"></span> and Δ<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \psi }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>ψ</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \psi }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/45e5789e5d9c8f7c79744f43ecaaf8ba42a8553a" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.513ex; height:2.509ex;" alt="{\displaystyle \psi }"></span>.</figcaption></figure> <p>The Newmanry was staffed by cryptanalysts, operators from the <a href="/wiki/Women%27s_Royal_Naval_Service" title="Women's Royal Naval Service">Women's Royal Naval Service (WRNS)</a> – known as "Wrens" – and engineers who were permanently on hand for maintenance and repair. By the end of the war the staffing was 272 Wrens and 27 men.<sup id="cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_15_–_Some_Historical_Notes,_15C_Period_of_Expansion,_(b)_Colossus,_p._35_54-2" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_15_–_Some_Historical_Notes,_15C_Period_of_Expansion,_(b)_Colossus,_p._35-54"><span class="cite-bracket">[</span>50<span class="cite-bracket">]</span></a></sup> </p><p>The first job in operating Colossus for a new message was to prepare the paper tape loop. This was performed by the Wrens who stuck the two ends together using <a href="/wiki/Bostik" title="Bostik">Bostik</a> glue, ensuring that there was a 150-character length of blank tape between the end and the start of the message.<sup id="cite_ref-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus_53A_Introduction,_p.333_67-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus_53A_Introduction,_p.333-67"><span class="cite-bracket">[</span>61<span class="cite-bracket">]</span></a></sup> Using a special hand punch they inserted a start hole between the third and fourth channels <style data-mw-deduplicate="TemplateStyles:r1154941027">.mw-parser-output .frac{white-space:nowrap}.mw-parser-output .frac .num,.mw-parser-output .frac .den{font-size:80%;line-height:0;vertical-align:super}.mw-parser-output .frac .den{vertical-align:sub}.mw-parser-output .sr-only{border:0;clip:rect(0,0,0,0);clip-path:polygon(0px 0px,0px 0px,0px 0px);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}</style><span class="frac">2<span class="sr-only">+</span><span class="num">1</span>⁄<span class="den">2</span></span> sprocket holes from the end of the blank section, and a stop hole between the fourth and fifth channels <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1154941027"><span class="frac">1<span class="sr-only">+</span><span class="num">1</span>⁄<span class="den">2</span></span> sprocket holes from the end of the characters of the message.<sup id="cite_ref-FOOTNOTEFlowers1983241,_242_68-0" class="reference"><a href="#cite_note-FOOTNOTEFlowers1983241,_242-68"><span class="cite-bracket">[</span>62<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus_53B_The_Z_stream,_p.333_69-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus_53B_The_Z_stream,_p.333-69"><span class="cite-bracket">[</span>63<span class="cite-bracket">]</span></a></sup> These were read by specially positioned photocells and indicated when the message was about to start and when it ended. The operator would then thread the paper tape through the gate and around the pulleys of the bedstead and adjust the tension. The two-tape bedstead design had been carried on from Heath Robinson so that one tape could be loaded whilst the previous one was being run. A switch on the Selection Panel specified the "near" or the "far" tape.<sup id="cite_ref-FOOTNOTEFensom2006303_70-0" class="reference"><a href="#cite_note-FOOTNOTEFensom2006303-70"><span class="cite-bracket">[</span>64<span class="cite-bracket">]</span></a></sup> </p><p>After performing various resetting and zeroizing tasks, the Wren operators would, under instruction from the cryptanalyst, operate the "set total" decade switches and the K2 panel switches to set the desired algorithm. They would then start the bedstead tape motor and lamp and, when the tape was up to speed, operate the master start switch.<sup id="cite_ref-FOOTNOTEFensom2006303_70-1" class="reference"><a href="#cite_note-FOOTNOTEFensom2006303-70"><span class="cite-bracket">[</span>64<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Programming">Programming</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=5" title="Edit section: Programming"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Colossus_computer_Q_panel.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/7/74/Colossus_computer_Q_panel.png/300px-Colossus_computer_Q_panel.png" decoding="async" width="300" height="445" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/74/Colossus_computer_Q_panel.png/450px-Colossus_computer_Q_panel.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/74/Colossus_computer_Q_panel.png/600px-Colossus_computer_Q_panel.png 2x" data-file-width="828" data-file-height="1229" /></a><figcaption>Colossus K2 switch panel showing switches for specifying the algorithm (on the left) and the counters to be selected (on the right)</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Picture111Shopped.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/c6/Picture111Shopped.jpg/300px-Picture111Shopped.jpg" decoding="async" width="300" height="158" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/c6/Picture111Shopped.jpg/450px-Picture111Shopped.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/c6/Picture111Shopped.jpg/600px-Picture111Shopped.jpg 2x" data-file-width="1297" data-file-height="683" /></a><figcaption>Colossus 'set total' switch panel</figcaption></figure><p> Howard Campaigne, a mathematician and cryptanalyst from the US Navy's <a href="/wiki/OP-20-G" title="OP-20-G">OP-20-G</a>, wrote the following in a foreword to Flowers' 1983 paper "The Design of Colossus".<style data-mw-deduplicate="TemplateStyles:r1244412712">.mw-parser-output .templatequote{overflow:hidden;margin:1em 0;padding:0 32px}.mw-parser-output .templatequotecite{line-height:1.5em;text-align:left;margin-top:0}@media(min-width:500px){.mw-parser-output .templatequotecite{padding-left:1.6em}}</style></p><blockquote class="templatequote"><p>My view of Colossus was that of cryptanalyst-programmer. I told the machine to make certain calculations and counts, and after studying the results, told it to do another job. It did not remember the previous result, nor could it have acted upon it if it did. Colossus and I alternated in an interaction that sometimes achieved an analysis of an unusual German cipher system, called "Geheimschreiber" by the Germans, and "Fish" by the cryptanalysts.<sup id="cite_ref-FOOTNOTEFlowers1983239–252_71-0" class="reference"><a href="#cite_note-FOOTNOTEFlowers1983239–252-71"><span class="cite-bracket">[</span>65<span class="cite-bracket">]</span></a></sup> </p></blockquote> <p>Colossus was not a <a href="/wiki/Stored-program_computer" title="Stored-program computer">stored-program computer</a>. The input data for the five parallel processors was read from the looped message paper tape and the electronic pattern generators for the <i>chi</i>, <i>psi</i> and motor wheels.<sup id="cite_ref-FOOTNOTESmall1944108_72-0" class="reference"><a href="#cite_note-FOOTNOTESmall1944108-72"><span class="cite-bracket">[</span>66<span class="cite-bracket">]</span></a></sup> The programs for the processors were set and held on the switches and jack panel connections. Each processor could evaluate a Boolean function and count and display the number of times it yielded the specified value of "false" (0) or "true" (1) for each pass of the message tape. </p><p>Input to the processors came from two sources, the shift registers from tape reading and the thyratron rings that emulated the wheels of the Tunny machine.<sup id="cite_ref-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus,_pp._333–353_73-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus,_pp._333–353-73"><span class="cite-bracket">[</span>67<span class="cite-bracket">]</span></a></sup> The characters on the paper tape were called <b>Z</b> and the characters from the Tunny emulator were referred to by the Greek letters that Bill Tutte had given them when working out the logical structure of the machine. On the selection panel, switches specified either <b>Z</b> or <b>ΔZ</b>, either <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \chi }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>χ</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \chi }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/656111758322ace96d80a9371771aa6d3de25437" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.455ex; height:2.009ex;" alt="{\displaystyle \chi }"></span> or <b>Δ</b><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \chi }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>χ</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \chi }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/656111758322ace96d80a9371771aa6d3de25437" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.455ex; height:2.009ex;" alt="{\displaystyle \chi }"></span> and either <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \psi }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>ψ</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \psi }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/45e5789e5d9c8f7c79744f43ecaaf8ba42a8553a" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.513ex; height:2.509ex;" alt="{\displaystyle \psi }"></span> or <b>Δ</b><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \psi }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>ψ</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \psi }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/45e5789e5d9c8f7c79744f43ecaaf8ba42a8553a" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.513ex; height:2.509ex;" alt="{\displaystyle \psi }"></span> for the data to be passed to the jack field and 'K2 switch panel'. These signals from the wheel simulators could be specified as stepping on with each new pass of the message tape or not. </p><p>The K2 switch panel had a group of switches on the left-hand side to specify the algorithm. The switches on the right-hand side selected the counter to which the result was fed. The plugboard allowed less specialized conditions to be imposed. Overall the K2 switch panel switches and the plugboard allowed about five billion different combinations of the selected variables.<sup id="cite_ref-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus_53A_Introduction,_p.333_67-1" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus_53A_Introduction,_p.333-67"><span class="cite-bracket">[</span>61<span class="cite-bracket">]</span></a></sup> </p><p>As an example: a set of runs for a message tape might initially involve two <i>chi</i> wheels, as in Tutte's 1+2 algorithm. Such a two-wheel run was called a long run, taking on average eight minutes unless the parallelism was utilised to cut the time by a factor of five. The subsequent runs might only involve setting one <i>chi</i> wheel, giving a short run taking about two minutes. Initially, after the initial long run, the choice of the next algorithm to be tried was specified by the cryptanalyst. Experience showed, however, that decision trees for this iterative process could be produced for use by the Wren operators in a proportion of cases.<sup id="cite_ref-FOOTNOTEBudiansky200662_74-0" class="reference"><a href="#cite_note-FOOTNOTEBudiansky200662-74"><span class="cite-bracket">[</span>68<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Influence_and_fate">Influence and fate</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=6" title="Edit section: Influence and fate"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Although the Colossus was the first of the electronic digital machines with programmability, albeit limited by modern standards,<sup id="cite_ref-75" class="reference"><a href="#cite_note-75"><span class="cite-bracket">[</span>69<span class="cite-bracket">]</span></a></sup> it was not a general-purpose machine, being designed for a range of cryptanalytic tasks, most involving counting the results of evaluating Boolean algorithms. </p><p>A Colossus computer was thus not a fully <a href="/wiki/Turing_complete" class="mw-redirect" title="Turing complete">Turing complete</a> machine. However, <a href="/wiki/University_of_San_Francisco" title="University of San Francisco">University of San Francisco</a> professor Benjamin Wells has shown that if all ten Colossus machines made were rearranged in a specific <a href="/wiki/Computer_cluster" title="Computer cluster">cluster</a>, then the entire set of computers could have simulated a <a href="/wiki/Universal_Turing_machine" title="Universal Turing machine">universal Turing machine</a>, and thus be Turing complete.<sup id="cite_ref-76" class="reference"><a href="#cite_note-76"><span class="cite-bracket">[</span>70<span class="cite-bracket">]</span></a></sup> </p><p>Colossus and the reasons for its construction were highly secret and remained so for 30 years after the War. Consequently, it was not included in the <a href="/wiki/History_of_computing_hardware" title="History of computing hardware">history of computing hardware</a> for many years, and Flowers and his associates were deprived of the recognition they were due. All but two of the Colossi were dismantled after the war and parts returned to the Post Office. Some parts, sanitised as to their original purpose, were taken to Max Newman's <a href="/wiki/Royal_Society" title="Royal Society">Royal Society</a> <a href="/wiki/Computing_Machine_Laboratory" title="Computing Machine Laboratory">Computing Machine Laboratory</a> at <a href="/wiki/Manchester_University" class="mw-redirect" title="Manchester University">Manchester University</a>.<sup id="cite_ref-77" class="reference"><a href="#cite_note-77"><span class="cite-bracket">[</span>71<span class="cite-bracket">]</span></a></sup> Two Colossi, along with two Tunny machines, were retained and moved to <a href="/wiki/Government_Communications_Headquarters" class="mw-redirect" title="Government Communications Headquarters">GCHQ</a>'s new headquarters at <a href="/wiki/Eastcote" title="Eastcote">Eastcote</a> in April 1946, and then to <a href="/wiki/Cheltenham" title="Cheltenham">Cheltenham</a> between 1952 and 1954.<sup id="cite_ref-FOOTNOTECopeland_et_al.2006173–175_78-0" class="reference"><a href="#cite_note-FOOTNOTECopeland_et_al.2006173–175-78"><span class="cite-bracket">[</span>72<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-FOOTNOTEGCHQ2024_11-2" class="reference"><a href="#cite_note-FOOTNOTEGCHQ2024-11"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> One of the Colossi, known as <i>Colossus Blue</i>, was dismantled in 1959; the other in the 1960s.<sup id="cite_ref-FOOTNOTECopeland_et_al.2006173–175_78-1" class="reference"><a href="#cite_note-FOOTNOTECopeland_et_al.2006173–175-78"><span class="cite-bracket">[</span>72<span class="cite-bracket">]</span></a></sup> Tommy Flowers was ordered to destroy all documentation. He duly burnt them in a furnace and later said of that order: </p> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1244412712"><blockquote class="templatequote"><p>That was a terrible mistake. I was instructed to destroy all the records, which I did. I took all the drawings and the plans and all the information about Colossus on paper and put it in the boiler fire. And saw it burn.<sup id="cite_ref-FOOTNOTEMcKay2010270–271_79-0" class="reference"><a href="#cite_note-FOOTNOTEMcKay2010270–271-79"><span class="cite-bracket">[</span>73<span class="cite-bracket">]</span></a></sup> </p></blockquote><p>The Colossi were adapted for other purposes, with varying degrees of success; in their later years they were used for training.<sup id="cite_ref-80" class="reference"><a href="#cite_note-80"><span class="cite-bracket">[</span>74<span class="cite-bracket">]</span></a></sup> <a href="/wiki/I._J._Good" title="I. J. Good">Jack Good</a> related how he was the first to use Colossus after the war, persuading the US <a href="/wiki/National_Security_Agency" title="National Security Agency">National Security Agency</a> that it could be used to perform a function for which they were planning to build a special-purpose machine.<sup id="cite_ref-FOOTNOTECopeland_et_al.2006173–175_78-2" class="reference"><a href="#cite_note-FOOTNOTECopeland_et_al.2006173–175-78"><span class="cite-bracket">[</span>72<span class="cite-bracket">]</span></a></sup> Colossus was also used to perform character counts on <a href="/wiki/One-time_pad" title="One-time pad">one-time pad</a> tape to test for non-randomness.<sup id="cite_ref-FOOTNOTECopeland_et_al.2006173–175_78-3" class="reference"><a href="#cite_note-FOOTNOTECopeland_et_al.2006173–175-78"><span class="cite-bracket">[</span>72<span class="cite-bracket">]</span></a></sup> </p><p>A small number of people who were associated with Colossus—and knew that large-scale, reliable, high-speed electronic digital computing devices were feasible—played significant roles in early computer work in the UK and probably in the US. However, being so secret, it had little direct influence on the development of later computers; it was <a href="/wiki/EDVAC" title="EDVAC">EDVAC</a> that was the seminal computer architecture of the time.<sup id="cite_ref-81" class="reference"><a href="#cite_note-81"><span class="cite-bracket">[</span>75<span class="cite-bracket">]</span></a></sup> In 1972, <a href="/wiki/Herman_Goldstine" title="Herman Goldstine">Herman Goldstine</a>, who was unaware of Colossus and its legacy to the projects of people such as Alan Turing (<a href="/wiki/ACE_(computer)" class="mw-redirect" title="ACE (computer)">ACE</a>), Max Newman (<a href="/wiki/Manchester_computers" title="Manchester computers">Manchester computers</a>) and <a href="/wiki/Harry_Huskey" title="Harry Huskey">Harry Huskey</a> (<a href="/wiki/Bendix_G-15" title="Bendix G-15">Bendix G-15</a>), wrote that, </p> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1244412712"><blockquote class="templatequote"><p>Britain had such vitality that it could immediately after the war embark on so many well-conceived and well-executed projects in the computer field.<sup id="cite_ref-FOOTNOTEGoldstine1980321_82-0" class="reference"><a href="#cite_note-FOOTNOTEGoldstine1980321-82"><span class="cite-bracket">[</span>76<span class="cite-bracket">]</span></a></sup> </p></blockquote> <p>Professor <a href="/wiki/Brian_Randell" title="Brian Randell">Brian Randell</a>, who unearthed information about Colossus in the 1970s, commented on this, saying that: </p> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1244412712"><blockquote class="templatequote"><p>It is my opinion that the COLOSSUS project was an important source of this vitality, one that has been largely unappreciated, as has the significance of its places in the chronology of the invention of the digital computer.<sup id="cite_ref-FOOTNOTERandell198087_83-0" class="reference"><a href="#cite_note-FOOTNOTERandell198087-83"><span class="cite-bracket">[</span>77<span class="cite-bracket">]</span></a></sup> </p></blockquote> <p>Randell's efforts started to bear fruit in the mid-1970s. The secrecy about Bletchley Park had been broken when <a href="/wiki/F._W._Winterbotham" title="F. W. Winterbotham">Group Captain Winterbotham</a> published his book <i>The Ultra Secret</i> in 1974.<sup id="cite_ref-84" class="reference"><a href="#cite_note-84"><span class="cite-bracket">[</span>78<span class="cite-bracket">]</span></a></sup> Randell was researching the history of computer science in Britain for a conference on the history of computing held at the Los Alamos Scientific Laboratory, New Mexico on 10–15 June 1976, and got permission to present a paper on wartime development of the COLOSSI at the <a href="/wiki/Post_Office_Research_Station" title="Post Office Research Station">Post Office Research Station</a>, Dollis Hill (in October 1975 the British Government had released a series of captioned photographs from the Public Record Office). The interest in the "revelations" in his paper resulted in a special evening meeting when Randell and Coombs answered further questions. Coombs later wrote that <i>no member of our team could ever forget the fellowship, the sense of purpose and, above all, the breathless excitement of those days</i>. In 1977 Randell published an article <i>The First Electronic Computer</i> in several journals. <sup id="cite_ref-85" class="reference"><a href="#cite_note-85"><span class="cite-bracket">[</span>g<span class="cite-bracket">]</span></a></sup> <sup id="cite_ref-86" class="reference"><a href="#cite_note-86"><span class="cite-bracket">[</span>79<span class="cite-bracket">]</span></a></sup> </p><p>In October 2000, a 500-page technical report on the Tunny cipher and its cryptanalysis—entitled <i>General Report on Tunny</i><sup id="cite_ref-FOOTNOTEGoodMichieTimms1945_87-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms1945-87"><span class="cite-bracket">[</span>80<span class="cite-bracket">]</span></a></sup>—was released by GCHQ to the national <a href="/wiki/Public_Record_Office" title="Public Record Office">Public Record Office</a>, and it contains a fascinating <a href="/wiki/Paean" title="Paean">paean</a> to Colossus by the cryptographers who worked with it: </p> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1244412712"><blockquote class="templatequote"><p>It is regretted that it is not possible to give an adequate idea of the fascination of a Colossus at work; its sheer bulk and apparent complexity; the fantastic speed of thin paper tape round the glittering pulleys; the childish pleasure of not-not, span, print main header and other gadgets; the wizardry of purely mechanical decoding letter by letter (one novice thought she was being hoaxed); the uncanny action of the typewriter in printing the correct scores without and beyond human aid; the stepping of the display; periods of eager expectation culminating in the sudden appearance of the longed-for score; and the strange rhythms characterizing every type of run: the stately break-in, the erratic short run, the regularity of wheel-breaking, the stolid rectangle interrupted by the wild leaps of the carriage-return, the frantic chatter of a motor run, even the ludicrous frenzy of hosts of bogus scores.<sup id="cite_ref-FOOTNOTEGoodMichieTimms19455_Machines:_51_Introductory,_(j)_Impressions_of_Colossus,_p._327_88-0" class="reference"><a href="#cite_note-FOOTNOTEGoodMichieTimms19455_Machines:_51_Introductory,_(j)_Impressions_of_Colossus,_p._327-88"><span class="cite-bracket">[</span>81<span class="cite-bracket">]</span></a></sup> </p></blockquote> <div class="mw-heading mw-heading2"><h2 id="Reconstruction">Reconstruction</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=7" title="Edit section: Reconstruction"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:ColossusRebuild_11.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e0/ColossusRebuild_11.jpg/300px-ColossusRebuild_11.jpg" decoding="async" width="300" height="319" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e0/ColossusRebuild_11.jpg/450px-ColossusRebuild_11.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e0/ColossusRebuild_11.jpg/600px-ColossusRebuild_11.jpg 2x" data-file-width="2281" data-file-height="2423" /></a><figcaption>A team led by <a href="/wiki/Anthony_Sale" class="mw-redirect" title="Anthony Sale">Tony Sale</a> (right) reconstructed a Colossus Mark II at Bletchley Park. Here, in 2006, Sale supervises the breaking of an enciphered message with the completed machine.</figcaption></figure> <p>A team led by Tony Sale built a fully functional reconstruction<sup id="cite_ref-89" class="reference"><a href="#cite_note-89"><span class="cite-bracket">[</span>82<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-90" class="reference"><a href="#cite_note-90"><span class="cite-bracket">[</span>83<span class="cite-bracket">]</span></a></sup> of a Colossus Mark 2 between 1993 and 2008.<sup id="cite_ref-The_Colossus_Computer_14-2" class="reference"><a href="#cite_note-The_Colossus_Computer-14"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-auto_13-1" class="reference"><a href="#cite_note-auto-13"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> In spite of the blueprints and hardware being destroyed, a surprising amount of material had survived, mainly in engineers' notebooks, but a considerable amount of it in the U.S. The optical tape reader might have posed the biggest problem, but <a href="/wiki/Arnold_Lynch" title="Arnold Lynch">Dr. Arnold Lynch</a>, its original designer was able to redesign it to his own original specification. The reconstruction is on display, in the historically correct place for Colossus No. 9, at <a href="/wiki/The_National_Museum_of_Computing" title="The National Museum of Computing">The National Museum of Computing</a>, in H Block <a href="/wiki/Bletchley_Park" title="Bletchley Park">Bletchley Park</a> in <a href="/wiki/Milton_Keynes" title="Milton Keynes">Milton Keynes</a>, Buckinghamshire. </p><p>In November 2007, to celebrate the project completion and to mark the start of a fundraising initiative for The National Museum of Computing, a Cipher Challenge<sup id="cite_ref-91" class="reference"><a href="#cite_note-91"><span class="cite-bracket">[</span>84<span class="cite-bracket">]</span></a></sup> pitted the rebuilt Colossus against radio amateurs worldwide in being first to receive and decode three messages enciphered using the <a href="/wiki/Lorenz_SZ42" class="mw-redirect" title="Lorenz SZ42">Lorenz SZ42</a> and transmitted from radio station DL0HNF in the <i>Heinz Nixdorf MuseumsForum</i> computer museum. The challenge was easily won by <a href="/wiki/Radio_amateur" class="mw-redirect" title="Radio amateur">radio amateur</a> Joachim Schüth, who had carefully prepared<sup id="cite_ref-92" class="reference"><a href="#cite_note-92"><span class="cite-bracket">[</span>85<span class="cite-bracket">]</span></a></sup> for the event and developed his own signal processing and code-breaking code using <a href="/wiki/Ada_(programming_language)" title="Ada (programming language)">Ada</a>.<sup id="cite_ref-93" class="reference"><a href="#cite_note-93"><span class="cite-bracket">[</span>86<span class="cite-bracket">]</span></a></sup> The Colossus team were hampered by their wish to use World War II radio equipment,<sup id="cite_ref-94" class="reference"><a href="#cite_note-94"><span class="cite-bracket">[</span>87<span class="cite-bracket">]</span></a></sup> delaying them by a day because of poor reception conditions. Nevertheless, the victor's 1.4 GHz laptop, running his own code, took less than a minute to find the settings for all 12 wheels. The German codebreaker said: "My laptop digested ciphertext at a speed of 1.2 million characters per second—240 times faster than Colossus. If you scale the CPU frequency by that factor, you get an equivalent clock of 5.8 MHz for Colossus. That is a remarkable speed for a computer built in 1944."<sup id="cite_ref-95" class="reference"><a href="#cite_note-95"><span class="cite-bracket">[</span>88<span class="cite-bracket">]</span></a></sup> </p><p>The Cipher Challenge verified the successful completion of the rebuilding project. "On the strength of today's performance Colossus is as good as it was six decades ago", commented Tony Sale. "We are delighted to have produced a fitting tribute to the people who worked at Bletchley Park and whose brainpower devised these fantastic machines which broke these ciphers and shortened the war by many months."<sup id="cite_ref-96" class="reference"><a href="#cite_note-96"><span class="cite-bracket">[</span>89<span class="cite-bracket">]</span></a></sup> </p> <figure class="mw-default-size mw-halign-center" typeof="mw:File/Thumb"><a href="/wiki/File:Frontal_view_of_the_reconstructed_Colossus_at_The_National_Museum_of_Computing,_Bletchley_Park.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Frontal_view_of_the_reconstructed_Colossus_at_The_National_Museum_of_Computing%2C_Bletchley_Park.jpg/740px-Frontal_view_of_the_reconstructed_Colossus_at_The_National_Museum_of_Computing%2C_Bletchley_Park.jpg" decoding="async" width="740" height="285" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Frontal_view_of_the_reconstructed_Colossus_at_The_National_Museum_of_Computing%2C_Bletchley_Park.jpg/1110px-Frontal_view_of_the_reconstructed_Colossus_at_The_National_Museum_of_Computing%2C_Bletchley_Park.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Frontal_view_of_the_reconstructed_Colossus_at_The_National_Museum_of_Computing%2C_Bletchley_Park.jpg/1480px-Frontal_view_of_the_reconstructed_Colossus_at_The_National_Museum_of_Computing%2C_Bletchley_Park.jpg 2x" data-file-width="6860" data-file-height="2639" /></a><figcaption>Front view of the Colossus reconstruction showing, from right to left: (1) The "bedstead" containing the message tape in its continuous loop and with a second one loaded. (2) The J-rack containing the Selection Panel and Plug Panel. (3) The K-rack with the large "Q" switch panel and sloping patch panel. (4) The double S-rack containing the control panel and, above the image of a postage stamp, five two-line counter displays. (5) The electric typewriter in front of the five sets of four "set total" decade switches in the C-rack.<sup id="cite_ref-97" class="reference"><a href="#cite_note-97"><span class="cite-bracket">[</span>90<span class="cite-bracket">]</span></a></sup></figcaption></figure> <div class="mw-heading mw-heading2"><h2 id="Other_meanings">Other meanings</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=8" title="Edit section: Other meanings"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/List_of_fictional_computers" title="List of fictional computers">List of fictional computers</a></div> <p>There was a fictional computer named <i>Colossus</i> in the 1970 film <i><a href="/wiki/Colossus:_The_Forbin_Project" title="Colossus: The Forbin Project">Colossus: The Forbin Project</a></i> which was based on the 1966 novel <i><a href="/wiki/Colossus_(novel)" title="Colossus (novel)">Colossus</a></i> by <a href="/wiki/Dennis_Feltham_Jones" title="Dennis Feltham Jones">D. F. Jones</a>. This was a coincidence as it pre-dates the public release of information about Colossus, or even its name. </p><p><a href="/wiki/Neal_Stephenson" title="Neal Stephenson">Neal Stephenson</a>'s novel <i><a href="/wiki/Cryptonomicon" title="Cryptonomicon">Cryptonomicon</a></i> (1999) also contains a fictional treatment of the historical role played by Turing and Bletchley Park. </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=9" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/History_of_computing_hardware" title="History of computing hardware">History of computing hardware</a></li> <li><a href="/wiki/List_of_vacuum-tube_computers" title="List of vacuum-tube computers">List of vacuum-tube computers</a></li> <li><a href="/wiki/Manchester_Baby" title="Manchester Baby">Manchester Baby</a></li> <li><a href="/wiki/Z3_(computer)" title="Z3 (computer)">Z3</a></li> <li><a href="/wiki/Z4_(computer)" title="Z4 (computer)">Z4</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="Footnotes">Footnotes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=10" title="Edit section: Footnotes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-lower-alpha"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text">The two operators have been variously identified as Dorothy Du Boisson (left), Elsie Booker, Vivian Vorster (left), Catherine Kennedy, (unknown) and Patricia Davis (right).<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (July 2018)">citation needed</span></a></i>]</sup></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text">Based on what the National Museum of Computing state is the power consumption of the Colossus rebuild. In the absence of information to the contrary, the original is presumed to be similar.</span> </li> <li id="cite_note-27"><span class="mw-cite-backlink"><b><a href="#cite_ref-27">^</a></b></span> <span class="reference-text">The <a href="/wiki/Truth_function" title="Truth function">Boolean or "truth" function</a> <a href="/wiki/Exclusive_or" title="Exclusive or">XOR</a>, also known as <a href="/wiki/Exclusive_disjunction" class="mw-redirect" title="Exclusive disjunction">Exclusive disjunction and Exclusive or</a>, is the same as binary <a href="/wiki/Modular_arithmetic" title="Modular arithmetic">modulo</a> 2 addition and subtraction.</span> </li> <li id="cite_note-37"><span class="mw-cite-backlink"><b><a href="#cite_ref-37">^</a></b></span> <span class="reference-text">Flowers had been appointed MBE in June 1943.</span> </li> <li id="cite_note-61"><span class="mw-cite-backlink"><b><a href="#cite_ref-61">^</a></b></span> <span class="reference-text">For comparison, later <a href="/wiki/Stored-program_computer" title="Stored-program computer">stored-program computers</a> such as the <a href="/wiki/Manchester_Mark_1" title="Manchester Mark 1">Manchester Mark 1</a> of 1949 used 4,050 valves,<sup id="cite_ref-60" class="reference"><a href="#cite_note-60"><span class="cite-bracket">[</span>56<span class="cite-bracket">]</span></a></sup> while <a href="/wiki/ENIAC" title="ENIAC">ENIAC</a> (1946) used 17,468 valves.</span> </li> <li id="cite_note-64"><span class="mw-cite-backlink"><b><a href="#cite_ref-64">^</a></b></span> <span class="reference-text">This would now be called a <a href="/wiki/Systolic_array" title="Systolic array">systolic array</a>.</span> </li> <li id="cite_note-85"><span class="mw-cite-backlink"><b><a href="#cite_ref-85">^</a></b></span> <span class="reference-text"> <i>New Scientist</i>, 10 February 1977 & <i>IBM UK News,</i> 4 March 1967 </span> </li> </ol></div></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239543626"><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-tnmoc-3"><span class="mw-cite-backlink">^ <a href="#cite_ref-tnmoc_3-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-tnmoc_3-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-tnmoc_3-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.tnmoc.org/colossus">"Colossus"</a>. <i>The National Museum of Computing</i><span class="reference-accessdate">. Retrieved <span class="nowrap">25 January</span> 2021</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=The+National+Museum+of+Computing&rft.atitle=Colossus&rft_id=https%3A%2F%2Fwww.tnmoc.org%2Fcolossus&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTECopeland_"Introduction"20062-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTECopeland_"Introduction"20062_4-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFCopeland_"Introduction"2006">Copeland "Introduction" 2006</a>, p. 2.</span> </li> <li id="cite_note-FOOTNOTESale2000-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTESale2000_5-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFSale2000">Sale 2000</a>.</span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGolden1999" class="citation cs2">Golden, Frederic (29 March 1999), <a rel="nofollow" class="external text" href="https://web.archive.org/web/20060106193802/http://www.time.com/time/magazine/article/0,9171,990596,00.html">"Who Built The First Computer?"</a>, <i><a href="/wiki/Time_(magazine)" title="Time (magazine)">Time</a></i>, vol. 153, no. 12, archived from <a rel="nofollow" class="external text" href="http://www.time.com/time/magazine/article/0,9171,990596,00.html">the original</a> on 6 January 2006</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Time&rft.atitle=Who+Built+The+First+Computer%3F&rft.volume=153&rft.issue=12&rft.date=1999-03-29&rft.aulast=Golden&rft.aufirst=Frederic&rft_id=http%3A%2F%2Fwww.time.com%2Ftime%2Fmagazine%2Farticle%2F0%2C9171%2C990596%2C00.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCopeland" class="citation cs2"><a href="/wiki/Jack_Copeland" title="Jack Copeland">Copeland, Jack</a>, <a rel="nofollow" class="external text" href="http://www.colossus-computer.com/colossus1.html#sdfootnote96sym">"Colossus: The first large scale electronic computer"</a>, <i>Colossus-computer.com</i><span class="reference-accessdate">, retrieved <span class="nowrap">21 October</span> 2012</span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Colossus-computer.com&rft.atitle=Colossus%3A+The+first+large+scale+electronic+computer&rft.aulast=Copeland&rft.aufirst=Jack&rft_id=http%3A%2F%2Fwww.colossus-computer.com%2Fcolossus1.html%23sdfootnote96sym&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTEFlowers1983246-8"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTEFlowers1983246_8-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTEFlowers1983246_8-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFFlowers1983">Flowers 1983</a>, p. 246.</span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBarber2015" class="citation book cs1">Barber, Nicola (21 December 2015). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=mRprCwAAQBAJ&q=Bletchley+destroyed+Colossus+machines+and+plans&pg=PT59"><i>Who Broke the Wartime Codes?</i></a>. Capstone. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9781484635599" title="Special:BookSources/9781484635599"><bdi>9781484635599</bdi></a><span class="reference-accessdate">. Retrieved <span class="nowrap">26 October</span> 2017</span> – via Google Books.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Who+Broke+the+Wartime+Codes%3F&rft.pub=Capstone&rft.date=2015-12-21&rft.isbn=9781484635599&rft.aulast=Barber&rft.aufirst=Nicola&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DmRprCwAAQBAJ%26q%3DBletchley%2Bdestroyed%2BColossus%2Bmachines%2Band%2Bplans%26pg%3DPT59&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-lorenz-10"><span class="mw-cite-backlink">^ <a href="#cite_ref-lorenz_10-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-lorenz_10-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPreneel2000" class="citation cs2">Preneel, Bart, ed. (2000), <a rel="nofollow" class="external text" href="https://www.iacr.org/archive/eurocrypt2000/1807/18070423-new.pdf">"Colossus and the German Lorenz Cipher – Code Breaking in WW II"</a> <span class="cs1-format">(PDF)</span>, <i>Advances in Cryptology - EUROCRYPT 2000: International Conference on the Theory and Application of Cryptographic Techniques Bruges, Belgium May 14-18, 2000, Proceedings</i>, Lecture Notes in Computer Science, Springer, p. 417, <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1007%2F3-540-45539-6_29">10.1007/3-540-45539-6_29</a></span>, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3540675174" title="Special:BookSources/978-3540675174"><bdi>978-3540675174</bdi></a>, <a rel="nofollow" class="external text" href="https://web.archive.org/web/20081120221724/http://www.iacr.org/archive/eurocrypt2000/1807/18070423-new.pdf">archived</a> <span class="cs1-format">(PDF)</span> from the original on 20 November 2008</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Colossus+and+the+German+Lorenz+Cipher+%E2%80%93+Code+Breaking+in+WW+II&rft.btitle=Advances+in+Cryptology+-+EUROCRYPT+2000%3A+International+Conference+on+the+Theory+and+Application+of+Cryptographic+Techniques+Bruges%2C+Belgium+May+14-18%2C+2000%2C+Proceedings&rft.series=Lecture+Notes+in+Computer+Science&rft.pages=417&rft.pub=Springer&rft.date=2000&rft_id=info%3Adoi%2F10.1007%2F3-540-45539-6_29&rft.isbn=978-3540675174&rft_id=https%3A%2F%2Fwww.iacr.org%2Farchive%2Feurocrypt2000%2F1807%2F18070423-new.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTEGCHQ2024-11"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTEGCHQ2024_11-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTEGCHQ2024_11-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-FOOTNOTEGCHQ2024_11-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFGCHQ2024">GCHQ 2024</a>.</span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.codesandciphers.org.uk/lorenz/pods/coltalk_2.html">"coltalk_2"</a>. <i>Codesandciphers.org.uk</i><span class="reference-accessdate">. Retrieved <span class="nowrap">26 October</span> 2017</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Codesandciphers.org.uk&rft.atitle=coltalk_2&rft_id=https%3A%2F%2Fwww.codesandciphers.org.uk%2Florenz%2Fpods%2Fcoltalk_2.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-auto-13"><span class="mw-cite-backlink">^ <a href="#cite_ref-auto_13-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-auto_13-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCampbell-Kelly2011" class="citation web cs1">Campbell-Kelly, Martin (31 August 2011). <a rel="nofollow" class="external text" href="https://www.theguardian.com/theguardian/2011/aug/31/tony-sale-obituary">"Tony Sale obituary"</a>. <i>The Guardian</i><span class="reference-accessdate">. Retrieved <span class="nowrap">26 October</span> 2017</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=The+Guardian&rft.atitle=Tony+Sale+obituary&rft.date=2011-08-31&rft.aulast=Campbell-Kelly&rft.aufirst=Martin&rft_id=https%3A%2F%2Fwww.theguardian.com%2Ftheguardian%2F2011%2Faug%2F31%2Ftony-sale-obituary&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-The_Colossus_Computer-14"><span class="mw-cite-backlink">^ <a href="#cite_ref-The_Colossus_Computer_14-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-The_Colossus_Computer_14-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-The_Colossus_Computer_14-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation cs2"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20150418230306/http://www.tnmoc.org/colossus-rebuild-story"><i>Colossus – The Rebuild Story</i></a>, The National Museum of Computing, archived from <a rel="nofollow" class="external text" href="http://www.tnmoc.org/colossus-rebuild-story">the original</a> on 18 April 2015<span class="reference-accessdate">, retrieved <span class="nowrap">13 May</span> 2017</span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Colossus+%E2%80%93+The+Rebuild+Story&rft.pub=The+National+Museum+of+Computing&rft_id=http%3A%2F%2Fwww.tnmoc.org%2Fcolossus-rebuild-story&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11B_The_Tunny_Cipher_Machine,_p._6-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11B_The_Tunny_Cipher_Machine,_p._6_15-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 1 Introduction: 11 German Tunny, 11B The Tunny Cipher Machine, p. 6.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11A_Fish_Machines,_(c)_The_German_Ciphered_Teleprinter,_p._4-16"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11A_Fish_Machines,_(c)_The_German_Ciphered_Teleprinter,_p._4_16-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11A_Fish_Machines,_(c)_The_German_Ciphered_Teleprinter,_p._4_16-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 1 Introduction: 11 German Tunny, 11A Fish Machines, (c) The German Ciphered Teleprinter, p. 4.</span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHinsleyStripp2001" class="citation book cs1">Hinsley, F. H.; Stripp, Alan (2001). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=j1MC2d2LPAcC&pg=PA139">"PART THREE: Fish"</a>. <i>Codebreakers: The Inside Story of Bletchley Park</i>. Oxford University Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-19-280132-6" title="Special:BookSources/978-0-19-280132-6"><bdi>978-0-19-280132-6</bdi></a><span class="reference-accessdate">. Retrieved <span class="nowrap">26 October</span> 2017</span> – via Google Books.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=PART+THREE%3A+Fish&rft.btitle=Codebreakers%3A+The+Inside+Story+of+Bletchley+Park&rft.pub=Oxford+University+Press&rft.date=2001&rft.isbn=978-0-19-280132-6&rft.aulast=Hinsley&rft.aufirst=F.+H.&rft.au=Stripp%2C+Alan&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3Dj1MC2d2LPAcC%26pg%3DPA139&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTEBudiansky200655–56-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEBudiansky200655–56_18-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFBudiansky2006">Budiansky 2006</a>, pp. 55–56.</span> </li> <li id="cite_note-FOOTNOTETutte2006357-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTETutte2006357_19-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFTutte2006">Tutte 2006</a>, p. 357.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11C_Wheel_Patterns,_(b)_Differenced_and_Undifferenced_Wheels,_p._11-20"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11C_Wheel_Patterns,_(b)_Differenced_and_Undifferenced_Wheels,_p._11_20-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11C_Wheel_Patterns,_(b)_Differenced_and_Undifferenced_Wheels,_p._11_20-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 1 Introduction: 11 German Tunny, 11C Wheel Patterns, (b) Differenced and Undifferenced Wheels, p. 11.</span> </li> <li id="cite_note-FOOTNOTECopeland_"Turingery"2006378–385-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTECopeland_"Turingery"2006378–385_21-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFCopeland_"Turingery"2006">Copeland "Turingery" 2006</a>, pp. 378–385.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms194524_–_Rectangling:_24B_Making_and_Entering_Rectangles_pp._114–115,_119–120-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGoodMichieTimms194524_–_Rectangling:_24B_Making_and_Entering_Rectangles_pp._114–115,_119–120_22-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 24 – Rectangling: 24B Making and Entering Rectangles pp. 114–115, 119–120.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11E_The_Tunny_Network,_(b)_Wheel-breaking_and_Setting,_p._15-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11E_The_Tunny_Network,_(b)_Wheel-breaking_and_Setting,_p._15_23-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 1 Introduction: 11 German Tunny, 11E The Tunny Network, (b) Wheel-breaking and Setting, p. 15.</span> </li> <li id="cite_note-FOOTNOTESmall194415-24"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTESmall194415_24-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTESmall194415_24-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFSmall1944">Small 1944</a>, p. 15.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_12_Cryptographic_Aspects,_12A_The_Problem,_(a)_Formulae_and_Notation,_p._16-25"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_12_Cryptographic_Aspects,_12A_The_Problem,_(a)_Formulae_and_Notation,_p._16_25-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_12_Cryptographic_Aspects,_12A_The_Problem,_(a)_Formulae_and_Notation,_p._16_25-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 1 Introduction: 12 Cryptographic Aspects, 12A The Problem, (a) Formulae and Notation, p. 16.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11B_The_Tunny_Cipher_Machine,_(e)_Psi-key,_p._7-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11B_The_Tunny_Cipher_Machine,_(e)_Psi-key,_p._7_26-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 1 Introduction: 11 German Tunny, 11B The Tunny Cipher Machine, (e) Psi-key, p. 7.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11B_The_Tunny_Cipher_Machine,_(a)_Addition,_p._5-28"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_11_German_Tunny,_11B_The_Tunny_Cipher_Machine,_(a)_Addition,_p._5_28-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 1 Introduction: 11 German Tunny, 11B The Tunny Cipher Machine, (a) Addition, p. 5.</span> </li> <li id="cite_note-FOOTNOTEBudiansky200658–59-29"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEBudiansky200658–59_29-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFBudiansky2006">Budiansky 2006</a>, pp. 58–59.</span> </li> <li id="cite_note-FOOTNOTECarter200818–19-30"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTECarter200818–19_30-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFCarter2008">Carter 2008</a>, pp. 18–19.</span> </li> <li id="cite_note-FOOTNOTESmall194465-31"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTESmall194465_31-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFSmall1944">Small 1944</a>, p. 65.</span> </li> <li id="cite_note-32"><span class="mw-cite-backlink"><b><a href="#cite_ref-32">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRoberts2009" class="citation audio-visual cs1"><a href="/wiki/Jerry_Roberts" title="Jerry Roberts">Roberts, Jerry</a> (2009). <a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=m1bJHG95Xn8"><i>Capt. Jerry Roberts: My Top Secret Codebreaking at Bletchley Park 1941 to 45: Lecture on 11 March 2009</i></a>. University College London. 34 minutes in. <a rel="nofollow" class="external text" href="https://ghostarchive.org/varchive/youtube/20211124/m1bJHG95Xn8">Archived</a> from the original on 24 November 2021 – via YouTube.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Capt.+Jerry+Roberts%3A+My+Top+Secret+Codebreaking+at+Bletchley+Park+1941+to+45%3A+Lecture+on+11+March+2009&rft.pub=University+College+London&rft.date=2009&rft.aulast=Roberts&rft.aufirst=Jerry&rft_id=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Dm1bJHG95Xn8&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTECopeland200677-33"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTECopeland200677_33-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFCopeland2006">Copeland 2006</a>, p. 77.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19453_Organisation:_31_Mr_Newman's_section,_p._276-34"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGoodMichieTimms19453_Organisation:_31_Mr_Newman's_section,_p._276_34-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 3 Organisation: 31 Mr Newman's section, p. 276.</span> </li> <li id="cite_note-FOOTNOTEAnderson20078-35"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEAnderson20078_35-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFAnderson2007">Anderson 2007</a>, p. 8.</span> </li> <li id="cite_note-36"><span class="mw-cite-backlink"><b><a href="#cite_ref-36">^</a></b></span> <span class="reference-text">Exhibit in the National Cryptologic Museum, Fort Meade, Maryland, USA</span> </li> <li id="cite_note-FOOTNOTERandell19809-38"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTERandell19809_38-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFRandell1980">Randell 1980</a>, p. 9.</span> </li> <li id="cite_note-FOOTNOTEBudiansky2000314-39"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEBudiansky2000314_39-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFBudiansky2000">Budiansky 2000</a>, p. 314.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_15_Some_Historical_Notes,_15A_First_Stages_in_Machine_Development,_(c)_Heath_Robinson,_p._33-40"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_15_Some_Historical_Notes,_15A_First_Stages_in_Machine_Development,_(c)_Heath_Robinson,_p._33_40-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 1 Introduction: 15 Some Historical Notes, 15A First Stages in Machine Development, (c) Heath Robinson, p. 33.</span> </li> <li id="cite_note-FOOTNOTEFlowers200696-41"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTEFlowers200696_41-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTEFlowers200696_41-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFFlowers2006">Flowers 2006</a>, p. 96.</span> </li> <li id="cite_note-FOOTNOTEFlowers1983244-42"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEFlowers1983244_42-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFFlowers1983">Flowers 1983</a>, p. 244.</span> </li> <li id="cite_note-FOOTNOTECopeland_"Machine_against_Machine"200672-43"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTECopeland_"Machine_against_Machine"200672_43-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFCopeland_"Machine_against_Machine"2006">Copeland "Machine against Machine" 2006</a>, p. 72.</span> </li> <li id="cite_note-FOOTNOTECopeland_"Machine_against_Machine"200674-44"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTECopeland_"Machine_against_Machine"200674_44-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFCopeland_"Machine_against_Machine"2006">Copeland "Machine against Machine" 2006</a>, p. 74.</span> </li> <li id="cite_note-FOOTNOTEFlowers200680-45"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTEFlowers200680_45-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTEFlowers200680_45-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFFlowers2006">Flowers 2006</a>, p. 80.</span> </li> <li id="cite_note-FOOTNOTERandell2006143-46"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTERandell2006143_46-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFRandell2006">Randell 2006</a>, p. 143.</span> </li> <li id="cite_note-47"><span class="mw-cite-backlink"><b><a href="#cite_ref-47">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBoden2000" class="citation cs2"><a href="/wiki/Margaret_Boden" title="Margaret Boden">Boden, Margaret</a> (2000), <a rel="nofollow" class="external text" href="https://archive.org/details/mindasmachinehis0001bode/page/159"><i>Mind as Machine: A History of Cognitive Science</i></a>, Oxford University Press, p. <a rel="nofollow" class="external text" href="https://archive.org/details/mindasmachinehis0001bode/page/159">159</a>, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0199241446" title="Special:BookSources/978-0199241446"><bdi>978-0199241446</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Mind+as+Machine%3A+A+History+of+Cognitive+Science&rft.pages=159&rft.pub=Oxford+University+Press&rft.date=2000&rft.isbn=978-0199241446&rft.aulast=Boden&rft.aufirst=Margaret&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fmindasmachinehis0001bode%2Fpage%2F159&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-48"><span class="mw-cite-backlink"><b><a href="#cite_ref-48">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAtkinson2010" class="citation cs2">Atkinson, Paul (2010), <a rel="nofollow" class="external text" href="https://archive.org/details/computer0000atki/page/29"><i>Computer (Objekt)</i></a>, Reaktion Books, p. <a rel="nofollow" class="external text" href="https://archive.org/details/computer0000atki/page/29">29</a>, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1861896643" title="Special:BookSources/978-1861896643"><bdi>978-1861896643</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Computer+%28Objekt%29&rft.pages=29&rft.pub=Reaktion+Books&rft.date=2010&rft.isbn=978-1861896643&rft.aulast=Atkinson&rft.aufirst=Paul&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fcomputer0000atki%2Fpage%2F29&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTECopeland2010-49"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTECopeland2010_49-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFCopeland2010">Copeland 2010</a>.</span> </li> <li id="cite_note-50"><span class="mw-cite-backlink"><b><a href="#cite_ref-50">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFensom2010" class="citation cs2">Fensom, Jim (8 November 2010), <a rel="nofollow" class="external text" href="https://www.theguardian.com/theguardian/2010/nov/08/harry-fensom-obituary">"Harry Fensom obituary"</a>, <i>The Guardian</i>, London<span class="reference-accessdate">, retrieved <span class="nowrap">17 October</span> 2012</span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Guardian&rft.atitle=Harry+Fensom+obituary&rft.date=2010-11-08&rft.aulast=Fensom&rft.aufirst=Jim&rft_id=https%3A%2F%2Fwww.theguardian.com%2Ftheguardian%2F2010%2Fnov%2F08%2Fharry-fensom-obituary&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-51"><span class="mw-cite-backlink"><b><a href="#cite_ref-51">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSterling2007" class="citation cs2">Sterling, Christopher H., ed. (2007), <i>Military Communications: From Ancient Times to the 21st Century</i>, ABC-CLIO, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1851097326" title="Special:BookSources/978-1851097326"><bdi>978-1851097326</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Military+Communications%3A+From+Ancient+Times+to+the+21st+Century&rft.pub=ABC-CLIO&rft.date=2007&rft.isbn=978-1851097326&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTECopeland_"Machine_against_Machine"200675-52"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTECopeland_"Machine_against_Machine"200675_52-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFCopeland_"Machine_against_Machine"2006">Copeland "Machine against Machine" 2006</a>, p. 75.</span> </li> <li id="cite_note-FOOTNOTEGannon2007283-53"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGannon2007283_53-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGannon2007">Gannon 2007</a>, p. 283.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19451_Introduction:_15_–_Some_Historical_Notes,_15C_Period_of_Expansion,_(b)_Colossus,_p._35-54"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_15_–_Some_Historical_Notes,_15C_Period_of_Expansion,_(b)_Colossus,_p._35_54-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_15_–_Some_Historical_Notes,_15C_Period_of_Expansion,_(b)_Colossus,_p._35_54-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-FOOTNOTEGoodMichieTimms19451_Introduction:_15_–_Some_Historical_Notes,_15C_Period_of_Expansion,_(b)_Colossus,_p._35_54-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 1 Introduction: 15 – Some Historical Notes, 15C Period of Expansion, (b) Colossus, p. 35.</span> </li> <li id="cite_note-55"><span class="mw-cite-backlink"><b><a href="#cite_ref-55">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRandellFensomMilne1995" class="citation cs2"><a href="/wiki/Brian_Randell" title="Brian Randell">Randell, Brian</a>; Fensom, Harry; Milne, Frank A. (15 March 1995), <a rel="nofollow" class="external text" href="https://www.independent.co.uk/news/people/obituary-allen-coombs-1611270.html">"Obituary: Allen Coombs"</a>, <i>The Independent</i>, London<span class="reference-accessdate">, retrieved <span class="nowrap">18 October</span> 2012</span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Independent&rft.atitle=Obituary%3A+Allen+Coombs&rft.date=1995-03-15&rft.aulast=Randell&rft.aufirst=Brian&rft.au=Fensom%2C+Harry&rft.au=Milne%2C+Frank+A.&rft_id=https%3A%2F%2Fwww.independent.co.uk%2Fnews%2Fpeople%2Fobituary-allen-coombs-1611270.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTEKenyon201960-56"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEKenyon201960_56-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFKenyon2019">Kenyon 2019</a>, p. 60.</span> </li> <li id="cite_note-FOOTNOTEFlowers1983249–252-57"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEFlowers1983249–252_57-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFFlowers1983">Flowers 1983</a>, pp. 249–252.</span> </li> <li id="cite_note-FOOTNOTEFlowers1983243,_245-58"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEFlowers1983243,_245_58-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFFlowers1983">Flowers 1983</a>, pp. 243, 245.</span> </li> <li id="cite_note-FOOTNOTECoombs1983-59"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTECoombs1983_59-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFCoombs1983">Coombs 1983</a>.</span> </li> <li id="cite_note-60"><span class="mw-cite-backlink"><b><a href="#cite_ref-60">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLavington1977" class="citation cs2">Lavington, S. H. (July 1977), <a rel="nofollow" class="external text" href="http://www.cs.ucf.edu/courses/cda5106/summer03/papers/mark1.atlas.1.pdf">"The Manchester Mark 1 and Atlas: a Historical Perspective"</a> <span class="cs1-format">(PDF)</span>, <i>Communications of the ACM</i>, <b>21</b> (1): 4–12, <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1145%2F359327.359331">10.1145/359327.359331</a>, <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:10301670">10301670</a>, <a rel="nofollow" class="external text" href="https://web.archive.org/web/20040114142723/http://www.cs.ucf.edu/courses/cda5106/summer03/papers/mark1.atlas.1.pdf">archived</a> <span class="cs1-format">(PDF)</span> from the original on 14 January 2004<span class="reference-accessdate">, retrieved <span class="nowrap">8 February</span> 2009</span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Communications+of+the+ACM&rft.atitle=The+Manchester+Mark+1+and+Atlas%3A+a+Historical+Perspective&rft.volume=21&rft.issue=1&rft.pages=4-12&rft.date=1977-07&rft_id=info%3Adoi%2F10.1145%2F359327.359331&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A10301670%23id-name%3DS2CID&rft.aulast=Lavington&rft.aufirst=S.+H.&rft_id=http%3A%2F%2Fwww.cs.ucf.edu%2Fcourses%2Fcda5106%2Fsummer03%2Fpapers%2Fmark1.atlas.1.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTEFlowers1983-62"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEFlowers1983_62-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFFlowers1983">Flowers 1983</a>.</span> </li> <li id="cite_note-FOOTNOTEFlowers2006100-63"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTEFlowers2006100_63-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTEFlowers2006100_63-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFFlowers2006">Flowers 2006</a>, p. 100.</span> </li> <li id="cite_note-FOOTNOTECopeland2011-65"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTECopeland2011_65-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFCopeland2011">Copeland 2011</a>.</span> </li> <li id="cite_note-66"><span class="mw-cite-backlink"><b><a href="#cite_ref-66">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20190819115149/https://uwaterloo.ca/combinatorics-and-optimization/about/professor-william-t-tutte/biography-professor-tutte#bletchley">"Biography of Professor Tutte - Combinatorics and Optimization"</a>. <i>Uwaterloo.ca</i>. 13 March 2015. Archived from <a rel="nofollow" class="external text" href="https://uwaterloo.ca/combinatorics-and-optimization/about/professor-william-t-tutte/biography-professor-tutte#bletchley">the original</a> on 19 August 2019<span class="reference-accessdate">. Retrieved <span class="nowrap">26 October</span> 2017</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Uwaterloo.ca&rft.atitle=Biography+of+Professor+Tutte+-+Combinatorics+and+Optimization&rft.date=2015-03-13&rft_id=https%3A%2F%2Fuwaterloo.ca%2Fcombinatorics-and-optimization%2Fabout%2Fprofessor-william-t-tutte%2Fbiography-professor-tutte%23bletchley&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus_53A_Introduction,_p.333-67"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus_53A_Introduction,_p.333_67-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus_53A_Introduction,_p.333_67-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 5 Machines: 53 Colossus 53A Introduction, p.333.</span> </li> <li id="cite_note-FOOTNOTEFlowers1983241,_242-68"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEFlowers1983241,_242_68-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFFlowers1983">Flowers 1983</a>, pp. 241, 242.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus_53B_The_Z_stream,_p.333-69"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus_53B_The_Z_stream,_p.333_69-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 5 Machines: 53 Colossus 53B The Z stream, p.333.</span> </li> <li id="cite_note-FOOTNOTEFensom2006303-70"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTEFensom2006303_70-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTEFensom2006303_70-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFFensom2006">Fensom 2006</a>, p. 303.</span> </li> <li id="cite_note-FOOTNOTEFlowers1983239–252-71"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEFlowers1983239–252_71-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFFlowers1983">Flowers 1983</a>, pp. 239–252.</span> </li> <li id="cite_note-FOOTNOTESmall1944108-72"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTESmall1944108_72-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFSmall1944">Small 1944</a>, p. 108.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus,_pp._333–353-73"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGoodMichieTimms19455_Machines:_53_Colossus,_pp._333–353_73-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 5 Machines: 53 Colossus, pp. 333–353.</span> </li> <li id="cite_note-FOOTNOTEBudiansky200662-74"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEBudiansky200662_74-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFBudiansky2006">Budiansky 2006</a>, p. 62.</span> </li> <li id="cite_note-75"><span class="mw-cite-backlink"><b><a href="#cite_ref-75">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.alanturing.net/turing_archive/pages/Reference%20Articles/BriefHistofComp.html#Col">"A Brief History of Computing. Jack Copeland, June 2000"</a>. <i>Alanturing.net</i><span class="reference-accessdate">. Retrieved <span class="nowrap">26 October</span> 2017</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Alanturing.net&rft.atitle=A+Brief+History+of+Computing.+Jack+Copeland%2C+June+2000&rft_id=http%3A%2F%2Fwww.alanturing.net%2Fturing_archive%2Fpages%2FReference%2520Articles%2FBriefHistofComp.html%23Col&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-76"><span class="mw-cite-backlink"><b><a href="#cite_ref-76">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWells2009" class="citation conference cs1">Wells, Benjamin (2009). "Advances in I/O, Speedup, and Universality on Colossus, an Unconventional Computer". <i>Proceedings of the 8th International Conference on Unconventional Computation 2009 (UC09), Ponta Delgada, Portugal</i>. Lecture Notes in Computer Science. Vol. 5175. Berlin, Heidelberg: Springer-Verlag. pp. 247–261. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2F978-3-642-03745-0_27">10.1007/978-3-642-03745-0_27</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-642-03744-3" title="Special:BookSources/978-3-642-03744-3"><bdi>978-3-642-03744-3</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=conference&rft.atitle=Advances+in+I%2FO%2C+Speedup%2C+and+Universality+on+Colossus%2C+an+Unconventional+Computer&rft.btitle=Proceedings+of+the+8th+International+Conference+on+Unconventional+Computation+2009+%28UC09%29%2C+Ponta+Delgada%2C+Portugal&rft.place=Berlin%2C+Heidelberg&rft.series=Lecture+Notes+in+Computer+Science&rft.pages=247-261&rft.pub=Springer-Verlag&rft.date=2009&rft_id=info%3Adoi%2F10.1007%2F978-3-642-03745-0_27&rft.isbn=978-3-642-03744-3&rft.aulast=Wells&rft.aufirst=Benjamin&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-77"><span class="mw-cite-backlink"><b><a href="#cite_ref-77">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.alanturing.net/turing_archive/pages/Reference%20Articles/BriefHistofComp.html#ACE">"A Brief History of Computing"</a>. alanturing.net<span class="reference-accessdate">. Retrieved <span class="nowrap">26 January</span> 2010</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=A+Brief+History+of+Computing&rft.pub=alanturing.net&rft_id=http%3A%2F%2Fwww.alanturing.net%2Fturing_archive%2Fpages%2FReference%2520Articles%2FBriefHistofComp.html%23ACE&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTECopeland_et_al.2006173–175-78"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTECopeland_et_al.2006173–175_78-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTECopeland_et_al.2006173–175_78-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-FOOTNOTECopeland_et_al.2006173–175_78-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-FOOTNOTECopeland_et_al.2006173–175_78-3"><sup><i><b>d</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFCopeland_et_al.2006">Copeland et al. 2006</a>, pp. 173–175.</span> </li> <li id="cite_note-FOOTNOTEMcKay2010270–271-79"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEMcKay2010270–271_79-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFMcKay2010">McKay 2010</a>, pp. 270–271.</span> </li> <li id="cite_note-80"><span class="mw-cite-backlink"><b><a href="#cite_ref-80">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHorwood1973" class="citation audio-visual cs1">Horwood, D.C. (1973). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20140402160011/http://www.youtube.com/watch?v=JF48sl15OCg"><i>A technical description of Colossus I: PRO HW 25/24</i></a>. Archived from <a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=JF48sl15OCg">the original</a> on 2 April 2014<span class="reference-accessdate">. Retrieved <span class="nowrap">16 March</span> 2014</span> – via YouTube.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=A+technical+description+of+Colossus+I%3A+PRO+HW+25%2F24&rft.date=1973&rft.aulast=Horwood&rft.aufirst=D.C.&rft_id=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DJF48sl15OCg&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-81"><span class="mw-cite-backlink"><b><a href="#cite_ref-81">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFChodos2022" class="citation journal cs1">Chodos, Alan (2022). <a rel="nofollow" class="external text" href="https://www.aps.org/publications/apsnews/200208/history.cfm">"August 1946: The Moore School Lectures"</a>. <i>APS News</i>. <b>11</b> (4)<span class="reference-accessdate">. Retrieved <span class="nowrap">25 January</span> 2022</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=APS+News&rft.atitle=August+1946%3A+The+Moore+School+Lectures&rft.volume=11&rft.issue=4&rft.date=2022&rft.aulast=Chodos&rft.aufirst=Alan&rft_id=https%3A%2F%2Fwww.aps.org%2Fpublications%2Fapsnews%2F200208%2Fhistory.cfm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTEGoldstine1980321-82"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGoldstine1980321_82-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGoldstine1980">Goldstine 1980</a>, p. 321.</span> </li> <li id="cite_note-FOOTNOTERandell198087-83"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTERandell198087_83-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFRandell1980">Randell 1980</a>, p. 87.</span> </li> <li id="cite_note-84"><span class="mw-cite-backlink"><b><a href="#cite_ref-84">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWinterbotham2000" class="citation cs2"><a href="/wiki/F.W._Winterbotham" class="mw-redirect" title="F.W. Winterbotham">Winterbotham, F.W.</a> (2000) [1974], <i>The Ultra secret: the inside story of Operation Ultra, Bletchley Park and Enigma</i>, London: Orion Books Ltd, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780752837512" title="Special:BookSources/9780752837512"><bdi>9780752837512</bdi></a>, <a href="/wiki/OCLC_(identifier)" class="mw-redirect" title="OCLC (identifier)">OCLC</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/oclc/222735270">222735270</a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Ultra+secret%3A+the+inside+story+of+Operation+Ultra%2C+Bletchley+Park+and+Enigma&rft.place=London&rft.pub=Orion+Books+Ltd&rft.date=2000&rft_id=info%3Aoclcnum%2F222735270&rft.isbn=9780752837512&rft.aulast=Winterbotham&rft.aufirst=F.W.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-86"><span class="mw-cite-backlink"><b><a href="#cite_ref-86">^</a></b></span> <span class="reference-text"><i>COLOSSUS and the History of Computing: Dollis Hill's Important Contribution</i> by A.W.M. Coombs in The Post Office Electrical Engineers' Journal (POEEJ; Volume70, 1977/78 part 2, July 1977, pages 108-110)</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms1945-87"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGoodMichieTimms1945_87-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>.</span> </li> <li id="cite_note-FOOTNOTEGoodMichieTimms19455_Machines:_51_Introductory,_(j)_Impressions_of_Colossus,_p._327-88"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEGoodMichieTimms19455_Machines:_51_Introductory,_(j)_Impressions_of_Colossus,_p._327_88-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFGoodMichieTimms1945">Good, Michie & Timms 1945</a>, 5 Machines: 51 Introductory, (j) Impressions of Colossus, p. 327.</span> </li> <li id="cite_note-89"><span class="mw-cite-backlink"><b><a href="#cite_ref-89">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.codesandciphers.org.uk/lorenz/rebuild.htm">"Colossus Rebuild - Tony Sale"</a>. <i>Codesandciphers.org.uk</i><span class="reference-accessdate">. Retrieved <span class="nowrap">26 October</span> 2017</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Codesandciphers.org.uk&rft.atitle=Colossus+Rebuild+-+Tony+Sale&rft_id=http%3A%2F%2Fwww.codesandciphers.org.uk%2Florenz%2Frebuild.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-90"><span class="mw-cite-backlink"><b><a href="#cite_ref-90">^</a></b></span> <span class="reference-text">* <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSale2008" class="citation web cs1"><a href="/wiki/Tony_Sale" title="Tony Sale">Sale, Tony</a> (2008). <a rel="nofollow" class="external text" href="https://www.codesandciphers.org.uk/lorenz/pods/coltalk_2.html">"Video of Tony Sale talking about rebuilt Colossus 2008-6-19"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">13 May</span> 2017</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Video+of+Tony+Sale+talking+about+rebuilt+Colossus+2008-6-19&rft.date=2008&rft.aulast=Sale&rft.aufirst=Tony&rft_id=https%3A%2F%2Fwww.codesandciphers.org.uk%2Florenz%2Fpods%2Fcoltalk_2.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-91"><span class="mw-cite-backlink"><b><a href="#cite_ref-91">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20080801175842/http://www.tnmoc.org/cipher1.htm">"Cipher Challenge"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.tnmoc.org/cipher1.htm">the original</a> on 1 August 2008<span class="reference-accessdate">. Retrieved <span class="nowrap">1 February</span> 2012</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Cipher+Challenge&rft_id=http%3A%2F%2Fwww.tnmoc.org%2Fcipher1.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-92"><span class="mw-cite-backlink"><b><a href="#cite_ref-92">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.schlaupelz.de/SZ42/SZ42_software.html">"SZ42 codebreaking software"</a>. <i>Schlaupelz.de</i><span class="reference-accessdate">. Retrieved <span class="nowrap">26 October</span> 2017</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Schlaupelz.de&rft.atitle=SZ42+codebreaking+software&rft_id=http%3A%2F%2Fwww.schlaupelz.de%2FSZ42%2FSZ42_software.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-93"><span class="mw-cite-backlink"><b><a href="#cite_ref-93">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120208010213/http://www.adacore.com/home/ada_answers/lorenz-code/">"Cracking the Lorenz Code"</a>. <i>Ada Answers</i>. AdaCore. Archived from <a rel="nofollow" class="external text" href="http://www.adacore.com/home/ada_answers/lorenz-code/">the original</a> on 8 February 2012<span class="reference-accessdate">. Retrieved <span class="nowrap">26 October</span> 2017</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Ada+Answers&rft.atitle=Cracking+the+Lorenz+Code&rft_id=http%3A%2F%2Fwww.adacore.com%2Fhome%2Fada_answers%2Florenz-code%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-94"><span class="mw-cite-backlink"><b><a href="#cite_ref-94">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWard2007" class="citation news cs1">Ward, Mark (16 November 2007). <a rel="nofollow" class="external text" href="http://news.bbc.co.uk/1/hi/technology/7098005.stm">"Colossus loses code-cracking race"</a>. <i>BBC News</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2 January</span> 2010</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=BBC+News&rft.atitle=Colossus+loses+code-cracking+race&rft.date=2007-11-16&rft.aulast=Ward&rft.aufirst=Mark&rft_id=http%3A%2F%2Fnews.bbc.co.uk%2F1%2Fhi%2Ftechnology%2F7098005.stm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-95"><span class="mw-cite-backlink"><b><a href="#cite_ref-95">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130102214431/http://www.bletchleypark.org.uk/news/docview.rhtm/487682">"German Codebreaker receives Bletchley Park Honours"</a>. Bletchley Park National Codes Centre. 27 January 2008. Archived from <a rel="nofollow" class="external text" href="http://www.bletchleypark.org.uk/news/docview.rhtm/487682">the original</a> on 2 January 2013<span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2012</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=German+Codebreaker+receives+Bletchley+Park+Honours&rft.pub=Bletchley+Park+National+Codes+Centre&rft.date=2008-01-27&rft_id=http%3A%2F%2Fwww.bletchleypark.org.uk%2Fnews%2Fdocview.rhtm%2F487682&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-96"><span class="mw-cite-backlink"><b><a href="#cite_ref-96">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20080418084956/http://www.tnmoc.org/cipher7.htm">"Latest Cipher Challenge News 16.11.2007"</a>. <i>TNMoC - Cipher Challenge!</i>. Archived from <a rel="nofollow" class="external text" href="http://www.tnmoc.org/cipher7.htm">the original</a> on 18 April 2008.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=TNMoC+-+Cipher+Challenge%21&rft.atitle=Latest+Cipher+Challenge+News+16.11.2007&rft_id=http%3A%2F%2Fwww.tnmoc.org%2Fcipher7.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> <li id="cite_note-97"><span class="mw-cite-backlink"><b><a href="#cite_ref-97">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSale" class="citation web cs1"><a href="/wiki/Anthony_Sale" class="mw-redirect" title="Anthony Sale">Sale, Tony</a>. <a rel="nofollow" class="external text" href="http://www.codesandciphers.org.uk/virtualbp/fish/colossus.htm">"The Colossus its purpose and operation"</a>. <i>Codesandciphers.org.uk</i><span class="reference-accessdate">. Retrieved <span class="nowrap">26 October</span> 2017</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Codesandciphers.org.uk&rft.atitle=The+Colossus+its+purpose+and+operation&rft.aulast=Sale&rft.aufirst=Tony&rft_id=http%3A%2F%2Fwww.codesandciphers.org.uk%2Fvirtualbp%2Ffish%2Fcolossus.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=11" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239549316">.mw-parser-output .refbegin{margin-bottom:0.5em}.mw-parser-output .refbegin-hanging-indents>ul{margin-left:0}.mw-parser-output .refbegin-hanging-indents>ul>li{margin-left:0;padding-left:3.2em;text-indent:-3.2em}.mw-parser-output .refbegin-hanging-indents ul,.mw-parser-output .refbegin-hanging-indents ul li{list-style:none}@media(max-width:720px){.mw-parser-output .refbegin-hanging-indents>ul>li{padding-left:1.6em;text-indent:-1.6em}}.mw-parser-output .refbegin-columns{margin-top:0.3em}.mw-parser-output .refbegin-columns ul{margin-top:0}.mw-parser-output .refbegin-columns li{page-break-inside:avoid;break-inside:avoid-column}@media screen{.mw-parser-output .refbegin{font-size:90%}}</style><div class="refbegin refbegin-columns references-column-width" style="column-width: 30em"> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAnderson2007" class="citation cs2">Anderson, David (2007), <a rel="nofollow" class="external text" href="https://web.archive.org/web/20150923192838/http://www.bcs.org/upload/pdf/ewic_tur04_paper3.pdf"><i>Was the Manchester Baby conceived at Bletchley Park?</i></a> <span class="cs1-format">(PDF)</span>, British Computer Society, archived from <a rel="nofollow" class="external text" href="http://bcs.org/upload/pdf/ewic_tur04_paper3.pdf">the original</a> <span class="cs1-format">(PDF)</span> on 23 September 2015<span class="reference-accessdate">, retrieved <span class="nowrap">25 April</span> 2015</span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Was+the+Manchester+Baby+conceived+at+Bletchley+Park%3F&rft.pub=British+Computer+Society&rft.date=2007&rft.aulast=Anderson&rft.aufirst=David&rft_id=http%3A%2F%2Fbcs.org%2Fupload%2Fpdf%2Fewic_tur04_paper3.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBudiansky2000" class="citation cs2">Budiansky, Stephen (2000), <span class="id-lock-registration" title="Free registration required"><a rel="nofollow" class="external text" href="https://archive.org/details/battleofwitscomp00budi"><i>Battle of wits: The Complete Story of Codebreaking in World War II</i></a></span>, Free Press, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0684859323" title="Special:BookSources/978-0684859323"><bdi>978-0684859323</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Battle+of+wits%3A+The+Complete+Story+of+Codebreaking+in+World+War+II&rft.pub=Free+Press&rft.date=2000&rft.isbn=978-0684859323&rft.aulast=Budiansky&rft.aufirst=Stephen&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fbattleofwitscomp00budi&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBudiansky2006" class="citation cs2"><a href="/wiki/Stephen_Budiansky" title="Stephen Budiansky">Budiansky, Stephen</a> (2006), <i>Colossus, Codebreaking, and the Digital Age</i>, pp. 52–63</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Colossus%2C+Codebreaking%2C+and+the+Digital+Age&rft.pages=52-63&rft.date=2006&rft.aulast=Budiansky&rft.aufirst=Stephen&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> in <a href="#CITEREFCopeland2006">Copeland (2006)</a></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCarter2008" class="citation cs2">Carter, Frank (2008), <i>Codebreaking with the Colossus Computer</i>, Bletchley Park Reports, vol. 1 (New ed.), Bletchley Park Trust, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1-906723-00-2" title="Special:BookSources/978-1-906723-00-2"><bdi>978-1-906723-00-2</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Codebreaking+with+the+Colossus+Computer&rft.series=Bletchley+Park+Reports&rft.edition=New&rft.pub=Bletchley+Park+Trust&rft.date=2008&rft.isbn=978-1-906723-00-2&rft.aulast=Carter&rft.aufirst=Frank&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFChandler1983" class="citation cs2">Chandler, W. W. (1983), "The Installation and Maintenance of Colossus", <i><a href="/wiki/IEEE_Annals_of_the_History_of_Computing" title="IEEE Annals of the History of Computing">IEEE Annals of the History of Computing</a></i>, <b>5</b> (3): 260–262, <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2FMAHC.1983.10083">10.1109/MAHC.1983.10083</a>, <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:15674470">15674470</a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=IEEE+Annals+of+the+History+of+Computing&rft.atitle=The+Installation+and+Maintenance+of+Colossus&rft.volume=5&rft.issue=3&rft.pages=260-262&rft.date=1983&rft_id=info%3Adoi%2F10.1109%2FMAHC.1983.10083&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A15674470%23id-name%3DS2CID&rft.aulast=Chandler&rft.aufirst=W.+W.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCoombs1983" class="citation cs2"><a href="/wiki/Allen_Coombs" title="Allen Coombs">Coombs, Allen W. M.</a> (July 1983), <a rel="nofollow" class="external text" href="http://www.ivorcatt.com/47d.htm">"The Making of Colossus"</a>, <i><a href="/wiki/IEEE_Annals_of_the_History_of_Computing" title="IEEE Annals of the History of Computing">IEEE Annals of the History of Computing</a></i>, <b>5</b> (3): 253–259, <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2FMAHC.1983.10085">10.1109/MAHC.1983.10085</a>, <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:597530">597530</a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=IEEE+Annals+of+the+History+of+Computing&rft.atitle=The+Making+of+Colossus&rft.volume=5&rft.issue=3&rft.pages=253-259&rft.date=1983-07&rft_id=info%3Adoi%2F10.1109%2FMAHC.1983.10085&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A597530%23id-name%3DS2CID&rft.aulast=Coombs&rft.aufirst=Allen+W.+M.&rft_id=http%3A%2F%2Fwww.ivorcatt.com%2F47d.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCopeland2004" class="citation cs2"><a href="/wiki/Jack_Copeland" title="Jack Copeland">Copeland, B. J.</a> (October–December 2004), "Colossus: its origins and originators", <i><a href="/wiki/IEEE_Annals_of_the_History_of_Computing" title="IEEE Annals of the History of Computing">IEEE Annals of the History of Computing</a></i>, <b>26</b> (4): 38–45, <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2FMAHC.2004.26">10.1109/MAHC.2004.26</a>, <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:20209254">20209254</a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=IEEE+Annals+of+the+History+of+Computing&rft.atitle=Colossus%3A+its+origins+and+originators&rft.volume=26&rft.issue=4&rft.pages=38-45&rft.date=2004-10%2F2004-12&rft_id=info%3Adoi%2F10.1109%2FMAHC.2004.26&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A20209254%23id-name%3DS2CID&rft.aulast=Copeland&rft.aufirst=B.+J.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCopeland2006" class="citation cs2"><a href="/wiki/Jack_Copeland" title="Jack Copeland">Copeland, B. Jack</a>, ed. (2006), <i>Colossus: The Secrets of Bletchley Park's Codebreaking Computers</i>, Oxford: Oxford University Press, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-19-284055-4" title="Special:BookSources/978-0-19-284055-4"><bdi>978-0-19-284055-4</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Colossus%3A+The+Secrets+of+Bletchley+Park%27s+Codebreaking+Computers&rft.place=Oxford&rft.pub=Oxford+University+Press&rft.date=2006&rft.isbn=978-0-19-284055-4&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCopeland_"Introduction"2006" class="citation cs2"><a href="/wiki/Jack_Copeland" title="Jack Copeland">Copeland, B. Jack</a> (2006), <i>Introduction</i></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Introduction&rft.date=2006&rft.aulast=Copeland&rft.aufirst=B.+Jack&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> in <a href="#CITEREFCopeland2006">Copeland (2006)</a></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCopeland_"Machine_against_Machine"2006" class="citation cs2"><a href="/wiki/Jack_Copeland" title="Jack Copeland">Copeland, B. Jack</a> (2006), <i>Machine against Machine</i></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Machine+against+Machine&rft.date=2006&rft.aulast=Copeland&rft.aufirst=B.+Jack&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> in <a href="#CITEREFCopeland2006">Copeland (2006)</a></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCopeland_"Turingery"2006" class="citation cs2"><a href="/wiki/Jack_Copeland" title="Jack Copeland">Copeland, B. Jack</a> (2006), <i>Turingery</i></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Turingery&rft.date=2006&rft.aulast=Copeland&rft.aufirst=B.+Jack&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> in <a href="#CITEREFCopeland2006">Copeland (2006)</a></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCopeland_et_al.2006" class="citation cs2"><a href="/wiki/Jack_Copeland" title="Jack Copeland">Copeland, B. Jack</a>; et al. (2006), <i><span></span></i>"Mr Newman's section"<i><span></span></i></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=%22Mr+Newman%27s+section%22&rft.date=2006&rft.aulast=Copeland&rft.aufirst=B.+Jack&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> in <a href="#CITEREFCopeland2006">Copeland (2006)</a></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCopeland2010" class="citation cs2"><a href="/wiki/Jack_Copeland" title="Jack Copeland">Copeland, B. Jack</a> (2010), "Colossus: Breaking the German 'Tunny' Code at Bletchley Park. An Illustrated History", <i>The Rutherford Journal</i>, <b>3</b></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Rutherford+Journal&rft.atitle=Colossus%3A+Breaking+the+German+%27Tunny%27+Code+at+Bletchley+Park.+An+Illustrated+History&rft.volume=3&rft.date=2010&rft.aulast=Copeland&rft.aufirst=B.+Jack&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCopeland2011" class="citation cs2"><a href="/wiki/Jack_Copeland" title="Jack Copeland">Copeland, B. Jack</a> (2011), <i>Colossus and the Dawning of the Computer Age</i>, pp. 305–327</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Colossus+and+the+Dawning+of+the+Computer+Age&rft.pages=305-327&rft.date=2011&rft.aulast=Copeland&rft.aufirst=B.+Jack&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> in <a href="#CITEREFErskineSmith2011">Erskine & Smith (2011)</a></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFErskineSmith2011" class="citation cs2">Erskine, Ralph; <a href="/wiki/Michael_Smith_(newspaper_reporter)" title="Michael Smith (newspaper reporter)">Smith, Michael</a>, eds. (2011), <i>The Bletchley Park Codebreakers</i>, Biteback Publishing Ltd, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9781849540780" title="Special:BookSources/9781849540780"><bdi>9781849540780</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Bletchley+Park+Codebreakers&rft.pub=Biteback+Publishing+Ltd&rft.date=2011&rft.isbn=9781849540780&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> Updated and extended version of <i>Action This Day: From Breaking of the Enigma Code to the Birth of the Modern Computer</i> Bantam Press 2001</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFensom2006" class="citation cs2">Fensom, Harry (2006), <i>How Colossus was Built and Operated – One of its Engineers Reveals its Secrets</i>, pp. 297–303</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=How+Colossus+was+Built+and+Operated+%E2%80%93+One+of+its+Engineers+Reveals+its+Secrets&rft.pages=297-303&rft.date=2006&rft.aulast=Fensom&rft.aufirst=Harry&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> in <a href="#CITEREFCopeland2006">Copeland (2006)</a></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFlowers1983" class="citation cs2"><a href="/wiki/Tommy_Flowers" title="Tommy Flowers">Flowers, Thomas H.</a> (1983), <a rel="nofollow" class="external text" href="http://www.ivorcatt.com/47c.htm">"The Design of Colossus"</a>, <i>Annals of the History of Computing</i>, <b>5</b> (3): 239–252, <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2FMAHC.1983.10079">10.1109/MAHC.1983.10079</a>, <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:39816473">39816473</a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Annals+of+the+History+of+Computing&rft.atitle=The+Design+of+Colossus&rft.volume=5&rft.issue=3&rft.pages=239-252&rft.date=1983&rft_id=info%3Adoi%2F10.1109%2FMAHC.1983.10079&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A39816473%23id-name%3DS2CID&rft.aulast=Flowers&rft.aufirst=Thomas+H.&rft_id=http%3A%2F%2Fwww.ivorcatt.com%2F47c.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFlowers2006" class="citation cs2">Flowers, Thomas H. (2006), <i>Colossus</i></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Colossus&rft.date=2006&rft.aulast=Flowers&rft.aufirst=Thomas+H.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> in <a href="#CITEREFCopeland2006">Copeland (2006)</a></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGannon2007" class="citation cs2">Gannon, Paul (2007), <i>Colossus: Bletchley Park's Greatest Secret</i>, London: Atlantic Books, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1-84354-331-2" title="Special:BookSources/978-1-84354-331-2"><bdi>978-1-84354-331-2</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Colossus%3A+Bletchley+Park%27s+Greatest+Secret&rft.place=London&rft.pub=Atlantic+Books&rft.date=2007&rft.isbn=978-1-84354-331-2&rft.aulast=Gannon&rft.aufirst=Paul&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGCHQ2024" class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.gchq.gov.uk/news/colossus-80">"GCHQ Celebrates 80 Years of Colossus"</a>. GCHQ. 18 January 2024<span class="reference-accessdate">. Retrieved <span class="nowrap">21 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=GCHQ+Celebrates+80+Years+of+Colossus&rft.pub=GCHQ&rft.date=2024-01-18&rft_id=https%3A%2F%2Fwww.gchq.gov.uk%2Fnews%2Fcolossus-80&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGoldstine1980" class="citation cs2"><a href="/wiki/Herman_H._Goldstine" class="mw-redirect" title="Herman H. Goldstine">Goldstine, Herman H.</a> (1980), <i>The Computer from Pascal to von Neumann</i>, Princeton University Press, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-691-02367-0" title="Special:BookSources/978-0-691-02367-0"><bdi>978-0-691-02367-0</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Computer+from+Pascal+to+von+Neumann&rft.pub=Princeton+University+Press&rft.date=1980&rft.isbn=978-0-691-02367-0&rft.aulast=Goldstine&rft.aufirst=Herman+H.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGoodMichieTimms1945" class="citation cs2"><a href="/wiki/I._J._Good" title="I. J. Good">Good, Jack</a>; <a href="/wiki/Donald_Michie" title="Donald Michie">Michie, Donald</a>; Timms, Geoffrey (1945), <i>General Report on Tunny: With Emphasis on Statistical Methods</i>, UK Public Record Office HW 25/4 and HW 25/5</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=General+Report+on+Tunny%3A+With+Emphasis+on+Statistical+Methods&rft.date=1945&rft.aulast=Good&rft.aufirst=Jack&rft.au=Michie%2C+Donald&rft.au=Timms%2C+Geoffrey&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20100917074406/http://www.alanturing.net/turing_archive/archive/index/tunnyreportindex.html">"(facsimile)"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.alanturing.net/turing_archive/archive/index/tunnyreportindex.html">the original</a> on 17 September 2010<span class="reference-accessdate">. Retrieved <span class="nowrap">15 September</span> 2010</span> – via AlanTuring.net.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=%28facsimile%29&rft_id=http%3A%2F%2Fwww.alanturing.net%2Fturing_archive%2Farchive%2Findex%2Ftunnyreportindex.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a href="/wiki/Anthony_Sale" class="mw-redirect" title="Anthony Sale">Sale, Tony</a> (2001). <a rel="nofollow" class="external text" href="http://www.codesandciphers.org.uk/documents/newman/newman.pdf">"Part of the "General Report on Tunny", the Newmanry History, formatted by Tony Sale"</a> <span class="cs1-format">(PDF)</span>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20050515031645/http://www.codesandciphers.org.uk/documents/newman/newman.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on 15 May 2005<span class="reference-accessdate">. Retrieved <span class="nowrap">20 September</span> 2010</span> – via codesandciphers.org.uk.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Part+of+the+%22General+Report+on+Tunny%22%2C+the+Newmanry+History%2C+formatted+by+Tony+Sale&rft.date=2001&rft.aulast=Sale&rft.aufirst=Tony&rft_id=http%3A%2F%2Fwww.codesandciphers.org.uk%2Fdocuments%2Fnewman%2Fnewman.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.ellsbury.com/tunny/tunny-001.htm">"General Report on Tunny, Part 1"</a>. Graham Ellsbury<span class="reference-accessdate">. Retrieved <span class="nowrap">30 November</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=General+Report+on+Tunny%2C+Part+1&rft.pub=Graham+Ellsbury&rft_id=http%3A%2F%2Fwww.ellsbury.com%2Ftunny%2Ftunny-001.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.ellsbury.com/tunny/tunny-037.htm">"General Report on Tunny, Part 2"</a>. Graham Ellsbury<span class="reference-accessdate">. Retrieved <span class="nowrap">30 November</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=General+Report+on+Tunny%2C+Part+2&rft.pub=Graham+Ellsbury&rft_id=http%3A%2F%2Fwww.ellsbury.com%2Ftunny%2Ftunny-037.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li></ul></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGood1979" class="citation cs2"><a href="/wiki/I._J._Good" title="I. J. Good">Good, I. J.</a> (1979), "Early Work on Computers at Bletchley", <i>IEEE Annals of the History of Computing</i>, <b>1</b> (1): 38–48, <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2FMAHC.1979.10011">10.1109/MAHC.1979.10011</a>, <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:22670337">22670337</a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=IEEE+Annals+of+the+History+of+Computing&rft.atitle=Early+Work+on+Computers+at+Bletchley&rft.volume=1&rft.issue=1&rft.pages=38-48&rft.date=1979&rft_id=info%3Adoi%2F10.1109%2FMAHC.1979.10011&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A22670337%23id-name%3DS2CID&rft.aulast=Good&rft.aufirst=I.+J.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGood1980" class="citation cs2"><a href="/wiki/I._J._Good" title="I. J. Good">Good, I. J.</a> (1980), "Pioneering Work on Computers at Bletchley", in Metropolis, Nicholas; Howlett, J.; Rota, Gian-Carlo (eds.), <span class="id-lock-registration" title="Free registration required"><a rel="nofollow" class="external text" href="https://archive.org/details/historyofcomputi0000inte"><i>A History of Computing in the Twentieth Century</i></a></span>, New York: Academic Press, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0124916503" title="Special:BookSources/0124916503"><bdi>0124916503</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Pioneering+Work+on+Computers+at+Bletchley&rft.btitle=A+History+of+Computing+in+the+Twentieth+Century&rft.place=New+York&rft.pub=Academic+Press&rft.date=1980&rft.isbn=0124916503&rft.aulast=Good&rft.aufirst=I.+J.&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fhistoryofcomputi0000inte&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKenyon2019" class="citation book cs1">Kenyon, David (2019). <i>Bletchley Park and D-Day: The Untold Story of How the Battle for Normandy Was Won</i>. New Haven and London: Yale University Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-300-24357-4" title="Special:BookSources/978-0-300-24357-4"><bdi>978-0-300-24357-4</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Bletchley+Park+and+D-Day%3A+The+Untold+Story+of+How+the+Battle+for+Normandy+Was+Won&rft.place=New+Haven+and+London&rft.pub=Yale+University+Press&rft.date=2019&rft.isbn=978-0-300-24357-4&rft.aulast=Kenyon&rft.aufirst=David&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMcKay2010" class="citation cs2">McKay, Sinclair (2010), <i>The Secret Life of Bletchley Park: The WWII Codebreaking Centre and the men and women who worked there</i>, London: Aurum Press, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9781845135393" title="Special:BookSources/9781845135393"><bdi>9781845135393</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Secret+Life+of+Bletchley+Park%3A+The+WWII+Codebreaking+Centre+and+the+men+and+women+who+worked+there&rft.place=London&rft.pub=Aurum+Press&rft.date=2010&rft.isbn=9781845135393&rft.aulast=McKay&rft.aufirst=Sinclair&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRandell1982" class="citation cs2"><a href="/wiki/Brian_Randell" title="Brian Randell">Randell, Brian</a> (1982) [1977], "Colossus: Godfather of the Computer", <i>The Origins of Digital Computers: Selected Papers</i>, New York: <a href="/wiki/Springer_Science%2BBusiness_Media" title="Springer Science+Business Media">Springer-Verlag</a>, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9783540113195" title="Special:BookSources/9783540113195"><bdi>9783540113195</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Colossus%3A+Godfather+of+the+Computer&rft.btitle=The+Origins+of+Digital+Computers%3A+Selected+Papers&rft.place=New+York&rft.pub=Springer-Verlag&rft.date=1982&rft.isbn=9783540113195&rft.aulast=Randell&rft.aufirst=Brian&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRandell1980" class="citation cs2"><a href="/wiki/Brian_Randell" title="Brian Randell">Randell, Brian</a> (1980), <a rel="nofollow" class="external text" href="http://www.cs.ncl.ac.uk/publications/books/papers/133.pdf">"The Colossus"</a> <span class="cs1-format">(PDF)</span>, in <a href="/wiki/Nicholas_Metropolis" title="Nicholas Metropolis">Metropolis, N.</a>; <a href="/wiki/Jack_Howlett" title="Jack Howlett">Howlett, J.</a>; <a href="/wiki/Gian-Carlo_Rota" title="Gian-Carlo Rota">Rota, Gian-Carlo</a> (eds.), <a rel="nofollow" class="external text" href="https://archive.org/details/historyofcomputi0000inte/page/47"><i>A History of Computing in the Twentieth Century</i></a>, Elsevier Science, pp. <a rel="nofollow" class="external text" href="https://archive.org/details/historyofcomputi0000inte/page/47">47–92</a>, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0124916500" title="Special:BookSources/978-0124916500"><bdi>978-0124916500</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=The+Colossus&rft.btitle=A+History+of+Computing+in+the+Twentieth+Century&rft.pages=47-92&rft.pub=Elsevier+Science&rft.date=1980&rft.isbn=978-0124916500&rft.aulast=Randell&rft.aufirst=Brian&rft_id=http%3A%2F%2Fwww.cs.ncl.ac.uk%2Fpublications%2Fbooks%2Fpapers%2F133.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRandell2006" class="citation cs2"><a href="/wiki/Brian_Randell" title="Brian Randell">Randell, Brian</a> (2006), <i>Of Men and Machines</i>, pp. 141–149</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Of+Men+and+Machines&rft.pages=141-149&rft.date=2006&rft.aulast=Randell&rft.aufirst=Brian&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> in <a href="#CITEREFCopeland2006">Copeland (2006)</a></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSale2000" class="citation cs2"><a href="/wiki/Tony_Sale" title="Tony Sale">Sale, Tony</a> (2000), "The Colossus of Bletchley Park – The German Cipher System", in Rojas, Raúl; Hashagen, Ulf (eds.), <i>The First Computers: History and Architecture</i>, Cambridge, Massachusetts: The MIT Press, pp. 351–364, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-262-18197-5" title="Special:BookSources/0-262-18197-5"><bdi>0-262-18197-5</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=The+Colossus+of+Bletchley+Park+%E2%80%93+The+German+Cipher+System&rft.btitle=The+First+Computers%3A+History+and+Architecture&rft.place=Cambridge%2C+Massachusetts&rft.pages=351-364&rft.pub=The+MIT+Press&rft.date=2000&rft.isbn=0-262-18197-5&rft.aulast=Sale&rft.aufirst=Tony&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSmall1944" class="citation cs2">Small, Albert W. (December 1944), <a rel="nofollow" class="external text" href="http://www.codesandciphers.org.uk/documents/small/smallix.htm"><i>The Special Fish Report</i></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Special+Fish+Report&rft.date=1944-12&rft.aulast=Small&rft.aufirst=Albert+W.&rft_id=http%3A%2F%2Fwww.codesandciphers.org.uk%2Fdocuments%2Fsmall%2Fsmallix.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> describes the operation of Colossus in breaking Tunny messages</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFTutte2006" class="citation cs2"><a href="/wiki/W._T._Tutte" title="W. T. Tutte">Tutte, William T.</a> (2006), <i>Appendix 4: My Work at Bletchley Park</i>, pp. 352–369</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Appendix+4%3A+My+Work+at+Bletchley+Park&rft.pages=352-369&rft.date=2006&rft.aulast=Tutte&rft.aufirst=William+T.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> in <a href="#CITEREFCopeland2006">Copeland (2006)</a></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWells2004" class="citation cs2">Wells, B (2004), "A Universal Turing Machine Can Run on a Cluster of Colossi", <i>Abstracts of the American Mathematical Society</i>, <b>25</b>: 441</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Abstracts+of+the+American+Mathematical+Society&rft.atitle=A+Universal+Turing+Machine+Can+Run+on+a+Cluster+of+Colossi&rft.volume=25&rft.pages=441&rft.date=2004&rft.aulast=Wells&rft.aufirst=B&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWells2006" class="citation cs2">Wells, Benjamin (2006), <i><span></span></i>"The PC-User's Guide to Colossus"<i><span></span></i>, pp. 116–140</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=%22The+PC-User%27s+Guide+to+Colossus%22&rft.pages=116-140&rft.date=2006&rft.aulast=Wells&rft.aufirst=Benjamin&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> in <a href="#CITEREFCopeland2006">Copeland (2006)</a></li></ul> </div> <div class="mw-heading mw-heading2"><h2 id="Further_reading">Further reading</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=12" title="Edit section: Further reading"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCampaigneFarley1990" class="citation cs2">Campaigne, Howard; Farley, Robert D. (28 February 1990), <a rel="nofollow" class="external text" href="https://www.nsa.gov/news-features/declassified-documents/oral-history-interviews/assets/files/nsa-oh-14-83-campaigne.pdf"><i>Oral History Interview: NSA-OH-14-83 Campaigne, Howard, Dr. 29 June 83 Annopalis, MD By: Robert G. Farley</i></a> <span class="cs1-format">(PDF)</span>, National Security Agency<span class="reference-accessdate">, retrieved <span class="nowrap">16 October</span> 2016</span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Oral+History+Interview%3A+NSA-OH-14-83+Campaigne%2C+Howard%2C+Dr.+29+June+83+Annopalis%2C+MD+By%3A+Robert+G.+Farley&rft.pub=National+Security+Agency&rft.date=1990-02-28&rft.aulast=Campaigne&rft.aufirst=Howard&rft.au=Farley%2C+Robert+D.&rft_id=https%3A%2F%2Fwww.nsa.gov%2Fnews-features%2Fdeclassified-documents%2Foral-history-interviews%2Fassets%2Ffiles%2Fnsa-oh-14-83-campaigne.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=knXWMjIA59c"><span class="plainlinks">Colossus: Creating a Giant</span></a> on <a href="/wiki/YouTube_video_(identifier)" class="mw-redirect" title="YouTube video (identifier)">YouTube</a> A short film made by Google to celebrate Colossus and those who built it, in particular Tommy Flowers.</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCragon2003" class="citation cs2">Cragon, Harvey G. (2003), <i>From Fish to Colossus: How the German Lorenz Cipher was Broken at Bletchley Park</i>, Dallas: Cragon Books, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-9743045-0-6" title="Special:BookSources/0-9743045-0-6"><bdi>0-9743045-0-6</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=From+Fish+to+Colossus%3A+How+the+German+Lorenz+Cipher+was+Broken+at+Bletchley+Park&rft.place=Dallas&rft.pub=Cragon+Books&rft.date=2003&rft.isbn=0-9743045-0-6&rft.aulast=Cragon&rft.aufirst=Harvey+G.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> – A detailed description of the cryptanalysis of Tunny, and some details of Colossus (contains some minor errors)</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFEnever1999" class="citation cs2">Enever, Ted (1999), <i>Britain's Best Kept Secret: Ultra's Base at Bletchley Park</i> (3rd ed.), Sutton Publishing, Gloucestershire, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-7509-2355-2" title="Special:BookSources/978-0-7509-2355-2"><bdi>978-0-7509-2355-2</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Britain%27s+Best+Kept+Secret%3A+Ultra%27s+Base+at+Bletchley+Park&rft.edition=3rd&rft.pub=Sutton+Publishing%2C+Gloucestershire&rft.date=1999&rft.isbn=978-0-7509-2355-2&rft.aulast=Enever&rft.aufirst=Ted&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li></ul> <dl><dd><dl><dd><dl><dd>A guided tour of the history and geography of the Park, written by one of the founder members of the Bletchley Park Trust</dd></dl></dd></dl></dd></dl> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGannon2006" class="citation book cs1">Gannon, Paul (2006). <i>Colossus: Bletchley Park's Greatest Secret</i>. London: Atlantic Books. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/1-84354-330-3" title="Special:BookSources/1-84354-330-3"><bdi>1-84354-330-3</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Colossus%3A+Bletchley+Park%27s+Greatest+Secret&rft.place=London&rft.pub=Atlantic+Books&rft.date=2006&rft.isbn=1-84354-330-3&rft.aulast=Gannon&rft.aufirst=Paul&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPrice2021" class="citation book cs1">Price, David A. (2021). <a rel="nofollow" class="external text" href="https://www.kirkusreviews.com/book-reviews/david-a-price/geniuses-at-war/"><i>Geniuses at War; Bletchley Park, Colossus, and the Dawn of the Digital Age</i></a>. New York: Knopf. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-525-52154-9" title="Special:BookSources/978-0-525-52154-9"><bdi>978-0-525-52154-9</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Geniuses+at+War%3B+Bletchley+Park%2C+Colossus%2C+and+the+Dawn+of+the+Digital+Age&rft.place=New+York&rft.pub=Knopf&rft.date=2021&rft.isbn=978-0-525-52154-9&rft.aulast=Price&rft.aufirst=David+A.&rft_id=https%3A%2F%2Fwww.kirkusreviews.com%2Fbook-reviews%2Fdavid-a-price%2Fgeniuses-at-war%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRojasHashagen2000" class="citation cs2">Rojas, R.; Hashagen, U. (2000), <i>The First Computers: History and Architectures</i>, MIT Press, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-262-18197-5" title="Special:BookSources/0-262-18197-5"><bdi>0-262-18197-5</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+First+Computers%3A+History+and+Architectures&rft.pub=MIT+Press&rft.date=2000&rft.isbn=0-262-18197-5&rft.aulast=Rojas&rft.aufirst=R.&rft.au=Hashagen%2C+U.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> – Comparison of the first computers, with a chapter about Colossus and its reconstruction by Tony Sale.</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSale2004" class="citation cs2"><a href="/wiki/Tony_Sale" title="Tony Sale">Sale, Tony</a> (2004), <i>The Colossus Computer 1943–1996: How It Helped to Break the German Lorenz Cipher in WWII</i>, Kidderminster: M.&M. Baldwin, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-947712-36-4" title="Special:BookSources/0-947712-36-4"><bdi>0-947712-36-4</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Colossus+Computer+1943%E2%80%931996%3A+How+It+Helped+to+Break+the+German+Lorenz+Cipher+in+WWII&rft.place=Kidderminster&rft.pub=M.%26M.+Baldwin&rft.date=2004&rft.isbn=0-947712-36-4&rft.aulast=Sale&rft.aufirst=Tony&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span> A slender (20-page) booklet, containing the same material as Tony Sale's website (see below)</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSmith2007" class="citation cs2"><a href="/wiki/Michael_Smith_(newspaper_reporter)" title="Michael Smith (newspaper reporter)">Smith, Michael</a> (2007) [1998], <i>Station X: The Codebreakers of Bletchley Park</i>, Pan Grand Strategy Series (Pan Books ed.), London: Pan MacMillan Ltd, <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-330-41929-1" title="Special:BookSources/978-0-330-41929-1"><bdi>978-0-330-41929-1</bdi></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Station+X%3A+The+Codebreakers+of+Bletchley+Park&rft.place=London&rft.series=Pan+Grand+Strategy+Series&rft.edition=Pan+Books&rft.pub=Pan+MacMillan+Ltd&rft.date=2007&rft.isbn=978-0-330-41929-1&rft.aulast=Smith&rft.aufirst=Michael&rfr_id=info%3Asid%2Fen.wikipedia.org%3AColossus+computer" class="Z3988"></span></li></ul> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Colossus_computer&action=edit&section=13" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1235681985">.mw-parser-output .side-box{margin:4px 0;box-sizing:border-box;border:1px solid #aaa;font-size:88%;line-height:1.25em;background-color:var(--background-color-interactive-subtle,#f8f9fa);display:flow-root}.mw-parser-output .side-box-abovebelow,.mw-parser-output .side-box-text{padding:0.25em 0.9em}.mw-parser-output .side-box-image{padding:2px 0 2px 0.9em;text-align:center}.mw-parser-output .side-box-imageright{padding:2px 0.9em 2px 0;text-align:center}@media(min-width:500px){.mw-parser-output .side-box-flex{display:flex;align-items:center}.mw-parser-output .side-box-text{flex:1;min-width:0}}@media(min-width:720px){.mw-parser-output .side-box{width:238px}.mw-parser-output .side-box-right{clear:right;float:right;margin-left:1em}.mw-parser-output .side-box-left{margin-right:1em}}</style><style data-mw-deduplicate="TemplateStyles:r1237033735">@media print{body.ns-0 .mw-parser-output .sistersitebox{display:none!important}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}</style><div class="side-box side-box-right plainlinks sistersitebox"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"> <div class="side-box-flex"> <div class="side-box-image"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png" decoding="async" width="30" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/45px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/59px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span></div> <div class="side-box-text plainlist">Wikimedia Commons has media related to <span style="font-weight: bold; font-style: italic;"><a href="https://commons.wikimedia.org/wiki/Category:Colossus_computer" class="extiw" title="commons:Category:Colossus computer">Colossus computer</a></span>.</div></div> </div> <ul><li><a rel="nofollow" class="external text" href="http://curation.cs.manchester.ac.uk/computer50/www.computer50.org/mark1/contemporary.html">Early computer development</a></li> <li><a rel="nofollow" class="external text" href="http://www.tnmoc.org/">The National Museum of Computing (TNMOC)</a> <ul><li><a rel="nofollow" class="external text" href="http://www.tnmoc.org/news/news-releases/colossus-decrypts-be-revealed-after-75-years/">TNMOC: The 75th anniversary of the first attack</a></li></ul></li> <li><a rel="nofollow" class="external text" href="http://www.codesandciphers.org.uk/index.htm">Tony Sale's Codes and Ciphers</a> Contains a great deal of information, including: <ul><li><a rel="nofollow" class="external text" href="http://www.codesandciphers.org.uk/virtualbp/fish/colossus.htm">Colossus, the revolution in code breaking</a></li> <li><a rel="nofollow" class="external text" href="http://www.codesandciphers.org.uk/lorenz/index.htm">Lorenz Cipher and the Colossus</a> <ul><li><a rel="nofollow" class="external text" href="http://www.codesandciphers.org.uk/lorenz/colossus.htm">The machine age comes to Fish codebreaking</a></li> <li><a rel="nofollow" class="external text" href="http://www.codesandciphers.org.uk/lorenz/rebuild.htm">The Colossus Rebuild Project</a></li> <li><a rel="nofollow" class="external text" href="http://www.codesandciphers.org.uk/lorenz/mk2.htm">The Colossus Rebuild Project: Evolving to the Colossus Mk 2</a></li> <li><a rel="nofollow" class="external text" href="http://www.codesandciphers.org.uk/lorenz/colwalk/colossus.htm">Walk around Colossus</a> A detailed tour of the replica Colossus – make sure to click on the "More Text" links on each image to see the informative detailed text about that part of Colossus</li></ul></li> <li><a rel="nofollow" class="external text" href="http://www.codesandciphers.org.uk/lectures/ieee.txt">IEEE lecture</a> – Transcript of a lecture Tony Sale gave describing the reconstruction project</li></ul></li> <li><a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=WCeLTWPCEFI">Brian Randell's 1976 lecture on the Colossus</a></li> <li><a rel="nofollow" class="external text" href="http://news.bbc.co.uk/1/hi/technology/3754887.stm">BBC news article reporting on the replica Colossus</a></li> <li><a rel="nofollow" class="external text" href="http://news.bbc.co.uk/1/hi/technology/7094881.stm">BBC news article: "Colossus cracks codes once more"</a></li> <li><a rel="nofollow" class="external text" href="http://news.bbc.co.uk/1/hi/technology/8492762.stm">BBC news article: BBC news article: "Bletchley's code-cracking Colossus" with video interviews 2010-02-02</a></li> <li><a rel="nofollow" class="external text" href="http://www.colossus-computer.com/contents.htm">Website on Copeland's 2006 book</a> with much information and links to recently declassified information</li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20081031050216/http://www.bcs.org/upload/pdf/ewic_tur04_paper3.pdf">Was the Manchester Baby conceived at Bletchley Park?</a></li> <li><a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=NWYzwIjSk6s"><span class="plainlinks">Walk through video of the Colossus rebuild at Bletchley Park</span></a> on <a href="/wiki/YouTube_video_(identifier)" class="mw-redirect" title="YouTube video (identifier)">YouTube</a></li> <li><a rel="nofollow" class="external text" href="http://www.virtualcolossus.co.uk">online virtual simulation of Colossus</a></li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist 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class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/SILLIAC" title="SILLIAC">SILLIAC</a> (1956)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Israel</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/WEIZAC" title="WEIZAC">WEIZAC</a> (1955)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Japan</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/FACOM" title="FACOM">FACOM</a> (1954)</li> <li><a href="/wiki/FUJIC" title="FUJIC">FUJIC</a> (1949)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Sweden</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/SARA_(computer)" title="SARA (computer)">SARA</a> (1957)</li> <li><a href="/wiki/SMIL_(computer)" title="SMIL (computer)">SMIL</a> (1956)</li> <li><a href="/wiki/FACIT_EDB" title="FACIT EDB">EDB-1</a> (1957)</li> <li><a href="/wiki/TRASK_(computer)" title="TRASK (computer)">TRASK</a> (1964)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Soviet Union</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/BESM-6" title="BESM-6">BESM-6</a></li> <li><a href="/w/index.php?title=ES-2701&action=edit&redlink=1" class="new" title="ES-2701 (page does not exist)">ES-2701</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://ru.wikipedia.org/wiki/%D0%95%D0%A1-2701" class="extiw" title="ru:ЕС-2701">ru</a>]</span></li> <li><a href="/w/index.php?title=Mars_(computer)&action=edit&redlink=1" class="new" title="Mars (computer) (page does not exist)">Mars</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://ru.wikipedia.org/wiki/%D0%9C%D0%90%D0%A0%D0%A1_(%D0%BA%D0%BE%D0%BC%D0%BF%D1%8C%D1%8E%D1%82%D0%B5%D1%80)" class="extiw" title="ru:МАРС (компьютер)">ru</a>]</span></li> <li><a href="/wiki/PS-2000" title="PS-2000">PS-2000</a></li> <li><a href="/w/index.php?title=PS-3000&action=edit&redlink=1" class="new" title="PS-3000 (page does not exist)">PS-3000</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://ru.wikipedia.org/wiki/%D0%9F%D0%A1-3000" class="extiw" title="ru:ПС-3000">ru</a>]</span></li> <li><a href="/w/index.php?title=SVS_(computer)&action=edit&redlink=1" class="new" title="SVS (computer) (page does not exist)">SVS</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://ru.wikipedia.org/wiki/%D0%A1%D0%92%D0%A1_(%D0%BA%D0%BE%D0%BC%D0%BF%D1%8C%D1%8E%D1%82%D0%B5%D1%80)" class="extiw" title="ru:СВС (компьютер)">ru</a>]</span></li> <li><a href="/wiki/Elbrus_(computer)" title="Elbrus (computer)">Elbrus</a></li> <li><a href="/w/index.php?title=Electronika_SS_VLSI&action=edit&redlink=1" class="new" title="Electronika SS VLSI (page does not exist)">Electronika SS VLSI</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://ru.wikipedia.org/wiki/%D0%AD%D0%BB%D0%B5%D0%BA%D1%82%D1%80%D0%BE%D0%BD%D0%B8%D0%BA%D0%B0_%D0%A1%D0%A1_%D0%91%D0%98%D0%A1" class="extiw" title="ru:Электроника СС БИС">ru</a>]</span></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">See also</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Template:List_of_Soviet_computer_systems" title="Template:List of Soviet computer systems">Soviet computer systems</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">United States</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/IAS_machine" title="IAS machine">IAS family</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th id="1950s" scope="row" class="navbox-group" style="width:1%">1950s</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/ILLIAC" title="ILLIAC">ILLIAC</a> (1952)</li> <li><a href="/wiki/AVIDAC" title="AVIDAC">AVIDAC</a> (1953)</li> <li><a href="/wiki/BESK" title="BESK">BESK</a> (1953)</li> <li><a href="/wiki/IBM_701" title="IBM 701">IBM 701</a> (1953)</li> <li><a href="/wiki/JOHNNIAC" title="JOHNNIAC">JOHNNIAC</a> (1953)</li> <li><a href="/wiki/ORACLE_(computer)" title="ORACLE (computer)">ORACLE</a> (1953)</li> <li><a href="/wiki/ORDVAC" title="ORDVAC">ORDVAC</a> (1952)</li> <li><a href="/wiki/WEIZAC" title="WEIZAC">WEIZAC</a> (1955)</li> <li><a href="/wiki/DASK" title="DASK">DASK</a> (1955)</li> <li><a href="/wiki/SARA_(computer)" title="SARA (computer)">SARA</a> (1957)</li> <li><a href="/wiki/SILLIAC" title="SILLIAC">SILLIAC</a> (1956)</li> <li><a href="/wiki/SMIL_(computer)" title="SMIL (computer)">SMIL</a> (1956)</li> <li><a href="/wiki/MANIAC_I" title="MANIAC I">MANIAC I</a> (1956)</li> <li><a href="/wiki/MANIAC_II" title="MANIAC II">MANIAC II</a> (1956)</li> <li><a href="/wiki/MISTIC" title="MISTIC">MISTIC</a> (1957)</li> <li><a href="/wiki/MUSASINO-1" title="MUSASINO-1">MUSASINO-1</a> (1957)</li> <li><a href="/wiki/FACIT_EDB" title="FACIT EDB">EDB-1</a> (1957)</li> <li><a href="/wiki/FACIT_EDB" title="FACIT EDB">EDB-2/3</a> (1957)</li> <li><a href="/wiki/Cyclone_(computer)" title="Cyclone (computer)">Cyclone</a> (1959)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">1960s</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/w/index.php?title=FACOM_201&action=edit&redlink=1" class="new" title="FACOM 201 (page does not exist)">FACOM 201</a> (1960)</li> <li><a href="/wiki/TRASK_(computer)" title="TRASK (computer)">TRASK</a> (1964)</li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/University_of_Illinois_Urbana-Champaign" title="University of Illinois Urbana-Champaign">University of Illinois</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/ORDVAC" title="ORDVAC">ORDVAC</a> (1952)</li> <li><a href="/wiki/ILLIAC_I" title="ILLIAC I">ILLIAC I</a> (1952)</li> <li><a href="/wiki/ILLIAC_II" title="ILLIAC II">ILLIAC II</a> (1958)</li> <li><a href="/wiki/ILLIAC_III" title="ILLIAC III">ILLIAC III</a> (1966)</li> <li><a href="/wiki/ILLIAC_IV" title="ILLIAC IV">ILLIAC IV</a> (1965)</li> <li><a href="/wiki/ILLIAC#CEDAR" title="ILLIAC">CEDAR</a> (1988)</li> <li><a href="/wiki/ILLIAC#ILLIAC_6" title="ILLIAC">ILLIAC 6</a> (2005)</li> <li><a href="/wiki/ILLIAC#Trusted_ILLIAC" title="ILLIAC">Trusted ILLIAC</a> (2006)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Harvard_University" title="Harvard University">Harvard University</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Harvard_Mark_I" title="Harvard Mark I">Harvard Mark I</a> (1944)</li> <li><a href="/wiki/Harvard_Mark_II" title="Harvard Mark II">Harvard Mark II</a> (1947)</li> <li><a href="/wiki/Harvard_Mark_III" title="Harvard Mark III">Harvard Mark III</a> (1949)</li> <li><a href="/wiki/Harvard_Mark_IV" title="Harvard Mark IV">Harvard Mark IV</a> (1952)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">IBM</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"><div class="navbox-styles"></div><div role="navigation" class="navbox" aria-labelledby="IBM_vacuum_tube_computers" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:IBM_vacuum_tube_computers" title="Template:IBM vacuum tube computers"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:IBM_vacuum_tube_computers" title="Template talk:IBM vacuum tube computers"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:IBM_vacuum_tube_computers" title="Special:EditPage/Template:IBM vacuum tube computers"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="IBM_vacuum_tube_computers" style="font-size:114%;margin:0 4em">IBM vacuum tube computers</div></th></tr><tr><td colspan="2" class="navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/IBM_305_RAMAC" title="IBM 305 RAMAC">305 RAMAC</a></li> <li><a href="/wiki/IBM_610" title="IBM 610">610</a></li> <li><a href="/wiki/IBM_650" title="IBM 650">650</a></li> <li><a href="/wiki/IBM_701" title="IBM 701">701</a></li> <li><a href="/wiki/IBM_702" title="IBM 702">702</a></li> <li><a href="/wiki/IBM_704" title="IBM 704">704</a></li> <li><a href="/wiki/IBM_705" class="mw-redirect" title="IBM 705">705</a></li> <li><a href="/wiki/IBM_709" title="IBM 709">709</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Semi-Automatic_Ground_Environment" title="Semi-Automatic Ground Environment">SAGE</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/AN/FSQ-7_Combat_Direction_Central" title="AN/FSQ-7 Combat Direction Central">AN/FSQ-7</a></li> <li><a href="/wiki/AN/FSQ-8_Combat_Control_Central" title="AN/FSQ-8 Combat Control Central">AN/FSQ-8</a></li></ul> </div></td></tr></tbody></table></div></div></td></tr><tr><td colspan="2" class="navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"><a href="/wiki/Template:IBM_mainframes" title="Template:IBM mainframes">IBM mainframes</a></div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/University_of_Pennsylvania" title="University of Pennsylvania">University of Pennsylvania</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/ENIAC" title="ENIAC">ENIAC</a> (1945)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Eckert%E2%80%93Mauchly_Computer_Corporation" title="Eckert–Mauchly Computer Corporation">EMCC</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/EDVAC" title="EDVAC">EDVAC</a> (1949)</li> <li><a href="/wiki/UNIVAC_I" title="UNIVAC I">UNIVAC I</a> (1951)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Remington_Rand" title="Remington Rand">Remington</a>/<a href="/wiki/Sperry_Rand" class="mw-redirect" title="Sperry Rand">Sperry Rand</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/UNIVAC_II" title="UNIVAC II">UNIVAC II</a></li> <li>See also: <a href="/wiki/List_of_UNIVAC_products" title="List of UNIVAC products">Computers built 1955 through 1978</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Raytheon_Technologies" class="mw-redirect" title="Raytheon Technologies">Raytheon</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/RAYDAC" title="RAYDAC">RAYDAC</a> (1953)</li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">United Kingdom</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a class="mw-selflink selflink">Colossus computer</a> (1943)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Related</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Transistor_computer" title="Transistor computer">Transistor computer</a> <ul><li><a href="/wiki/List_of_transistorized_computers" title="List of transistorized computers">list</a></li></ul></li> <li><a href="/wiki/Vacuum-tube_computer" title="Vacuum-tube computer">Vacuum-tube computer</a> <ul><li><a href="/wiki/List_of_vacuum-tube_computers" title="List of vacuum-tube computers">list</a></li></ul></li> <li><a href="/wiki/History_of_computing_hardware" title="History of computing hardware">History of computing hardware</a></li> <li><a href="/wiki/History_of_computing_hardware_(1960s%E2%80%93present)" title="History of computing hardware (1960s–present)">History of computing hardware (1960s–present)</a></li> <li><a href="/wiki/List_of_pioneers_in_computer_science" title="List of pioneers in computer science">List of pioneers in computer science</a></li></ul> </div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" 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Template:Cite_web"," 9.51% 132.660 1 Template:Mainframes"," 9.10% 126.941 1 Template:Infobox_information_appliance"," 8.61% 120.085 1 Template:Infobox"," 7.17% 99.973 1 Template:Short_description"]},"scribunto":{"limitreport-timeusage":{"value":"0.873","limit":"10.000"},"limitreport-memusage":{"value":10534447,"limit":52428800},"limitreport-logs":"anchor_id_list = table#1 {\n [\"CITEREFAnderson2007\"] = 1,\n [\"CITEREFAtkinson2010\"] = 1,\n [\"CITEREFBarber2015\"] = 1,\n [\"CITEREFBoden2000\"] = 1,\n [\"CITEREFBudiansky2000\"] = 1,\n [\"CITEREFBudiansky2006\"] = 1,\n [\"CITEREFCampaigneFarley1990\"] = 1,\n [\"CITEREFCampbell-Kelly2011\"] = 1,\n [\"CITEREFCarter2008\"] = 1,\n [\"CITEREFChandler1983\"] = 1,\n [\"CITEREFChodos2022\"] = 1,\n [\"CITEREFCoombs1983\"] = 1,\n [\"CITEREFCopeland\"] = 1,\n [\"CITEREFCopeland2004\"] = 1,\n [\"CITEREFCopeland2006\"] = 1,\n [\"CITEREFCopeland2010\"] = 1,\n [\"CITEREFCopeland2011\"] = 1,\n [\"CITEREFCopeland_\u0026quot;Introduction\u0026quot;2006\"] = 1,\n [\"CITEREFCopeland_\u0026quot;Machine_against_Machine\u0026quot;2006\"] = 1,\n [\"CITEREFCopeland_\u0026quot;Turingery\u0026quot;2006\"] = 1,\n [\"CITEREFCopeland_et_al.2006\"] = 1,\n [\"CITEREFCragon2003\"] = 1,\n [\"CITEREFEnever1999\"] = 1,\n [\"CITEREFErskineSmith2011\"] = 1,\n [\"CITEREFFensom2006\"] = 1,\n [\"CITEREFFensom2010\"] = 1,\n [\"CITEREFFlowers1983\"] = 1,\n [\"CITEREFFlowers2006\"] = 1,\n [\"CITEREFGCHQ2024\"] = 1,\n [\"CITEREFGannon2006\"] = 1,\n [\"CITEREFGannon2007\"] = 1,\n [\"CITEREFGolden1999\"] = 1,\n [\"CITEREFGoldstine1980\"] = 1,\n [\"CITEREFGood1979\"] = 1,\n [\"CITEREFGood1980\"] = 1,\n [\"CITEREFGoodMichieTimms1945\"] = 1,\n [\"CITEREFHinsleyStripp2001\"] = 1,\n [\"CITEREFHorwood1973\"] = 1,\n [\"CITEREFKenyon2019\"] = 1,\n [\"CITEREFLavington1977\"] = 1,\n [\"CITEREFMcKay2010\"] = 1,\n [\"CITEREFPreneel2000\"] = 1,\n [\"CITEREFPrice2021\"] = 1,\n [\"CITEREFRandell1980\"] = 1,\n [\"CITEREFRandell1982\"] = 1,\n [\"CITEREFRandell2006\"] = 1,\n [\"CITEREFRandellFensomMilne1995\"] = 1,\n [\"CITEREFRoberts2009\"] = 1,\n [\"CITEREFRojasHashagen2000\"] = 1,\n [\"CITEREFSale\"] = 1,\n [\"CITEREFSale2000\"] = 1,\n [\"CITEREFSale2004\"] = 1,\n [\"CITEREFSale2008\"] = 1,\n [\"CITEREFSmall1944\"] = 1,\n [\"CITEREFSmith2007\"] = 1,\n [\"CITEREFSterling2007\"] = 1,\n [\"CITEREFTutte2006\"] = 1,\n [\"CITEREFWard2007\"] = 1,\n [\"CITEREFWells2004\"] = 1,\n [\"CITEREFWells2006\"] = 1,\n [\"CITEREFWells2009\"] = 1,\n [\"CITEREFWinterbotham2000\"] = 1,\n}\ntemplate_list = table#1 {\n [\"Blockquote\"] = 5,\n [\"Cbignore\"] = 1,\n [\"Citation\"] = 49,\n [\"Citation needed\"] = 2,\n [\"Cite AV media\"] = 2,\n [\"Cite book\"] = 5,\n [\"Cite conference\"] = 1,\n [\"Cite journal\"] = 1,\n [\"Cite news\"] = 1,\n [\"Cite web\"] = 19,\n [\"Commons category\"] = 1,\n [\"Convert\"] = 1,\n [\"Distinguish\"] = 1,\n [\"Efn\"] = 7,\n [\"Frac\"] = 2,\n [\"Harvp\"] = 11,\n [\"Infobox information appliance\"] = 1,\n [\"Mainframes\"] = 1,\n [\"Notelist\"] = 1,\n [\"Plainlist\"] = 2,\n [\"Refbegin\"] = 1,\n [\"Refend\"] = 1,\n [\"Reflist\"] = 1,\n [\"See also\"] = 2,\n [\"Sfn\"] = 73,\n [\"Sfnref\"] = 5,\n [\"Short description\"] = 1,\n [\"Start date\"] = 2,\n [\"Use dmy dates\"] = 1,\n [\"YouTube\"] = 2,\n}\narticle_whitelist = table#1 {\n}\n"},"cachereport":{"origin":"mw-api-int.codfw.main-7f85796d66-xw8z2","timestamp":"20241127132821","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"Colossus computer","url":"https:\/\/en.wikipedia.org\/wiki\/Colossus_computer","sameAs":"http:\/\/www.wikidata.org\/entity\/Q770597","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q770597","author":{"@type":"Organization","name":"Contributors to Wikimedia projects"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2001-09-06T16:48:11Z","dateModified":"2024-11-14T16:18:40Z","image":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/4\/4b\/Colossus.jpg","headline":"Early British cryptanalysis computer"}</script> </body> </html>