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class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Peripheral_Expansion_Box"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>Peripheral Expansion Box</span> </div> </a> <ul id="toc-Peripheral_Expansion_Box-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Speech_synthesizer" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Speech_synthesizer"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.2</span> <span>Speech synthesizer</span> </div> </a> <ul id="toc-Speech_synthesizer-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-History" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#History"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>History</span> </div> </a> <button aria-controls="toc-History-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle History subsection</span> </button> <ul id="toc-History-sublist" class="vector-toc-list"> <li id="toc-99/4" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#99/4"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>99/4</span> </div> </a> <ul id="toc-99/4-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-99/4A" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#99/4A"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>99/4A</span> </div> </a> <ul id="toc-99/4A-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Lack_of_third-party_development" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Lack_of_third-party_development"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.3</span> <span>Lack of third-party development</span> </div> </a> <ul id="toc-Lack_of_third-party_development-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Discontinuation" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Discontinuation"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.4</span> <span>Discontinuation</span> </div> </a> <ul id="toc-Discontinuation-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Architecture" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Architecture"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Architecture</span> </div> </a> <ul id="toc-Architecture-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Technical_specifications" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Technical_specifications"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Technical specifications</span> </div> </a> <button aria-controls="toc-Technical_specifications-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Technical specifications subsection</span> </button> <ul id="toc-Technical_specifications-sublist" class="vector-toc-list"> <li id="toc-CPU" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#CPU"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.1</span> <span>CPU</span> </div> </a> <ul id="toc-CPU-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Memory" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Memory"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.2</span> <span>Memory</span> </div> </a> <ul id="toc-Memory-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Video" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Video"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.3</span> <span>Video</span> </div> </a> <ul id="toc-Video-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Sound" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Sound"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.4</span> <span>Sound</span> </div> </a> <ul id="toc-Sound-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Games" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Games"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Games</span> </div> </a> <ul id="toc-Games-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Unreleased_hardware" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Unreleased_hardware"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>Unreleased hardware</span> </div> </a> <button aria-controls="toc-Unreleased_hardware-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Unreleased hardware subsection</span> </button> <ul id="toc-Unreleased_hardware-sublist" class="vector-toc-list"> <li id="toc-Hex-Bus" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Hex-Bus"> <div class="vector-toc-text"> <span class="vector-toc-numb">7.1</span> <span>Hex-Bus</span> </div> </a> <ul id="toc-Hex-Bus-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-TI-99/4A_successors" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#TI-99/4A_successors"> <div class="vector-toc-text"> <span class="vector-toc-numb">7.2</span> <span>TI-99/4A successors</span> </div> </a> <ul id="toc-TI-99/4A_successors-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Legacy" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Legacy"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>Legacy</span> </div> </a> <button aria-controls="toc-Legacy-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Legacy subsection</span> </button> <ul id="toc-Legacy-sublist" class="vector-toc-list"> <li id="toc-Post-TI_development" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Post-TI_development"> <div class="vector-toc-text"> <span class="vector-toc-numb">8.1</span> <span>Post-TI development</span> </div> </a> <ul id="toc-Post-TI_development-sublist" class="vector-toc-list"> </ul> </li> </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-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">10</span> <span>References</span> </div> </a> <ul id="toc-References-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">11</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> 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Available in 17 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-17" 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">17 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/%D8%AA%D9%8A_%D8%A2%D9%8A-99_/4%D8%A3%D9%8A%D9%87" title="تي آي-99 /4أيه – Arabic" lang="ar" hreflang="ar" data-title="تي آي-99 /4أيه" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Texas_Instruments_TI-99/4A" title="Texas Instruments TI-99/4A – Catalan" lang="ca" hreflang="ca" data-title="Texas Instruments TI-99/4A" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-de badge-Q17437796 badge-featuredarticle mw-list-item" title="featured article badge"><a href="https://de.wikipedia.org/wiki/Texas_Instruments_TI-99/4A" title="Texas Instruments TI-99/4A – German" lang="de" hreflang="de" data-title="Texas Instruments TI-99/4A" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Texas_Instruments_TI-99/4A" title="Texas Instruments TI-99/4A – Spanish" lang="es" hreflang="es" data-title="Texas Instruments TI-99/4A" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/TI-99/4A" title="TI-99/4A – Esperanto" lang="eo" hreflang="eo" data-title="TI-99/4A" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/TI-99/4A" title="TI-99/4A – French" lang="fr" hreflang="fr" data-title="TI-99/4A" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/TI-99/4A" title="TI-99/4A – Croatian" lang="hr" hreflang="hr" data-title="TI-99/4A" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Texas_Instruments_TI-99/4A" title="Texas Instruments TI-99/4A – Italian" lang="it" hreflang="it" data-title="Texas Instruments TI-99/4A" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Texas_Instruments_TI-99/4A" title="Texas Instruments TI-99/4A – Dutch" lang="nl" hreflang="nl" data-title="Texas Instruments TI-99/4A" 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/TI-99/4A" title="TI-99/4A – Japanese" lang="ja" hreflang="ja" data-title="TI-99/4A" 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-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/TI-99/4A" title="TI-99/4A – Portuguese" lang="pt" hreflang="pt" data-title="TI-99/4A" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/TI-99/4A" title="TI-99/4A – Russian" lang="ru" hreflang="ru" data-title="TI-99/4A" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/%D0%A2%D0%B5%D0%BA%D1%81%D0%B0%D1%81_%D0%B8%D0%BD%D1%81%D1%82%D1%80%D1%83%D0%BC%D0%B5%D0%BD%D1%82%D1%81_TI-99/4A" title="Тексас инструментс TI-99/4A – Serbian" lang="sr" hreflang="sr" data-title="Тексас инструментс TI-99/4A" 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-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Texas_Instruments_TI-99/4A" title="Texas Instruments TI-99/4A – Serbo-Croatian" lang="sh" hreflang="sh" data-title="Texas Instruments TI-99/4A" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="Serbo-Croatian" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/TI-99/4A" title="TI-99/4A – Finnish" lang="fi" hreflang="fi" data-title="TI-99/4A" 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/Texas_Instruments_TI-99/4A" title="Texas Instruments TI-99/4A – Swedish" lang="sv" hreflang="sv" data-title="Texas Instruments TI-99/4A" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/TI-99/4A" title="TI-99/4A – Ukrainian" lang="uk" hreflang="uk" data-title="TI-99/4A" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q454390#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div 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.mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">"Texas Instruments home computer" redirects here. For the computer known as the Texas Instruments PC, see <a href="/wiki/Texas_Instruments_Professional_Computer" title="Texas Instruments Professional Computer">Texas Instruments Professional Computer</a>.</div> <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">TI-99/4</caption><tbody><tr><td colspan="2" class="infobox-image"><span class="mw-default-size" typeof="mw:File/Frameless"><a href="/wiki/File:TI-994_logo.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/a8/TI-994_logo.svg/250px-TI-994_logo.svg.png" decoding="async" width="220" height="55" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/a8/TI-994_logo.svg/330px-TI-994_logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/a8/TI-994_logo.svg/500px-TI-994_logo.svg.png 2x" data-file-width="512" data-file-height="128" /></a></span></td></tr><tr><td colspan="2" class="infobox-image"><span class="mw-default-size" typeof="mw:File/Frameless"><a href="/wiki/File:Texas_Instruments_TI-99-4_(white_bg).jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/25/Texas_Instruments_TI-99-4_%28white_bg%29.jpg/250px-Texas_Instruments_TI-99-4_%28white_bg%29.jpg" decoding="async" width="220" height="147" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/25/Texas_Instruments_TI-99-4_%28white_bg%29.jpg/330px-Texas_Instruments_TI-99-4_%28white_bg%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/25/Texas_Instruments_TI-99-4_%28white_bg%29.jpg/500px-Texas_Instruments_TI-99-4_%28white_bg%29.jpg 2x" data-file-width="3258" data-file-height="2172" /></a></span></td></tr><tr><th scope="row" class="infobox-label">Developer</th><td class="infobox-data"><a href="/wiki/Texas_Instruments" title="Texas Instruments">Texas Instruments</a></td></tr><tr><th scope="row" class="infobox-label">Manufacturer</th><td class="infobox-data">Texas Instruments</td></tr><tr><th scope="row" class="infobox-label">Type</th><td class="infobox-data"><a href="/wiki/Home_computer" title="Home computer">Home computer</a></td></tr><tr><th scope="row" class="infobox-label">Release date</th><td class="infobox-data">October 1979<span style="display: none;"> (<span class="bday dtstart published updated itvstart">1979-10</span>)</span></td></tr><tr><th scope="row" class="infobox-label">Introductory price</th><td class="infobox-data"><span style="white-space: nowrap">US$1,150</span> (equivalent to $4,980 in 2024)</td></tr><tr><th scope="row" class="infobox-label">Discontinued</th><td class="infobox-data">June 1981</td></tr><tr><th scope="row" class="infobox-label">Units shipped</th><td class="infobox-data">≈20,000</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"><a href="/wiki/TMS9900" title="TMS9900">TMS9900</a> @ 3 MHz</td></tr><tr><th scope="row" class="infobox-label">Graphics</th><td class="infobox-data"><a href="/wiki/TMS9918" title="TMS9918">TMS9918</a></td></tr><tr><th scope="row" class="infobox-label">Successor</th><td class="infobox-data">TI-99/4A</td></tr></tbody></table> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1257001546" /><table class="infobox hproduct vevent"><caption class="infobox-title fn summary">TI-99/4A</caption><tbody><tr><td colspan="2" class="infobox-image"><span class="mw-default-size" typeof="mw:File/Frameless"><a href="/wiki/File:TI-994A_logo.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/1/19/TI-994A_logo.svg/250px-TI-994A_logo.svg.png" decoding="async" width="220" height="45" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/19/TI-994A_logo.svg/330px-TI-994A_logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/19/TI-994A_logo.svg/500px-TI-994A_logo.svg.png 2x" data-file-width="512" data-file-height="105" /></a></span></td></tr><tr><td colspan="2" class="infobox-image"><span class="mw-default-size" typeof="mw:File/Frameless"><a href="/wiki/File:Texas_Instruments_TI-99-4A_(white_bg).jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Texas_Instruments_TI-99-4A_%28white_bg%29.jpg/220px-Texas_Instruments_TI-99-4A_%28white_bg%29.jpg" decoding="async" width="220" height="147" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Texas_Instruments_TI-99-4A_%28white_bg%29.jpg/330px-Texas_Instruments_TI-99-4A_%28white_bg%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Texas_Instruments_TI-99-4A_%28white_bg%29.jpg/440px-Texas_Instruments_TI-99-4A_%28white_bg%29.jpg 2x" data-file-width="4647" data-file-height="3098" /></a></span></td></tr><tr><th scope="row" class="infobox-label">Manufacturer</th><td class="infobox-data">Texas Instruments</td></tr><tr><th scope="row" class="infobox-label">Type</th><td class="infobox-data"><a href="/wiki/Home_computer" title="Home computer">Home computer</a></td></tr><tr><th scope="row" class="infobox-label">Release date</th><td class="infobox-data">June 1981<span style="display: none;"> (<span class="bday dtstart published updated itvstart">1981-06</span>)</span></td></tr><tr><th scope="row" class="infobox-label">Introductory price</th><td class="infobox-data"><span style="white-space: nowrap">US$525</span> (equivalent to $1,820 in 2024)</td></tr><tr><th scope="row" class="infobox-label">Discontinued</th><td class="infobox-data">March 1984</td></tr><tr><th scope="row" class="infobox-label">Units shipped</th><td class="infobox-data">2.8 million<sup id="cite_ref-oldcomputers_1-0" class="reference"><a href="#cite_note-oldcomputers-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup></td></tr><tr><th scope="row" class="infobox-label">Media</th><td class="infobox-data"><style data-mw-deduplicate="TemplateStyles:r1280115419">.mw-parser-output ul.cslist,.mw-parser-output ul.sslist,.mw-parser-output ul.andlist,.mw-parser-output ul.andlistoxford{margin:0;padding:0;display:inline-block;list-style:none}.mw-parser-output ul.cslist-embedded{display:inline}.mw-parser-output .cslist li,.mw-parser-output .sslist li,.mw-parser-output .andlist li,.mw-parser-output .andlistoxford li{margin:0;padding:0 0.25em 0 0;display:inline-block}.mw-parser-output .cslist li:after,.mw-parser-output .andlistoxford li:after{content:", "}.mw-parser-output .sslist li:after{content:"; "}.mw-parser-output .cslist li:last-child:after,.mw-parser-output .sslist li:last-child:after,.mw-parser-output .andlist li:last-child:after,.mw-parser-output .andlistoxford li:last-child:after{content:none}.mw-parser-output .andlist li:nth-last-child(2):after{content:" and "}.mw-parser-output .andlistoxford li:nth-last-child(2):after{content:", and "}</style><ul class="cslist"><li><a href="/wiki/ROM_cartridge" title="ROM cartridge">ROM cartridge</a></li><li><a href="/wiki/Cassette_tape#Data_recording" class="mw-redirect" title="Cassette tape">cassette</a></li><li><a href="/wiki/Floppy_disk" title="Floppy disk">floppy disk</a></li></ul></td></tr><tr><th scope="row" class="infobox-label"><a href="/wiki/Operating_system" title="Operating system">Operating system</a></th><td class="infobox-data"><a href="/wiki/TI_BASIC_(TI_99/4A)" title="TI BASIC (TI 99/4A)">TI BASIC</a></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"><a href="/wiki/TMS9900" title="TMS9900">TMS9900</a> @ 3 MHz</td></tr><tr><th scope="row" class="infobox-label">Memory</th><td class="infobox-data">16 <a href="/wiki/Kilobyte" title="Kilobyte">KB</a> RAM<br />256 bytes scratchpad RAM</td></tr><tr><th scope="row" class="infobox-label">Graphics</th><td class="infobox-data"><a href="/wiki/TMS9918A" class="mw-redirect" title="TMS9918A">TMS9918A</a></td></tr><tr><th scope="row" class="infobox-label">Sound</th><td class="infobox-data">TMS9919, later <a href="/wiki/SN94624" class="mw-redirect" title="SN94624">SN94624</a></td></tr><tr><th scope="row" class="infobox-label">Predecessor</th><td class="infobox-data">TI-99/4</td></tr></tbody></table> <p>The <b>TI-99/4</b> and <b>TI-99/4A</b> are <a href="/wiki/Home_computer" title="Home computer">home computers</a> released by <a href="/wiki/Texas_Instruments" title="Texas Instruments">Texas Instruments</a> in 1979 and 1981, respectively.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> Based on Texas Instruments's own <a href="/wiki/TMS9900" title="TMS9900">TMS9900</a> <a href="/wiki/Microprocessor" title="Microprocessor">microprocessor</a> originally used in <a href="/wiki/Minicomputer" title="Minicomputer">minicomputers</a>, the TI-99/4 was the first <a href="/wiki/16-bit" class="mw-redirect" title="16-bit">16-bit</a> home computer.<sup id="cite_ref-oldcomp_3-0" class="reference"><a href="#cite_note-oldcomp-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> The associated <a href="/wiki/TMS9918" title="TMS9918">TMS9918</a> <a href="/wiki/Video_display_controller" title="Video display controller">video display controller</a> provides color graphics and <a href="/wiki/Sprite_(computer_graphics)" title="Sprite (computer graphics)">sprite</a> support which were only comparable with those of the <a href="/wiki/Atari_8-bit_computers" title="Atari 8-bit computers">Atari 400 and 800</a> released a month later. The TI-99 series also initially competed with the <a href="/wiki/Apple_II" title="Apple II">Apple II</a> and <a href="/wiki/TRS-80" title="TRS-80">TRS-80</a>.<sup id="cite_ref-death_1984_04_texasmonthly_4-0" class="reference"><a href="#cite_note-death_1984_04_texasmonthly-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> </p><p>The calculator-style keyboard of the TI-99/4 and the high price were cited as a weak points. TI's reliance on <a href="/wiki/ROM_cartridge" title="ROM cartridge">ROM cartridges</a> and their practice of limiting developer information to select third parties resulted in a lack of software for the system. The TI-99/4A was released in June 1981 with a simplified internal design, full-travel keyboard, improved graphics, and a unique expansion system. At half the price of the original model, sales picked up significantly and TI supported the 4A with peripherals, including a <a href="/wiki/Speech_synthesizer" class="mw-redirect" title="Speech synthesizer">speech synthesizer</a> and a "Peripheral Expansion System" box to contain hardware add-ons. TI released developer information and tools, but the insistence on remaining sole publisher continued to starve the platform of software.<sup id="cite_ref-death_1984_04_texasmonthly_4-1" class="reference"><a href="#cite_note-death_1984_04_texasmonthly-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> Architectural quirks of both models reduced the performance benefits of the 16-bit CPU. </p><p>The 1981 US launch of the TI-99/4A followed <a href="/wiki/Commodore_International" title="Commodore International">Commodore</a>'s <a href="/wiki/VIC-20" title="VIC-20">VIC-20</a> by several months. Commodore CEO <a href="/wiki/Jack_Tramiel" title="Jack Tramiel">Jack Tramiel</a> began a <a href="/wiki/Price_war" title="Price war">price war</a> by repeatedly lowering the price of the VIC-20 and forcing TI to do the same. In late 1982, TI was shipping 5,000 computers a day from their factory in <a href="/wiki/Lubbock,_Texas" title="Lubbock, Texas">Lubbock, Texas</a>.<sup id="cite_ref-death_1984_04_texasmonthly_4-2" class="reference"><a href="#cite_note-death_1984_04_texasmonthly-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> By 1983, the 99/4A was selling at a loss for under <span style="white-space: nowrap">US$100</span>. Even with the increased user base created by the heavy discounts, Texas Instruments lost US$330 million in the third quarter of 1983<sup id="cite_ref-ahl198403_5-0" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> and announced the discontinuation of the TI-99/4A in October 1983. Production ended in March 1984.<sup id="cite_ref-death_1984_04_texasmonthly_4-3" class="reference"><a href="#cite_note-death_1984_04_texasmonthly-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> </p><p>The TI-99/4 was intended to fit in the middle of a planned range of TI-99 computers, none of which were released, but prototypes and documentation have been found after the TI-99/4A was discontinued. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Features">Features</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=1" title="Edit section: Features"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The TI-99/4A is a self-contained console with the <a href="/wiki/Motherboard" title="Motherboard">motherboard</a>, <a href="/wiki/ROM_cartridge" title="ROM cartridge">ROM cartridge</a> slot, and full-travel keyboard in the same case. The power supply is external. An <a href="/wiki/RF_modulator" title="RF modulator">RF modulator</a> allows the use of a television as a monitor. Lowercase letters are displayed as <a href="/wiki/Small_caps" title="Small caps">small caps</a>, rather than separate glyphs. <a href="/wiki/TI_BASIC_(TI_99/4A)" title="TI BASIC (TI 99/4A)">TI BASIC</a>, an <a href="/wiki/American_National_Standards_Institute" title="American National Standards Institute">ANSI</a>-compliant <a href="/wiki/BASIC" title="BASIC">BASIC</a> interpreter based on <a href="/wiki/Dartmouth_BASIC" title="Dartmouth BASIC">Dartmouth BASIC</a>, is built-in and includes support for graphics, sound, and file system access. Later versions of the 99/4A, identified by <code>(C)1983 TEXAS INSTRUMENTS V2.2</code> on the title page, prevent the use of unlicensed <a href="/wiki/Read-only_memory" title="Read-only memory">ROM</a> cartridges from third-party manufacturers such as <a href="/wiki/Atarisoft" title="Atarisoft">Atarisoft</a>. </p><p>Both TI-99/4 models use the <a href="/wiki/16-bit" class="mw-redirect" title="16-bit">16-bit</a> <a href="/wiki/Texas_Instruments_TMS9900" class="mw-redirect" title="Texas Instruments TMS9900">TMS9900</a> <a href="/wiki/Central_processing_unit" title="Central processing unit">CPU</a> running at 3 <a href="/wiki/Hertz" title="Hertz">MHz</a>. The TMS9900 is a single-chip implementation of a <a href="/wiki/TI-990" title="TI-990">TI-990</a> minicomputer. Although a full 16-bit processor, only the system ROM and 256 bytes of scratchpad RAM are available on the 16-bit bus.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> </p><p>Peripherals include a 5¼" <a href="/wiki/Floppy_disk_drive" class="mw-redirect" title="Floppy disk drive">floppy disk drive</a> and controller, an <a href="/wiki/RS-232" title="RS-232">RS-232</a> card with two serial ports and one parallel port, a <a href="/wiki/UCSD_Pascal" title="UCSD Pascal">P-code</a> card for <a href="/wiki/Pascal_(programming_language)" title="Pascal (programming language)">Pascal</a> support, a <a href="/wiki/Thermal_printing" title="Thermal printing">thermal printer</a>, a 300-<a href="/wiki/Baud" title="Baud">baud</a> <a href="/wiki/Acoustic_coupler" title="Acoustic coupler">acoustic coupler</a>, a <a href="/wiki/Tape_drive" title="Tape drive">tape drive</a> using standard <a href="/wiki/Cassette_tape#Data_recording" class="mw-redirect" title="Cassette tape">audio cassettes</a> as media, and a 32 <a href="/wiki/Kilobyte" title="Kilobyte">KB</a> memory <a href="/wiki/Expansion_card" title="Expansion card">expansion card</a>. </p> <div class="mw-heading mw-heading3"><h3 id="Video_display_processor">Video display processor</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=2" title="Edit section: Video display processor"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Graphics in the 99/4A are generated by a <a href="/wiki/TMS9918A" class="mw-redirect" title="TMS9918A">TMS9918A</a> Video Display Processor (VDP), with a variant for PAL territories. The VDP was developed by Texas Instruments and also sold independently, allowing it to be used in other systems. It serves as the video processor for the <a href="/wiki/ColecoVision" title="ColecoVision">ColecoVision</a> and <a href="/wiki/SG-1000" title="SG-1000">SG-1000</a> consoles, and an earlier model is part of the <a href="/wiki/MSX" title="MSX">MSX</a> computer standard. </p><p>The TMS9918A supports character-based and <a href="/wiki/Bitmap" title="Bitmap">bitmap</a> display modes as well as hardware <a href="/wiki/Sprite_(computer_graphics)" title="Sprite (computer graphics)">sprites</a>. There are 32 single-color sprites total, but only a maximum of 4 can be displayed per <a href="/wiki/Scan_line" title="Scan line">scan line</a>. Each sprite is either 8×8 or 16×16 pixels and can be scaled 2× to 16×16 or 32×32. </p><p>16 KB of RAM is provided for the Video Display Processor. VDP RAM is the largest block of writeable memory in the unexpanded TI-99/4A architecture, and is used for storing <a href="/wiki/Disk_buffer" title="Disk buffer">disk I/O buffers</a> and <a href="/wiki/TI_BASIC_(TI_99/4A)" title="TI BASIC (TI 99/4A)">TI BASIC</a> user programs. Access to this memory has to use the VDP as an intermediary. </p> <div class="mw-heading mw-heading2"><h2 id="Expansion">Expansion</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=3" title="Edit section: Expansion"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>TI-99 peripherals contain <a href="/wiki/Device_driver" title="Device driver">device drivers</a> in ROMs in the hardware. When a new peripheral is attached, it is immediately available for any software that wants to use it. All device access uses a generic file-based I/O mechanism, allowing new devices to be added without updating software. The Peripheral Expansion System can hold two RS-232 cards, for a total of four RS-232 ports and two parallel printer ports. </p><p>The computer supports two cassette drives through a dedicated port, using a <a href="/wiki/List_of_cassette_tape_data_storage_formats#TI-99" class="mw-redirect" title="List of cassette tape data storage formats">custom data format</a>. <a href="/wiki/Composite_video" title="Composite video">Composite video</a> and audio are output through another port on <a href="/wiki/NTSC" title="NTSC">NTSC</a>-based machines, and combine through an external RF modulator for use with a television. <a href="/wiki/PAL" title="PAL">PAL</a>-based machines output a more complex <a href="/wiki/YUV" class="mw-redirect" title="YUV">YUV</a> signal which is also modulated to <a href="/wiki/UHF" class="mw-redirect" title="UHF">UHF</a> externally. </p><p>Two digital <a href="/wiki/Joystick" title="Joystick">joysticks</a> can be connected through a single <a href="/wiki/DE-9" class="mw-redirect" title="DE-9">DE-9</a> port. It is identical to the <a href="/wiki/Atari_joystick_port" title="Atari joystick port">Atari joystick port</a>, but with incompatible pins. Aftermarket adapters allow the use of <a href="/wiki/Atari_CX40_joystick" title="Atari CX40 joystick">Atari compatible joysticks</a>.<sup id="cite_ref-mace19840409_7-0" class="reference"><a href="#cite_note-mace19840409-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p><p>TI sold an official 32 KB RAM expansion.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> The memory is not available to all uses. For example, an Extended Basic program is restricted to using 24 KB with the remaining 8 KB available for <a href="/wiki/Machine_code" title="Machine code">machine code</a> routines. The Mini Memory plug-in module contains 4 KB of battery-backed RAM that can be used as a persistent <a href="/wiki/RAM_disk" class="mw-redirect" title="RAM disk">RAM disk</a> or to load a machine-code program.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Peripheral_Expansion_Box">Peripheral Expansion Box</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=4" title="Edit section: Peripheral Expansion Box"><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:TI99expansion.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d8/TI99expansion.jpg/250px-TI99expansion.jpg" decoding="async" width="220" height="132" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d8/TI99expansion.jpg/330px-TI99expansion.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d8/TI99expansion.jpg/500px-TI99expansion.jpg 2x" data-file-width="688" data-file-height="412" /></a><figcaption>Peripheral Expansion Box or PEB</figcaption></figure> <p>The TI-99/4A can be upgraded via expansion cards added to an eight-slot, external chassis containing its own linear power supply and a full-height 5¼" floppy bay.<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> Encased in silver plastic, but made from <a href="/wiki/Sheet_steel" class="mw-redirect" title="Sheet steel">sheet steel</a>, this is labeled as the Peripheral Expansion System by TI, but usually called the Peripheral Expansion Box or PEB. Each card has an <a href="/wiki/Light-emitting_diode" title="Light-emitting diode">LED</a> that blinks or flickers when being accessed by software. The section of the power supply that powers the card slots is unregulated. Each card has on-board regulators for its own requirements, which reduces power consumption on a partially-loaded PEB and allows for cards with unusual voltage requirements. </p><p>The PEB carries an analog sound input on the expansion bus, allowing the Speech Synthesizer's audio to be carried through the console to the monitor. The audio is also carried through the <a href="/wiki/Ribbon_cable" title="Ribbon cable">ribbon cable</a> to the PEB, both allowing the relocation of the Speech Synthesizer to the PEB and the possibility of audio cards offering more features than the console's built-in sound. No official cards from TI do this. </p><p>Official cards from TI that were released and could be placed inside the PEB include </p> <ul><li>32 KB RAM expansion card</li> <li>RS-232 and parallel port card</li> <li>P-code card, implementing the UCSD p-system IV.0 by acting as a ROM-disk</li> <li>Diskette drive control card. The design allowed controlling both drives internally in the PEB and external drives.</li></ul> <p>Peripherals designed to be used without the PEB existed too. </p> <div class="mw-heading mw-heading3"><h3 id="Speech_synthesizer">Speech synthesizer</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=5" title="Edit section: Speech synthesizer"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><span><audio id="mwe_player_0" controls="" preload="none" data-mw-tmh="" class="mw-file-element" width="220" style="width:220px;" data-durationhint="4" data-mwtitle="Texas_Instruments_TI-99_4A_speech_demo.flac" data-mwprovider="wikimediacommons" resource="/wiki/File:Texas_Instruments_TI-99_4A_speech_demo.flac"><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/4/44/Texas_Instruments_TI-99_4A_speech_demo.flac/Texas_Instruments_TI-99_4A_speech_demo.flac.ogg" type="audio/ogg; codecs="vorbis"" data-transcodekey="ogg" data-width="0" data-height="0" /><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/4/44/Texas_Instruments_TI-99_4A_speech_demo.flac/Texas_Instruments_TI-99_4A_speech_demo.flac.mp3" type="audio/mpeg" data-transcodekey="mp3" data-width="0" data-height="0" /><source src="//upload.wikimedia.org/wikipedia/commons/4/44/Texas_Instruments_TI-99_4A_speech_demo.flac" type="audio/flac" data-width="0" data-height="0" /><track src="https://commons.wikimedia.org/w/api.php?action=timedtext&title=File%3ATexas_Instruments_TI-99_4A_speech_demo.flac&lang=en&trackformat=vtt&origin=%2A" kind="subtitles" type="text/vtt" srclang="en" label="English ‪(en)‬" data-dir="ltr" /></audio></span><figcaption>TI-99/4A speech demo using the built-in vocabulary</figcaption></figure> <p>In the late 1970s and early 1980s, TI was a pioneer in <a href="/wiki/Speech_synthesis" title="Speech synthesis">speech synthesis</a> because of its <a href="/wiki/Texas_Instruments_LPC_Speech_Chips" title="Texas Instruments LPC Speech Chips">Texas Instruments LPC Speech Chips</a> which were used in its <a href="/wiki/Speak_%26_Spell_(toy)" title="Speak & Spell (toy)">Speak & Spell</a> toys. A plug-in speech synthesizer module was available for the TI-99/4 and 4A. Speech synthesizers were offered free with the purchase of a number of cartridges and were used by video games such as <i><a href="/wiki/Alpiner_(video_game)" title="Alpiner (video game)">Alpiner</a></i> and <a href="/wiki/Parsec_(video_game)" title="Parsec (video game)"><i>Parsec</i></a>. <i>Alpiner</i><span class="nowrap" style="padding-left:0.1em;">'</span>s speech includes male and female voices and can be sarcastic when the player makes a bad move. </p><p>The synthesizer uses a variant of <a href="/wiki/Linear_predictive_coding" title="Linear predictive coding">linear predictive coding</a> and has a small in-built vocabulary. The original intent was to release small cartridges that plugged directly into the synthesizer unit to increase the device's vocabulary. However, the success of software <a href="/wiki/Text-to-speech" class="mw-redirect" title="Text-to-speech">text-to-speech</a> in the Terminal Emulator II cartridge cancelled that plan.<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. (October 2019)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=6" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In 1977, groups within Texas Instruments were designing a <a href="/wiki/Video_game_console" title="Video game console">video game console</a>, a home computer to compete against the TRS-80 and Apple II, and a high-end business personal computer with a <a href="/wiki/Hard_drive" class="mw-redirect" title="Hard drive">hard drive</a>. The first two groups were both working at TI's consumer products division in <a href="/wiki/Lubbock,_Texas" title="Lubbock, Texas">Lubbock, Texas</a>, and continually competed. According to <a href="/wiki/Wally_Rhines" title="Wally Rhines">Wally Rhines</a>, the 99/4's "ultracheap keyboard" (with calculator-style keys), <a href="/wiki/RF_modulator" title="RF modulator">RF modulator</a>, and ROM cartridges came from the console design. Eventually, the two teams were merged and directed towards the home computer market. Meanwhile, the third team was merged into TI's Data Systems Division, which had a line of minicomputer products and various <a href="/wiki/Computer_terminal" title="Computer terminal">computer terminals</a>; they viewed the all-in-one machine as a threat and the project was eventually killed.<sup id="cite_ref-rhines20170622_11-0" class="reference"><a href="#cite_note-rhines20170622-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </p><p>Others within the company persuaded the Lubbock group to use TI's TMS9900 CPU. This was in keeping with TI's "one company, one computer architecture" concept, where a single processor model would scale from consoles to its high-end minicomputers. The TMS9900 is a single-chip implementation of TI's 16-bit <a href="/wiki/TI-990" title="TI-990">TI-990</a> mini design, and is the CPU in low-end models of that platform.<sup id="cite_ref-rhines2_12-0" class="reference"><a href="#cite_note-rhines2-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> Feature-limited single-chip versions of popular minicomputer designs from the 1960s were popular in the mid-1970s and newly designed 16-bit and <a href="/wiki/32-bit" class="mw-redirect" title="32-bit">32-bit</a> CPUs like the <a href="/wiki/Intel_8088" title="Intel 8088">Intel 8088</a> and <a href="/wiki/Motorola_68000" title="Motorola 68000">Motorola 68000</a>, respectively, quickly rendered these earlier designs obsolete.<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. (May 2021)">citation needed</span></a></i>]</sup> Many of the TMS9900's quirky features, like <a href="/wiki/Processor_register" title="Processor register">processor registers</a> in <a href="/wiki/Main_memory" class="mw-redirect" title="Main memory">main memory</a>, came from its minicomputer roots where such concepts were more common.<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. (May 2021)">citation needed</span></a></i>]</sup> </p><p>Meanwhile, another home computer product was emerging from TI's European headquarters, where a third party consulting firm was contracted to produce a prototype <a href="/wiki/Project_code_name" class="mw-redirect" title="Project code name">codenamed</a> "Mojo". This was based on TI's version of the <a href="/wiki/8-bit" class="mw-redirect" title="8-bit">8-bit</a> <a href="/wiki/Intel_8080" title="Intel 8080">Intel 8080</a> supported by an all-TI chip set. After a series of discussions, Mojo was abandoned and the Consumer Products concept moved forward.<sup id="cite_ref-rhines20170622_11-1" class="reference"><a href="#cite_note-rhines20170622-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="99/4"><span id="99.2F4"></span>99/4</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=7" title="Edit section: 99/4"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In 1979, TI was a successful manufacturer of large computers<sup id="cite_ref-rhines2_12-1" class="reference"><a href="#cite_note-rhines2-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> and was the largest <a href="/wiki/Semiconductor" title="Semiconductor">semiconductor</a> manufacturer in the world.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> Its catalog included a huge variety of analog and digital integrated circuits already widely used in <a href="/wiki/Microcomputer" title="Microcomputer">microcomputers</a>, giving it a single-source advantage no other company could meet. It used this position to take over markets, as it did in the mid-1970s introducing its first <a href="/wiki/Scientific_calculator" title="Scientific calculator">scientific calculators</a>. These underpriced its former customers like <a href="/wiki/Commodore_International" title="Commodore International">Commodore</a> and drove them out of the calculator business.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> Observers expected TI would do the same to the microcomputer market if it released a competitive system.<sup id="cite_ref-rhines20170622_11-2" class="reference"><a href="#cite_note-rhines20170622-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> <i><a href="/wiki/The_New_York_Times" title="The New York Times">The New York Times</a></i> suggested that the entry of TI and <a href="/wiki/Hewlett-Packard" title="Hewlett-Packard">Hewlett-Packard</a> would reshape the entire industry.<sup id="cite_ref-schuyten19781206_15-0" class="reference"><a href="#cite_note-schuyten19781206-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </p><p>Through the development period, several companies attempting to enter the home computer market were faced with significant pushback from the <a href="/wiki/Federal_Communications_Commission" title="Federal Communications Commission">Federal Communications Commission</a> (FCC). The FCC had developed new rules for consumer devices that connected directly to <a href="/wiki/Television" title="Television">televisions</a> in an effort to control ongoing complaints about interference by poorly <a href="/wiki/Electromagnetic_shielding" title="Electromagnetic shielding">shielded</a> devices. Televisions of the era generally had only a single antenna input, and thus connecting to them required the internal video signal of the device to be converted to <a href="/wiki/Radio_frequency" title="Radio frequency">radio frequency</a> using an <a href="/wiki/RF_modulator" title="RF modulator">RF modulator</a>. If these were poorly shielded the signal would leak out and could be picked up in the antennas of nearby televisions.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> </p><p>The new rules were extremely stringent and difficult to meet. TI continued battling the FCC both in the lab and in Congress, where it had considerable power due to its position within Texas's high-tech industry. It failed to meet the FCC requirements as the release date approached. The company eventually gave up and bundled a modified <a href="/wiki/Zenith_Electronics#History" title="Zenith Electronics">Zenith Electronics</a> television with the computer, as a <a href="/wiki/Computer_monitor" title="Computer monitor">computer monitor</a>, eliminating the need for the RF modulator by connecting directly to the TV's internal circuitry using a <a href="/wiki/Composite_video" title="Composite video">composite video</a> signal. This put the introductory price at <span style="white-space: nowrap">US$1,150</span> (equivalent to $4,389 in 2024).<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> </p><p>The 99/4 sold poorly. Very little software was available, as few developers ported their products to its 16-bit CPU.<sup id="cite_ref-black2022_18-0" class="reference"><a href="#cite_note-black2022-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> The machine was met with almost universal disdain when it was released. Every review complained about the keyboard, the lack of lower case characters, any sort of expansion, and lack of software. In July 1980, <a href="/wiki/Adam_Osborne" title="Adam Osborne">Adam Osborne</a> reported that, despite poor sales, TI had raised the price of a complete system to <span style="white-space: nowrap">$1,400</span>, higher than the popular Apple II, which started at <span style="white-space: nowrap">$950</span>. Osborne said, "Some dealers, who have offered the complete system (including the monitor) for less than the price of the Apple, have still been unable to sell it".<sup id="cite_ref-osborne19800707_19-0" class="reference"><a href="#cite_note-osborne19800707-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-mace19830530saddle_20-0" class="reference"><a href="#cite_note-mace19830530saddle-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> TI experimented with $200 rebates, and dealers decreased the price to as low as $699 not including rebates,<sup id="cite_ref-libes198012_21-0" class="reference"><a href="#cite_note-libes198012-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> but the company sold fewer than 20,000 computers by summer 1981, less than one tenth Apple or <a href="/wiki/Radio_Shack" class="mw-redirect" title="Radio Shack">Radio Shack</a>'s volume. <a href="/wiki/Atari,_Inc." title="Atari, Inc.">Atari, Inc.</a> had an <a href="/wiki/Installed_base" title="Installed base">installed base</a> of <a href="/wiki/Atari_8-bit_computers" title="Atari 8-bit computers">Atari 8-bit computers</a> more than twice as large.<sup id="cite_ref-hogan19810914state_22-0" class="reference"><a href="#cite_note-hogan19810914state-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> <a href="/wiki/David_H._Ahl" title="David H. Ahl">David H. Ahl</a> described the 99/4 as "vastly overpriced, particularly considering its strange keyboard, non-standard Basic, and lack of software".<sup id="cite_ref-ahl198403_5-1" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> The <i>Times</i> called it an "embarrassing failure".<sup id="cite_ref-pollack19830619_23-0" class="reference"><a href="#cite_note-pollack19830619-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="99/4A"><span id="99.2F4A"></span>99/4A</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=8" title="Edit section: 99/4A"><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:TI99-4A_beige_front.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/49/TI99-4A_beige_front.jpg/250px-TI99-4A_beige_front.jpg" decoding="async" width="220" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/49/TI99-4A_beige_front.jpg/330px-TI99-4A_beige_front.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/49/TI99-4A_beige_front.jpg/500px-TI99-4A_beige_front.jpg 2x" data-file-width="650" data-file-height="354" /></a><figcaption>Late period, cost-reduced version of the TI-99/4A with beige case</figcaption></figure> <p>In May 1981 TI released the 99/4A. With a lower $525 price, the company added a typewriter-style keyboard<sup id="cite_ref-mace19830530saddle_20-1" class="reference"><a href="#cite_note-mace19830530saddle-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup>—keeping the non-standard layout—and more expansion options. The expansion system extends from the right side of the chassis, with modules that can be <a href="/wiki/Daisy_chain_(electrical_engineering)" title="Daisy chain (electrical engineering)">daisy-chained</a>. There is a practical limitation to this, because each module increases the width of the system. The price was initially <span style="white-space: nowrap">US$525</span>, less than half that of the 99/4.<sup id="cite_ref-ahl198403_5-2" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p><p>TI continued lowering the price through 1981, first to <span style="white-space: nowrap">$449.95</span>, and then to <span style="white-space: nowrap">$399.95</span> in early 1982, in competition with Commodore's <span style="white-space: nowrap">$300</span> <a href="/wiki/VIC-20" title="VIC-20">VIC-20</a>. This turned into a <a href="/wiki/Price_war" title="Price war">price war</a> with Commodore. TI responded by cutting the wholesale price of the 99 by <span style="white-space: nowrap">$100</span>, while also offering a <span style="white-space: nowrap">$100</span> rebate directly to consumers, lowering the street price to about <span style="white-space: nowrap">$200</span>. <a href="/wiki/Bill_Cosby_in_advertising" title="Bill Cosby in advertising">Bill Cosby in advertising</a> for TI marketed the refund.<sup id="cite_ref-mace19830530saddle_20-2" class="reference"><a href="#cite_note-mace19830530saddle-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-pollack19830619_23-1" class="reference"><a href="#cite_note-pollack19830619-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-ahl198403_5-3" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-yt20070601_24-0" class="reference"><a href="#cite_note-yt20070601-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> By mid-1982, <a href="/wiki/Jerry_Pournelle" title="Jerry Pournelle">Jerry Pournelle</a> wrote that TI was "practically giving away the TI-99/4A".<sup id="cite_ref-pournelle198207_25-0" class="reference"><a href="#cite_note-pournelle198207-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> An industry joke stated that the company was losing money on each computer, but was making up for it in volume.<sup id="cite_ref-ahl198403_5-4" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-pollack19830619_23-2" class="reference"><a href="#cite_note-pollack19830619-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> Commodore matched the <span style="white-space: nowrap">$200</span> price in December 1982.<sup id="cite_ref-ahl198403_5-5" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p><p>TI celebrated the 99/4A's market success at the January 1983 <a href="/wiki/Consumer_Electronics_Show" class="mw-redirect" title="Consumer Electronics Show">Consumer Electronics Show</a> in Las Vegas, where Cosby joked how easy it was to sell a computer by paying people <span style="white-space: nowrap">$100</span> to buy one.<sup id="cite_ref-pollack19830619_23-3" class="reference"><a href="#cite_note-pollack19830619-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-ahl198403_5-6" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> Sales peaked at 30,000 a week that month, but on 10 January 1983 Commodore lowered the price of its computers. In February TI responded with a 99/4A retail price of <span style="white-space: nowrap">$150</span>. In April, the VIC-20's bundled retail price reached <span style="white-space: nowrap">$100</span> and the 99/4A followed suit. In the spring of 1983, TI attempted to reduce the parts count to maintain a competitive edge by combining multiple chips into a single custom chip, renaming the 4A PCB as a "QI" (Quality Improved) board and began production of plastic beige cases without the former aluminum trim of the black console. In May, it began offering the PEB for free with the purchase of three peripherals. In August the company reduced prices of peripherals by 50% and offered <span style="white-space: nowrap">$100</span> of free software; in September, it reduced software prices by up to 43%.<sup id="cite_ref-pollack19830619_23-4" class="reference"><a href="#cite_note-pollack19830619-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-ahl198403_5-7" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-maceti19831121_26-0" class="reference"><a href="#cite_note-maceti19831121-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> The $100 rebate ended in April 1983, but by then TI had effectively reduced the retail price by that amount; by June the 99/4A sold for as little as $99 in some stores, comparable to the VIC-20's price.<sup id="cite_ref-mace19830530saddle_20-3" class="reference"><a href="#cite_note-mace19830530saddle-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Lack_of_third-party_development">Lack of third-party development</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=9" title="Edit section: Lack of third-party development"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The president of <a href="/wiki/Spectravideo" title="Spectravideo">Spectravideo</a> later said that "TI got suckered by" <a href="/wiki/Jack_Tramiel" title="Jack Tramiel">Jack Tramiel</a>, head of Commodore.<sup id="cite_ref-ahl198403_5-8" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> The company could not make a profit on the TI-99/4A at a price of $99<sup id="cite_ref-mitchell19830906_27-0" class="reference"><a href="#cite_note-mitchell19830906-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup>—it was much more expensive to manufacture than the VIC-20<sup id="cite_ref-ahl198403_5-9" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup>—but hoped that selling many inexpensive computers would increase sales of more profitable software and peripherals. Because such a <a href="/wiki/Razor_and_blades_business_model" class="mw-redirect" title="Razor and blades business model">razor and blades business model</a> requires that <a href="/wiki/First-party_software" class="mw-redirect" title="First-party software">such products be its own</a>,<sup id="cite_ref-pollack19830619_23-5" class="reference"><a href="#cite_note-pollack19830619-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> TI strictly controlled development for the computer, discouraging hobbyists and third-party developers.<sup id="cite_ref-thornburg198104_28-0" class="reference"><a href="#cite_note-thornburg198104-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-pournelle198207_25-1" class="reference"><a href="#cite_note-pournelle198207-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> It wanted unsophisticated consumers to buy its computers like an appliance, and not technical users who might want to write their own software,<sup id="cite_ref-black2022_18-1" class="reference"><a href="#cite_note-black2022-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> despite the latter being what Pournelle described as "a large unpaid R&D department" for computer companies.<sup id="cite_ref-pournelle198307_29-0" class="reference"><a href="#cite_note-pournelle198307-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> The company advertised its calculators in almost every issue of <i>BYTE</i> starting in 1980, but deliberately excluded its home computer from the ads except briefly in late 1982. TI also used its preexisting calculator sales channel of mass-market retailers, and not specialized computer stores.<sup id="cite_ref-black2022_18-2" class="reference"><a href="#cite_note-black2022-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> </p><p>TI did not provide an editor, assembler, or hardware technical information when it released the computer. Pournelle stated that "TI's message is loud and clear: 'Drop dead, hobbyists!<span style="padding-right:.15em;">'</span>",<sup id="cite_ref-pournelle198307_29-1" class="reference"><a href="#cite_note-pournelle198307-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> and added that the company "worked very hard at keeping you outside the machine".<sup id="cite_ref-pournelle198207_25-2" class="reference"><a href="#cite_note-pournelle198207-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> Citing <i><a href="/wiki/Money_(magazine)" class="mw-redirect" title="Money (magazine)">Money</a></i>, publisher of <i><a href="/wiki/Kilobaud_Microcomputing" title="Kilobaud Microcomputing">Kilobaud Microcomputing</a></i> <a href="/wiki/Wayne_Green" title="Wayne Green">Wayne Green</a> reported in August 1980 that TI planned to have only 100 applications available by the end of 1981, stating that "This tiny figure has to put a chill on the whole industry". Green's company, <a href="/wiki/Instant_Software" title="Instant Software">Instant Software</a>, was a prolific publisher for the <a href="/wiki/TRS-80" title="TRS-80">TRS-80</a> but could not find anyone to port software to the TI. He wrote, "We understand the problems with the system and the efforts Texas Instruments made to make translation difficult".<sup id="cite_ref-green198008_30-0" class="reference"><a href="#cite_note-green198008-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup> A <a href="/wiki/Spinnaker_Software" title="Spinnaker Software">Spinnaker Software</a> executive said that the 99/4A had "the worst software in the business", and Ahl noted that unlike other computers, it did not have "<a href="/wiki/Microsoft_BASIC" title="Microsoft BASIC">Microsoft BASIC</a>, <a href="/wiki/VisiCalc" title="VisiCalc">VisiCalc</a>, <a href="/wiki/WordStar" title="WordStar">WordStar</a>, or any popular games".<sup id="cite_ref-ahl198403_5-10" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> Peripherals cost about twice as much as for other computers.<sup id="cite_ref-mitchell19830906_27-1" class="reference"><a href="#cite_note-mitchell19830906-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-pollack19830619_23-6" class="reference"><a href="#cite_note-pollack19830619-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> TI joysticks were of poor quality and difficult to find, for example; one reseller reported that its best-selling product was the <a href="/wiki/Atari_CX40_joystick" title="Atari CX40 joystick">Atari CX40 joystick</a> adapter cable.<sup id="cite_ref-mace19840409_7-1" class="reference"><a href="#cite_note-mace19840409-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p><p>Pournelle added, "TI had rightly concluded that the hobbyists and hackers were a tiny part of the market and <i>wrongly</i> concluded that they were therefore unimportant".<sup id="cite_ref-pournelle198207_25-3" class="reference"><a href="#cite_note-pournelle198207-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> Rivals were more open with information. <i>Kilobaud Microcomputing</i> reported that a Commodore executive promised the VIC-20 would have "enough additional documentation to enable an experienced programmer/hobbyist to get inside and let his imagination work".<sup id="cite_ref-kb198009_31-0" class="reference"><a href="#cite_note-kb198009-31"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-thornburg198104_28-1" class="reference"><a href="#cite_note-thornburg198104-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup> Even when competitors did not disclose technical information, because their computers used <a href="/wiki/Commercial_off-the-shelf" title="Commercial off-the-shelf">commercial off-the-shelf</a> parts like <a href="/wiki/MOS_Technology_6502" title="MOS Technology 6502">MOS 6502</a> and <a href="/wiki/Zilog_Z80" title="Zilog Z80">Zilog Z80</a>, much more information was public than for TI's proprietary components.<sup id="cite_ref-black2022_18-3" class="reference"><a href="#cite_note-black2022-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> IBM learned from TI's mistake, Pournelle said. The company released software and hardware technical information when the <a href="/wiki/IBM_Personal_Computer" title="IBM Personal Computer">IBM PC</a> was announced in 1981,<sup id="cite_ref-pournelle198207_25-4" class="reference"><a href="#cite_note-pournelle198207-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> stating that "the definition of a personal computer <i>is</i> third-party hardware and software".<sup id="cite_ref-bunnell19820405_32-0" class="reference"><a href="#cite_note-bunnell19820405-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> </p><p>TI had also learned from its mistake and no longer ignored hobbyists, Pournelle said in 1982.<sup id="cite_ref-pournelle198207_25-5" class="reference"><a href="#cite_note-pournelle198207-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-pournelle198307_29-2" class="reference"><a href="#cite_note-pournelle198307-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> The company advertised in <i>BYTE</i> its program for publishing others' software, and job openings for software developers.<sup id="cite_ref-black2022_18-4" class="reference"><a href="#cite_note-black2022-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> By mid-1983 more than 1000 applications were available.<sup id="cite_ref-mace19830530saddle_20-4" class="reference"><a href="#cite_note-mace19830530saddle-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> TI insisted on being the sole publisher for the system, however, which many developers refused to agree to.<sup id="cite_ref-pollack19830619_23-7" class="reference"><a href="#cite_note-pollack19830619-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> After <a href="/wiki/Third-party_developer" class="mw-redirect" title="Third-party developer">third-party developers</a>' games for the Atari 2600 became very successful, the company at the June 1983 <a href="/wiki/Consumer_Electronics_Show" class="mw-redirect" title="Consumer Electronics Show">Consumer Electronics Show</a> announced that only cartridges with a TI-licensed <a href="/wiki/Lockout_chip" title="Lockout chip">lockout chip</a> would work in the 99/4A.<sup id="cite_ref-mitchell19830906_27-2" class="reference"><a href="#cite_note-mitchell19830906-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> TI held a patent on a <a href="/wiki/Program_counter" title="Program counter">program counter</a> implemented in software in GROM, which a future operating system revision would require in cartridges.<sup id="cite_ref-mace19830530_33-0" class="reference"><a href="#cite_note-mace19830530-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-ti994aqimodel_34-0" class="reference"><a href="#cite_note-ti994aqimodel-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup> The <i><a href="/wiki/Boston_Phoenix" class="mw-redirect" title="Boston Phoenix">Boston Phoenix</a></i> predicted that "most [software developers] just won't bother making TI-compatible versions of their programs",<sup id="cite_ref-mitchell19830906_27-3" class="reference"><a href="#cite_note-mitchell19830906-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> and Pournelle wrote that "TI once again tells the hobbyists to drop dead".<sup id="cite_ref-pournelle198307_29-3" class="reference"><a href="#cite_note-pournelle198307-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> </p><p>No official technical documentation from TI was released until the "Editor/Assembler" development suite was announced in 1981 and released in 1982, and no system schematics were ever released to the public until after TI had discontinued the computer. </p> <div class="mw-heading mw-heading3"><h3 id="Discontinuation">Discontinuation</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=10" title="Edit section: Discontinuation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>After TI in mid-1983 unexpectedly announced a <span style="white-space: nowrap">$100 million</span> loss in the second calendar quarter—implying a pretax loss from home computers of <span class="nowrap"><span data-sort-value="7008200000000000000♠"></span>$200–250 million</span>—its stock dropped by one third in two days. The <i>Times</i> stated in June 1983 that Cosby's <span style="white-space: nowrap">$100</span> refund "joke is no longer funny", and that "future options are slim". The low price affected the 99/4A's reputation; "When they went to <span style="white-space: nowrap">$99</span>, people started asking 'What's wrong with it?'", one retail executive said. An <a href="/wiki/L.F._Rothschild" title="L.F. Rothschild">L.F. Rothschild</a> <a href="/wiki/Sell-side_analyst" title="Sell-side analyst">sell-side analyst</a> estimated that TI had prepared to manufacture three million computers in 1983, but would only be able to sell two million;<sup id="cite_ref-pollack19830619_23-8" class="reference"><a href="#cite_note-pollack19830619-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> another analyst forecast one million for the year.<sup id="cite_ref-mace19830530saddle_20-5" class="reference"><a href="#cite_note-mace19830530saddle-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> </p><p>Some observers predicted after the second quarter's loss that the 99/4A would not be able to recover; even if the company did not plan to discontinue the computer, the fear that it would become <a href="/wiki/Orphaned_technology" title="Orphaned technology">orphaned technology</a> might cause retailers to avoid ordering inventory.<sup id="cite_ref-pollack19830619_23-9" class="reference"><a href="#cite_note-pollack19830619-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> Others thought that TI could sell excess inventory and continue producing the computer.<sup id="cite_ref-ahl198403_5-11" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> After losing <span style="white-space: nowrap">$111 million</span> after taxes in the third calendar quarter of 1983, TI announced plans to discontinue the 99/4A, while continuing to sell the <a href="/wiki/TI_Professional" class="mw-redirect" title="TI Professional">TI Professional</a> <a href="/wiki/MS-DOS" title="MS-DOS">MS-DOS</a>-compatible computer.<sup id="cite_ref-maceti19831121_26-1" class="reference"><a href="#cite_note-maceti19831121-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> (TI stock rose by 25% after the announcement, because the company's other businesses were strong.)<sup id="cite_ref-ap19831101_35-0" class="reference"><a href="#cite_note-ap19831101-35"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-maceti19831121_26-2" class="reference"><a href="#cite_note-maceti19831121-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> With another TI price cut, retailers sold remaining inventory of the former <span style="white-space: nowrap">$1,150</span> computer during Christmas for $49.<sup id="cite_ref-maceti19831121_26-3" class="reference"><a href="#cite_note-maceti19831121-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-ahl198403_5-12" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-kleinfield19841222_36-0" class="reference"><a href="#cite_note-kleinfield19841222-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> The 90 <a href="/wiki/Child_World" title="Child World">Child World</a> stores quickly sold over 40,000 computers<sup id="cite_ref-rosenberg19831208_37-0" class="reference"><a href="#cite_note-rosenberg19831208-37"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup> at a price referred to as "nearly a stocking stuffer" in a <i>Times</i> article.<sup id="cite_ref-nyt19831210_38-0" class="reference"><a href="#cite_note-nyt19831210-38"><span class="cite-bracket">[</span>38<span class="cite-bracket">]</span></a></sup> </p><p>A total of 2.8 million units were shipped before the TI-99/4A was discontinued in March 1984,<sup id="cite_ref-oldcomputers_1-1" class="reference"><a href="#cite_note-oldcomputers-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-39" class="reference"><a href="#cite_note-39"><span class="cite-bracket">[</span>39<span class="cite-bracket">]</span></a></sup> perhaps the largest installed base among all personal computers.<sup id="cite_ref-maceti19831121_26-4" class="reference"><a href="#cite_note-maceti19831121-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> The 99/4A became the first in a series of home computers to be orphaned by their manufacturer over the next few years, along with the <a href="/wiki/Coleco_Adam" title="Coleco Adam">Coleco Adam</a>, <a href="/wiki/Mattel_Aquarius" title="Mattel Aquarius">Mattel Aquarius</a>, <a href="/wiki/Timex_Sinclair_1000" title="Timex Sinclair 1000">Timex Sinclair 1000</a>, and <a href="/wiki/IBM_PCjr" title="IBM PCjr">IBM PCjr</a>. </p> <div class="mw-heading mw-heading2"><h2 id="Architecture">Architecture</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=11" title="Edit section: Architecture"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In order to build a complete 16-bit system, TI would have had to redesign many of their existing 8-bit support chips. Instead, TI decided to use existing devices for the majority of the system. The result is that only a small portion of the system is 16-bit and uses a second 8-bit <a href="/wiki/Computer_bus" class="mw-redirect" title="Computer bus">computer bus</a> for the rest.<sup id="cite_ref-rhines2_12-2" class="reference"><a href="#cite_note-rhines2-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </p><p>One of the key features of the TMS9900 from the minicomputer design that spawned it is the inclusion of several sets of <a href="/wiki/Processor_register" title="Processor register">processor registers</a>. In a minicomputer setting, the system was typically running a <a href="/wiki/Time-sharing" title="Time-sharing">time-sharing</a> or <a href="/wiki/Computer_multitasking" title="Computer multitasking">multitasking</a> <a href="/wiki/Operating_system" title="Operating system">operating system</a>, or being used for <a href="/wiki/Real-time_computing" title="Real-time computing">real-time computing</a>, both of which benefit from being able to quickly switch among programs. To do this, the TMS9900 stores several sets of registers in main memory and can switch between the sets of sixteen 16-bit registers by changing the single workspace pointer register, thereby allowing very rapid <a href="/wiki/Context_switch" title="Context switch">context switching</a>. </p><p>The new design put 256 bytes of <a href="/wiki/Random-access_memory" title="Random-access memory">random-access memory</a> (RAM) on the 16-bit bus to store up to eight sets of registers. This area of RAM is known as the "<a href="/wiki/Scratchpad_memory" title="Scratchpad memory">scratchpad memory</a>". As the processor's instructions are all 16-bit as well, the 8 KB internal system <a href="/wiki/Read-only_memory" title="Read-only memory">read-only memory</a> (ROM) was also on the 16-bit side.<sup id="cite_ref-arch_40-0" class="reference"><a href="#cite_note-arch-40"><span class="cite-bracket">[</span>40<span class="cite-bracket">]</span></a></sup> Only the <a href="/wiki/Program_counter" title="Program counter">program counter</a>, status register, and workspace pointer registers are actually implemented on the chip itself.<sup id="cite_ref-arch_40-1" class="reference"><a href="#cite_note-arch-40"><span class="cite-bracket">[</span>40<span class="cite-bracket">]</span></a></sup> </p><p>Included on the 8-bit side of the system is the majority of the RAM and almost all of the support chips, especially the <a href="/wiki/Video_display_controller" title="Video display controller">video display controller</a> (VDP). All accesses to the VDP system are executed eight bits at a time.<sup id="cite_ref-41" class="reference"><a href="#cite_note-41"><span class="cite-bracket">[</span>41<span class="cite-bracket">]</span></a></sup> The system's RAM is managed by the VDP, which provides access to the CPU only when the VDP is not using the memory. This means that user programs and data are read over two <a href="/wiki/Instruction_cycle" title="Instruction cycle">machine cycles</a>, reducing speed by half. According to TI's former manager for microprocessors who oversaw TMS9900 development, this negates the performance advantage of a 16-bit processor.<sup id="cite_ref-rhines2_12-3" class="reference"><a href="#cite_note-rhines2-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </p><p>The TMS9900's <a href="/wiki/Machine_language" class="mw-redirect" title="Machine language">machine language</a> instructions must be word-aligned, so at least 16-bits are needed for every instruction. At the time, memory was expensive, so the size of this format was a concern. Additionally, programming the 8-bit side of the system from 16-bit code is somewhat complex. To address this, TI developed a pseudo-<a href="/wiki/Assembly_language" title="Assembly language">assembly language</a> known as "Graphic Programming Language", or GPL. This is a compact 8-bit language interpreted by the CPU which dynamically translates the GPL instructions into one or more TMS9900 instructions. GPL includes utility routines that appear as single instructions in GPL code, such as clearing a block of memory. All software originally distributed on <a href="/wiki/ROM_cartridge" title="ROM cartridge">ROM cartridges</a> were written using GPL, and are sometimes referred to as GROMs.<sup id="cite_ref-arch_40-2" class="reference"><a href="#cite_note-arch-40"><span class="cite-bracket">[</span>40<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-mace19830530_33-1" class="reference"><a href="#cite_note-mace19830530-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p><p>At the time of launch, the system included only a single user-accessible <a href="/wiki/Programming_language" title="Programming language">programming language</a>: TI's built-in BASIC interpreter, written in GPL. On the <a href="/wiki/Creative_Computing_Benchmark" title="Creative Computing Benchmark">Creative Computing Benchmark</a>, it runs at roughly half the speed of the <a href="/wiki/Apple_II" title="Apple II">Apple II</a>.<sup id="cite_ref-42" class="reference"><a href="#cite_note-42"><span class="cite-bracket">[</span>42<span class="cite-bracket">]</span></a></sup> </p><p>Computers manufactured from August 1983 and later may have the lockout chip preventing use of unlicensed cartridges. Such "QI" units have a 1983 copyright date at bootup.<sup id="cite_ref-ti994aqimodel_34-1" class="reference"><a href="#cite_note-ti994aqimodel-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Technical_specifications">Technical specifications</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=12" title="Edit section: Technical specifications"><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:TI-99_4A_Basic_Program_Running.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e0/TI-99_4A_Basic_Program_Running.png/250px-TI-99_4A_Basic_Program_Running.png" decoding="async" width="220" height="166" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e0/TI-99_4A_Basic_Program_Running.png/330px-TI-99_4A_Basic_Program_Running.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e0/TI-99_4A_Basic_Program_Running.png/500px-TI-99_4A_Basic_Program_Running.png 2x" data-file-width="1195" data-file-height="900" /></a><figcaption>A BASIC program running on a TI-99/4A</figcaption></figure> <div class="mw-heading mw-heading3"><h3 id="CPU">CPU</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=13" title="Edit section: CPU"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/TMS9900" title="TMS9900">TMS9900</a> @ 3 <a href="/wiki/Megahertz" class="mw-redirect" title="Megahertz">MHz</a>, <a href="/wiki/16-bit" class="mw-redirect" title="16-bit">16-bit</a>, 64-pin <a href="/wiki/Dual_in-line_package" title="Dual in-line package">DIP</a> </p> <div class="mw-heading mw-heading3"><h3 id="Memory">Memory</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=14" title="Edit section: Memory"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li>8 KB of monitor ROM and GPL interpreter</li> <li>8 KB of RAM, if memory expansion is attached<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Category:All_self-contradictory_articles" title="Category:All self-contradictory articles"><span title="Due to poor phrasing, this bullet appears to contradict the one about 24 KB RAM. How much RAM is provided if the memory expansion is attached? It can't be both 8 and 24 K. I could guess what was really meant by this, but I would be guessing, and there's the rub. (March 2025)">contradictory</span></a></i>]</sup></li> <li>8 KB allocated to expansion devices (e.g. disk drive controller)</li> <li>8 KB allocated to ROM/RAM in expansion cartridges</li> <li>256 bytes scratchpad RAM for the CPU</li> <li>Memory ports for Video Display Processor, sound, speech etc.</li> <li>24 KB RAM, if memory expansion is attached<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Category:All_self-contradictory_articles" title="Category:All self-contradictory articles"><span title="Due to poor phrasing, this bullet appears to contradict the one about 8 KB of RAM. How much RAM is provided if the memory expansion is attached? It can't be both 8 and 24 K. I could guess what was really meant by this, but I would be guessing, and there's the rub. (March 2025)">contradictory</span></a></i>]</sup></li> <li>16 KB Video Display Processor RAM accessible via the VDP (not in CPU's memory map)</li></ul> <div class="mw-heading mw-heading3"><h3 id="Video">Video</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=15" title="Edit section: Video"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/TMS9918A" class="mw-redirect" title="TMS9918A">TMS9918A</a> video display processor, 40 pin <a href="/wiki/Dual_in-line_package" title="Dual in-line package">DIP</a>. The earlier 99/4 uses the TMS9918. PAL systems use the "9929" versions of each. </p> <ul><li>32 single-color <a href="/wiki/Sprite_(computer_graphics)" title="Sprite (computer graphics)">sprites</a> in defined layers allowing higher-numbered sprites to transparently flow over lower-numbered sprites. Sprites are available at 8×8 pixels or 16×16 pixels, with a "magnify" bit that doubled all sprites' size but not their resolution. A single bit is available in hardware for <a href="/wiki/Collision_detection" title="Collision detection">collision detection</a>, and the console supports automatic movement via an interrupt routine in the ROM. There can only be 4 visible sprites per <a href="/wiki/Scan_line" title="Scan line">scan line</a>.</li> <li>16 fixed colors (15 visible, one color reserved for "transparent" which shows the background color). Transparent is intended for the 9918's <a href="/wiki/Genlock" title="Genlock">genlock</a> which is disabled in the system.</li> <li>Text mode: 40×24 characters (256 6×8 user-definable characters, no sprites, foreground and background color only, not accessible in BASIC, standard in the p-system/Pascal, assembly editor and word processor)</li> <li>Graphics mode: 32×24 characters (256 8×8 user-definable characters), full 15 color palette + transparent (available in groups of 8 through the character table) and 32 sprites (The only mode available in BASIC. Extended BASIC is required for sprites, and can access only 28 of them.)</li> <li>Bitmap mode: 256×192 pixels (no more than two colors in an eight-pixel row, full 15 color palette + transparent, all 32 sprites available but interrupt-based motion through the ROM routine is not due to the memory layout, not available to BASIC or the original 9918).</li> <li>Multicolor mode: 64×48 pixels (each pixel may be any color, all 32 sprites are available)</li> <li>All of the above comprise 36 layers starting with the video overlay input, then the background color, then two graphics mode layers, then a layer for each of the 32 sprites. A higher layer obscures a lower layer in hardware, unless that higher layer is transparent.</li></ul> <div class="mw-heading mw-heading3"><h3 id="Sound">Sound</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=16" title="Edit section: Sound"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>TMS9919, later <a href="/wiki/SN94624" class="mw-redirect" title="SN94624">SN94624</a>, identical to the <a href="/wiki/SN76489" class="mw-redirect" title="SN76489">SN76489</a> used in many other systems </p> <ul><li>3 voices, 1 noise (white or periodic)</li> <li>Voices generate square waves from 110 Hz to approximately 115 kHz</li> <li>Console ROM includes interrupt-driven music playback</li></ul> <div class="mw-heading mw-heading2"><h2 id="Games">Games</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=17" title="Edit section: Games"><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:Tiinvaders2.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/en/thumb/b/b7/Tiinvaders2.png/250px-Tiinvaders2.png" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/b/b7/Tiinvaders2.png 1.5x" data-file-width="280" data-file-height="210" /></a><figcaption><i><a href="/wiki/TI_Invaders" title="TI Invaders">TI Invaders</a></i> is a 1981 clone of <i>Space Invaders</i></figcaption></figure> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951" /><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Category:TI-99/4A_games" title="Category:TI-99/4A games">Category:TI-99/4A games</a></div> <p>Roughly 100 games were published for the TI-99/4A, with most published by Texas Instruments.<sup id="cite_ref-mace19840507_43-0" class="reference"><a href="#cite_note-mace19840507-43"><span class="cite-bracket">[</span>43<span class="cite-bracket">]</span></a></sup> Some of the games released only for the 99/4A are <a href="/wiki/Parsec_(video_game)" title="Parsec (video game)"><i>Parsec</i></a>, <a href="/wiki/Alpiner_(video_game)" title="Alpiner (video game)"><i>Alpiner</i></a>, <i><a href="/wiki/Tombstone_City:_21st_Century" title="Tombstone City: 21st Century">Tombstone City: 21st Century</a></i>, <i><a href="/wiki/Tunnels_of_Doom" title="Tunnels of Doom">Tunnels of Doom</a></i>, and <i><a href="/wiki/The_Attack_(video_game)" title="The Attack (video game)">The Attack</a></i>. <i><a href="/wiki/TI_Invaders" title="TI Invaders">TI Invaders</a></i> and <a href="/wiki/Car_Wars_(video_game)" title="Car Wars (video game)"><i>Car Wars</i></a> are TI's renditions of <i><a href="/wiki/Space_Invaders" title="Space Invaders">Space Invaders</a></i> and <i><a href="/wiki/Head_On_(video_game)" title="Head On (video game)">Head On</a></i> respectively. <i><a href="/wiki/Munch_Man" title="Munch Man">Munch Man</a></i> is similar to <i><a href="/wiki/Pac-Man" title="Pac-Man">Pac-Man</a></i>, but the title character fills the maze with a pattern rather than emptying it of dots. </p><p>The <a href="/wiki/Adventure_International" title="Adventure International">Adventure International</a> <a href="/wiki/Text_adventure" class="mw-redirect" title="Text adventure">text adventures</a> require the Adventure Command Module cartridge.<sup id="cite_ref-derushakemp19820412_44-0" class="reference"><a href="#cite_note-derushakemp19820412-44"><span class="cite-bracket">[</span>44<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Tigervision" title="Tigervision">Tigervision</a> offered a solution to the memory limitation of the standard cartridge slot in the form of a 24 KB memory expansion cartridge that attached to the side expansion interface, emulating an expansion device. This allowed the company to implement a larger game completely in machine code, which was used for <i>Espial</i> and <i><a href="/wiki/Miner_2049er" title="Miner 2049er">Miner 2049er</a></i>. Exceltec also released two similar side cartridges: <i>Arcturus</i><sup id="cite_ref-45" class="reference"><a href="#cite_note-45"><span class="cite-bracket">[</span>45<span class="cite-bracket">]</span></a></sup> and <i>Killer Caterpillar</i>. </p><p>The media criticized the computer's game library as mediocre.<sup id="cite_ref-ahl198403_5-13" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-mace19840507_43-1" class="reference"><a href="#cite_note-mace19840507-43"><span class="cite-bracket">[</span>43<span class="cite-bracket">]</span></a></sup> TI not only discouraged third-party development, including games, but it also failed to license popular arcade games like <i><a href="/wiki/Zaxxon" title="Zaxxon">Zaxxon</a></i> and <i><a href="/wiki/Frogger" title="Frogger">Frogger</a></i>.<sup id="cite_ref-pollack19830619_23-10" class="reference"><a href="#cite_note-pollack19830619-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Unreleased_hardware">Unreleased hardware</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=18" title="Edit section: Unreleased hardware"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Hex-Bus">Hex-Bus</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=19" title="Edit section: Hex-Bus"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The <a href="/wiki/Hex-Bus" title="Hex-Bus">Hex-Bus</a> interface was designed in 1982 and intended for commercial release in late 1983. It connects the console to peripherals via a high-speed serial link. Though it is similar to today's <a href="/wiki/Universal_Serial_Bus" class="mw-redirect" title="Universal Serial Bus">USB</a> (<a href="/wiki/Plug_and_play" title="Plug and play">plug and play</a>, <a href="/wiki/Hot-swappable" class="mw-redirect" title="Hot-swappable">hot-swappable</a>, etc.), it was never released, with only a small number of prototypes appearing in collector hands after TI pulled out of the market. </p> <div class="mw-heading mw-heading3"><h3 id="TI-99/4A_successors"><span id="TI-99.2F4A_successors"></span>TI-99/4A successors</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=20" title="Edit section: TI-99/4A successors"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The TI-99/4 was intended to fit in the middle of a planned range of TI-99 computers, with prototypes and documentation created for other models. Initial plans were for a lower-end TI-99/2 and a more powerful TI-99/8. Later ideas for expanding the range included a bargain-priced TI-99/3, a terminal TI-99/7, and a direct follow-up to the TI-99/4A referred to as either TI-99/4B or TI-99/5.<sup id="cite_ref-46" class="reference"><a href="#cite_note-46"><span class="cite-bracket">[</span>46<span class="cite-bracket">]</span></a></sup> </p><p>At the time they left the home computer market, TI had been actively developing two successors to the TI-99/4A that went through several prototypes but never entered production. Some of these prototypes are now in the hands of TI-99/4A collectors. Both machines would have been substantially faster than the original TI-99/4A and used the <a href="/wiki/Hex-Bus" title="Hex-Bus">Hex-Bus</a> serial interface. </p> <ul><li>TI-99/2,<sup id="cite_ref-47" class="reference"><a href="#cite_note-47"><span class="cite-bracket">[</span>47<span class="cite-bracket">]</span></a></sup> a 4K RAM, 32K ROM computer with no color, sound, or joystick port and a <a href="/wiki/Mylar" class="mw-redirect" title="Mylar">Mylar</a> keyboard. TI designed the computer in four and a half months to sell for under $100 and compete with the <a href="/wiki/ZX81" title="ZX81">Sinclair ZX81</a> and <a href="/wiki/Timex_Sinclair_1000" title="Timex Sinclair 1000">Timex Sinclair 1000</a>. Based on the TMS9995 CPU running at 10.7 MHz and with a built-in RF modulator, performance greatly increased when the screen was blank. The <a href="/wiki/University_of_Louisiana_at_Lafayette" title="University of Louisiana at Lafayette">University of Southwestern Louisiana</a> developed system software. 99/2 software ran on the 99/4A, but not vice versa. Working prototypes appeared at the January 1983 Consumer Electronic Show (CES).<sup id="cite_ref-byte198306_48-0" class="reference"><a href="#cite_note-byte198306-48"><span class="cite-bracket">[</span>48<span class="cite-bracket">]</span></a></sup> By mid-1983 the 99/4A sold for $99, however.<sup id="cite_ref-mace19830530saddle_20-6" class="reference"><a href="#cite_note-mace19830530saddle-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-lock198306_49-0" class="reference"><a href="#cite_note-lock198306-49"><span class="cite-bracket">[</span>49<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-pollack19830619_23-11" class="reference"><a href="#cite_note-pollack19830619-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> The company canceled the 99/2 in April 1983,<sup id="cite_ref-maceti19831121_26-5" class="reference"><a href="#cite_note-maceti19831121-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> but planned to exhibit it at the June CES until other companies' press conferences there indicated that competition would increase.<sup id="cite_ref-mitchell19830906_27-4" class="reference"><a href="#cite_note-mitchell19830906-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup></li> <li>TI-99/8 and 99/6.<sup id="cite_ref-50" class="reference"><a href="#cite_note-50"><span class="cite-bracket">[</span>50<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-mitchell19830906_27-5" class="reference"><a href="#cite_note-mitchell19830906-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> The 99/8 reportedly had a $200 wholesale price.<sup id="cite_ref-ahl198403_5-14" class="reference"><a href="#cite_note-ahl198403-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> Privately shown to dealers but not announced at June CES, it was formally canceled in October 1983. It included 64 KB of RAM<sup id="cite_ref-maceti19831121_26-6" class="reference"><a href="#cite_note-maceti19831121-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> expandable to 15 <a href="/wiki/Megabyte" title="Megabyte">megabytes</a>, a larger keyboard, built-in speech synthesis, built-in <a href="/wiki/UCSD_Pascal" title="UCSD Pascal">UCSD Pascal</a> operating environment, and the full 16-bit data bus available on the expansion port. It was abandoned in the prototype stage. The <a href="/wiki/Multi_Emulator_Super_System" title="Multi Emulator Super System">Multi Emulator Super System</a> is capable of running what are believed<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Manual_of_Style/Words_to_watch#Unsupported_attributions" title="Wikipedia:Manual of Style/Words to watch"><span title="The material near this tag may use weasel words or too-vague attribution. (October 2020)">by whom?</span></a></i>]</sup> to be the system's ROMs.</li></ul> <div class="mw-heading mw-heading2"><h2 id="Legacy">Legacy</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=21" title="Edit section: Legacy"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><span class="anchor" id="Tomy_Tutor"></span> The <a href="/wiki/Tomy_Tutor" title="Tomy Tutor">Tomy Tutor</a> and its sibling systems are Japanese computers similar in architecture and firmware to the 99/8. Unlike the 99/8, it was released commercially, but sold poorly outside Japan. Portions of the operating system and BASIC code are similar to the 99/8. </p><p>The annual Chicago TI Faire is now in its 42nd year.<sup id="cite_ref-51" class="reference"><a href="#cite_note-51"><span class="cite-bracket">[</span>51<span class="cite-bracket">]</span></a></sup> where people celebrated the TI-99 family of computers. </p> <div class="mw-heading mw-heading3"><h3 id="Post-TI_development">Post-TI development</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=TI-99/4A&action=edit&section=22" title="Edit section: Post-TI development"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The Myarc <a href="/wiki/Geneve_9640" title="Geneve 9640">Geneve 9640</a> is an enhanced TI-99/4A clone built by Myarc as a card to fit into the TI Peripheral Expansion System.<sup id="cite_ref-ti_52-0" class="reference"><a href="#cite_note-ti-52"><span class="cite-bracket">[</span>52<span class="cite-bracket">]</span></a></sup> It uses an <a href="/wiki/IBM_PC/XT" class="mw-redirect" title="IBM PC/XT">IBM PC/XT</a> detached keyboard. Released in 1987, it is similar to the unreleased TI-99/8 system. It includes a 12 MHz TMS9995 processor, enhanced graphics with 80-column text mode, 16-bit wide RAM, <a href="/wiki/Myarc_Disk_Operating_System" title="Myarc Disk Operating System">MDOS</a>, and is compatible with nearly all TI software and slot-mounted hardware. A toggle switch slows the computer to the speed of the original. </p><p>The Second Generation CPU card (SGCPU) was released by the System 99 User Group in 1996 as a card to be installed in the PEB.<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. (October 2020)">citation needed</span></a></i>]</sup> </p><p>In 2004, a <a href="/wiki/Universal_Serial_Bus" class="mw-redirect" title="Universal Serial Bus">Universal Serial Bus</a> card and <a href="/wiki/Advanced_Technology_Attachment" class="mw-redirect" title="Advanced Technology Attachment">Advanced Technology Attachment</a> controller for <a href="/wiki/Integrated_drive_electronics" class="mw-redirect" title="Integrated drive electronics">IDE</a> <a href="/wiki/Hard_disk" class="mw-redirect" title="Hard disk">hard disks</a> for the PEB were released. </p><p>A range of plug-in cartridge boards have been developed, allowing software projects to be distributed on cartridge.<sup id="cite_ref-53" class="reference"><a href="#cite_note-53"><span class="cite-bracket">[</span>53<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-54" class="reference"><a href="#cite_note-54"><span class="cite-bracket">[</span>54<span class="cite-bracket">]</span></a></sup> </p><p>The Phoenix G2,<sup id="cite_ref-55" class="reference"><a href="#cite_note-55"><span class="cite-bracket">[</span>55<span class="cite-bracket">]</span></a></sup> was designed in 2010 by Gary Smith, a member of TI-User Group UK. It uses two FPGAs to emulate the entire architecture of the Myarc Geneve 9640 and the TMS9995 microprocessor. It incorporates an <a href="/wiki/Secure_Digital" class="mw-redirect" title="Secure Digital">SD card</a> reader, Ethernet, <a href="/wiki/Video_Graphics_Array" title="Video Graphics Array">VGA</a> output, and 64 MB RAM. </p><p>An FPGA-based TMS9918 compatible graphics chip, called the F18A, is a drop-in replacement for the original 9918 VDP, but features VGA output, bypassing the TMS9918A's native composite output, and contains other enhancements such as removal of the restriction of 4 sprites per scan line.<sup id="cite_ref-56" class="reference"><a href="#cite_note-56"><span class="cite-bracket">[</span>56<span class="cite-bracket">]</span></a></sup> </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=TI-99/4A&action=edit&section=23" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Compact_Computer_40" title="Compact Computer 40">Compact Computer 40</a> (1983)</li> <li><a href="/wiki/Texas_Instruments_Professional_Computer" title="Texas Instruments Professional Computer">Texas Instruments Professional Computer</a> (1983 – <abbr title="circa">c.</abbr><span style="white-space:nowrap;"> 1985</span>)</li> <li><a href="/wiki/Texas_Instruments_Professional_Portable_Computer" title="Texas Instruments Professional Portable Computer">Texas Instruments Professional Portable Computer</a> (1983)</li></ul> <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=TI-99/4A&action=edit&section=24" title="Edit section: References"><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"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-oldcomputers-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-oldcomputers_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-oldcomputers_1-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://oldcomputers.net/">Steve's Old Computer Museum!</a></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"><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 id="CITEREFBryan_Roppolo_Boulder" class="citation web cs1">Bryan Roppolo Boulder. <a rel="nofollow" class="external text" href="http://www.ti994.com/1979/brochures/">"1979 TI-99/4 Home Computer Literature"</a>. Ti994.com<span class="reference-accessdate">. Retrieved <span class="nowrap">2019-10-28</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=1979+TI-99%2F4+Home+Computer+Literature&rft.pub=Ti994.com&rft.au=Bryan+Roppolo+Boulder&rft_id=http%3A%2F%2Fwww.ti994.com%2F1979%2Fbrochures%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-oldcomp-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-oldcomp_3-0">^</a></b></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/20170313202831/http://www.old-computers.com/history/detail.asp?n=54&t=3"><i>Texas Instruments TI-99/4, First 16-bit Home Computer</i></a>, Old-Computers.com, archived from <a rel="nofollow" class="external text" href="http://www.old-computers.com/history/detail.asp?n=54&t=3">the original</a> on 13 March 2017<span class="reference-accessdate">, retrieved <span class="nowrap">23 September</span> 2014</span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Texas+Instruments+TI-99%2F4%2C+First+16-bit+Home+Computer&rft.pub=Old-Computers.com&rft_id=http%3A%2F%2Fwww.old-computers.com%2Fhistory%2Fdetail.asp%3Fn%3D54%26t%3D3&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-death_1984_04_texasmonthly-4"><span class="mw-cite-backlink">^ <a href="#cite_ref-death_1984_04_texasmonthly_4-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-death_1984_04_texasmonthly_4-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-death_1984_04_texasmonthly_4-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-death_1984_04_texasmonthly_4-3"><sup><i><b>d</b></i></sup></a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://www.texasmonthly.com/news-politics/death-of-texas-instruments-home-computer/">"Death of a Computer,"</a> April 1984, <i><a href="/wiki/Texas_Monthly" title="Texas Monthly">Texas Monthly</a>,</i> retrieved September 20, 2023</span> </li> <li id="cite_note-ahl198403-5"><span class="mw-cite-backlink">^ <a href="#cite_ref-ahl198403_5-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-ahl198403_5-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-ahl198403_5-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-ahl198403_5-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-ahl198403_5-4"><sup><i><b>e</b></i></sup></a> <a href="#cite_ref-ahl198403_5-5"><sup><i><b>f</b></i></sup></a> <a href="#cite_ref-ahl198403_5-6"><sup><i><b>g</b></i></sup></a> <a href="#cite_ref-ahl198403_5-7"><sup><i><b>h</b></i></sup></a> <a href="#cite_ref-ahl198403_5-8"><sup><i><b>i</b></i></sup></a> <a href="#cite_ref-ahl198403_5-9"><sup><i><b>j</b></i></sup></a> <a href="#cite_ref-ahl198403_5-10"><sup><i><b>k</b></i></sup></a> <a href="#cite_ref-ahl198403_5-11"><sup><i><b>l</b></i></sup></a> <a href="#cite_ref-ahl198403_5-12"><sup><i><b>m</b></i></sup></a> <a href="#cite_ref-ahl198403_5-13"><sup><i><b>n</b></i></sup></a> <a href="#cite_ref-ahl198403_5-14"><sup><i><b>o</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFAhl,_David_H.1984" class="citation news cs1"><a href="/wiki/David_H._Ahl" title="David H. Ahl">Ahl, David H.</a> (March 1984). <a rel="nofollow" class="external text" href="http://www.atarimagazines.com/creative/v10n3/30_Texas_Instruments.php">"Texas Instruments"</a>. <i>Creative Computing</i>. pp. <span class="nowrap">30–</span>32<span class="reference-accessdate">. Retrieved <span class="nowrap">6 February</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Creative+Computing&rft.atitle=Texas+Instruments&rft.pages=%3Cspan+class%3D%22nowrap%22%3E30-%3C%2Fspan%3E32&rft.date=1984-03&rft.au=Ahl%2C+David+H.&rft_id=http%3A%2F%2Fwww.atarimagazines.com%2Fcreative%2Fv10n3%2F30_Texas_Instruments.php&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></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 class="citation book cs1"><i>TI-99/4A Console Technical Data</i>. Texas Instruments Inc. 1983. p. 10.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=TI-99%2F4A+Console+Technical+Data&rft.pages=10&rft.pub=Texas+Instruments+Inc.&rft.date=1983&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-mace19840409-7"><span class="mw-cite-backlink">^ <a href="#cite_ref-mace19840409_7-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-mace19840409_7-1"><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="CITEREFMace,_Scott1984" class="citation news cs1">Mace, Scott (1984-04-09). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=jC4EAAAAMBAJ&pg=PA50">"Atarisoft vs. Commodore"</a>. <i>InfoWorld</i>. p. 50<span class="reference-accessdate">. Retrieved <span class="nowrap">4 February</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=InfoWorld&rft.atitle=Atarisoft+vs.+Commodore&rft.pages=50&rft.date=1984-04-09&rft.au=Mace%2C+Scott&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DjC4EAAAAMBAJ%26pg%3DPA50&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</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://shawweb.myzen.co.uk/stephen/book9.htm#mem">"Getting Started with the TI-99/4A"</a>. 1983.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Getting+Started+with+the+TI-99%2F4A&rft.date=1983&rft_id=http%3A%2F%2Fshawweb.myzen.co.uk%2Fstephen%2Fbook9.htm%23mem&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></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 class="citation cs2"><a rel="nofollow" class="external text" href="http://shawweb.myzen.co.uk/stephen/book8.htm"><i>Getting Started with the TI-99/4A</i></a>, 1983</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Getting+Started+with+the+TI-99%2F4A&rft.date=1983&rft_id=http%3A%2F%2Fshawweb.myzen.co.uk%2Fstephen%2Fbook8.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation cs2">"TI-99/4A user-dismantled PEB", <a rel="nofollow" class="external text" href="http://www.99er.net/994apic.html"><i>99er</i></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=TI-99%2F4A+user-dismantled+PEB&rft.btitle=99er&rft_id=http%3A%2F%2Fwww.99er.net%2F994apic.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-rhines20170622-11"><span class="mw-cite-backlink">^ <a href="#cite_ref-rhines20170622_11-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-rhines20170622_11-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-rhines20170622_11-2"><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 id="CITEREFRhines2017" class="citation magazine cs1"><a href="/wiki/Walden_C._Rhines" class="mw-redirect" title="Walden C. 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JHU Press. pp. <span class="nowrap">130–</span>132. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1-4214-4353-9" title="Special:BookSources/978-1-4214-4353-9"><bdi>978-1-4214-4353-9</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Transparent+Designs%3A+Personal+Computing+and+the+Politics+of+User-Friendliness&rft.pages=%3Cspan+class%3D%22nowrap%22%3E130-%3C%2Fspan%3E132&rft.pub=JHU+Press&rft.date=2022-03-29&rft.isbn=978-1-4214-4353-9&rft.aulast=Black&rft.aufirst=Michael+L.&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DHDhiEAAAQBAJ%26q%3Dcosby%252520%25252299%252F4a%252522%252520%252522%2524100%252522%26pg%3DPA130&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-osborne19800707-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-osborne19800707_19-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFOsborne,_Adam1980" class="citation news cs1">Osborne, Adam (1980-07-07). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=Tz4EAAAAMBAJ&pg=PT8">"Radio Shack's Videotex"</a>. <i>InfoWorld</i>. pp. 9, 28<span class="reference-accessdate">. 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Maybe Next Year". <i>The Boston Globe</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Boston+Globe&rft.atitle=Home+Computer%3F+Maybe+Next+Year&rft.date=1983-12-08&rft.aulast=Rosenberg&rft.aufirst=Ronald&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-nyt19831210-38"><span class="mw-cite-backlink"><b><a href="#cite_ref-nyt19831210_38-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation news cs1"><a rel="nofollow" class="external text" href="https://www.nytimes.com/1983/12/10/business/under-1983-christmas-tree-expect-the-home-computer.html">"Under 1983 Christmas Tree, Expect the Home Computer"</a>. <i>The New York Times</i>. 1983-12-10. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0362-4331">0362-4331</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2017-07-02</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+New+York+Times&rft.atitle=Under+1983+Christmas+Tree%2C+Expect+the+Home+Computer&rft.date=1983-12-10&rft.issn=0362-4331&rft_id=https%3A%2F%2Fwww.nytimes.com%2F1983%2F12%2F10%2Fbusiness%2Funder-1983-christmas-tree-expect-the-home-computer.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-39"><span class="mw-cite-backlink"><b><a href="#cite_ref-39">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://99er.net/hist4.html">TI-99 Home Computer Timeline Bill Gaskill</a></span> </li> <li id="cite_note-arch-40"><span class="mw-cite-backlink">^ <a href="#cite_ref-arch_40-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-arch_40-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-arch_40-2"><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 web cs1"><a rel="nofollow" class="external text" href="https://www.unige.ch/medecine/nouspikel/ti99/architec.htm">"The TI-99/4A internal architecture"</a>. 16 August 2000.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=The+TI-99%2F4A+internal+architecture&rft.date=2000-08-16&rft_id=https%3A%2F%2Fwww.unige.ch%2Fmedecine%2Fnouspikel%2Fti99%2Farchitec.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-41"><span class="mw-cite-backlink"><b><a href="#cite_ref-41">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation book cs1"><i>TI-99/4A Console Technical Data</i>. Texas Instruments Inc. 1983. p. 4.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=TI-99%2F4A+Console+Technical+Data&rft.pages=4&rft.pub=Texas+Instruments+Inc.&rft.date=1983&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-42"><span class="mw-cite-backlink"><b><a href="#cite_ref-42">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFKnight2016" class="citation web cs1">Knight, Daniel (10 January 2016). <a rel="nofollow" class="external text" href="https://lowendmac.com/2016/how-fast-were-those-late-1970s-home-computers/">"How Fast Were Those Late 1970s Home Computers?"</a>. <i>Low End Mac</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Low+End+Mac&rft.atitle=How+Fast+Were+Those+Late+1970s+Home+Computers%3F&rft.date=2016-01-10&rft.aulast=Knight&rft.aufirst=Daniel&rft_id=https%3A%2F%2Flowendmac.com%2F2016%2Fhow-fast-were-those-late-1970s-home-computers%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-mace19840507-43"><span class="mw-cite-backlink">^ <a href="#cite_ref-mace19840507_43-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-mace19840507_43-1"><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="CITEREFMace,_Scott1984" class="citation news cs1">Mace, Scott (1984-05-07). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=ti4EAAAAMBAJ&pg=PA56">"In Praise of Classics"</a>. <i>InfoWorld</i>. p. 56<span class="reference-accessdate">. Retrieved <span class="nowrap">6 February</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=InfoWorld&rft.atitle=In+Praise+of+Classics&rft.pages=56&rft.date=1984-05-07&rft.au=Mace%2C+Scott&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3Dti4EAAAAMBAJ%26pg%3DPA56&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-derushakemp19820412-44"><span class="mw-cite-backlink"><b><a href="#cite_ref-derushakemp19820412_44-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFDe_RushaKemp1982" class="citation magazine cs1">De Rusha, Lawrence R. Jr.; Kemp, Jack (1982-04-12). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=YjAEAAAAMBAJ&pg=PA26">"Adventure Series: Games from Texas Instruments"</a>. <i>InfoWorld</i>. pp. <span class="nowrap">26–</span>27<span class="reference-accessdate">. Retrieved <span class="nowrap">2025-03-16</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=InfoWorld&rft.atitle=Adventure+Series%3A+Games+from+Texas+Instruments&rft.pages=%3Cspan+class%3D%22nowrap%22%3E26-%3C%2Fspan%3E27&rft.date=1982-04-12&rft.aulast=De+Rusha&rft.aufirst=Lawrence+R.+Jr.&rft.au=Kemp%2C+Jack&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DYjAEAAAAMBAJ%26pg%3DPA26&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-45"><span class="mw-cite-backlink"><b><a href="#cite_ref-45">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation cs2">"Cartridge pictures", <a rel="nofollow" class="external text" href="http://hexbus.com/TI-99_4A_Home_Computer_Page/Cartridge_Pictures.html#13"><i>TI-99/4A home computer</i></a>, Hex bus</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Cartridge+pictures&rft.btitle=TI-99%2F4A+home+computer&rft.pub=Hex+bus&rft_id=http%3A%2F%2Fhexbus.com%2FTI-99_4A_Home_Computer_Page%2FCartridge_Pictures.html%2313&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-46"><span class="mw-cite-backlink"><b><a href="#cite_ref-46">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFShaw" class="citation web cs1">Shaw, Stephen. <a rel="nofollow" class="external text" href="https://stephen.shawweb.co.uk/tihistory.html">"Home Computing with Texas Instruments"</a>. <i>stephen.shawweb.co.uk</i><span class="reference-accessdate">. Retrieved <span class="nowrap">26 February</span> 2022</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=stephen.shawweb.co.uk&rft.atitle=Home+Computing+with+Texas+Instruments&rft.aulast=Shaw&rft.aufirst=Stephen&rft_id=https%3A%2F%2Fstephen.shawweb.co.uk%2Ftihistory.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></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 class="citation cs2">"99/2", <a rel="nofollow" class="external text" href="http://www.99er.net/992.html"><i>99er</i></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=99%2F2&rft.btitle=99er&rft_id=http%3A%2F%2Fwww.99er.net%2F992.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-byte198306-48"><span class="mw-cite-backlink"><b><a href="#cite_ref-byte198306_48-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFLittlejohn,_HarryJander,_Mark1983" class="citation news cs1">Littlejohn, Harry; Jander, Mark (June 1983). <a rel="nofollow" class="external text" href="https://archive.org/stream/byte-magazine-1983-06/1983_06_BYTE_08-06_16-Bit_Designs#page/n129/mode/2up">"Texas Instruments' 99/2 Basic Computer"</a>. <i>BYTE</i>. p. 128<span class="reference-accessdate">. Retrieved <span class="nowrap">19 October</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=BYTE&rft.atitle=Texas+Instruments%27+99%2F2+Basic+Computer&rft.pages=128&rft.date=1983-06&rft.au=Littlejohn%2C+Harry&rft.au=Jander%2C+Mark&rft_id=https%3A%2F%2Farchive.org%2Fstream%2Fbyte-magazine-1983-06%2F1983_06_BYTE_08-06_16-Bit_Designs%23page%2Fn129%2Fmode%2F2up&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-lock198306-49"><span class="mw-cite-backlink"><b><a href="#cite_ref-lock198306_49-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFLock,_Robert1983" class="citation news cs1">Lock, Robert (June 1983). <a rel="nofollow" class="external text" href="https://archive.org/stream/1983-06-compute-magazine/Compute_Issue_037_1983_Jun#page/n7/mode/2up">"Editor's Notes"</a>. <i>Compute!</i>. p. 6<span class="reference-accessdate">. Retrieved <span class="nowrap">30 October</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Compute%21&rft.atitle=Editor%27s+Notes&rft.pages=6&rft.date=1983-06&rft.au=Lock%2C+Robert&rft_id=https%3A%2F%2Farchive.org%2Fstream%2F1983-06-compute-magazine%2FCompute_Issue_037_1983_Jun%23page%2Fn7%2Fmode%2F2up&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></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 class="citation cs2">"99/8", <a rel="nofollow" class="external text" href="http://www.99er.net/998.html"><i>99er</i></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=99%2F8&rft.btitle=99er&rft_id=http%3A%2F%2Fwww.99er.net%2F998.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" 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 class="citation cs2">"Faire", <a rel="nofollow" class="external text" href="https://sites.google.com/view/chicagotiug"><i>TI-99</i></a>, Main byte</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Faire&rft.btitle=TI-99&rft.pub=Main+byte&rft_id=https%3A%2F%2Fsites.google.com%2Fview%2Fchicagotiug&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-ti-52"><span class="mw-cite-backlink"><b><a href="#cite_ref-ti_52-0">^</a></b></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="http://www.old-computers.com/museum/doc.asp?c=1208"><i>OldComputers</i></a> (online museum)</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=OldComputers&rft_id=http%3A%2F%2Fwww.old-computers.com%2Fmuseum%2Fdoc.asp%3Fc%3D1208&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-53"><span class="mw-cite-backlink"><b><a href="#cite_ref-53">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation cs2">"Hardware projects", <a rel="nofollow" class="external text" href="http://hexbus.com/TI-99_4A_Home_Computer_Page/Hardware_Projects.html"><i>TI-99/4A home computer</i></a>, Hex bus</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Hardware+projects&rft.btitle=TI-99%2F4A+home+computer&rft.pub=Hex+bus&rft_id=http%3A%2F%2Fhexbus.com%2FTI-99_4A_Home_Computer_Page%2FHardware_Projects.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-54"><span class="mw-cite-backlink"><b><a href="#cite_ref-54">^</a></b></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://www.youtube.com/watch?v=Mt5hekfjUXc"><i>You Tube</i></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=You+Tube&rft_id=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DMt5hekfjUXc&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></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 class="citation cs2">"G2", <a rel="nofollow" class="external text" href="https://web.archive.org/web/20100919161603/http://www.ti99ug.co.uk/g2.htm"><i>TI-99 UG</i></a>, UK, archived from <a rel="nofollow" class="external text" href="http://www.ti99ug.co.uk/g2.htm">the original</a> on 2010-09-19</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=G2&rft.btitle=TI-99+UG&rft.place=UK&rft_id=http%3A%2F%2Fwww.ti99ug.co.uk%2Fg2.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> <li id="cite_note-56"><span class="mw-cite-backlink"><b><a href="#cite_ref-56">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation cs2">"Archives", <a rel="nofollow" class="external text" href="http://codehackcreate.com/archives/30"><i>Code hack create</i></a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Archives&rft.btitle=Code+hack+create&rft_id=http%3A%2F%2Fcodehackcreate.com%2Farchives%2F30&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATI-99%2F4A" class="Z3988"></span></span> </li> </ol></div></div> <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=TI-99/4A&action=edit&section=25" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Commons-logo.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/20px-Commons-logo.svg.png" decoding="async" width="12" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/40px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></a></span> Media related to <a href="https://commons.wikimedia.org/wiki/Category:Texas_Instruments_TI-99/4A" class="extiw" title="commons:Category:Texas Instruments TI-99/4A">Texas Instruments TI-99/4A</a> at Wikimedia Commons </p> <ul><li><a rel="nofollow" class="external text" href="http://www.ninerpedia.org/">Ninerpedia</a> wiki devoted to the TI-99 series</li> <li><a rel="nofollow" class="external text" href="http://www.ti994.com/">1979 TI-99/4</a></li> <li><a rel="nofollow" class="external text" href="http://www.99er.net/">The TI-99/4A Home Computer Page</a></li> <li><a rel="nofollow" class="external text" href="https://4apedia.com/index.php?title=Main_Page">TI-99/4A - 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