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data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </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">1</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-Parallel_interface" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Parallel_interface"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.1</span> <span>Parallel interface</span> </div> </a> <ul id="toc-Parallel_interface-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Modern_SCSI" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Modern_SCSI"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.2</span> <span>Modern SCSI</span> </div> </a> <ul id="toc-Modern_SCSI-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Interfaces" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Interfaces"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Interfaces</span> </div> </a> <button aria-controls="toc-Interfaces-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 Interfaces subsection</span> </button> <ul id="toc-Interfaces-sublist" class="vector-toc-list"> <li id="toc-Parallel_SCSI" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Parallel_SCSI"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>Parallel SCSI</span> </div> </a> <ul id="toc-Parallel_SCSI-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-SCSI_interfaces" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#SCSI_interfaces"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.2</span> <span>SCSI interfaces</span> </div> </a> <ul id="toc-SCSI_interfaces-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Cabling" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Cabling"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Cabling</span> </div> </a> <button aria-controls="toc-Cabling-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 Cabling subsection</span> </button> <ul id="toc-Cabling-sublist" class="vector-toc-list"> <li id="toc-SCSI_Parallel_Interface" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#SCSI_Parallel_Interface"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>SCSI Parallel Interface</span> </div> </a> <ul id="toc-SCSI_Parallel_Interface-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Fibre_Channel" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Fibre_Channel"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>Fibre Channel</span> </div> </a> <ul id="toc-Fibre_Channel-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Serial_attached_SCSI" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Serial_attached_SCSI"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.3</span> <span>Serial attached SCSI</span> </div> </a> <ul id="toc-Serial_attached_SCSI-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-iSCSI" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#iSCSI"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.4</span> <span>iSCSI</span> </div> </a> <ul id="toc-iSCSI-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-SRP" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#SRP"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.5</span> <span>SRP</span> </div> </a> <ul id="toc-SRP-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-USB_Attached_SCSI" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#USB_Attached_SCSI"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.6</span> <span>USB Attached SCSI</span> </div> </a> <ul id="toc-USB_Attached_SCSI-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Automation/Drive_Interface" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Automation/Drive_Interface"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.7</span> <span>Automation/Drive Interface</span> </div> </a> <ul id="toc-Automation/Drive_Interface-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-SCSI_command_protocol" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#SCSI_command_protocol"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>SCSI command protocol</span> </div> </a> <ul id="toc-SCSI_command_protocol-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Device_identification" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Device_identification"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Device identification</span> </div> </a> <button aria-controls="toc-Device_identification-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 Device identification subsection</span> </button> <ul id="toc-Device_identification-sublist" class="vector-toc-list"> <li id="toc-Parallel_interface_2" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Parallel_interface_2"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.1</span> <span>Parallel interface</span> </div> </a> <ul id="toc-Parallel_interface_2-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-General" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#General"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.2</span> <span>General</span> </div> </a> <ul id="toc-General-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Device_Type" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Device_Type"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Device Type</span> </div> </a> <ul id="toc-Device_Type-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-SCSI_enclosure_services" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#SCSI_enclosure_services"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>SCSI enclosure services</span> </div> </a> <ul id="toc-SCSI_enclosure_services-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Notes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Notes"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>Notes</span> </div> </a> <ul id="toc-Notes-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-Bibliography" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Bibliography"> <div class="vector-toc-text"> <span class="vector-toc-numb">11</span> <span>Bibliography</span> </div> </a> <ul id="toc-Bibliography-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">12</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">SCSI</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 37 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-37" 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">37 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D9%88%D8%A7%D8%AC%D9%87%D8%A9_%D8%A7%D9%84%D9%86%D8%B8%D8%A7%D9%85_%D8%A7%D9%84%D8%AD%D8%A7%D8%B3%D9%88%D8%A8%D9%8A_%D8%A7%D9%84%D8%B5%D8%BA%D9%8A%D8%B1" title="واجهة النظام الحاسوبي الصغير – Arabic" lang="ar" hreflang="ar" data-title="واجهة النظام الحاسوبي الصغير" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-az mw-list-item"><a href="https://az.wikipedia.org/wiki/Ki%C3%A7ik_komp%C3%BCter_sisteml%C9%99ri_interfeysi" title="Kiçik kompüter sistemləri interfeysi – Azerbaijani" lang="az" hreflang="az" data-title="Kiçik kompüter sistemləri interfeysi" data-language-autonym="Azərbaycanca" data-language-local-name="Azerbaijani" class="interlanguage-link-target"><span>Azərbaycanca</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/SCSI" title="SCSI – Bosnian" lang="bs" hreflang="bs" data-title="SCSI" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/SCSI" title="SCSI – Catalan" lang="ca" hreflang="ca" data-title="SCSI" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/SCSI" title="SCSI – Czech" lang="cs" hreflang="cs" data-title="SCSI" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/SCSI" title="SCSI – Danish" lang="da" hreflang="da" data-title="SCSI" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Small_Computer_System_Interface" title="Small Computer System Interface – German" lang="de" hreflang="de" data-title="Small Computer System Interface" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/V%C3%A4ikearvutis%C3%BCsteemi_liides" title="Väikearvutisüsteemi liides – Estonian" lang="et" hreflang="et" data-title="Väikearvutisüsteemi liides" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/SCSI" title="SCSI – Greek" lang="el" hreflang="el" data-title="SCSI" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Small_Computer_System_Interface" title="Small Computer System Interface – Spanish" lang="es" hreflang="es" data-title="Small Computer System Interface" 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/SCSI" title="SCSI – Esperanto" lang="eo" hreflang="eo" data-title="SCSI" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D9%85%DB%8C%D8%A7%D9%86%D8%AC%DB%8C_%D8%B3%D8%A7%D9%85%D8%A7%D9%86%D9%87_%D8%B1%D8%A7%DB%8C%D8%A7%D9%86%D9%87%E2%80%8C%D8%A7%DB%8C_%DA%A9%D9%88%DA%86%DA%A9" title="میانجی سامانه رایانه‌ای کوچک – Persian" lang="fa" hreflang="fa" data-title="میانجی سامانه رایانه‌ای کوچک" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Small_Computer_System_Interface" title="Small Computer System Interface – French" lang="fr" hreflang="fr" data-title="Small Computer System Interface" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/SCSI" title="SCSI – Galician" lang="gl" hreflang="gl" data-title="SCSI" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/SCSI" title="SCSI – Korean" lang="ko" hreflang="ko" data-title="SCSI" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/SCSI" title="SCSI – Croatian" lang="hr" hreflang="hr" data-title="SCSI" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/SCSI" title="SCSI – Indonesian" lang="id" hreflang="id" data-title="SCSI" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Small_Computer_System_Interface" title="Small Computer System Interface – Italian" lang="it" hreflang="it" data-title="Small Computer System Interface" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/SCSI" title="SCSI – Hebrew" lang="he" hreflang="he" data-title="SCSI" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/SCSI" title="SCSI – Lithuanian" lang="lt" hreflang="lt" data-title="SCSI" data-language-autonym="Lietuvių" data-language-local-name="Lithuanian" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/SCSI" title="SCSI – Hungarian" lang="hu" hreflang="hu" data-title="SCSI" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/SCSI" title="SCSI – Dutch" lang="nl" hreflang="nl" data-title="SCSI" 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/Small_Computer_System_Interface" title="Small Computer System Interface – Japanese" lang="ja" hreflang="ja" data-title="Small Computer System Interface" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Small_computer_system_interface" title="Small computer system interface – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Small computer system interface" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/SCSI" title="SCSI – Polish" lang="pl" hreflang="pl" data-title="SCSI" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/SCSI" title="SCSI – Portuguese" lang="pt" hreflang="pt" data-title="SCSI" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/SCSI" title="SCSI – Romanian" lang="ro" hreflang="ro" data-title="SCSI" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/SCSI" title="SCSI – Russian" lang="ru" hreflang="ru" data-title="SCSI" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/SCSI" title="SCSI – Simple English" lang="en-simple" hreflang="en-simple" data-title="SCSI" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/SCSI" title="SCSI – Slovak" lang="sk" hreflang="sk" data-title="SCSI" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/SCSI" title="SCSI – Serbian" lang="sr" hreflang="sr" data-title="SCSI" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/SCSI" title="SCSI – Finnish" lang="fi" hreflang="fi" data-title="SCSI" 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/Scsi" title="Scsi – Swedish" lang="sv" hreflang="sv" data-title="Scsi" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B9%80%E0%B8%AD%E0%B8%AA%E0%B8%8B%E0%B8%B5%E0%B9%80%E0%B8%AD%E0%B8%AA%E0%B9%84%E0%B8%AD" title="เอสซีเอสไอ – Thai" lang="th" hreflang="th" data-title="เอสซีเอสไอ" data-language-autonym="ไทย" data-language-local-name="Thai" class="interlanguage-link-target"><span>ไทย</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/SCSI" title="SCSI – Turkish" lang="tr" hreflang="tr" data-title="SCSI" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/SCSI" title="SCSI – Ukrainian" lang="uk" hreflang="uk" data-title="SCSI" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E5%B0%8F%E5%9E%8B%E8%AE%A1%E7%AE%97%E6%9C%BA%E7%B3%BB%E7%BB%9F%E6%8E%A5%E5%8F%A3" title="小型计算机系统接口 – Chinese" lang="zh" hreflang="zh" data-title="小型计算机系统接口" data-language-autonym="中文" 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class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Set of computer and peripheral connection standards</div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">"Scuzzy" redirects here. For the historic sternwheeler known by that name, see <a href="/wiki/Skuzzy_(sternwheeler)" title="Skuzzy (sternwheeler)">Skuzzy (sternwheeler)</a>.</div> <p class="mw-empty-elt"> </p> <style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox infobox-table"><caption class="infobox-title">SCSI<br />Small Computer System Interface</caption><tbody><tr><td colspan="4" class="infobox-image"> <span class="mw-default-size" typeof="mw:File/Frameless"><a href="/wiki/File:Scsi_logo.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/6e/Scsi_logo.svg/220px-Scsi_logo.svg.png" decoding="async" width="220" height="224" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/6e/Scsi_logo.svg/330px-Scsi_logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/6e/Scsi_logo.svg/440px-Scsi_logo.svg.png 2x" data-file-width="512" data-file-height="522" /></a></span></td></tr><tr><th scope="row" class="infobox-label">Type</th><td colspan="3" class="infobox-data"> <a href="/wiki/Bus_(computing)" title="Bus (computing)">Bus</a></td></tr><tr><th colspan="4" class="infobox-header" style="background:#ccccff">Production history</th></tr><tr><th scope="row" class="infobox-label">Designer</th><td colspan="3" class="infobox-data"> Team led by Larry Boucher at <a href="/wiki/Shugart_Associates" title="Shugart Associates">Shugart Associates</a></td></tr><tr><th scope="row" class="infobox-label">Designed</th><td colspan="3" class="infobox-data"> September 1981<span class="noprint">; 43 years ago</span><span style="display:none"> (<span class="bday dtstart published updated">1981-09</span>)</span><sup id="cite_ref-draft_1-0" class="reference"><a href="#cite_note-draft-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup></td></tr><tr><th scope="row" class="infobox-label">Standardized</th><td colspan="3" class="infobox-data"> <a href="/wiki/American_National_Standards_Institute" title="American National Standards Institute">ANSI</a> X3.131-1986, June 1986</td></tr><tr><th scope="row" class="infobox-label">Produced</th><td colspan="3" class="infobox-data"> Since 1983</td></tr></tbody></table> <p><b>Small Computer System Interface</b> (<b>SCSI</b>, <span class="rt-commentedText nowrap"><span class="IPA nopopups noexcerpt" lang="en-fonipa"><a href="/wiki/Help:IPA/English" title="Help:IPA/English">/<span style="border-bottom:1px dotted"><span title="/ˈ/: primary stress follows">ˈ</span><span title="'s' in 'sigh'">s</span><span title="'k' in 'kind'">k</span><span title="/ʌ/: 'u' in 'cut'">ʌ</span><span title="'z' in 'zoom'">z</span><span title="/i/: 'y' in 'happy'">i</span></span>/</a></span></span> <a href="/wiki/Help:Pronunciation_respelling_key" title="Help:Pronunciation respelling key"><i title="English pronunciation respelling"><span style="font-size:90%">SKUZ</span>-ee</i></a>)<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> is a set of standards for physically connecting and transferring data between computers and <a href="/wiki/Peripheral" title="Peripheral">peripheral devices</a>, best known for its use with storage devices such as <a href="/wiki/Hard_disk_drive" title="Hard disk drive">hard disk drives</a>. SCSI was introduced in the 1980s and has seen widespread use on servers and high-end workstations, with new SCSI standards being published as recently as <a href="/wiki/Serial_Attached_SCSI" title="Serial Attached SCSI">SAS-4</a> in 2017. </p><p>The SCSI standards define <a href="/wiki/SCSI_command" title="SCSI command">commands</a>, protocols, electrical, optical and logical <a href="/wiki/Interface_(computing)" title="Interface (computing)">interfaces</a>. The SCSI standard defines command sets for specific <a href="/wiki/SCSI_Peripheral_Device_Type" title="SCSI Peripheral Device Type">peripheral device types</a>; the presence of "unknown" as one of these types means that in theory it can be used as an interface to almost any device, but the standard is highly pragmatic and addressed toward commercial requirements. The initial <a href="/wiki/Parallel_SCSI" title="Parallel SCSI">Parallel SCSI</a> was most commonly used for <a href="/wiki/Hard_disk_drive" title="Hard disk drive">hard disk drives</a> and <a href="/wiki/Tape_drive" title="Tape drive">tape drives</a>, but it can connect a wide range of other devices, including scanners and <a href="/wiki/CD-ROM" title="CD-ROM">CD</a> <a href="/wiki/Optical_disc_drive" title="Optical disc drive">drives</a>, although not all controllers can handle all devices. </p><p>The ancestral SCSI standard, X3.131-1986, generally referred to as SCSI-1, was published by the X3T9 technical committee of the <a href="/wiki/American_National_Standards_Institute" title="American National Standards Institute">American National Standards Institute</a> (ANSI) in 1986. SCSI-2 was published in August 1990 as X3.T9.2/86-109, with further revisions in 1994 and subsequent adoption of a multitude of interfaces. Further refinements have resulted in improvements in performance and support for ever-increasing data storage capacity.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p> <meta property="mw:PageProp/toc" /> <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=SCSI&action=edit&section=1" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Parallel_interface">Parallel interface</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=2" title="Edit section: Parallel interface"><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:Adaptec_ACB-4000A_SASI_card.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/ad/Adaptec_ACB-4000A_SASI_card.jpg/220px-Adaptec_ACB-4000A_SASI_card.jpg" decoding="async" width="220" height="164" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/ad/Adaptec_ACB-4000A_SASI_card.jpg/330px-Adaptec_ACB-4000A_SASI_card.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/ad/Adaptec_ACB-4000A_SASI_card.jpg/440px-Adaptec_ACB-4000A_SASI_card.jpg 2x" data-file-width="2906" data-file-height="2170" /></a><figcaption>Adaptec ACB-4000A SASI card from 1985</figcaption></figure> <p>SCSI is derived from the <a href="/wiki/Shugart_Associates" title="Shugart Associates">Shugart Associates</a> System Interface (SASI),<sup id="cite_ref-glass198902_4-0" class="reference"><a href="#cite_note-glass198902-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> developed beginning 1979<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> and publicly disclosed in 1981.<sup id="cite_ref-draft_1-1" class="reference"><a href="#cite_note-draft-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> <a href="/w/index.php?title=Larry_Boucher&action=edit&redlink=1" class="new" title="Larry Boucher (page does not exist)">Larry Boucher</a> is considered to be the "father" of SASI and ultimately SCSI due to his pioneering work first at Shugart Associates and then at <a href="/wiki/Adaptec" title="Adaptec">Adaptec</a>, which he founded in 1981.<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>A SASI controller provided a bridge between a hard disk drive's low-level interface and a host computer, which needed to read blocks of data. SASI controller boards were typically the size of a hard disk drive and were usually physically mounted to the drive's chassis. SASI, which was used in mini- and early microcomputers, defined the interface as using a 50-pin flat ribbon connector which was adopted as the SCSI-1 connector. SASI is a fully compliant subset of SCSI-1 so that many, if not all, of the then-existing SASI controllers were SCSI-1 compatible.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p><p>In around 1980, <a href="/wiki/NCR_Corporation" class="mw-redirect" title="NCR Corporation">NCR Corporation</a> had been developing a competing interface standard by the name of BYSE. In the summer of 1981, NCR abandoned their in-house efforts in favor of pursuing SASI and improving on its design for their own computer systems. Fearing that their extension of the SASI standard would induce market confusion, however, NCR briefly cancelled their contract with Shugart. NCR's proposed improvements to the design of SCSI piqued the interest of Optimem, a subsidiary of Shugart, who requested that NCR and Shugart collaborate on a unified standard. In October 1981, the two companies agreed to co-develop SASI and present their standard jointly with ANSI.<sup id="cite_ref-spt_8-0" class="reference"><a href="#cite_note-spt-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup><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><p>Until at least February 1982, ANSI developed the specification as "SASI" and "Shugart Associates System Interface".<sup id="cite_ref-ANSI_10-0" class="reference"><a href="#cite_note-ANSI-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> However, the committee documenting the standard would not allow it to be named after a company. Almost a full day was devoted to agreeing to name the standard "Small Computer System Interface", which Boucher intended to be pronounced "sexy", but ENDL's<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> Dal Allan pronounced the new acronym as "scuzzy" and that stuck.<sup id="cite_ref-CHM_12-0" class="reference"><a href="#cite_note-CHM-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </p><p>The NCR facility in <a href="/wiki/Wichita,_Kansas" title="Wichita, Kansas">Wichita, Kansas</a> developed the industry's first SCSI controller chip, the NCR 5385, released in 1983. According to its developers, the chip worked the first time it was tested.<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><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> A number of companies, such as Adaptec and Optimem, were early supporters of SCSI.<sup id="cite_ref-ANSI_10-1" class="reference"><a href="#cite_note-ANSI-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> By late 1990 at least 45 manufactures offered 251 models of parallel SCSI host adapters<sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> Today, such host adapters have largely been displaced by the faster serial SCSI (SAS) host adapters.<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 "small" reference in "small computer system interface" is historical; since the mid-1990s, SCSI has been available on even the largest of computer systems. </p><p>Since its standardization in 1986, SCSI has been commonly used in the <a href="/wiki/Amiga" title="Amiga">Amiga</a>, <a href="/wiki/Atari_Corporation" title="Atari Corporation">Atari</a>, <a href="/wiki/Macintosh" class="mw-redirect" title="Macintosh">Apple Macintosh</a> and <a href="/wiki/Sun_Microsystems" title="Sun Microsystems">Sun Microsystems</a> computer lines and PC server systems. Apple started using the less-expensive <a href="/wiki/Parallel_ATA" title="Parallel ATA">parallel ATA</a> (PATA, also known as <i>IDE</i>) for its low-end machines with the <a href="/wiki/Macintosh_Quadra" title="Macintosh Quadra">Macintosh Quadra</a> 630 in 1994, and added it to its high-end desktops starting with the Power Macintosh G3 in 1997. Apple dropped on-board SCSI completely in favor of IDE and <a href="/wiki/IEEE_1394" title="IEEE 1394">FireWire</a> with the (Blue & White) Power Mac G3 in 1999, while still offering a <a href="/wiki/Conventional_PCI" class="mw-redirect" title="Conventional PCI">PCI</a> SCSI host adapter as an option on up to the Power Macintosh G4 (AGP Graphics) models.<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> Sun switched its lower-end range to <a href="/wiki/Parallel_ATA" title="Parallel ATA">Parallel ATA</a> (PATA) with introduction of their <a href="/wiki/Ultra_5/10" title="Ultra 5/10">Ultra 5 and 10</a> low end workstations using <a href="/wiki/CMD640" title="CMD640">CMD640</a> IDE controller and continued this trend with the later <a href="/wiki/Sun_Blade_(workstation)" title="Sun Blade (workstation)">Blade 100 and 150</a> entry level systems and did not switch to contemporary <a href="/wiki/SATA" title="SATA">SATA</a> interface even with the introduction of the Blade 1500 in 2003 while the higher end Blade 2500 released at the same time used Ultra320 Parallel SCSI-3. Sun moved to <a href="/wiki/SATA" title="SATA">SATA</a> and <a href="/wiki/Serial_Attached_SCSI" title="Serial Attached SCSI">SAS</a> interfaces with their last UltraSPARC-III based workstations in 2006 with the entry level Ultra 25 and mid-range Ultra 45. Commodore included SCSI on the Amiga 3000/3000T systems and it was an add-on to previous Amiga 500/2000 models. Starting with the Amiga 600/1200/4000 systems Commodore switched to the IDE interface. Atari included SCSI as standard in its <a href="/wiki/Atari_MEGA_STE" title="Atari MEGA STE">Atari MEGA STE</a>, <a href="/wiki/Atari_TT" class="mw-redirect" title="Atari TT">Atari TT</a> and <a href="/wiki/Atari_Falcon" title="Atari Falcon">Atari Falcon</a> computer models. SCSI has never been popular in the low-priced IBM PC world, owing to the lower cost and adequate performance of ATA hard disk standard. However, SCSI drives and even SCSI <a href="/wiki/RAID" title="RAID">RAIDs</a> became common in PC workstations for video or audio production. </p> <div class="mw-heading mw-heading3"><h3 id="Modern_SCSI"><span class="anchor" id="SERIAL-VARIANTS"></span>Modern SCSI</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=3" title="Edit section: Modern SCSI"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Recent physical versions of SCSI‍—‌<a href="/wiki/Serial_Attached_SCSI" title="Serial Attached SCSI">Serial Attached SCSI</a> (SAS), SCSI-over-<a href="/wiki/Fibre_Channel_Protocol" title="Fibre Channel Protocol">Fibre Channel Protocol</a> (FCP), and <a href="/wiki/USB_Attached_SCSI" title="USB Attached SCSI">USB Attached SCSI</a> (UAS)‍—‌break from the traditional <a href="/wiki/Parallel_SCSI" title="Parallel SCSI">parallel SCSI</a> <a href="/wiki/Bus_(computing)" title="Bus (computing)">bus</a> and perform data transfer via serial communications using <a href="/wiki/Point-to-point_(telecommunications)" title="Point-to-point (telecommunications)">point-to-point</a> links. Although much of the SCSI documentation talks about the parallel interface, all modern development efforts use serial interfaces. Serial interfaces have a number of advantages over parallel SCSI, including higher data rates, simplified cabling, longer reach, improved fault isolation and <a href="/wiki/Full-duplex" class="mw-redirect" title="Full-duplex">full-duplex</a> capability. The primary reason for the shift to serial interfaces is the <a href="/wiki/Clock_skew" title="Clock skew">clock skew</a> issue of high-speed parallel interfaces, which makes the faster variants of parallel SCSI susceptible to problems caused by cabling and termination.<sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> </p><p>The non-physical <a href="/wiki/ISCSI" title="ISCSI">iSCSI</a> preserves the basic SCSI <a href="/wiki/Paradigm" title="Paradigm">paradigm</a>, especially the command set, almost unchanged, through embedding of SCSI-3 over <a href="/wiki/TCP/IP" class="mw-redirect" title="TCP/IP">TCP/IP</a>. Therefore, iSCSI uses <i>logical connections</i> instead of physical links and can run on top of any network supporting IP. The actual physical links are realized on lower <a href="/wiki/OSI_model" title="OSI model">network layers</a>, independently from iSCSI. Predominantly, <a href="/wiki/Ethernet" title="Ethernet">Ethernet</a> is used which is also of serial nature. </p><p>SCSI is popular on high-performance workstations, servers, and storage appliances. Almost all RAID subsystems on servers have used some kind of SCSI hard disk drives for decades (initially Parallel SCSI, interim Fibre Channel, recently SAS), though a number of manufacturers offer <a href="/wiki/Serial_ATA" class="mw-redirect" title="Serial ATA">SATA</a>-based RAID subsystems as a cheaper option. Moreover, SAS offers compatibility with SATA devices, creating a much broader range of options for RAID subsystems together with the existence of <a href="/wiki/Nearline_SAS" class="mw-redirect" title="Nearline SAS">nearline SAS</a> (NL-SAS) drives. Instead of SCSI, modern desktop computers and notebooks typically use SATA interfaces for internal hard disk drives, with <a href="/wiki/NVME" class="mw-redirect" title="NVME">NVMe</a> over PCIe gaining popularity as SATA can bottleneck modern <a href="/wiki/Solid-state_drive" title="Solid-state drive">solid-state drives</a>. </p> <div class="mw-heading mw-heading2"><h2 id="Interfaces">Interfaces</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=4" title="Edit section: Interfaces"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/SCSI_connector" title="SCSI connector">SCSI connector</a></div> <p>SCSI is available in a variety of interfaces. The first was <a href="/wiki/Parallel_SCSI" title="Parallel SCSI">parallel SCSI</a> (also called SCSI Parallel Interface or SPI), which uses a <a href="/wiki/Parallel_communications" class="mw-redirect" title="Parallel communications">parallel</a> <a href="/wiki/Bus_(computing)" title="Bus (computing)">bus</a> design. Since 2005, SPI was gradually replaced by <a href="/wiki/Serial_Attached_SCSI" title="Serial Attached SCSI">Serial Attached SCSI</a> (SAS), which uses a <a href="/wiki/Serial_communications" class="mw-redirect" title="Serial communications">serial</a> design but retains other aspects of the technology. Many other interfaces which do not rely on complete SCSI standards still implement the <a href="#SCSI_command_protocol">SCSI command protocol</a>; others drop physical implementation entirely while retaining the <a href="/wiki/SCSI_architectural_model" title="SCSI architectural model">SCSI architectural model</a>. <a href="/wiki/ISCSI" title="ISCSI">iSCSI</a>, for example, uses <a href="/wiki/TCP/IP" class="mw-redirect" title="TCP/IP">TCP/IP</a> as a transport mechanism, which is most often transported over <a href="/wiki/Gigabit_Ethernet" title="Gigabit Ethernet">Gigabit Ethernet</a> or faster <a href="/wiki/Computer_network" title="Computer network">network</a> links. </p><p>SCSI interfaces have often been included on computers from various manufacturers for use under <a href="/wiki/Microsoft_Windows" title="Microsoft Windows">Microsoft Windows</a>, <a href="/wiki/Classic_Mac_OS" title="Classic Mac OS">classic Mac OS</a>, <a href="/wiki/Unix" title="Unix">Unix</a>, <a href="/wiki/Amiga" title="Amiga">Amiga</a> and <a href="/wiki/Linux" title="Linux">Linux</a> operating systems, either implemented on the <a href="/wiki/Motherboard" title="Motherboard">motherboard</a> or by the means of plug-in adaptors. With the advent of <a href="/wiki/Serial_Attached_SCSI" title="Serial Attached SCSI">SAS</a> and <a href="/wiki/Serial_ATA" class="mw-redirect" title="Serial ATA">SATA</a> drives, provision for parallel SCSI on motherboards was discontinued.<sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Parallel_SCSI">Parallel SCSI</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=5" title="Edit section: Parallel SCSI"><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:Scsi-connectors.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/0/0d/Scsi-connectors.jpg/220px-Scsi-connectors.jpg" decoding="async" width="220" height="149" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/0d/Scsi-connectors.jpg/330px-Scsi-connectors.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/0d/Scsi-connectors.jpg/440px-Scsi-connectors.jpg 2x" data-file-width="2124" data-file-height="1440" /></a><figcaption>Assorted Parallel SCSI connectors</figcaption></figure> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Parallel_SCSI" title="Parallel SCSI">Parallel SCSI</a></div> <p>Initially, the <i>SCSI Parallel Interface</i> (SPI) was the only interface using the SCSI protocol. Its standardization started as a <a href="/wiki/Single-ended_signaling" title="Single-ended signaling">single-ended</a> 8-bit <a href="/wiki/System_bus" title="System bus">bus</a> in 1986, transferring up to 5 MB/s, and evolved into a low-voltage <a href="/wiki/Differential_signaling" class="mw-redirect" title="Differential signaling">differential</a> 16-bit bus capable of up to 320 MB/s. The last SPI-5 standard from 2003 also defined a 640 MB/s speed which failed to be realized. </p><p>Parallel SCSI specifications include several synchronous transfer modes for the parallel cable, and an asynchronous mode. The asynchronous mode is a classic request/acknowledge protocol, which allows systems with a slow bus or simple systems to also use SCSI devices. Faster synchronous modes are used more frequently. </p> <div class="mw-heading mw-heading3"><h3 id="SCSI_interfaces"><span class="anchor" id="SCSI-EXPRESS"></span>SCSI interfaces</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=6" title="Edit section: SCSI interfaces"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <table class="wikitable"> <tbody><tr> <th rowspan="2">Interface </th> <th rowspan="2">Alternative<br />names </th> <th rowspan="2">Specification<br />body / document </th> <th rowspan="2">Width<br />(bits) </th> <th rowspan="2">Clock<sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>a<span class="cite-bracket">]</span></a></sup> </th> <th rowspan="2"><a href="/wiki/Line_code" title="Line code">Line code</a> </th> <th colspan="3">Maximum </th></tr> <tr> <th>Throughput </th> <th>Length<sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>b<span class="cite-bracket">]</span></a></sup> </th> <th>Devices<sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>c<span class="cite-bracket">]</span></a></sup> </th></tr> <tr> <td>Ultra-320 SCSI </td> <td>Ultra-4; Fast-160 </td> <td>SPI-5 (INCITS 367-2003) </td> <td>16 </td> <td>80 MHz DDR </td> <td>none </td> <td>320 MB/s (2560 Mbit/s) </td> <td>12 m </td> <td>16 </td></tr> <tr> <td><a href="/wiki/Serial_Storage_Architecture" title="Serial Storage Architecture">SSA</a> </td> <td rowspan="2">Serial Storage Architecture </td> <td>T10 / INCITS 309-1997 </td> <td>serial </td> <td>200 Mbit/s </td> <td rowspan="2"><a href="/wiki/8b/10b_encoding" title="8b/10b encoding">8b10b</a> </td> <td>20 MB/s<sup id="cite_ref-spatial_reuse_23-0" class="reference"><a href="#cite_note-spatial_reuse-23"><span class="cite-bracket">[</span>d<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-fdx_24-0" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-0" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> (160 Mbit/s) </td> <td>25 m </td> <td>96 </td></tr> <tr> <td>SSA 40 </td> <td>T10 / INCITS 309-1997 </td> <td>serial </td> <td>400 Mbit/s </td> <td>40 MB/s<sup id="cite_ref-spatial_reuse_23-1" class="reference"><a href="#cite_note-spatial_reuse-23"><span class="cite-bracket">[</span>d<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-fdx_24-1" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-1" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> (320 Mbit/s) </td> <td>25 m </td> <td>96 </td></tr> <tr> <td><a href="/wiki/Fibre_Channel" title="Fibre Channel">Fibre Channel</a> 1 Gbit </td> <td>1GFC </td> <td>T11 / X3T11/94-175v0 FC-PH Draft, Revision 4.3 </td> <td>serial </td> <td>1.0625 Gbit/s </td> <td rowspan="4">8b10b </td> <td>98.4 MB/s<sup id="cite_ref-fdx_24-2" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-2" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> (850 Mbit/s) </td> <td>500 m / 10 km<sup id="cite_ref-fcdist_26-0" class="reference"><a href="#cite_note-fcdist-26"><span class="cite-bracket">[</span>g<span class="cite-bracket">]</span></a></sup> </td> <td>127 (<a href="/wiki/FC-AL" class="mw-redirect" title="FC-AL">FC-AL</a>)<br />2<sup>24</sup> (<a href="/wiki/Switched_fabric" title="Switched fabric">FC-SW</a>) </td></tr> <tr> <td>Fibre Channel 2 Gbit </td> <td>2GFC </td> <td>T11 / X3T11/96-402v0 FC-PH-2, Rev 7.4 </td> <td>serial </td> <td>2.125 Gbit/s </td> <td>197 MB/s<sup id="cite_ref-fdx_24-3" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-3" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> (1,700 Mbit/s) </td> <td>500 m / 10 km<sup id="cite_ref-fcdist_26-1" class="reference"><a href="#cite_note-fcdist-26"><span class="cite-bracket">[</span>g<span class="cite-bracket">]</span></a></sup> </td> <td>127/2<sup>24</sup> </td></tr> <tr> <td>Fibre Channel 4 Gbit </td> <td>4GFC </td> <td>T11 / INCITS Project 2118-D / Rev 6.10 </td> <td>serial </td> <td>4.25 Gbit/s </td> <td>394 MB/s<sup id="cite_ref-fdx_24-4" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-4" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> (3,400 Mbit/s) </td> <td>500 m / 10 km<sup id="cite_ref-fcdist_26-2" class="reference"><a href="#cite_note-fcdist-26"><span class="cite-bracket">[</span>g<span class="cite-bracket">]</span></a></sup> </td> <td>127/2<sup>24</sup> </td></tr> <tr> <td>Fibre Channel 8 Gbit </td> <td>8GFC </td> <td>T11 / INCITS Project 2118-D / Rev 6.10 </td> <td>serial </td> <td>8.5 Gbit/s </td> <td>788 MB/s<sup id="cite_ref-fdx_24-5" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-5" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> (6,800 Mbit/s) </td> <td>500 m / 10 km<sup id="cite_ref-fcdist_26-3" class="reference"><a href="#cite_note-fcdist-26"><span class="cite-bracket">[</span>g<span class="cite-bracket">]</span></a></sup> </td> <td>127/2<sup>24</sup> </td></tr> <tr> <td>Fibre Channel 16 Gbit </td> <td>16GFC </td> <td>T11 / INCITS Project 2118-D / Rev 6.10 </td> <td>serial </td> <td>14.025 Gbit/s </td> <td><a href="/wiki/64b/66b_encoding" title="64b/66b encoding">64b66b</a> </td> <td>1,575 MB/s<sup id="cite_ref-fdx_24-6" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-6" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> (13,600 Mbit/s) </td> <td>500 m / 10 km<sup id="cite_ref-fcdist_26-4" class="reference"><a href="#cite_note-fcdist-26"><span class="cite-bracket">[</span>g<span class="cite-bracket">]</span></a></sup> </td> <td>127/2<sup>24</sup> </td></tr> <tr> <td><a href="/wiki/Serial_attached_SCSI" class="mw-redirect" title="Serial attached SCSI">SAS</a> 1.1 </td> <td rowspan="4">Serial attached SCSI </td> <td>T10 / <a rel="nofollow" class="external text" href="http://www.t10.org/drafts.htm#SCSI3_SAS">INCITS 417-2006</a> </td> <td>serial </td> <td>3 Gbit/s </td> <td rowspan="3">8b10b </td> <td>300 MB/s<sup id="cite_ref-fdx_24-7" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-7" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> (2,400 Mbit/s) </td> <td>6 m </td> <td>16,256<sup id="cite_ref-128per_27-0" class="reference"><a href="#cite_note-128per-27"><span class="cite-bracket">[</span>h<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>SAS 2.1 </td> <td>T10 / <a rel="nofollow" class="external text" href="http://www.t10.org/drafts.htm#SCSI3_SAS">INCITS 478-2011</a> </td> <td>serial </td> <td>6 Gbit/s </td> <td>600 MB/s<sup id="cite_ref-fdx_24-8" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-8" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> (4,800 Mbit/s) </td> <td>6 m </td> <td>16,256<sup id="cite_ref-128per_27-1" class="reference"><a href="#cite_note-128per-27"><span class="cite-bracket">[</span>h<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>SAS 3.0 </td> <td>T10 / <a rel="nofollow" class="external text" href="http://www.t10.org/cgi-bin/ac.pl?t=f&f=sas3r06.pdf">INCITS 519</a> </td> <td>serial </td> <td>12 Gbit/s </td> <td>1,200 MB/s<sup id="cite_ref-fdx_24-9" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-9" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> (9,600 Mbit/s) </td> <td>6 m </td> <td>16,256<sup id="cite_ref-128per_27-2" class="reference"><a href="#cite_note-128per-27"><span class="cite-bracket">[</span>h<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>SAS 4.0 </td> <td>T10 / <a rel="nofollow" class="external text" href="http://www.t10.org/cgi-bin/ac.pl?t=f&f=sas4r01.pdf">INCITS 534</a> (draft) </td> <td>serial </td> <td>22.5 Gbit/s </td> <td><a href="/w/index.php?title=128b/150b_encoding&action=edit&redlink=1" class="new" title="128b/150b encoding (page does not exist)">128b150b</a> </td> <td>2,400 MB/s<sup id="cite_ref-fdx_24-10" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-10" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> (19,200 Mbit/s) </td> <td>tbd </td> <td>16,256<sup id="cite_ref-128per_27-3" class="reference"><a href="#cite_note-128per-27"><span class="cite-bracket">[</span>h<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td><a href="/wiki/IEEE_1394" title="IEEE 1394">IEEE 1394</a>-2008 </td> <td>Firewire S3200, i.Link, Serial Bus Protocol (SBP) </td> <td><a rel="nofollow" class="external text" href="https://ieeexplore.ieee.org/document/4659233">IEEE Std. 1394-2008</a> </td> <td>serial </td> <td>3.145728 Gbit/s </td> <td>8b10b </td> <td>315 MB/s (2,517 Mbit/s) </td> <td>4.5 m </td> <td>63 </td></tr> <tr> <td>SCSI Express </td> <td>SCSI over <a href="/wiki/PCI_Express" title="PCI Express">PCIe</a> (SOP) </td> <td>T10 / <a rel="nofollow" class="external text" href="http://www.t10.org/drafts.htm#SCSI3_PCI">INCITS 489</a> </td> <td>serial </td> <td>8 <a href="/wiki/Transfer_(computing)" class="mw-redirect" title="Transfer (computing)">GT/s</a> (<a href="/wiki/PCIe" class="mw-redirect" title="PCIe">PCIe</a> 3.0) </td> <td><a href="/wiki/128b/130b_encoding" class="mw-redirect" title="128b/130b encoding">128b130b</a> </td> <td>985 MB/s<sup id="cite_ref-fdx_24-11" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-11" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-28" class="reference"><a href="#cite_note-28"><span class="cite-bracket">[</span>i<span class="cite-bracket">]</span></a></sup> (7,877 Mbit/s) </td> <td>short, <a href="/wiki/Backplane" title="Backplane">backplane</a> only </td> <td>2<sup>58</sup> </td></tr> <tr> <td><a href="/wiki/USB_Attached_SCSI" title="USB Attached SCSI">USB Attached SCSI</a> 2 </td> <td>UAS-2 </td> <td>T10 / <a rel="nofollow" class="external text" href="http://www.t10.org/drafts.htm#SCSI3_UAS">INCITS 520</a> </td> <td>serial </td> <td>10 Gbit/s (<a href="/wiki/USB_3.1" class="mw-redirect" title="USB 3.1">USB 3.1</a>) </td> <td><a href="/wiki/128b/132b_encoding" class="mw-redirect" title="128b/132b encoding">128b132b</a> </td> <td>~1,200 MB/s<sup id="cite_ref-fdx_24-12" class="reference"><a href="#cite_note-fdx-24"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-per_dir_25-12" class="reference"><a href="#cite_note-per_dir-25"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> (~9,500 Mbit/s) </td> <td>3 m<sup id="cite_ref-29" class="reference"><a href="#cite_note-29"><span class="cite-bracket">[</span>j<span class="cite-bracket">]</span></a></sup> </td> <td>127 </td></tr> <tr> <td><a href="/wiki/ATAPI" title="ATAPI">ATAPI</a> over <a href="/wiki/Parallel_ATA" title="Parallel ATA">Parallel ATA</a> </td> <td rowspan="2">ATA Packet Interface </td> <td rowspan="2">T13 / <a rel="nofollow" class="external text" href="https://web.archive.org/web/20131215111345/http://www.t10.org/t13/project/d1153r18-ATA-ATAPI-4.pdf">NCITS 317-1998</a> at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a> (archived 2013-12-15) </td> <td>16 </td> <td>33 MHz <a href="/wiki/Double_data_rate" title="Double data rate">DDR</a> </td> <td>none </td> <td>133 MB/s<sup id="cite_ref-30" class="reference"><a href="#cite_note-30"><span class="cite-bracket">[</span>k<span class="cite-bracket">]</span></a></sup> (1,064 Mbit/s) </td> <td>457 mm (18 inches) </td> <td>2 </td></tr> <tr> <td><a href="/wiki/ATAPI" title="ATAPI">ATAPI</a> over <a href="/wiki/Serial_ATA" class="mw-redirect" title="Serial ATA">Serial ATA</a> </td> <td>serial </td> <td>6 Gbit/s </td> <td>8b10b </td> <td>600 MB/s<sup id="cite_ref-31" class="reference"><a href="#cite_note-31"><span class="cite-bracket">[</span>l<span class="cite-bracket">]</span></a></sup> (4,800 Mbit/s) </td> <td>1 m </td> <td>1 (15 with <a href="/wiki/Port_multiplier" title="Port multiplier">port multiplier</a>) </td></tr> <tr> <td><a href="/wiki/ISCSI" title="ISCSI">iSCSI</a> </td> <td>Internet Small Computer System Interface, SCSI over <a href="/wiki/TCP/IP" class="mw-redirect" title="TCP/IP">IP</a> </td> <td><a href="/wiki/IETF" class="mw-redirect" title="IETF">IETF</a> / RFC 7143 </td> <td>mostly serial </td> <td colspan="2" style="text-align: center;">implementation- and network-dependent </td> <td>1,187 MB/s<sup id="cite_ref-32" class="reference"><a href="#cite_note-32"><span class="cite-bracket">[</span>m<span class="cite-bracket">]</span></a></sup> or 1,239 MB/s<sup id="cite_ref-33" class="reference"><a href="#cite_note-33"><span class="cite-bracket">[</span>n<span class="cite-bracket">]</span></a></sup> </td> <td style="text-align: center;">implementation- and network-dependent </td> <td>2<sup>128</sup> (<a href="/wiki/IPv6" title="IPv6">IPv6</a>) </td></tr> <tr> <td><a href="/wiki/SCSI_RDMA_Protocol" title="SCSI RDMA Protocol">SRP</a> </td> <td>SCSI RDMA Protocol (SCSI over <a href="/wiki/InfiniBand" title="InfiniBand">InfiniBand</a> and similar) </td> <td>T10 / <a rel="nofollow" class="external text" href="http://www.t10.org/drafts.htm#SCSI3_SRP">INCITS 365-2002</a> </td> <td colspan="5" style="text-align: center;">implementation- and network-dependent </td> <td> </td></tr></tbody></table> <div class="mw-heading mw-heading2"><h2 id="Cabling">Cabling</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=7" title="Edit section: Cabling"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:SCSI-terminator-exposed-hdr-0a.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/56/SCSI-terminator-exposed-hdr-0a.jpg/220px-SCSI-terminator-exposed-hdr-0a.jpg" decoding="async" width="220" height="158" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/56/SCSI-terminator-exposed-hdr-0a.jpg/330px-SCSI-terminator-exposed-hdr-0a.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/56/SCSI-terminator-exposed-hdr-0a.jpg/440px-SCSI-terminator-exposed-hdr-0a.jpg 2x" data-file-width="2271" data-file-height="1626" /></a><figcaption><a href="/wiki/Electrical_termination" title="Electrical termination">Bus terminator</a> with top cover removed</figcaption></figure> <div class="mw-heading mw-heading3"><h3 id="SCSI_Parallel_Interface">SCSI Parallel Interface</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=8" title="Edit section: SCSI Parallel Interface"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Internal parallel SCSI cables are usually <a href="/wiki/Ribbon_cables" class="mw-redirect" title="Ribbon cables">ribbons</a>, with two or more 50–, 68–, or 80–pin connectors attached. External cables are typically shielded (but may not be), with 50– or 68–pin connectors at each end, depending upon the specific SCSI bus width supported. The 80–pin <a href="/wiki/Single_Connector_Attachment" class="mw-redirect" title="Single Connector Attachment">Single Connector Attachment</a> (SCA) is typically used for hot-pluggable devices </p> <div class="mw-heading mw-heading3"><h3 id="Fibre_Channel">Fibre Channel</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=9" title="Edit section: Fibre Channel"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/Fibre_Channel" title="Fibre Channel">Fibre Channel</a> can be used to transport SCSI information units, as defined by the <a href="/wiki/Fibre_Channel_Protocol" title="Fibre Channel Protocol">Fibre Channel Protocol</a> for SCSI (FCP). These connections are hot-pluggable and are usually implemented with optical fiber. </p> <div class="mw-heading mw-heading3"><h3 id="Serial_attached_SCSI">Serial attached SCSI</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=10" title="Edit section: Serial attached SCSI"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/Serial_attached_SCSI" class="mw-redirect" title="Serial attached SCSI">Serial attached SCSI</a> (SAS) uses a <a href="/wiki/Serial_Attached_SCSI#Connectors" title="Serial Attached SCSI">modified</a> <a href="/wiki/Serial_ATA" class="mw-redirect" title="Serial ATA">Serial ATA</a> data and power cable. </p> <div class="mw-heading mw-heading3"><h3 id="iSCSI">iSCSI</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=11" title="Edit section: iSCSI"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/ISCSI" title="ISCSI">iSCSI</a> (Internet Small Computer System Interface) usually uses <a href="/wiki/Ethernet" title="Ethernet">Ethernet</a> connectors and cables as its physical transport, but can run over any physical transport capable of transporting <a href="/wiki/Internet_Protocol" title="Internet Protocol">IP</a>. </p> <div class="mw-heading mw-heading3"><h3 id="SRP">SRP</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=12" title="Edit section: SRP"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The <a href="/wiki/SCSI_RDMA_Protocol" title="SCSI RDMA Protocol">SCSI RDMA Protocol</a> (SRP) is a protocol that specifies how to transport SCSI commands over a reliable RDMA connection. This protocol can run over any RDMA-capable physical transport, e.g. <a href="/wiki/InfiniBand" title="InfiniBand">InfiniBand</a> or <a href="/wiki/Ethernet" title="Ethernet">Ethernet</a> when using <a href="/wiki/RDMA_over_Converged_Ethernet" title="RDMA over Converged Ethernet">RoCE</a> or <a href="/wiki/IWARP" title="IWARP">iWARP</a>. </p> <div class="mw-heading mw-heading3"><h3 id="USB_Attached_SCSI">USB Attached SCSI</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=13" title="Edit section: USB Attached SCSI"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/USB_Attached_SCSI" title="USB Attached SCSI">USB Attached SCSI</a> allows SCSI devices to use the <a href="/wiki/Universal_Serial_Bus" class="mw-redirect" title="Universal Serial Bus">Universal Serial Bus</a>. </p> <div class="mw-heading mw-heading3"><h3 id="Automation/Drive_Interface"><span id="Automation.2FDrive_Interface"></span>Automation/Drive Interface</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=14" title="Edit section: Automation/Drive Interface"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The Automation/Drive Interface − Transport Protocol (ADT) is used to connect removable media devices, such as tape drives, with the controllers of the libraries (automation devices) in which they are installed. The ADI standard specifies the use of <a href="/wiki/RS-422" title="RS-422">RS-422</a> for the physical connections. The second-generation ADT-2 standard defines iADT, use of the ADT protocol over IP (Internet Protocol) connections, such as over <a href="/wiki/Ethernet" title="Ethernet">Ethernet</a>. The Automation/Drive Interface − Commands standards (ADC, ADC-2, and ADC-3) define SCSI commands for these installations. </p> <div class="mw-heading mw-heading2"><h2 id="SCSI_command_protocol">SCSI command protocol</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=15" title="Edit section: SCSI command protocol"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/SCSI_command" title="SCSI command">SCSI command</a></div> <p>In addition to many different hardware implementations, the SCSI standards also include an extensive set of command definitions. The SCSI command architecture was originally defined for <a href="/wiki/Parallel_SCSI" title="Parallel SCSI">parallel SCSI</a> buses but has been carried forward with minimal change for use with iSCSI and serial SCSI. Other technologies which use the SCSI command set include the <a href="/wiki/ATAPI" title="ATAPI">ATA Packet Interface</a>, <a href="/wiki/USB_mass_storage_device_class" title="USB mass storage device class">USB Mass Storage class</a> and <a href="/wiki/Serial_Bus_Protocol_2" title="Serial Bus Protocol 2">FireWire SBP-2</a>. </p><p>In SCSI terminology, communication takes place between an <a href="/wiki/SCSI_initiator" class="mw-redirect" title="SCSI initiator">initiator</a> and a <a href="/wiki/SCSI_target" class="mw-redirect" title="SCSI target">target</a>. The initiator sends a <a href="/wiki/SCSI_command" title="SCSI command">command</a> to the target, which then responds. SCSI commands are sent in a Command Descriptor Block (<a href="/wiki/SCSI_CDB" title="SCSI CDB">CDB</a>). The CDB consists of a one byte operation code followed by five or more bytes containing command-specific parameters. </p><p>At the end of the command sequence, the target returns a <a href="/wiki/SCSI_Status_Code" title="SCSI Status Code">status code</a> byte, such as 00h for success, 02h for an error (called a <a href="/wiki/SCSI_check_condition" title="SCSI check condition">Check Condition</a>), or 08h for busy. When the target returns a Check Condition in response to a command, the initiator usually then issues a <a href="/w/index.php?title=SCSI_Request_Sense_Command&action=edit&redlink=1" class="new" title="SCSI Request Sense Command (page does not exist)">SCSI Request Sense command</a> in order to obtain a key code qualifier (<a href="/wiki/KCQ" class="mw-redirect" title="KCQ">KCQ</a>) from the target. The Check Condition and Request Sense sequence involves a special SCSI protocol called a <a href="/wiki/SCSI_contingent_allegiance_condition" title="SCSI contingent allegiance condition">Contingent Allegiance Condition</a>. </p><p>There are four categories of SCSI commands: N (non-data), W (writing data from initiator to target), R (reading data), and B (bidirectional). There are about 60 different <a href="/wiki/SCSI_command" title="SCSI command">SCSI commands</a> in total, with the most commonly used being: </p> <ul><li>Test unit ready: Queries device to see if it is ready for data transfers (disk spun up, media loaded, etc.).</li> <li>Inquiry: Returns basic device information.</li> <li>Request sense: Returns any error codes from the previous command that returned an error status.</li> <li>Send diagnostic and Receive diagnostic results: runs a simple self-test, or a specialised test defined in a <a href="/wiki/SCSI_diagnostic_pages" title="SCSI diagnostic pages">diagnostic page</a>.</li> <li>Start/Stop unit: Spins disks up and down, or loads/unloads media (CD, tape, etc.).</li> <li>Read capacity: Returns storage capacity.</li> <li>Format unit: Prepares a storage medium for use. In a disk, a <a href="/wiki/Low_level_format" class="mw-redirect" title="Low level format">low level format</a> will occur. Some tape drives will erase the tape in response to this command.</li> <li>Read: (four variants): Reads data from a device.</li> <li>Write: (four variants): Writes data to a device.</li> <li>Log sense: Returns current information from <a href="/wiki/SCSI_log_pages" title="SCSI log pages">log pages</a>.</li> <li>Mode sense: Returns current device parameters from <a href="/wiki/SCSI_mode_pages" class="mw-redirect" title="SCSI mode pages">mode pages</a>.</li> <li>Mode select: Sets device parameters in a mode page.</li></ul> <p>Each device on the SCSI bus is assigned a unique SCSI identification number or ID. Devices may encompass multiple logical units, which are addressed by <a href="/wiki/Logical_unit_number" title="Logical unit number">logical unit number</a> (LUN). Simple devices have just one LUN, more complex devices may have multiple LUNs. </p><p>A "direct access" (i.e. disk type) storage device consists of a number of logical blocks, addressed by Logical Block Address (<a href="/wiki/SCSI_LBA" class="mw-redirect" title="SCSI LBA">LBA</a>). A typical LBA equates to 512 bytes of storage. The usage of LBAs has evolved over time and so four different command variants are provided for reading and writing data. The Read(6) and Write(6) commands contain a 21-bit LBA address. The Read(10), Read(12), Read Long, Write(10), Write(12), and Write Long commands all contain a 32-bit LBA address plus various other parameter options. </p><p>The capacity of a "sequential access" (i.e. tape-type) device is not specified because it depends, amongst other things, on the length of the tape, which is not identified in a machine-readable way. Read and write operations on a sequential access device begin at the current tape position, not at a specific LBA. The block size on sequential access devices can either be fixed or variable, depending on the specific device. Tape devices such as half-inch <a href="/wiki/IBM_9_track" class="mw-redirect" title="IBM 9 track">9-track tape</a>, <a href="/wiki/Digital_Data_Storage" title="Digital Data Storage">DDS</a> (4 mm tapes physically similar to <a href="/wiki/Digital_audio_tape" class="mw-redirect" title="Digital audio tape">DAT</a>), <a href="/wiki/Exabyte_(company)" class="mw-redirect" title="Exabyte (company)">Exabyte</a>, etc., support variable block sizes. </p> <div class="mw-heading mw-heading2"><h2 id="Device_identification">Device identification</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=16" title="Edit section: Device identification"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Parallel_interface_2">Parallel interface</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=17" title="Edit section: Parallel interface"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}</style><table class="box-Technical plainlinks metadata ambox ambox-style ambox-technical" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/40px-Edit-clear.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/60px-Edit-clear.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/80px-Edit-clear.svg.png 2x" data-file-width="48" data-file-height="48" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">This section <b>may be too technical for most readers to understand</b>.<span class="hide-when-compact"> Please <a class="external text" href="https://en.wikipedia.org/w/index.php?title=SCSI&action=edit">help improve it</a> to <a href="/wiki/Wikipedia:Make_technical_articles_understandable" title="Wikipedia:Make technical articles understandable">make it understandable to non-experts</a>, without removing the technical details.</span> <span class="date-container"><i>(<span class="date">June 2008</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <p>On a parallel SCSI bus, a device (e.g. host adapter, disk drive) is identified by a "SCSI ID", which is a number in the range 0–7 on a narrow bus and in the range 0–15 on a wide bus. On earlier models a physical jumper or switch controls the <a href="/wiki/SCSI_ID" class="mw-redirect" title="SCSI ID">SCSI ID</a> of the initiator (<a href="/wiki/Host_adapter" title="Host adapter">host adapter</a>). On modern host adapters (since about 1997), doing I/O to the adapter sets the SCSI ID; for example, the adapter often contains a <a href="/wiki/Option_ROM" title="Option ROM">Option ROM</a> (SCSI BIOS) program that runs when the computer boots up and that program has menus that let the operator choose the SCSI ID of the host adapter. Alternatively, the host adapter may come with software that must be installed on the host computer to configure the SCSI ID. The traditional SCSI ID for a host adapter is 7, as that ID has the highest priority during bus arbitration (even on a 16 bit bus). </p><p>The SCSI ID of a device in a drive enclosure that has a back plane is set either by jumpers or by the slot in the enclosure the device is installed into, depending on the model of the enclosure. In the latter case, each slot on the enclosure's back plane delivers control signals to the drive to select a unique SCSI ID. A SCSI enclosure without a back plane often has a switch for each drive to choose the drive's SCSI ID. The enclosure is packaged with connectors that must be plugged into the drive where the jumpers are typically located; the switch emulates the necessary jumpers. While there is no standard that makes this work, drive designers typically set up their jumper headers in a consistent format that matches the way that these switches implement. </p><p>Setting the bootable (or first) hard disk to SCSI ID 0 is an accepted IT community recommendation. SCSI ID 2 is usually set aside for the floppy disk drive while SCSI ID 3 is typically for a CD-ROM drive.<sup id="cite_ref-34" class="reference"><a href="#cite_note-34"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="General">General</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=18" title="Edit section: General"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Note that a SCSI target device (which can be called a "physical unit") is sometimes divided into smaller "logical units". For example, a high-end disk subsystem may be a single SCSI device but contain dozens of individual disk drives, each of which is a logical unit. Further, a RAID array may be a single SCSI device, but may contain many logical units, each of which is a "virtual" disk—a stripe set or mirror set constructed from portions of real disk drives. The SCSI ID, WWN, etc. in this case identifies the whole subsystem, and a second number, the <a href="/wiki/Logical_unit_number" title="Logical unit number">logical unit number</a> (LUN) identifies a disk device (real or virtual) within the subsystem. </p><p>It is quite common, though incorrect, to refer to the logical unit itself as a "LUN".<sup id="cite_ref-35" class="reference"><a href="#cite_note-35"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> Sometimes, redundantly, the actual LUN may be called a "LUN number" or "LUN id".<sup id="cite_ref-36" class="reference"><a href="#cite_note-36"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> </p><p>In modern SCSI transport protocols, there is an automated process for the "discovery" of the IDs. The SSA initiator (normally the host computer through the 'host adaptor') "walk the loop" to determine what devices are connected and then assigns each one a 7-bit "hop-count" value. <a href="/wiki/Fibre_Channel" title="Fibre Channel">Fibre Channel</a> – Arbitrated Loop (FC-AL) initiators use the LIP (Loop Initialization Protocol) to interrogate each device port for its WWN (<a href="/wiki/World_Wide_Name" title="World Wide Name">World Wide Name</a>). For iSCSI, because of the unlimited scope of the (IP) network, the process is quite complicated. These discovery processes occur at power-on/initialization time and also if the bus topology changes later, for example if an extra device is added. </p><p>SCSI has the CTL (Channel, Target or Physical Unit Number, Logical Unit Number) identification mechanism per <a href="/wiki/Host_bus_adapter" class="mw-redirect" title="Host bus adapter">host bus adapter</a>, or the HCTL (HBA, Channel, PUN, LUN) identification mechanism, one host adapter may have more than one channels.<sup id="cite_ref-37" class="reference"><a href="#cite_note-37"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Device_Type">Device Type</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=19" title="Edit section: Device Type"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/SCSI_Peripheral_Device_Type" title="SCSI Peripheral Device Type">SCSI Peripheral Device Type</a></div> <p>While all SCSI controllers can work with read/write storage devices, i.e. disk and tape, some will not work with some other device types; older controllers are likely to be more limited,<sup id="cite_ref-38" class="reference"><a href="#cite_note-38"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> sometimes by their driver software, and more Device Types were added as SCSI evolved. Even CD-ROMs are not handled by all controllers. Device Type is a 5-bit field reported by a <a href="/w/index.php?title=SCSI_Inquiry_Command&action=edit&redlink=1" class="new" title="SCSI Inquiry Command (page does not exist)">SCSI Inquiry Command</a>; defined <a href="/wiki/SCSI_Peripheral_Device_Type" title="SCSI Peripheral Device Type">SCSI Peripheral Device Types</a> include, in addition to many varieties of storage device, printer, scanner, communications device, and a catch-all "processor" type for devices not otherwise listed. </p> <div class="mw-heading mw-heading2"><h2 id="SCSI_enclosure_services">SCSI enclosure services</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=20" title="Edit section: SCSI enclosure services"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In larger SCSI servers, the disk-drive devices are housed in an intelligent enclosure that supports <a href="/wiki/SCSI_Enclosure_Services" title="SCSI Enclosure Services">SCSI Enclosure Services (SES)</a>. The initiator can communicate with the enclosure using a specialized set of SCSI commands to access power, cooling, and other non-data characteristics. </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=SCSI&action=edit&section=21" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Fibre_Channel" title="Fibre Channel">Fibre Channel</a></li> <li><a href="/wiki/List_of_device_bandwidths" class="mw-redirect" title="List of device bandwidths">List of device bandwidths</a></li> <li><a href="/wiki/Parallel_SCSI" title="Parallel SCSI">Parallel SCSI</a></li> <li><a href="/wiki/Serial_Attached_SCSI" title="Serial Attached SCSI">Serial Attached SCSI</a></li> <li><a href="/wiki/Intelligent_Peripheral_Interface" title="Intelligent Peripheral Interface">Intelligent Peripheral Interface</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="Notes">Notes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=22" title="Edit section: Notes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-columns references-column-width reflist-lower-alpha" style="column-width: 30em;"> <ol class="references"> <li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text">Clock rate in <a href="/wiki/Hertz" title="Hertz">MHz</a> for parallel, or <a href="/wiki/Bitrate" class="mw-redirect" title="Bitrate">bitrate</a> (per second) for serial interfaces.</span> </li> <li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text">For daisy-chain designs, length of bus, from end to end; for point-to-point, length of a single link</span> </li> <li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text">Including any host adapters (i.e., computers count as a device)</span> </li> <li id="cite_note-spatial_reuse-23"><span class="mw-cite-backlink">^ <a href="#cite_ref-spatial_reuse_23-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-spatial_reuse_23-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">spatial reuse</span> </li> <li id="cite_note-fdx-24"><span class="mw-cite-backlink">^ <a href="#cite_ref-fdx_24-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-fdx_24-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-fdx_24-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-fdx_24-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-fdx_24-4"><sup><i><b>e</b></i></sup></a> <a href="#cite_ref-fdx_24-5"><sup><i><b>f</b></i></sup></a> <a href="#cite_ref-fdx_24-6"><sup><i><b>g</b></i></sup></a> <a href="#cite_ref-fdx_24-7"><sup><i><b>h</b></i></sup></a> <a href="#cite_ref-fdx_24-8"><sup><i><b>i</b></i></sup></a> <a href="#cite_ref-fdx_24-9"><sup><i><b>j</b></i></sup></a> <a href="#cite_ref-fdx_24-10"><sup><i><b>k</b></i></sup></a> <a href="#cite_ref-fdx_24-11"><sup><i><b>l</b></i></sup></a> <a href="#cite_ref-fdx_24-12"><sup><i><b>m</b></i></sup></a></span> <span class="reference-text"><a href="/wiki/Duplex_(telecommunications)" title="Duplex (telecommunications)">full duplex</a></span> </li> <li id="cite_note-per_dir-25"><span class="mw-cite-backlink">^ <a href="#cite_ref-per_dir_25-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-per_dir_25-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-per_dir_25-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-per_dir_25-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-per_dir_25-4"><sup><i><b>e</b></i></sup></a> <a href="#cite_ref-per_dir_25-5"><sup><i><b>f</b></i></sup></a> <a href="#cite_ref-per_dir_25-6"><sup><i><b>g</b></i></sup></a> <a href="#cite_ref-per_dir_25-7"><sup><i><b>h</b></i></sup></a> <a href="#cite_ref-per_dir_25-8"><sup><i><b>i</b></i></sup></a> <a href="#cite_ref-per_dir_25-9"><sup><i><b>j</b></i></sup></a> <a href="#cite_ref-per_dir_25-10"><sup><i><b>k</b></i></sup></a> <a href="#cite_ref-per_dir_25-11"><sup><i><b>l</b></i></sup></a> <a href="#cite_ref-per_dir_25-12"><sup><i><b>m</b></i></sup></a></span> <span class="reference-text">per direction</span> </li> <li id="cite_note-fcdist-26"><span class="mw-cite-backlink">^ <a href="#cite_ref-fcdist_26-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-fcdist_26-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-fcdist_26-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-fcdist_26-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-fcdist_26-4"><sup><i><b>e</b></i></sup></a></span> <span class="reference-text">500 meters for <a href="/wiki/Multi-mode_optical_fiber" title="Multi-mode optical fiber">multi-mode</a>, 10 kilometers for <a href="/wiki/Single-mode_optical_fiber" title="Single-mode optical fiber">single-mode</a></span> </li> <li id="cite_note-128per-27"><span class="mw-cite-backlink">^ <a href="#cite_ref-128per_27-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-128per_27-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-128per_27-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-128per_27-3"><sup><i><b>d</b></i></sup></a></span> <span class="reference-text">128 per expander</span> </li> <li id="cite_note-28"><span class="mw-cite-backlink"><b><a href="#cite_ref-28">^</a></b></span> <span class="reference-text">per PCIe 3.0 lane</span> </li> <li id="cite_note-29"><span class="mw-cite-backlink"><b><a href="#cite_ref-29">^</a></b></span> <span class="reference-text">not specified, practical limitation of USB 3.1</span> </li> <li id="cite_note-30"><span class="mw-cite-backlink"><b><a href="#cite_ref-30">^</a></b></span> <span class="reference-text">half duplex</span> </li> <li id="cite_note-31"><span class="mw-cite-backlink"><b><a href="#cite_ref-31">^</a></b></span> <span class="reference-text">half duplex</span> </li> <li id="cite_note-32"><span class="mw-cite-backlink"><b><a href="#cite_ref-32">^</a></b></span> <span class="reference-text">over <a href="/wiki/Ethernet" title="Ethernet">Ethernet</a>, per 10 Gbit/s, <a href="/wiki/Maximum_Transfer_Unit" class="mw-redirect" title="Maximum Transfer Unit">MTU</a> 1500</span> </li> <li id="cite_note-33"><span class="mw-cite-backlink"><b><a href="#cite_ref-33">^</a></b></span> <span class="reference-text">over Ethernet, per 10 Gbit/s, MTU 9000</span> </li> </ol></div> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=23" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239543626"><div class="reflist reflist-columns references-column-width" style="column-width: 30em;"> <ol class="references"> <li id="cite_note-draft-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-draft_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-draft_1-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">ANSI Draft SASI Standard, Rev D, February 17, 1982, pg. ii states, "9/15/81 first presentation to ANSI committee X3T9-3 (2 weeks following announcement in Electronic Design)."</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="CITEREFField" class="citation book cs1">Field. <i>The Book of SCSI</i>. p. 1.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Book+of+SCSI&rft.pages=1&rft.au=Field&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://global.ihs.com/doc_detail.cfm?document_name=ANSI%20INCITS%20131&item_s_key=00009673&item_key_date=911231">"ANSI INCITS 131 94th Edition, 2004"</a>. global.ihs.com<span class="reference-accessdate">. Retrieved <span class="nowrap">April 25,</span> 2017</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=ANSI+INCITS+131+94th+Edition%2C+2004&rft.pub=global.ihs.com&rft_id=https%3A%2F%2Fglobal.ihs.com%2Fdoc_detail.cfm%3Fdocument_name%3DANSI%2520INCITS%2520131%26item_s_key%3D00009673%26item_key_date%3D911231&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-glass198902-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-glass198902_4-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGlass1989" class="citation magazine cs1">Glass, Brett (February 1989). <a rel="nofollow" class="external text" href="https://archive.org/details/eu_BYTE-1989-02_OCR/page/n350/mode/1up?view=theater">"Hard Disk Interfaces"</a>. <i>BYTE</i>. pp. 293–297<span class="reference-accessdate">. Retrieved <span class="nowrap">October 8,</span> 2024</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=Hard+Disk+Interfaces&rft.pages=293-297&rft.date=1989-02&rft.aulast=Glass&rft.aufirst=Brett&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Feu_BYTE-1989-02_OCR%2Fpage%2Fn350%2Fmode%2F1up%3Fview%3Dtheater&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation book cs1"><i>Data Technology Corporation Prospectus</i>. May 27, 1987. <q>In 1979 the Company developed the first controller using the SASI interface ... in conjunction with Shugart Associates</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Data+Technology+Corporation+Prospectus&rft.date=1987-05-27&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" 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 id="CITEREFBahramiJ._Stuart_Evans2005" class="citation book cs1">Bahrami, Homa; J. Stuart Evans (2005). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=OlFUPUIcHoMC"><i>Super-flexibility for Knowledge Enterprises</i></a>. 9783540205760. p. 59. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9783540205760" title="Special:BookSources/9783540205760"><bdi>9783540205760</bdi></a> – via Google Books.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Super-flexibility+for+Knowledge+Enterprises&rft.pages=59&rft.pub=9783540205760&rft.date=2005&rft.isbn=9783540205760&rft.aulast=Bahrami&rft.aufirst=Homa&rft.au=J.+Stuart+Evans&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DOlFUPUIcHoMC&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text">ANSI SCSI Standard, X3.131-1986, June 23, 1986, 2nd, foreword.</span> </li> <li id="cite_note-spt-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-spt_8-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMusumeciMichael_Kosta_Loukides2002" class="citation book cs1">Musumeci, Gian-Paolo D.; Michael Kosta Loukides (2002). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=LqabAgAAQBAJ"><i>System Performance Tuning</i></a>. O'Reilly Media. p. 147. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780596002848" title="Special:BookSources/9780596002848"><bdi>9780596002848</bdi></a> – via Google Books.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=System+Performance+Tuning&rft.pages=147&rft.pub=O%27Reilly+Media&rft.date=2002&rft.isbn=9780596002848&rft.aulast=Musumeci&rft.aufirst=Gian-Paolo+D.&rft.au=Michael+Kosta+Loukides&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DLqabAgAAQBAJ&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" 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 id="CITEREFO'Reilly2016" class="citation book cs1">O'Reilly, James (2016). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=Vop4CgAAQBAJ"><i>Network Storage: Tools and Technologies for Storing Your Company's Data</i></a>. Elsevier Science. p. 255. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780128038659" title="Special:BookSources/9780128038659"><bdi>9780128038659</bdi></a> – via Google Books.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Network+Storage%3A+Tools+and+Technologies+for+Storing+Your+Company%27s+Data&rft.pages=255&rft.pub=Elsevier+Science&rft.date=2016&rft.isbn=9780128038659&rft.aulast=O%27Reilly&rft.aufirst=James&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DVop4CgAAQBAJ&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-ANSI-10"><span class="mw-cite-backlink">^ <a href="#cite_ref-ANSI_10-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-ANSI_10-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Working document for ANSI meeting on March 3, 1982, "SASI SHUGART ASSOCIATES SYSTEM INTERFACE, Revision D, February 17, 1982"</span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.endl.com/">"ENDL Inc. 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December 7, 2007. <a rel="nofollow" class="external text" href="https://ghostarchive.org/varchive/youtube/20211117/OiLUIJ3ke-o">Archived</a> from the original on November 17, 2021<span class="reference-accessdate">. Retrieved <span class="nowrap">May 11,</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=%22How+Computer+Storage+Became+a+Modern+Business%22%2C+Computer+History+Museum%2C+March+9%2C+2005&rft.pub=Youtube.com&rft.date=2007-12-07&rft_id=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DOiLUIJ3ke-o&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</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://smithsonianchips.si.edu/ncr/scsi-1.htm">"NCR Collection (LSI Logic)at Smithsonian Museum"</a>. Smithsonianchips.si.edu<span class="reference-accessdate">. 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Endeavor Business Media: 268 – via Gale. <q>NCR Corp., Microelectronics Division has announced the release of its NCR 5385 single-chip controller. NCR is the first to use the Small Computer System Interface (SCSI) protocol.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Electronic+Design&rft.atitle=Single-Chip+Controller+Handles+SCSI&rft.volume=31&rft.issue=9&rft.pages=268&rft.date=1983-04-28&rft.aulast=Bursky&rft.aufirst=D.&rft_id=https%3A%2F%2Flink.gale.com%2Fapps%2Fdoc%2FA536889%2FGPS%3Fsid%3Dwikipedia&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation report cs1">"SCSI Products - Host Bus Adapters". SCSI Source Guide (Report). Technology Forums Inc. Fourth Quarter 1990. pp. 195–260.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=report&rft.btitle=SCSI+Source+Guide&rft.pages=195-260&rft.pub=Technology+Forums+Inc&rft.date=1990&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSheldonSliwa" class="citation web cs1">Sheldon, Robert; Sliwa, Carol. <a rel="nofollow" class="external text" href="https://www.techtarget.com/searchstorage/definition/host-bus-adapter">"host bus adapter (HBA)"</a>. TechTarget<span class="reference-accessdate">. Retrieved <span class="nowrap">April 18,</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=host+bus+adapter+%28HBA%29&rft.pub=TechTarget&rft.aulast=Sheldon&rft.aufirst=Robert&rft.au=Sliwa%2C+Carol&rft_id=https%3A%2F%2Fwww.techtarget.com%2Fsearchstorage%2Fdefinition%2Fhost-bus-adapter&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://support.apple.com/kb/HT3074?viewlocale=en_US">"Power Macintosh G3, G4: Differences Between Available SCSI Cards"</a>. Apple, Inc. April 1, 2010<span class="reference-accessdate">. Retrieved <span class="nowrap">July 7,</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Power+Macintosh+G3%2C+G4%3A+Differences+Between+Available+SCSI+Cards&rft.pub=Apple%2C+Inc.&rft.date=2010-04-01&rft_id=http%3A%2F%2Fsupport.apple.com%2Fkb%2FHT3074%3Fviewlocale%3Den_US&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDavid_Allen2005" class="citation web cs1">David Allen (July 1, 2005). <a rel="nofollow" class="external text" href="https://www.infostor.com/index/articles/display/232832/articles/infostor/volume-9/issue-7/features/special-report/the-benefits-of-serial-attached-scsi-sas.html">"The benefits of Serial Attached SCSI (SAS)"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">February 6,</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=The+benefits+of+Serial+Attached+SCSI+%28SAS%29&rft.date=2005-07-01&rft.au=David+Allen&rft_id=http%3A%2F%2Fwww.infostor.com%2Findex%2Farticles%2Fdisplay%2F232832%2Farticles%2Finfostor%2Fvolume-9%2Fissue-7%2Ffeatures%2Fspecial-report%2Fthe-benefits-of-serial-attached-scsi-sas.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFShuangbao_Paul_Wang2013" class="citation book cs1">Shuangbao Paul Wang (January 10, 2013). <i>Computer Architecture and Security: Fundamentals of Designing Secure Computer Systems</i> (1st ed.). John Wiley & Sons. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1118168813" title="Special:BookSources/978-1118168813"><bdi>978-1118168813</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Computer+Architecture+and+Security%3A+Fundamentals+of+Designing+Secure+Computer+Systems&rft.edition=1st&rft.pub=John+Wiley+%26+Sons&rft.date=2013-01-10&rft.isbn=978-1118168813&rft.au=Shuangbao+Paul+Wang&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-34"><span class="mw-cite-backlink"><b><a href="#cite_ref-34">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGrothDan_Newland2001" class="citation book cs1">Groth, David; Dan Newland (January 2001). <a rel="nofollow" class="external text" href="http://www.bookfinder4u.com/IsbnSearch.aspx?isbn=0782128025&mode=direct"><i>A+ Complete Study Guide</i></a> (2nd ed.). Alameda, CA, USA: l Sybex. p. 183. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-7821-4244-0" title="Special:BookSources/978-0-7821-4244-0"><bdi>978-0-7821-4244-0</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=A%2B+Complete+Study+Guide&rft.place=Alameda%2C+CA%2C+USA&rft.pages=183&rft.edition=2nd&rft.pub=l+Sybex&rft.date=2001-01&rft.isbn=978-0-7821-4244-0&rft.aulast=Groth&rft.aufirst=David&rft.au=Dan+Newland&rft_id=http%3A%2F%2Fwww.bookfinder4u.com%2FIsbnSearch.aspx%3Fisbn%3D0782128025%26mode%3Ddirect&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-35"><span class="mw-cite-backlink"><b><a href="#cite_ref-35">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://library.netapp.com/ecmdocs/ECMP1511537/html/man1/na_lun.1.html">"na_lun(1) – Manual page for "lun" on NetApp DataONTAP"</a>. <a href="/wiki/NetApp" title="NetApp">NetApp</a>. July 7, 2009. <q>The lun command is used to create and manage luns[...]</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=na_lun%281%29+%E2%80%93+Manual+page+for+%22lun%22+on+NetApp+DataONTAP&rft.pub=NetApp&rft.date=2009-07-07&rft_id=https%3A%2F%2Flibrary.netapp.com%2Fecmdocs%2FECMP1511537%2Fhtml%2Fman1%2Fna_lun.1.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-36"><span class="mw-cite-backlink"><b><a href="#cite_ref-36">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://library.netapp.com/ecmdocs/ECMP1511537/html/man1/na_lun.1.html">"na_lun(1) – Manual page for "lun" on NetApp DataONTAP"</a>. <a href="/wiki/NetApp" title="NetApp">NetApp</a>. July 7, 2009. <q>If a LUN ID is not specified, the smallest number [...] is automatically picked.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=na_lun%281%29+%E2%80%93+Manual+page+for+%22lun%22+on+NetApp+DataONTAP&rft.pub=NetApp&rft.date=2009-07-07&rft_id=https%3A%2F%2Flibrary.netapp.com%2Fecmdocs%2FECMP1511537%2Fhtml%2Fman1%2Fna_lun.1.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-37"><span class="mw-cite-backlink"><b><a href="#cite_ref-37">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://tldp.org/HOWTO/SCSI-2.4-HOWTO/scsiaddr.html">"SCSI Addressing"</a>. <i>tldp.org</i><span class="reference-accessdate">. Retrieved <span class="nowrap">March 4,</span> 2021</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=tldp.org&rft.atitle=SCSI+Addressing&rft_id=https%3A%2F%2Ftldp.org%2FHOWTO%2FSCSI-2.4-HOWTO%2Fscsiaddr.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> <li id="cite_note-38"><span class="mw-cite-backlink"><b><a href="#cite_ref-38">^</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://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/V40F_HTML/MAN/MAN7/0003____.HTM">"An example of an old SCSI interface which supported only named mass storage devices"</a>. H30097.www3.hp.com<span class="reference-accessdate">. Retrieved <span class="nowrap">May 11,</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=An+example+of+an+old+SCSI+interface+which+supported+only+named+mass+storage+devices&rft.pub=H30097.www3.hp.com&rft_id=http%3A%2F%2Fh30097.www3.hp.com%2Fdocs%2Fbase_doc%2FDOCUMENTATION%2FV40F_HTML%2FMAN%2FMAN7%2F0003____.HTM&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></span> </li> </ol></div> <div class="mw-heading mw-heading2"><h2 id="Bibliography">Bibliography</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SCSI&action=edit&section=24" title="Edit section: Bibliography"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239549316">.mw-parser-output .refbegin{margin-bottom:0.5em}.mw-parser-output .refbegin-hanging-indents>ul{margin-left:0}.mw-parser-output .refbegin-hanging-indents>ul>li{margin-left:0;padding-left:3.2em;text-indent:-3.2em}.mw-parser-output .refbegin-hanging-indents ul,.mw-parser-output .refbegin-hanging-indents ul li{list-style:none}@media(max-width:720px){.mw-parser-output .refbegin-hanging-indents>ul>li{padding-left:1.6em;text-indent:-1.6em}}.mw-parser-output .refbegin-columns{margin-top:0.3em}.mw-parser-output .refbegin-columns ul{margin-top:0}.mw-parser-output .refbegin-columns li{page-break-inside:avoid;break-inside:avoid-column}@media screen{.mw-parser-output .refbegin{font-size:90%}}</style><div class="refbegin" style=""> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFieldPeter_RidgeJohn_LohmeyerGerhard_Islinger2000" class="citation book cs1">Field, Gary; Peter Ridge; John Lohmeyer; Gerhard Islinger; Stefan Groll (2000). <span class="id-lock-registration" title="Free registration required"><a rel="nofollow" class="external text" href="https://archive.org/details/isbn_9781886411104"><i>The Book of SCSI</i></a></span> (2nd ed.). No Starch Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1-886411-10-4" title="Special:BookSources/978-1-886411-10-4"><bdi>978-1-886411-10-4</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Book+of+SCSI&rft.edition=2nd&rft.pub=No+Starch+Press&rft.date=2000&rft.isbn=978-1-886411-10-4&rft.aulast=Field&rft.aufirst=Gary&rft.au=Peter+Ridge&rft.au=John+Lohmeyer&rft.au=Gerhard+Islinger&rft.au=Stefan+Groll&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fisbn_9781886411104&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASCSI" class="Z3988"></span></li></ul> </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=SCSI&action=edit&section=25" title="Edit section: External links"><span>edit</span></a><span 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