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RL02 - Wikipedia
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</div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Cartidge-based hard disk drive format</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 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class="mbox-text"><div class="mbox-text-span">This article <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/RL02" title="Special:EditPage/RL02">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a>. Unsourced material may be challenged and removed.<br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22RL02%22">"RL02"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22RL02%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22RL02%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22RL02%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22RL02%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22RL02%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">January 2022</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><b>RL01</b> and <b>RL02</b> drives are moving head <a href="/wiki/Magnetic_disk" class="mw-redirect" title="Magnetic disk">magnetic disk</a> drives manufactured by <a href="/wiki/Digital_Equipment_Corporation" title="Digital Equipment Corporation">Digital Equipment Corporation</a> for the <a href="/wiki/PDP-8" title="PDP-8">PDP-8</a> and <a href="/wiki/PDP-11" title="PDP-11">PDP-11</a> microcomputers. The RL01 and RL02 drives stored approximate 5MB and 10MB respectively, utilizing a removable data cartridge.<sup id="cite_ref-users-guide_1-0" class="reference"><a href="#cite_note-users-guide-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 1–3">: 1–3 </span></sup> The drives are typically mounted in a standard 19" rack and weigh 34 kg. Up to four RL02 or RL01 drives may be used, in any combination, from a single controller. Typically an RL11 in the case of a Unibus PDP-11 and an RLV11 or RLV12 in the case of a Q-bus PDP-11. On the PDP-8/a the controller is an RL8A which consists of an M8433 Hex wide Omnibus card. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Cartridge_format">Cartridge format</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=RL02&action=edit&section=1" title="Edit section: Cartridge format"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The RL01 and RL02 data cartridges are based on <a href="/wiki/History_of_IBM_magnetic_disk_drives#IBM_5444" title="History of IBM magnetic disk drives">IBM 5440</a> cartridges, but have servo tracking data pre-encoded onto the cartridge.<sup id="cite_ref-users-guide_1-1" class="reference"><a href="#cite_note-users-guide-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 1–3">: 1–3 </span></sup> This reduces the need for strict head alignment, allowing cartridges to be used in several drives (although there was no backwards compatibility between RL02 and RL01 cartridges, despite similar appearance<sup id="cite_ref-users-guide_1-2" class="reference"><a href="#cite_note-users-guide-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 1–4">: 1–4 </span></sup>). However, this prevents on-site low level formatting of cartridges. The drives have logic to prevent this servo data from being overwritten.<sup id="cite_ref-users-guide_1-3" class="reference"><a href="#cite_note-users-guide-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 1–3">: 1–3 </span></sup> RL01 cartridges have 256 tracks, and RL02 cartridges have 512 tracks.<sup id="cite_ref-users-guide_1-4" class="reference"><a href="#cite_note-users-guide-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 1–3">: 1–3 </span></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Data_format">Data format</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=RL02&action=edit&section=2" title="Edit section: Data format"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>On both RL01 and RL02 cartridges, each track is divided into 40 sectors of equal length. Each sector is divided into six fields, defined as follows (where each word is 16 bits).<sup id="cite_ref-users-guide_1-5" class="reference"><a href="#cite_note-users-guide-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 1–4">: 1–4 </span></sup>) </p> <ul><li><b>Header Preamble (PR1)</b> consists of three words of 47 zeros, followed by a single one for synchronization.</li> <li><b>Header,</b> consisting of three words. The first word identifies whether the sector is on the upper or lower side of the platter, followed by the track number (1 to 256 or 1 to 512) and finally the sector number (1 to 40). The second word is all zeros. The third word contains a <a href="/wiki/Cyclic_redundancy_check" title="Cyclic redundancy check">cyclic redundancy check</a> (CRC) of the header. This is checked during a read operation.</li> <li><b>Header Postamble (PO1)</b> of one word consisting only of zeros. This field separates the header and data fields, enabling for mechanical tolerances between drives.</li> <li><b>Data Preamble (PR2)</b> consists of three words of 47 zeros, followed by a single synchronization one bit.</li> <li><b>Data</b> contains 128 words (a total of 2048 bits), followed by single word (16 bits) <a href="/wiki/Cyclic_redundancy_check" title="Cyclic redundancy check">cyclic redundancy check</a></li> <li><b>Data Postamble (PO2)</b> contains 16 zero bits.</li></ul> <p>The header and data is preceded by two servo bursts (S1 and S2) which are prerecorded onto the data cartridge during manufacture. Data is encoded on the disk using <a href="/wiki/Modified_Frequency_Modulation" class="mw-redirect" title="Modified Frequency Modulation">Modified Frequency Modulation</a>, where a one bit will result in a magnetic flux reversal on the magnetic coating of the cartridge. </p><p>The last track of an RL01 and RL02 cartridge contains a table which lists all of the bad sectors on the cartridge. This track also contains the cartridges serial number.<sup id="cite_ref-users-guide_1-6" class="reference"><a href="#cite_note-users-guide-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 1-6–1-8">: 1-6–1-8 </span></sup>) The drive does not contain any logic for handling bad sectors - this must be performed by the operating system. Hence, one could potentially erase this table if the operating system does not prevent against it. </p> <div class="mw-heading mw-heading2"><h2 id="Interface">Interface</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=RL02&action=edit&section=3" title="Edit section: Interface"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Access to and from an RL drive is done serially, via a 40 pin cable running from the controller inside the computer to the drive. These lines are described in the table below.<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> </p> <table class="wikitable"> <caption> </caption> <tbody><tr> <th>Line Name </th> <th>Description </th> <th>Direction </th></tr> <tr> <td>Drive Select 0 </td> <td rowspan="2">These two lines are used to select the drive (0-3). As there are only four possible combinations, at least one of the four drives is always selected. Only the selected drive will output data on the Drive Ready through to Status lines. </td> <td rowspan="7">From the controller to the RL drive. </td></tr> <tr> <td>Drive Select 1 </td></tr> <tr> <td>Write Gate </td> <td>Only when this line is asserted will the writing circuitry be enabled within the drive. If this line is asserted while a sector pulse occurs, the drive will raise a Write Gate Error and the drive will no longer accept any commands. </td></tr> <tr> <td>Write Data </td> <td>When the Write Gate line is asserted, data may be transferred on this line. This data should be encoded in <a href="/wiki/Modified_Frequency_Modulation" class="mw-redirect" title="Modified Frequency Modulation">Modified Frequency Modulation</a>, as the drive does not encode or decode this data. </td></tr> <tr> <td>System Clock </td> <td>The system clock shifts data through the Drive Command line and also provides a reference for the disk servo motor. The drive will not spin up without these clock pulses. The clock pulses must be 4.1 MHz +/- 0.1%. </td></tr> <tr> <td>Drive Command </td> <td>This line is used to transfer the drive command word, shifted by the system clock. </td></tr> <tr> <td>Power Fail </td> <td>This line remains asserted at all times that the controller is active. If the computer or controller experience a power failure, this line will fall low, resulting in the drive unloading the heads and spinning down the platter. </td></tr> <tr> <td>Drive Ready </td> <td>This line will be asserted by the selected drive when the head is centred over the selected track, indicating that the drive is ready to receive commands from the controller. This temporarily goes low when a drive command word has been shifted. </td> <td rowspan="6">From the RL drive to the controller. </td></tr> <tr> <td>Status Clock </td> <td>This clock the delayed system clock and is only enabled during a transfer of the drive status word. </td></tr> <tr> <td>Sector Pulse </td> <td>This is a 625 microsecond pulse which is asserted high 40 times per disc revolution. This signal is generated from by the sector transducer. </td></tr> <tr> <td>Read Data </td> <td><a href="/wiki/Modified_Frequency_Modulation" class="mw-redirect" title="Modified Frequency Modulation">Modified Frequency Modulation</a> encoded data is transferred over this line whenever the drive is selected and the head is locked onto a track. </td></tr> <tr> <td>Drive Error </td> <td>This line is asserted when there has been certain drive errors. </td></tr> <tr> <td>Status </td> <td>The drive status word is transferred in serial using this line, clocked by the Status Clock. </td></tr></tbody></table> <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=RL02&action=edit&section=4" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-users-guide-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-users-guide_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-users-guide_1-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-users-guide_1-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-users-guide_1-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-users-guide_1-4"><sup><i><b>e</b></i></sup></a> <a href="#cite_ref-users-guide_1-5"><sup><i><b>f</b></i></sup></a> <a href="#cite_ref-users-guide_1-6"><sup><i><b>g</b></i></sup></a></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite class="citation book cs1"><a rel="nofollow" class="external text" href="http://bitsavers.org/pdf/dec/disc/rl01_rl02/EK-RL012-UG-004_RL01_RL02_Disk_Subsystem_Users_Guide_Oct80.pdf"><i>RL01/RL02 Disk Subsystem User's Guide</i></a> <span class="cs1-format">(PDF)</span>. <a href="/wiki/Digital_Equipment_Corporation" title="Digital Equipment Corporation">DEC</a>. October 1980. EK-RL012-UG-004.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=RL01%2FRL02+Disk+Subsystem+User%27s+Guide&rft.pub=DEC&rft.date=1980-10&rft_id=http%3A%2F%2Fbitsavers.org%2Fpdf%2Fdec%2Fdisc%2Frl01_rl02%2FEK-RL012-UG-004_RL01_RL02_Disk_Subsystem_Users_Guide_Oct80.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ARL02" class="Z3988"></span></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"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation book cs1"><a rel="nofollow" class="external text" href="http://bitsavers.org/pdf/dec/disc/rl01_rl02/EK-RL012-TM-PRE_RL01_RL02_Disk_Drive_Technical_Manual_Preliminary_Dec79.pdf"><i>RL01/RL02 DISK DRIVE Technical Manual (Preliminary)</i></a> <span class="cs1-format">(PDF)</span>. <a href="/wiki/Digital_Equipment_Corporation" title="Digital Equipment Corporation">DEC</a>. December 1979. pp. I/3-1-I/3-6. EK-RL012-TM-PRE.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=RL01%2FRL02+DISK+DRIVE+Technical+Manual+%28Preliminary%29&rft.pages=I%2F3-1-I%2F3-6&rft.pub=DEC&rft.date=1979-12&rft_id=http%3A%2F%2Fbitsavers.org%2Fpdf%2Fdec%2Fdisc%2Frl01_rl02%2FEK-RL012-TM-PRE_RL01_RL02_Disk_Drive_Technical_Manual_Preliminary_Dec79.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ARL02" class="Z3988"></span></span> </li> </ol></div></div> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output 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Equipment Corporation"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Digital_Equipment_Corporation" title="Special:EditPage/Template:Digital Equipment Corporation"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Digital_Equipment_Corporation" style="font-size:114%;margin:0 4em"><a href="/wiki/Digital_Equipment_Corporation" title="Digital Equipment Corporation">Digital Equipment Corporation</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Key people</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Ken_Olsen" title="Ken Olsen">Ken Olsen</a> (founder and CEO, 1957–1992)</li> <li><a href="/wiki/Harlan_Anderson" title="Harlan Anderson">Harlan Anderson</a> (co-founder)</li> <li><a href="/wiki/Gordon_Bell" title="Gordon Bell">Gordon Bell</a> (VP of engineering)</li> <li><a href="/wiki/Robert_Palmer_(computer_businessman)" title="Robert Palmer (computer businessman)">Robert Palmer</a> (CEO, 1992–1998)</li></ul> </div></td><td class="noviewer navbox-image" rowspan="9" style="width:1px;padding:0 0 0 2px"><div><span class="mw-default-size" typeof="mw:File/Frameless"><a href="/wiki/File:Digital_Equipment_Corporation_1993_logo.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/9/90/Digital_Equipment_Corporation_1993_logo.svg/110px-Digital_Equipment_Corporation_1993_logo.svg.png" decoding="async" width="110" height="33" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/90/Digital_Equipment_Corporation_1993_logo.svg/165px-Digital_Equipment_Corporation_1993_logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/90/Digital_Equipment_Corporation_1993_logo.svg/220px-Digital_Equipment_Corporation_1993_logo.svg.png 2x" data-file-width="3124" data-file-height="938" /></a></span></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Instruction_set_architecture" title="Instruction set architecture">Instruction set<br />architectures</a>,<br /><a href="/wiki/Processor_(computing)" title="Processor (computing)">processors</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/PDP-11_architecture" title="PDP-11 architecture">PDP-11</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li>LSI-11</li> <li>F-11</li> <li><a href="/wiki/DEC_T-11" title="DEC T-11">T-11</a></li> <li><a href="/wiki/DEC_J-11" title="DEC J-11">J-11</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/VAX" title="VAX">VAX</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/DEC_V-11" title="DEC V-11">V-11</a></li> <li><a href="/wiki/MicroVAX_78032" title="MicroVAX 78032">MicroVAX 78032</a></li> <li><a href="/wiki/CVAX" title="CVAX">CVAX</a> <ul><li><a href="/wiki/CVAX#SOC" title="CVAX">SOC</a></li></ul></li> <li><a href="/wiki/Rigel_(microprocessor)" title="Rigel (microprocessor)">Rigel</a> <ul><li><a href="/wiki/Rigel_(microprocessor)#Mariah" title="Rigel (microprocessor)">Mariah</a></li></ul></li> <li><a href="/wiki/NVAX" title="NVAX">NVAX</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/DEC_Alpha" title="DEC Alpha">Alpha</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Alpha_21064" title="Alpha 21064">Alpha 21064</a> <ul><li><a href="/wiki/Alpha_21064#Alpha_21066" title="Alpha 21064">21066</a></li> <li><a href="/wiki/Alpha_21064#Alpha_21068" title="Alpha 21064">21068</a></li></ul></li> <li><a href="/wiki/Alpha_21164" title="Alpha 21164">Alpha 21164</a> (<a href="/wiki/Alpha_21164#Alpha_21164PC_(PCA56)" title="Alpha 21164">21164PC</a>)</li> <li><a href="/wiki/Alpha_21264" title="Alpha 21264">Alpha 21264</a></li> <li><a href="/wiki/Alpha_21364" title="Alpha 21364">Alpha 21364</a></li> <li><a href="/wiki/Alpha_21464" title="Alpha 21464">Alpha 21464</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/DEC_PRISM" title="DEC PRISM">MicroPRISM</a></li> <li><a href="/wiki/StrongARM" title="StrongARM">StrongARM</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Computer_terminal" title="Computer terminal">Computer<br />terminals</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/VT05" title="VT05">VT05</a> (1970)</li> <li><a href="/wiki/DEC_GT40" title="DEC GT40">GT40</a> (1972)</li> <li><a href="/wiki/VT52" title="VT52">VT50/VT52</a> (1975)</li> <li><a href="/wiki/VT55" class="mw-redirect" title="VT55">VT55</a></li> <li><a href="/wiki/VT62" class="mw-redirect" title="VT62">VT62</a></li> <li><a href="/wiki/VT100" title="VT100">VT100</a> (1978)</li> <li><a href="/wiki/VT101" class="mw-redirect" title="VT101">VT101</a></li> <li><a href="/wiki/VT102" class="mw-redirect" title="VT102">VT102</a></li> <li><a href="/wiki/VT103" class="mw-redirect" title="VT103">VT103</a></li> <li><a href="/wiki/VT105" class="mw-redirect" title="VT105">VT105</a></li> <li><a href="/wiki/VT131" class="mw-redirect" title="VT131">VT131</a></li> <li><a href="/wiki/VT180" title="VT180">VT180</a></li> <li><a href="/wiki/VT220" title="VT220">VT220</a> (1983)</li> <li><a href="/wiki/VT240" class="mw-redirect" title="VT240">VT240</a></li> <li><a href="/wiki/VT241" class="mw-redirect" title="VT241">VT241</a></li> <li><a href="/wiki/VT320" title="VT320">VT320</a> (1987)</li> <li><a href="/wiki/VT330" class="mw-redirect" title="VT330">VT330</a></li> <li><a href="/wiki/VT340" class="mw-redirect" title="VT340">VT340</a></li> <li><a href="/wiki/VT420" title="VT420">VT420</a> (1990)</li> <li><a href="/wiki/VT1000" title="VT1000">VT1000</a> (1990)</li> <li><a href="/wiki/VT510" class="mw-redirect" title="VT510">VT510</a> (1993)</li> <li><a href="/wiki/VT520" title="VT520">VT520</a> (1994)</li> <li><a href="/wiki/VT525" class="mw-redirect" title="VT525">VT525</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Operating_system" title="Operating system">Operating<br />systems</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/PDP-7#Software" title="PDP-7">DECsys</a></li> <li><a href="/wiki/4K_Disk_Monitor_System" class="mw-redirect" title="4K Disk Monitor System">4K DMS</a></li> <li><a href="/wiki/Commercial_Operating_System" title="Commercial Operating System">COS</a></li> <li><a href="/wiki/TOPS-10" title="TOPS-10">TOPS-10</a></li> <li><a href="/wiki/RSX-15" class="mw-redirect" title="RSX-15">RSX-15</a></li> <li><a href="/wiki/TSS/8" title="TSS/8">TSS/8</a></li> <li><a href="/wiki/OS/8" title="OS/8">OS/8</a></li> <li><a href="/wiki/DEC_BATCH-11/DOS-11" title="DEC BATCH-11/DOS-11">DOS-11</a></li> <li><a href="/wiki/RT-11" title="RT-11">RT-11</a></li> <li><a href="/wiki/RSTS/E" title="RSTS/E">RSTS/E</a></li> <li><a href="/wiki/RSX-11" title="RSX-11">RSX-11</a> <ul><li><a href="/wiki/Interactive_Application_System" title="Interactive Application System">IAS</a></li></ul></li> <li><a href="/wiki/MUMPS#1970s" title="MUMPS">DSM-11</a></li> <li><a href="/wiki/TOPS-20" title="TOPS-20">TOPS-20</a></li> <li><a href="/wiki/OpenVMS" title="OpenVMS">VAX/VMS</a></li> <li><a href="/wiki/VAXELN" title="VAXELN">VAXELN</a></li> <li><a href="/wiki/Ultrix" title="Ultrix">Ultrix</a></li> <li><a href="/wiki/DEC_MICA" title="DEC MICA">MICA</a></li> <li><a href="/wiki/Digital_UNIX" class="mw-redirect" title="Digital UNIX">Digital UNIX</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Programming_language" title="Programming language">Programming<br />languages</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/BASIC-8" title="BASIC-8">BASIC-8</a></li> <li><a href="/wiki/DIBOL" title="DIBOL">DIBOL</a></li> <li><a href="/wiki/FOCAL_(programming_language)" title="FOCAL (programming language)">FOCAL</a></li> <li><a href="/wiki/MACRO-10" title="MACRO-10">MACRO-10</a></li> <li><a href="/wiki/MACRO-11" title="MACRO-11">MACRO-11</a></li> <li><a href="/wiki/MUMPS" title="MUMPS">MUMPS</a></li> <li><a href="/wiki/VAX_MACRO" title="VAX MACRO">VAX MACRO</a></li> <li><a href="/wiki/DIGITAL_Command_Language" title="DIGITAL Command Language">DIGITAL Command Language</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Character_encoding" title="Character encoding">Character sets</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Multinational_Character_Set" title="Multinational Character Set">Code page 1100</a> (Multinational)</li> <li><a href="/wiki/Code_page_1287" title="Code page 1287">Code page 1287</a> (Greek)</li> <li><a href="/wiki/Code_page_1288" title="Code page 1288">Code page 1288</a> (Turkish)</li> <li><a href="/wiki/DEC_Hebrew" title="DEC Hebrew">Hebrew</a></li> <li><a href="/wiki/National_Replacement_Character_Set" title="National Replacement Character Set">National Replacement</a></li> <li><a href="/wiki/DEC_RADIX_50" title="DEC RADIX 50">RADIX 50</a></li> <li><a href="/wiki/DEC_Special_Graphics" title="DEC Special Graphics">Special Graphics</a></li> <li><a href="/wiki/DEC_Technical_Character_Set" title="DEC Technical Character Set">Technical</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Bus_(computing)" title="Bus (computing)">Bus standards</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Digital_Storage_Systems_Interconnect" title="Digital Storage Systems Interconnect">Digital Storage Systems Interconnect</a></li> <li><a href="/wiki/Massbus" title="Massbus">Massbus</a></li> <li><a href="/wiki/Q-Bus" title="Q-Bus">Q-Bus</a></li> <li><a href="/wiki/Standard_Disk_Interconnect" title="Standard Disk Interconnect">Standard Disk Interconnect</a></li> <li><a href="/wiki/Synchronous_Backplane_Interconnect" title="Synchronous Backplane Interconnect">Synchronous Backplane Interconnect</a></li> <li><a href="/wiki/TURBOchannel" title="TURBOchannel">TURBOchannel</a></li> <li><a href="/wiki/Unibus" title="Unibus">Unibus</a></li> <li><a href="/wiki/VAXBI_bus" title="VAXBI bus">VAXBI bus</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other <a href="/wiki/Computer_hardware" title="Computer hardware">hardware</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/DECtalk" title="DECtalk">DECtalk</a></li> <li><a href="/wiki/DECtape" title="DECtape">DECtape</a></li> <li><a href="/wiki/DECwriter" title="DECwriter">DECwriter</a></li> <li><a href="/wiki/Digital_Linear_Tape" title="Digital Linear Tape">Digital Linear Tape</a></li> <li><a href="/wiki/Dynamically_Redefined_Character_Set" title="Dynamically Redefined Character Set">Dynamically Redefined Character Set</a></li> <li><a href="/wiki/Firefly_(cache_coherence_protocol)" title="Firefly (cache coherence protocol)">Firefly</a></li> <li><a href="/wiki/Flip-Chip_module" title="Flip-Chip module">Flip-Chip module</a></li> <li><a href="/wiki/Gold_key_(DEC)" title="Gold key (DEC)">Gold key</a></li> <li><a href="/wiki/LK201" title="LK201">LK201</a></li> <li><a href="/wiki/LK421" title="LK421">LK421</a></li> <li><a href="/wiki/Mass_Storage_Control_Protocol" title="Mass Storage Control Protocol">Mass Storage Control Protocol</a></li> <li><a href="/wiki/PALcode" title="PALcode">PALcode</a></li> <li><a href="/wiki/RA90" title="RA90">RA90</a></li> <li><a href="/wiki/RK05" title="RK05">RK05</a></li> <li><a class="mw-selflink selflink">RL02</a></li> <li><a href="/wiki/Star_coupler" title="Star coupler">Star coupler</a></li> <li><a href="/wiki/System_Module" title="System Module">System Module</a></li> <li><a href="/wiki/TU81" title="TU81">TU81</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Related topics</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/AdvFS" title="AdvFS">AdvFS</a></li> <li><a href="/wiki/AltaVista" title="AltaVista">AltaVista</a></li> <li><a href="/wiki/Compaq" title="Compaq">Compaq</a></li> <li><i><a href="/wiki/CPU_Wars" title="CPU Wars">CPU Wars</a></i></li> <li><a href="/wiki/DECnet" title="DECnet">DECnet</a></li> <li><a href="/wiki/DECUS" title="DECUS">DECUS</a> <ul><li><a href="/wiki/HP-Interex" title="HP-Interex">HP-Interex</a></li></ul></li> <li><a href="/wiki/Digital_Federal_Credit_Union" title="Digital Federal Credit Union">Digital Federal Credit Union</a></li> <li><a href="/wiki/Dynamic_debugging_technique" title="Dynamic debugging technique">Dynamic debugging technique</a></li> <li><a href="/wiki/FX!32" title="FX!32">FX!32</a></li> <li><a href="/wiki/Local_Area_Transport" title="Local Area Transport">Local Area Transport</a></li> <li><a href="/wiki/Maintenance_Operations_Protocol" title="Maintenance Operations Protocol">Maintenance Operations Protocol</a></li> <li><a href="/wiki/On-line_Debugging_Tool" title="On-line Debugging Tool">On-line Debugging Tool</a></li> <li><a href="/wiki/PALcode" title="PALcode">PALcode</a></li> <li><a href="/wiki/Record_Management_Services" title="Record Management Services">Record Management Services</a></li> <li><a href="/wiki/ReGIS" title="ReGIS">ReGIS</a></li> <li>Sequence and Batch Language</li> <li><a href="/wiki/Sixel" title="Sixel">Sixel</a></li> <li><a href="/wiki/System_Reference_Manual" class="mw-redirect" title="System Reference Manual">System Reference Manual</a></li> <li><a href="/wiki/DEC_Systems_Research_Center" title="DEC Systems Research Center">Systems Research Center</a></li> <li><a href="/wiki/TD/SMP" title="TD/SMP">TD/SMP</a></li> <li><i><a href="/wiki/The_Ultimate_Entrepreneur" title="The Ultimate Entrepreneur">The Ultimate Entrepreneur</a></i></li> <li><a href="/wiki/VT640" title="VT640">VT640</a></li> <li><a href="/wiki/WPS-8" title="WPS-8">WPS-8</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="3"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Template"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/8/83/Symbol_template_class_pink.svg/16px-Symbol_template_class_pink.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/83/Symbol_template_class_pink.svg/23px-Symbol_template_class_pink.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/83/Symbol_template_class_pink.svg/31px-Symbol_template_class_pink.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a 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