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<title>Compatible Time-Sharing System</title>

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<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Compatible Time-Sharing System</span></span>

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</style><div role="note" class="hatnote navigation-not-searchable">Not to be confused with <a href="CICS" title="CICS">CICS</a>.</div>

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</style><table class="infobox vevent"><tbody><tr><th colspan="2" class="infobox-above" style="background-color: #e0e0e0;">Compatible Time-Sharing System (CTSS)</th></tr><tr><td colspan="2" class="infobox-image"><span typeof="mw:File"></span><div class="infobox-caption">Preamble of two versions of the CTSS scheduler, one in <a href="MAD_(programming_language)" title="MAD (programming language)">MAD</a> and one in <a href="FAP_assembly" class="mw-redirect" title="FAP assembly">FAP</a></div></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Programmer" title="Programmer">Developer</a></th><td class="infobox-data"><a href="MIT_Computation_Center" title="MIT Computation Center">MIT Computation Center</a>, <a href="MIT_Computer_Science_and_Artificial_Intelligence_Laboratory#Project_MAC" title="MIT Computer Science and Artificial Intelligence Laboratory">Project MAC</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Programming_language" title="Programming language">Written in</a></th><td class="infobox-data"><a href="FAP_assembly" class="mw-redirect" title="FAP assembly">FAP assembly</a>, <a href="MAD_(programming_language)" title="MAD (programming language)">MAD</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Working state</th><td class="infobox-data">Discontinued, simulator available</td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Source model</th><td class="infobox-data"><a href="Open_source" title="Open source">Open source</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Initial release</th><td class="infobox-data">1961<span style="display:none"> (<span class="bday dtstart published updated">1961</span>)</span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Marketing target</th><td class="infobox-data">Colleges and universities<sup id="cite_ref-50th_1-0" class="reference"><a href="#cite_note-50th-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Available in</th><td class="infobox-data"><a href="English_language" title="English language">English</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Supported platforms</th><td class="infobox-data"><a href="IBM_7090" title="IBM 7090">IBM 7090</a>, <a href="IBM_7094" class="mw-redirect" title="IBM 7094">IBM 7094</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Kernel_(operating_system)" title="Kernel (operating system)">Kernel</a> type</th><td class="infobox-data"><a href="Monolithic_kernel" title="Monolithic kernel">Monolithic</a>, protected</td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="User_interface" title="User interface">Default<br>user interface</a></th><td class="infobox-data"><a href="Command-line_interface" title="Command-line interface">Command-line interface</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Software_license" title="Software license">License</a></th><td class="infobox-data"><span style="white-space:nowrap;font-size:85%;">[<i><span title="Wikipedia:Cleanup (May 2021)">data missing</span></i>]</span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Succeeded by</th><td class="infobox-data"><a href="Multics" title="Multics">Multics</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Official website</th><td class="infobox-data"><span class="url"><a rel="nofollow" class="external text" href="http://www.cozx.com/dpitts/ibm7090.html">www<wbr>.cozx<wbr>.com<wbr>/dpitts<wbr>/ibm7090<wbr>.html</a></span></td></tr></tbody></table>

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</style><table class="sidebar sidebar-collapse nomobile"><tbody><tr><th class="sidebar-title"><a href="History_of_IBM_mainframe_operating_systems" title="History of IBM mainframe operating systems">History of IBM mainframe operating systems</a></th></tr><tr><td class="sidebar-content">

<div class="sidebar-list mw-collapsible"><div class="sidebar-list-title" style="color: var(--color-base)">Early mainframe computer OSes</div><div class="sidebar-list-content mw-collapsible-content" style="text-align: left">

<li><a href="BESYS" title="BESYS">BESYS</a> (1957)</li>

<li><a href="IBM_7090/94_IBSYS" title="IBM 7090/94 IBSYS">IBSYS</a> (1960)</li>

<li>7040/7044 Operating System (16/32K) (7040-PR-150)</li>

<li>1410/7010 Operating System<br>(1410-PR-155)</li></ul></div></div></td>

</tr><tr><td class="sidebar-content">

<div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="color: var(--color-base)">Miscellaneous S/360 line OSes</div><div class="sidebar-list-content mw-collapsible-content" style="text-align: left">

<li><a href="ORVYL_and_WYLBUR" title="ORVYL and WYLBUR">ORVYL</a> (1967)</li>

<li>RACS (1965)

<ul><li><a href="IBM_Remote_Access_Computing" title="IBM Remote Access Computing">RAX</a> (1966)

<ul><li><a href="MUSIC/SP" title="MUSIC/SP">MUSIC</a> (1972)

<ul><li><a href="MUSIC/SP" title="MUSIC/SP">MUSIC/SP</a> (1985)</li></ul></li></ul></li></ul></li></ul></div></div></td>

</tr><tr><td class="sidebar-content">

<div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="color: var(--color-base)"><a href="DOS/360_and_successors" title="DOS/360 and successors">DOS/360 and successors</a> (1966)</div><div class="sidebar-list-content mw-collapsible-content" style="text-align: left">

<li><a href="DOS/VSE" class="mw-redirect" title="DOS/VSE">DOS/VSE</a> (1979)

</tr><tr><td class="sidebar-content">

<div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="color: var(--color-base)"><a href="OS/360_and_successors" title="OS/360 and successors">OS/360 and successors</a> (1966)</div><div class="sidebar-list-content mw-collapsible-content" style="text-align: left">

<li><a href="MFT_II" class="mw-redirect" title="MFT II">MFT II</a> (1968)

<li><a href="Multiprogramming_with_a_Variable_number_of_Tasks" class="mw-redirect" title="Multiprogramming with a Variable number of Tasks">MVT</a> (1967)

<li><a href="MVS" title="MVS">MVS</a> (OS/VS2R2 and later) (1974)

<li><a href="MVS/SP" class="mw-redirect" title="MVS/SP">MVS/SP</a> Version 1 (1980)</li>

</tr><tr><td class="sidebar-content">

<li>VM/BSE (BSEPP)</li>

</tr><tr><td class="sidebar-content">

</tr><tr><td class="sidebar-content">

<li>MVS/ESA <a href="MVS#MVS.2FESA" title="MVS">OpenEdition</a> (1993)</li>

<li>VM/ESA <a href="VM_(operating_system)#OpenEdition_extensions" title="VM (operating system)">OpenEdition</a> (1995)</li>

<li>OS/390 <a href="UNIX_System_Services" title="UNIX System Services">UNIX System Services</a> (1996)</li>

<li><a href="Linux_on_IBM_Z" title="Linux on IBM Z">Linux</a> (1999)</li>

<li>z/VM <a href="VM_(operating_system)#OpenEdition_extensions" title="VM (operating system)">OpenExtensions</a> (2000)</li>

<li>z/OS <a href="UNIX_System_Services" title="UNIX System Services">UNIX System Services</a> (2001)</li>

<li><a href="OpenSolaris_for_System_z" title="OpenSolaris for System z">OpenSolaris</a> (2008)</li></ul></div></div></td>

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<p>The <b>Compatible Time-Sharing System</b> (<b>CTSS</b>) was the first general purpose <a href="Time-sharing" title="Time-sharing">time-sharing</a> <a href="Operating_system" title="Operating system">operating system</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><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> Compatible Time Sharing referred to time sharing which was compatible with <a href="Batch_processing" title="Batch processing">batch processing</a>; it could offer both time sharing and batch processing concurrently.

</p><p>CTSS was developed at the <a href="MIT_Computation_Center" title="MIT Computation Center">MIT Computation Center</a> ("Comp Center"). CTSS was first demonstrated on MIT's modified <a href="IBM_709" title="IBM 709">IBM 709</a> in November 1961. The hardware was replaced with a modified <a href="IBM_7090" title="IBM 7090">IBM 7090</a> in 1962 and later a modified <a href="IBM_7094" class="mw-redirect" title="IBM 7094">IBM 7094</a> called the "blue machine" to distinguish it from the Project MAC CTSS IBM 7094. Routine service to MIT Comp Center users began in the summer of 1963 and was operated there until 1968.

</p><p>A second deployment of CTSS on a separate IBM 7094 that was received in October 1963 (the "red machine") was used early on in <a href="MIT_Computer_Science_and_Artificial_Intelligence_Laboratory#Project_MAC" title="MIT Computer Science and Artificial Intelligence Laboratory">Project MAC</a> until 1969 when the red machine was moved to the Information Processing Center<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> and operated until July 20, 1973. CTSS ran on only those two machines; however, there were remote CTSS users outside of MIT including ones in California, South America, the <a href="University_of_Edinburgh" title="University of Edinburgh">University of Edinburgh</a> and the <a href="University_of_Oxford" title="University of Oxford">University of Oxford</a>.<sup id="cite_ref-50th_1-1" class="reference"><a href="#cite_note-50th-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-ctsspg69_5-0" class="reference"><a href="#cite_note-ctsspg69-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup>

</p>

<div class="mw-heading mw-heading2"><h2 id="History">History</h2></div>

<p><a href="John_Backus" title="John Backus">John Backus</a> said in the 1954 summer session at <a href="Massachusetts_Institute_of_Technology" title="Massachusetts Institute of Technology">MIT</a> that "By time sharing, a big computer could be used as several small ones; there would need to be a reading station for each user".<sup id="cite_ref-jbackus_6-0" class="reference"><a href="#cite_note-jbackus-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> Computers at that time, like <a href="IBM_704" title="IBM 704">IBM 704</a>, were not powerful enough to implement such system, but at the end of 1958, MIT's Computation Center nevertheless added a typewriter input to its 704 with the intent that a programmer or operator could "obtain additional answers from the machine on a time-sharing basis with other programs using the machine simultaneously".<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 June 1959, <a href="Christopher_Strachey" title="Christopher Strachey">Christopher Strachey</a> published a paper "Time Sharing in Large Fast Computers" at the <a href="International_Federation_for_Information_Processing#History" title="International Federation for Information Processing">UNESCO Information Processing Conference</a> in Paris, where he envisaged a programmer <a href="Debugging" title="Debugging">debugging</a> a program at a console (like a <a href="Teleprinter" title="Teleprinter">teletype</a>) connected to the computer, while another program was running in the computer at the same time.<sup id="cite_ref-ctsspg63_8-0" class="reference"><a href="#cite_note-ctsspg63-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-mccarthyts_9-0" class="reference"><a href="#cite_note-mccarthyts-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> Debugging programs was an important problem at that time, because with batch processing, it then often took a day from submitting a changed code, to getting the results. <a href="John_McCarthy_(computer_scientist)" title="John McCarthy (computer scientist)">John McCarthy</a> wrote a memo about that at MIT, after which a preliminary study committee and a working committee were established at MIT, to develop time sharing. The committees envisaged many users using the computer at the same time, decided the details of implementing such system at MIT, and started the development of the system.

</p>

<div class="mw-heading mw-heading3"><h3 id="Experimental_Time_Sharing_System">Experimental Time Sharing System</h3></div>

<p>By July, 1961<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> a few time sharing commands had become operational on the Computation Center's IBM 709, and in November 1961, <a href="Fernando_J._Corbat%C3%B3" title="Fernando J. Corbató">Fernando J. Corbató</a> demonstrated at MIT what was called the <i>Experimental Time-Sharing System</i>. On May 3, 1962, F. J. Corbató, M. M. Daggett and R. C. Daley published a paper about that system at the <a href="Joint_Computer_Conference" title="Joint Computer Conference">Spring Joint Computer Conference</a>.<sup id="cite_ref-etss_11-0" class="reference"><a href="#cite_note-etss-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> "[M]ajor portions of [the CTSS system were largely prepared by]: Mrs. Marjorie M. Daggett, Mr. Robert Daley, Mr. Robert Creasy, Mrs. Jessica Hellwig, Mr. Richard Orenstein, and Professor F. J. Corbató".<sup id="cite_ref-CorbatVii_12-0" class="reference"><a href="#cite_note-CorbatVii-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup>

</p><p>The system used an <a href="IBM_7090" title="IBM 7090">IBM 7090</a>, modified by Herbert M. Teager, with added 3 <a href="Friden_Flexowriter" title="Friden Flexowriter">Flexowriters</a> for user consoles, and maybe a <a href="Programmable_interval_timer" title="Programmable interval timer">timer</a>. Each of the 3 users had two <a href="IBM_729" title="IBM 729">tape units</a>, one for the user's file directory, and one for dumping the core (program in memory). There was also one tape unit for the system commands, there were no disk drives. The <a href="Magnetic-core_memory" title="Magnetic-core memory">memory</a> was 27 k words (36-bit words) for users, and 5 k words for the supervisor (operating system). The input from the consoles was written to the buffers in the supervisor, by <a href="Interrupt" title="Interrupt">interrupts</a>, and when a <a href="Carriage_return" title="Carriage return">return character</a> was received, the control was given to the supervisor, which dumped the running code to the tape and decided what to run next. The console commands implemented at the time were <i>login, logout, input, edit, fap, mad, madtrn, load, use, start, skippm, listf, printf, xdump</i> and <i>xundump</i>.

</p><p>This became the initial version of the Compatible Time-Sharing System. This was apparently the first ever public demonstration of <a href="Time-sharing" title="Time-sharing">time-sharing</a>; there are other claims, but they refer to special-purpose systems, or with no known papers published. The "compatibility" of CTSS was with background jobs run on the same computer, which generally used more of the compute resources than the time-sharing functions.

</p>

<div class="mw-heading mw-heading2"><h2 id="Applications">Applications</h2></div>

<div class="mw-heading mw-heading3"><h3 id="DOTSYS_and_BRAILLEMBOSS">DOTSYS and BRAILLEMBOSS</h3></div>

<p>The first version of the DOTSYS <a href="Braille" title="Braille">braille</a> translation software ran on CTSS and could output to a BRAILLEMBOSS braille page printer.<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> DOTSYS on CTSS was first demonstrated on August 18, 1966, as part of a feasibility study where teletypesetter tape, in the form of news, was converted to Grade 2 Braille. The following month the feasibility of converting textbook information on teletypesetter tape to error-free Grade 2 Braille was successfully demonstrated.<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> As MIT CTSS was an academic system, a research vehicle and not a system for commercial computing, two years later a version of DOTSYS stripped of CTSS dependencies for software portability was used on an IBM 709 at the <a href="American_Printing_House_for_the_Blind" title="American Printing House for the Blind">American Printing House for the Blind</a> to print the first braille edition of a book produced from teletypesetter input, only a few weeks after the ink-print version.<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> The following year, on CTSS, a demonstration of printing mathematical tables in braille was shown. A short FORTRAN II program was written to produce a conversion table from inches to millimeters in braille via the BRAILLEMBOSS braille page printer.<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup>

</p>

<div class="mw-heading mw-heading3"><h3 id="Intrex">Intrex</h3></div>

<p>The Intrex Retrieval System ran on CTSS. Intrex was an experimental, pilot-model machine-oriented bibliographic storage and retrieval system with a database that stored a catalog of roughly 15,000 journal articles. It was used to develop and test concepts for library automation.<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><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><sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> A deployment of three BRISC <a href="Cathode-ray_tube" title="Cathode-ray tube">CRT</a> consoles for testing at the MIT Engineering Library showed that it was preferred over two other systems, ARDS and DATEL.<sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup>

</p>

<div class="mw-heading mw-heading2"><h2 id="Features">Features</h2></div>

<ul><li>The original <a href="ELIZA" title="ELIZA">ELIZA</a> ran on CTSS.<sup id="cite_ref-50th_1-2" class="reference"><a href="#cite_note-50th-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup></li>

<li>CTSS was the first computer system to implement <a href="Password" title="Password">password</a> login.<sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup></li>

<li>CTSS had one of the first computerized text editing and formatting utilities, called <a href="TYPSET_and_RUNOFF" title="TYPSET and RUNOFF">TYPSET and RUNOFF</a> (the successors of MEMO, MODIFY and DITTO).</li>

<li>CTSS had one of the first inter-user messaging implementations, pioneering <a href="Electronic_mail" class="mw-redirect" title="Electronic mail">electronic mail</a>.<sup id="cite_ref-thvv_24-0" class="reference"><a href="#cite_note-thvv-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup></li>

<li>CTSS had one of the first <a href="Instant_messaging" title="Instant messaging">instant messaging</a> systems similar to <a href="Write_(Unix)" title="Write (Unix)">write</a>.<sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup></li>

<li>MIT Computation Center staff member <a href="Louis_Pouzin" title="Louis Pouzin">Louis Pouzin</a> created for CTSS a command called <a href="RUNCOM" title="RUNCOM">RUNCOM</a>, which executed a list of commands contained in a file.<sup id="cite_ref-50th_1-3" class="reference"><a href="#cite_note-50th-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> RUNCOM also provided for parameter substitution.<sup id="cite_ref-ctsspg69_5-1" class="reference"><a href="#cite_note-ctsspg69-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> He later created a design for the <a href="Multics" title="Multics">Multics</a> <a href="Shell_(computing)" title="Shell (computing)">shell</a> that was implemented by <a href="Glenda_Schroeder" title="Glenda Schroeder">Glenda Schroeder</a> which in turn inspired Unix <a href="Shell_script" title="Shell script">shell scripts</a>.<sup id="cite_ref-26" class="reference"><a href="#cite_note-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-27" class="reference"><a href="#cite_note-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup></li>

<li>CTSS had an implementation of the text editor <a href="QED_(text_editor)" title="QED (text editor)">QED</a>, the predecessor of <a href="Ed_(text_editor)" class="mw-redirect" title="Ed (text editor)">ed</a>, <a href="Vi_(text_editor)" title="Vi (text editor)">vi</a>, and <a href="Vim_(text_editor)" title="Vim (text editor)">vim</a>, with regular expressions added by <a href="Ken_Thompson" title="Ken Thompson">Ken Thompson</a>.</li></ul>

<div class="mw-heading mw-heading2"><h2 id="Implementation">Implementation</h2></div>

<div class="mw-heading mw-heading3"><h3 id="Kernel">Kernel</h3></div>

<p>CTSS used a modified IBM 7090 mainframe computer<sup id="cite_ref-28" class="reference"><a href="#cite_note-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup> that had two 32,768 (32K) 36-bit-<a href="Word_(computer_architecture)" title="Word (computer architecture)">word</a> banks of <a href="Core_memory" class="mw-redirect" title="Core memory">core memory</a> instead of the default configuration which provides only one.<sup id="cite_ref-osc_29-0" class="reference"><a href="#cite_note-osc-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-30" class="reference"><a href="#cite_note-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup> One bank was reserved for the time-sharing supervisory program, the other for user programs. CTSS had a protected-mode kernel; the supervisor's functions in the A-core (memory bank A) could be called only by software interrupts, as in modern operating systems. Causing memory-protection interrupts were used for software interrupts.<sup id="cite_ref-ctsspg63_8-1" class="reference"><a href="#cite_note-ctsspg63-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> <a href="Central_processing_unit" title="Central processing unit">Processor</a> allocation <a href="Scheduling_(computing)" title="Scheduling (computing)">scheduling</a> with a quantum time unit 200 ms, was controlled by a <a href="Multilevel_feedback_queue" title="Multilevel feedback queue">multilevel feedback queue</a>.<sup id="cite_ref-osc_29-1" class="reference"><a href="#cite_note-osc-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> It also had some special memory-management hardware,<sup id="cite_ref-multiprogramming-package_31-0" class="reference"><a href="#cite_note-multiprogramming-package-31"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup> a clock interrupt,<sup id="cite_ref-32" class="reference"><a href="#cite_note-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> and the ability to trap certain instructions.<sup id="cite_ref-multiprogramming-package_31-1" class="reference"><a href="#cite_note-multiprogramming-package-31"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup>

</p>

<div class="mw-heading mw-heading3"><h3 id="Supervisor_subroutines">Supervisor subroutines</h3></div>

<ul><li>RDFLXA – Read an input line from console</li>

<li>WRFLX – Write an output line to console</li>

<li>DEAD – Put the user into dead status, with no program in memory</li>

<li>DORMNT – Put the user into dormant status, with program in memory</li>

<li>GETMEM – Get the size of the memory allocation</li>

<li>SETMEM – Set the size of the memory allocation</li>

<li>TSSFIL – Get access to the CTSS system files on the disk</li>

<li>USRFIL – Change back to user's own directory</li>

<li>GETBRK – Get the instruction location counter at quit</li></ul>

<div class="mw-heading mw-heading3"><h3 id="Programming_languages">Programming languages</h3></div>

<p>CTSS at first had only an assembler, <a href="FORTRAN_Assembly_Program" class="mw-redirect" title="FORTRAN Assembly Program">FAP</a>, and a compiler, MAD. Also, <a href="Fortran#FORTRAN_II" title="Fortran">Fortran II</a> code could be translated into MAD code by using MADTRN. Later half of the system was written in MAD. Later there were other programming languages including <a href="COMIT" title="COMIT">COMIT II</a>, <a href="Lisp_(programming_language)" title="Lisp (programming language)">LISP 1.5</a> and a version of <a href="ALGOL" title="ALGOL">ALGOL</a>.

</p>

<div class="mw-heading mw-heading3"><h3 id="File_system">File system</h3></div>

<p>Each user had their own <a href="Directory_(computing)" title="Directory (computing)">directory</a>, and there were also shared directories for groups of people with the same "problem number". Each <a href="Computer_file" title="Computer file">file</a> had two names, the second indicating its type as did the <a href="Filename_extension" title="Filename extension">extension</a> in later systems. At first, each file could have one of four modes: temporary, permanent, read-only class 1, and read-only class 2. Read-only class 1 allowed the user to change the mode of the file. Files could also be symbolically linked between directories. A directory listing by <i>listf</i>:

</p>

<pre> 10 FILES 20 TRACKS USED

DATE NAME MODE NO. TRACKS

5/20/63 MAIN MAD P 15

5/17/63 DPFA SYMTB P 1

5/17/63 DPFA BSS P 1

5/17/63 DPFA FAP P 2

</pre>

<div class="mw-heading mw-heading3"><h3 id="Peripherals">Peripherals</h3></div>

<p>Input-output hardware was mostly standard IBM <a href="Peripheral" title="Peripheral">peripherals</a>. These included six data channels connecting to:

</p>

<ul><li>Printers, <a href="Punched_card" title="Punched card">punched card</a> readers and punches</li>

<li><a href="IBM_729" title="IBM 729">IBM 729</a> tape drives, an <a href="IBM_1301" class="mw-redirect" title="IBM 1301">IBM 1301</a> disk storage, later upgraded to an <a href="IBM_1302" class="mw-redirect" title="IBM 1302">IBM 1302</a>, with 38 million word capacity</li>

<li>An <a href="IBM_7320" class="mw-redirect" title="IBM 7320">IBM 7320</a> drum memory with 186K words that could load a 32K-word memory bank in one second (later upgraded to 0.25 seconds)</li>

<li>Two custom high-speed vector graphics displays<sup id="cite_ref-33" class="reference"><a href="#cite_note-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup></li>

<li>An IBM 7750 transmission control unit capable of supporting up to 112 <a href="Teleprinter" title="Teleprinter">teleprinter</a> terminals, including <a href="IBM_1050" title="IBM 1050">IBM 1050</a> <a href="Selectric" class="mw-redirect" title="Selectric">Selectrics</a> and <a href="Teletype_Corporation#Teletype_Corporation" title="Teletype Corporation">Model 35s</a>. Some of the terminals were located remotely, and the system could be accessed using the public <a href="Telex" title="Telex">Telex and TWX</a> networks.</li></ul>

<div class="mw-heading mw-heading2"><h2 id="Influences">Influences</h2></div>

<p>CTSS was described in a paper presented at the 1962 <a href="Joint_Computer_Conference" title="Joint Computer Conference">Spring Joint Computer Conference</a>, and greatly influenced the design of other early time-sharing systems.

</p><p><a href="Maurice_Wilkes" title="Maurice Wilkes">Maurice Wilkes</a> witnessed CTSS and the design of the <a href="Titan_(1963_computer)" title="Titan (1963 computer)">Titan Supervisor</a> was inspired by that.<sup id="cite_ref-34" class="reference"><a href="#cite_note-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-35" class="reference"><a href="#cite_note-35"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup>

</p><p><a href="Dennis_Ritchie" title="Dennis Ritchie">Dennis Ritchie</a> wrote in 1977 that UNIX could be seen as a "modern implementation" of CTSS.<sup id="cite_ref-36" class="reference"><a href="#cite_note-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> Multics, which was also developed by Project MAC, was started in the 1960s as a successor to CTSS – and in turn inspired the development of Unix in 1969. One of the technical terms inherited by these systems from CTSS is <i><a href="Daemon_(computing)" title="Daemon (computing)">daemon</a></i>.

</p><p><a href="Incompatible_Timesharing_System" title="Incompatible Timesharing System">Incompatible Timesharing System</a> (ITS), another early, revolutionary, and influential MIT time-sharing system, was produced by people who disagreed with the direction taken by CTSS, and later, Multics; the name was a <a href="Parody" title="Parody">parody</a> of "CTSS", as later the name "Unix" was a parody of "Multics".<sup id="cite_ref-LevyWL_37-0" class="reference"><a href="#cite_note-LevyWL-37"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup> CTSS and ITS file systems have a number of design elements in common. Both have an M.F.D. (master file directory) and one or more U.F.D. (user file directories). Neither of them have nested directories (sub-directories). Both have file names consisting of two names which are a maximum of six-characters long. Both support linked files.<sup id="cite_ref-ctsspg69_5-2" class="reference"><a href="#cite_note-ctsspg69-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup>

</p>

<ul><li><a href="PLATO_(computer_system)" title="PLATO (computer system)">PLATO (computer system)</a></li>

<li><a href="Timeline_of_operating_systems" title="Timeline of operating systems">Timeline of operating systems</a></li>

<li><a href="Time-sharing_system_evolution" title="Time-sharing system evolution">Time-sharing system evolution</a></li></ul>

<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

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</style><cite id="CITEREFWaldenVan_Vleck2011" class="citation web cs1">Walden, David; <a href="Tom_Van_Vleck" title="Tom Van Vleck">Van Vleck, Tom</a>, eds. (2011). <a rel="nofollow" class="external text" href="https://multicians.org/thvv/compatible-time-sharing-system.pdf">"Compatible Time-Sharing System (1961-1973): Fiftieth Anniversary Commemorative Overview"</a> <span class="cs1-format">(PDF)</span>. IEEE Computer Society. <a rel="nofollow" class="external text" href="https://ghostarchive.org/archive/20221009/https://multicians.org/thvv/compatible-time-sharing-system.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on October 9, 2022<span class="reference-accessdate">. Retrieved <span class="nowrap">February 20,</span> 2022</span>.</cite></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"><cite id="CITEREFNoren2009" class="citation web cs1">Noren, Allen (April 10, 2009). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20170630062507/http://broadcast.oreilly.com/2009/04/an-interview-with-brian-kernig.html">"An Interview with Brian Kernighan: Breeding Little Languages"</a>. <i>O'Reilly Community</i>. Archived from <a rel="nofollow" class="external text" href="http://broadcast.oreilly.com/2009/04/an-interview-with-brian-kernig.html">the original</a> on June 30, 2017<span class="reference-accessdate">. Retrieved <span class="nowrap">July 28,</span> 2023</span>. <q>I was using CTSS, the first time-sharing system</q></cite></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"><cite id="CITEREFSinghMorgan1971" class="citation report cs1">Singh, Jai P.; Morgan, Robert P. (October 1971). <a rel="nofollow" class="external text" href="https://files.eric.ed.gov/fulltext/ED057575.pdf">Educational Computer Utilization and Computer Communications</a> <span class="cs1-format">(PDF)</span> (Report). St. Louis, MO: Washington University. p. 13. National Aeronautics and Space Administration Grant No. Y/NGL-26-008-054. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20230319003544/https://files.eric.ed.gov/fulltext/ED057575.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on March 19, 2023<span class="reference-accessdate">. Retrieved <span class="nowrap">March 8,</span> 2022</span>. <q>Much of the early development in the time-sharing field took place on university campuses.<sup>8</sup> Notable examples are the CTSS (Compatible Time-Sharing System) at MIT, which was the first general purpose time-sharing system...</q></cite></span>

</li>

<li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><cite class="citation news cs1"><a rel="nofollow" class="external text" href="https://www.nytimes.com/1968/11/11/archives/new-information-center-will-open-at-mit-today.html">"New Information Center Will Open at MIT Today"</a>. <i><a href="The_New_York_Times" title="The New York Times">The New York Times</a></i>. November 11, 1968.</cite></span>

</li>

<li id="cite_note-ctsspg69-5"><span class="mw-cite-backlink">^ <a href="#cite_ref-ctsspg69_5-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-ctsspg69_5-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-ctsspg69_5-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><cite id="CITEREFCrisman1969" class="citation book cs1">Crisman, Patricia A., ed. (December 31, 1969). <a rel="nofollow" class="external text" href="http://www.bitsavers.org/pdf/mit/ctss/CTSS_ProgrammersGuide_Dec69.pdf"><i>The Compatible Time-Sharing System, A Programmer's Guide</i></a> <span class="cs1-format">(PDF)</span> (Second ed.). The M.I.T Computation Center. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20240625150328/http://www.bitsavers.org/pdf/mit/ctss/CTSS_ProgrammersGuide_Dec69.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on June 25, 2024<span class="reference-accessdate">. Retrieved <span class="nowrap">March 10,</span> 2022</span>.</cite></span>

</li>

<li id="cite_note-jbackus-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-jbackus_6-0">^</a></b></span> <span class="reference-text"><cite id="CITEREFBackus1954" class="citation book cs1">Backus, John (1954). <a rel="nofollow" class="external text" href="https://bitsavers.org/pdf/mit/whirlwind/summer_session_1954/Digital_Computers_Advanced_Coding_Techniques_Summer_1954.pdf"><i>Digital Computer Advanced Coding Techniques</i></a> <span class="cs1-format">(PDF)</span>. MIT. pp. <span class="nowrap">16-2 –</span> <span class="nowrap">16-3</span>.</cite> The first known description of computer time-sharing.</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"><cite class="citation report cs1"><a rel="nofollow" class="external text" href="https://archive.org/details/cooperating-colleges-progress-4">Progress Report Number 4 of the Research and Educational Activities in Machine Computation by the Cooperating Colleges of New England</a> (Report). December 1958.</cite></span>

</li>

<li id="cite_note-ctsspg63-8"><span class="mw-cite-backlink">^ <a href="#cite_ref-ctsspg63_8-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-ctsspg63_8-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><cite id="CITEREFF._J._CorbatóM._M._DaggettR._C._DaleyR._J._Creasy1963" class="citation book cs1">F. J. Corbató; M. M. Daggett; R. C. Daley; R. J. Creasy; J. D. Hellwig; R. H. Orenstein; L. K. Korn (1963). <a rel="nofollow" class="external text" href="http://www.bitsavers.org/pdf/mit/ctss/CTSS_ProgrammersGuide.pdf"><i>The Compatible Time-Sharing System A Programmer's Guide</i></a> <span class="cs1-format">(PDF)</span>. MIT Press. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-0-262-03008-3</bdi>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20120527174321/http://www.bitsavers.org/pdf/mit/ctss/CTSS_ProgrammersGuide.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on 2012-05-27<span class="reference-accessdate">. Retrieved <span class="nowrap">2007-02-04</span></span>.</cite> <span class="cs1-hidden-error citation-comment"><code class="cs1-code">{{cite book}}</code>: </span><span class="cs1-hidden-error citation-comment">ISBN / Date incompatibility (help)</span> Describe the system and its commands</span>

</li>

<li id="cite_note-mccarthyts-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-mccarthyts_9-0">^</a></b></span> <span class="reference-text"><cite id="CITEREFJohn_McCarthy1983" class="citation web cs1">John McCarthy (1983). <a rel="nofollow" class="external text" href="https://www-formal.stanford.edu/jmc/history/timesharing/timesharing.html">"Reminiscences on the History of Time Sharing"</a>. <i>Stanford University</i>.</cite></span>

</li>

<li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><cite class="citation report cs1"><a rel="nofollow" class="external text" href="https://archive.org/details/cooperating-colleges-progress-9">Progress Report Number 9 of the Research and Educational Activities in Machine Computation by the Cooperating Colleges of New England</a> (Report). July 1961.</cite></span>

</li>

<li id="cite_note-etss-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-etss_11-0">^</a></b></span> <span class="reference-text"><cite id="CITEREFCorbatóMerwin_DaggettDaley1962" class="citation web cs1">Corbató, Fernando J.; Merwin Daggett, Marjorie; Daley, Robert C. (May 3, 1962). <a rel="nofollow" class="external text" href="http://larch-www.lcs.mit.edu:8001/~corbato/sjcc62/">"An Experimental Time-Sharing System"</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20090906104446/http://larch-www.lcs.mit.edu:8001/~corbato/sjcc62/">Archived</a> from the original on September 6, 2009<span class="reference-accessdate">. Retrieved <span class="nowrap">February 25,</span> 2022</span>.</cite></span>

</li>

<li id="cite_note-CorbatVii-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-CorbatVii_12-0">^</a></b></span> <span class="reference-text">Corbató, p. vii</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"><cite id="CITEREFMann1986" class="citation journal cs1">Mann, Robert W (October 1986). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=pxte14KRBokC&q=%22subsequently%20called%22">"Selected Perspectives on a Quarter Century of Rehabilitation Engineering"</a>. <i><a href="Journal_of_Rehabilitation_Research_and_Development" title="Journal of Rehabilitation Research and Development">Journal of Rehabilitation Research and Development</a></i>. <b>23</b> (4): <span class="nowrap">1–</span>6. <a href="PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/3820117">3820117</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20230920214023/https://books.google.com/books?id=pxte14KRBokC&q=%22subsequently%20called%22">Archived</a> from the original on September 20, 2023<span class="reference-accessdate">. Retrieved <span class="nowrap">March 13,</span> 2022</span>. <q>The modular software program for braille translation and automatic management of input and output modes, subsequently called "DOTSYS" was underway...</q></cite></span>

</li>

<li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"><cite id="CITEREFDalrymple1973" class="citation web cs1">Dalrymple, George F. (February 26, 1973). <a rel="nofollow" class="external text" href="https://files.eric.ed.gov/fulltext/ED074663.pdf">"Final Report Development and Demonstration of Communication Systems for the Blind and Deaf/Blind. Braille Communication Terminals and Tactile Paging Systems"</a> <span class="cs1-format">(PDF)</span>. The Sensory Aids Evaluation and Development Center Massachusetts Institute of Technology. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20240625150301/https://files.eric.ed.gov/fulltext/ED074663.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on June 25, 2024<span class="reference-accessdate">. Retrieved <span class="nowrap">March 13,</span> 2022</span>.</cite></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"><cite class="citation report cs1"><a rel="nofollow" class="external text" href="https://files.eric.ed.gov/fulltext/ED015609.pdf">Evaluation and Development of Sensory Aids and Devices. Final Report</a> <span class="cs1-format">(PDF)</span> (Report). The Sensory Aids Evaluation and Development Center Massachusetts Institute of Technology. April 3, 1967. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20240625150302/https://files.eric.ed.gov/fulltext/ED015609.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on June 25, 2024<span class="reference-accessdate">. Retrieved <span class="nowrap">March 13,</span> 2022</span>. <q>Demonstration on CTSS of teletypesetter-to-Grade 2 Braille</q></cite></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"><cite class="citation report cs1"><a rel="nofollow" class="external text" href="https://files.eric.ed.gov/fulltext/ED031016.pdf">Final Report to Social Rehabilitation Administration Department of Health, Education and Welfare Washington, D.C.</a> <span class="cs1-format">(PDF)</span> (Report). The Sensory Aids Evaluation and Development Center Massachusetts Institute of Technology. April 30, 1969<span class="reference-accessdate">. Retrieved <span class="nowrap">March 13,</span> 2022</span>. <q>These programs, originally written to operate on the CTSS system at M.I.T., were modified for the 709 at the American Printing House for the Blind. This involved rewriting those parts of the programs which were CTSS-dependent.</q></cite></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"><cite class="citation report cs1"><a rel="nofollow" class="external text" href="https://files.eric.ed.gov/fulltext/ED074663.pdf">Conversion Table, Inches to Millimeters a Braille Computer Generated Mathematical Table</a> <span class="cs1-format">(PDF)</span> (Report). The Sensory Aids Evaluation and Development Center Massachusetts Institute of Technology. August 14, 1970<span class="reference-accessdate">. Retrieved <span class="nowrap">March 13,</span> 2022</span>.</cite></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"><cite id="CITEREFOverhage1971" class="citation report cs1">Overhage, Carl F. J. (1971). <a rel="nofollow" class="external text" href="https://files.eric.ed.gov/fulltext/ED056732.pdf">Project Intrex - A Brief Description</a> <span class="cs1-format">(PDF)</span>. <i><a href="Education_Resources_Information_Center" title="Education Resources Information Center">ERIC</a></i> (Report). MIT<span class="reference-accessdate">. Retrieved <span class="nowrap">March 8,</span> 2022</span>.</cite></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"><cite id="CITEREFKehr1972" class="citation report cs1">Kehr, James E. (September 1972). <a rel="nofollow" class="external text" href="https://files.eric.ed.gov/fulltext/ED070506.pdf">Intrex Buffer-Controller Display System Operation and Software</a> <span class="cs1-format">(PDF)</span>. <i><a href="Education_Resources_Information_Center" title="Education Resources Information Center">ERIC</a></i> (Report). MIT. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20240625150302/https://files.eric.ed.gov/fulltext/ED070506.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on June 25, 2024<span class="reference-accessdate">. Retrieved <span class="nowrap">March 8,</span> 2022</span>.</cite></span>

</li>

<li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text"><cite id="CITEREFHurlburt1971" class="citation report cs1">Hurlburt, Charles E. (September 15, 1971). <a rel="nofollow" class="external text" href="https://files.eric.ed.gov/fulltext/ED057829.pdf">The Intrex Retrieval System Software</a> <span class="cs1-format">(PDF)</span>. <i>ERIC</i> (Report). MIT. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20240625150302/https://files.eric.ed.gov/fulltext/ED057829.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on June 25, 2024<span class="reference-accessdate">. Retrieved <span class="nowrap">March 8,</span> 2022</span>.</cite></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"><cite id="CITEREFOverhage1972" class="citation report cs1">Overhage, Carl F. J. (March 15, 1972). <a rel="nofollow" class="external text" href="https://files.eric.ed.gov/fulltext/ED060899.pdf">Project Intrex. Semiannual Activity Report, 15 September 1971 - 15 March 1972</a> <span class="cs1-format">(PDF)</span>. <i>ERIC</i> (Report). MIT. Intrex PR-13. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20240625150303/https://files.eric.ed.gov/fulltext/ED060899.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on June 25, 2024<span class="reference-accessdate">. Retrieved <span class="nowrap">March 17,</span> 2022</span>. <q>Since September 27, 1971, the BRISC has been available at the Engineering Library station on a two-hours a day basis.</q></cite></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"><cite id="CITEREFMcMillan2012" class="citation web cs1">McMillan, Robert (27 January 2012). <a rel="nofollow" class="external text" href="https://www.wired.com/2012/01/computer-password/">"The World's First Computer Password? It Was Useless Too"</a>. <a href="Wired_magazine" class="mw-redirect" title="Wired magazine">Wired magazine</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20240625150807/https://www.wired.com/2012/01/computer-password/">Archived</a> from the original on 25 June 2024<span class="reference-accessdate">. Retrieved <span class="nowrap">22 March</span> 2019</span>.</cite></span>

</li>

<li id="cite_note-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-23">^</a></b></span> <span class="reference-text"><cite id="CITEREFHunt2017" class="citation web cs1">Hunt, Troy (26 July 2017). <a rel="nofollow" class="external text" href="https://www.troyhunt.com/passwords-evolved-authentication-guidance-for-the-modern-era/">"Passwords Evolved: Authentication Guidance for the Modern Era"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">22 March</span> 2019</span>.</cite></span>

</li>

<li id="cite_note-thvv-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-thvv_24-0">^</a></b></span> <span class="reference-text"><a href="Tom_Van_Vleck" title="Tom Van Vleck">Tom Van Vleck</a>'s memoir of <a rel="nofollow" class="external text" href="http://www.multicians.org/thvv/mail-history.html">The History of Electronic Mail</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20171202025034/http://www.multicians.org/thvv/mail-history.html">Archived</a> 2017-12-02 at the <a href="Wayback_Machine" title="Wayback Machine">Wayback Machine</a></span>

</li>

<li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text"><cite id="CITEREFFetter2019" class="citation book cs1">Fetter, Mirko (2019). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=knqIDwAAQBAJ&dq=%22ctss%22+%22write+command%22&pg=PA38"><i>New Concepts for Presence and Availability in Ubiquitous and Mobile Computing</i></a>. <a href="University_of_Bamberg" title="University of Bamberg">University of Bamberg</a> Press. p. 38. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-3-86309-623-6</bdi>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20240625150926/https://books.google.com/books?id=knqIDwAAQBAJ&dq=%22ctss%22+%22write+command%22&pg=PA38#v=onepage&q=%22ctss%22%20%22write%20command%22&f=false">Archived</a> from the original on 2024-06-25<span class="reference-accessdate">. Retrieved <span class="nowrap">2023-03-19</span></span>. <q>The basic concept of sending instantaneously messages to logged in users came with ... CTSS ...</q></cite></span>

</li>

<li id="cite_note-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-26">^</a></b></span> <span class="reference-text"><cite id="CITEREFPouzin" class="citation web cs1"><a href="Louis_Pouzin" title="Louis Pouzin">Pouzin, Louis</a>. <a rel="nofollow" class="external text" href="https://www.multicians.org/shell.html">"The Origin of the Shell"</a>. <i>Multicians</i>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20171221142542/http://www.multicians.org/shell.html">Archived</a> from the original on December 21, 2017<span class="reference-accessdate">. Retrieved <span class="nowrap">February 17,</span> 2022</span>.</cite></span>

</li>

<li id="cite_note-27"><span class="mw-cite-backlink"><b><a href="#cite_ref-27">^</a></b></span> <span class="reference-text"><cite id="CITEREFRaymond2003" class="citation book cs1"><a href="Eric_S._Raymond" title="Eric S. Raymond">Raymond, Eric S.</a> (2003). <i>The Art of UNIX Programming</i>. Boston: Pearson Education. p. 234. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-0-13-246588-5</bdi>.</cite></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"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://people.csail.mit.edu/saltzer/Multics/CTSS-Documents/RPQs/RPQs.html">"Documents describing special hardware for CTSS"</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20240625150843/https://people.csail.mit.edu/saltzer/Multics/CTSS-Documents/RPQs/RPQs.html">Archived</a> from the original on 2024-06-25<span class="reference-accessdate">. Retrieved <span class="nowrap">2024-04-21</span></span>.</cite></span>

</li>

<li id="cite_note-osc-29"><span class="mw-cite-backlink">^ <a href="#cite_ref-osc_29-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-osc_29-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><cite id="CITEREFSilberschatzPeterson1988" class="citation book cs1">Silberschatz, Abraham; Peterson, James L. (June 1988). "13: Historical Perspective". <i>Operating System Concepts</i>. Addison-Wesley. p. 514. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>0-201-18760-4</bdi>.</cite></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"><cite class="citation book cs1"><a rel="nofollow" class="external text" href="https://people.csail.mit.edu/saltzer/Multics/CTSS-Documents/RPQs/L22-6636-1.pdf"><i>IBM 7090 and 7094 Data Processing Systems Additional Core Storage - RPO E02120 (7090) Dr RPO E15724 (7094)</i></a> <span class="cs1-format">(PDF)</span>. Special Systems Features Bulletin. IBM. L22-6636-1.</cite></span>

</li>

<li id="cite_note-multiprogramming-package-31"><span class="mw-cite-backlink">^ <a href="#cite_ref-multiprogramming-package_31-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-multiprogramming-package_31-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><cite class="citation book cs1"><a rel="nofollow" class="external text" href="https://people.csail.mit.edu/saltzer/Multics/CTSS-Documents/RPQs/L22-6641-3.pdf"><i>IBM 7090-7094 Multiprogramming Package RPO E07291 (7090) or RPO 880287 (7094)</i></a> <span class="cs1-format">(PDF)</span>. Special Systems Features Bulletin. IBM. L22-6641-3.</cite></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"><cite class="citation book cs1"><a rel="nofollow" class="external text" href="https://people.csail.mit.edu/saltzer/Multics/CTSS-Documents/RPQs/L22-6554-1.pdf"><i>Core Storage Clock and Interval Timer - RPO FB9349</i></a> <span class="cs1-format">(PDF)</span>. Special Systems Features Bulletin. IBM. L22-6554-1. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20230408045855/https://people.csail.mit.edu/saltzer/Multics/CTSS-Documents/RPQs/L22-6554-1.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on 2023-04-08<span class="reference-accessdate">. Retrieved <span class="nowrap">2024-04-21</span></span>.</cite></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"><cite id="CITEREFThornhillStozRossWard1968" class="citation web cs1">Thornhill, D. E.; Stoz, R. H.; Ross, T. T.; Ward, J. E. (1968). <a rel="nofollow" class="external text" href="http://www.bitsavers.org/pdf/mit/lcs/tr/MIT-LCS-TR-056.pdf">"An Integrated Hardware-Software System for Computer Graphics in Time Sharing"</a> <span class="cs1-format">(PDF)</span>. MIT Project MAC. ESL-R-356 and MAC-TR-56<span class="reference-accessdate">. Retrieved <span class="nowrap">February 20,</span> 2022</span>. <q>Console facilities include hardware projection of three-dimensional line drawings, automatic light pen tracking, and a flexible set of knob, switch, and push-button inputs. The console is attached to the Project MAC IBM 7094 Compatible Time-Sharing System either directly or through a PDP-7 Computer.</q></cite></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"><cite id="CITEREFHartley2004" class="citation book cs1"><a href="David_Hartley_(computer_scientist)" title="David Hartley (computer scientist)">Hartley, David</a> (2004). "The Titan Influence". <i>Computer Systems</i>. Springer. pp. <span class="nowrap">103–</span>108. <a href="CiteSeerX_(identifier)" class="mw-redirect" title="CiteSeerX (identifier)">CiteSeerX</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.14.9546">10.1.1.14.9546</a></span>. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-0-387-21821-2</bdi>. <q>Sir Maurice, as he is known today, had been inspired by CTSS to create a time-sharing system</q></cite></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"><cite id="CITEREFFraser2004" class="citation book cs1"><a href="Alexander_G._Fraser" title="Alexander G. Fraser">Fraser, Sandy</a> (2004). "An Historical Connection between Time-Sharing and Virtual Circuits". <i>Computer Systems</i>. Springer. pp. <span class="nowrap">85–</span>88. <a href="CiteSeerX_(identifier)" class="mw-redirect" title="CiteSeerX (identifier)">CiteSeerX</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.14.9546">10.1.1.14.9546</a></span>. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-0-387-21821-2</bdi>. <q>Maurice Wilkes discovered CTSS on a visit to MIT in about 1965, and returned to Cambridge to convince the rest of us that time-sharing was the way forward</q></cite></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"><cite id="CITEREFRitchie1977" class="citation conference cs1"><a href="Dennis_Ritchie" title="Dennis Ritchie">Ritchie, Dennis M.</a> (1977). <a rel="nofollow" class="external text" href="https://www.bell-labs.com/usr/dmr/www/retro.pdf"><i>The Unix Time-sharing System: A retrospective</i></a> <span class="cs1-format">(PDF)</span>. Tenth Hawaii International Conference on the System Sciences. <a rel="nofollow" class="external text" href="https://ghostarchive.org/archive/20221009/https://www.bell-labs.com/usr/dmr/www/retro.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on 2022-10-09<span class="reference-accessdate">. Retrieved <span class="nowrap">2022-02-19</span></span>.</cite></span>

</li>

<li id="cite_note-LevyWL-37"><span class="mw-cite-backlink"><b><a href="#cite_ref-LevyWL_37-0">^</a></b></span> <span class="reference-text"><cite id="CITEREFLevy2010" class="citation book cs1">Levy, Steven (2010). "Winners and Losers". <i>Hackers: Heroes of the Computer Revolution - 25th Anniversary Edition</i> (1st ed.). Sebastopol, California: O'Reilly Media. pp. <span class="nowrap">85–</span>102. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-1-4493-8839-3</bdi>.</cite></span>

</li>

</ol></div></div>

<div class="mw-heading mw-heading2"><h2 id="Further_reading">Further reading</h2></div>

<ul><li><cite id="CITEREFFano1964" class="citation web cs1">Fano, Robert M. (1964). <a rel="nofollow" class="external text" href="http://bitsavers.org/pdf/mit/lcs/tr/MIT-LCS-TR-0012.pdf">"The MAC System: A Progress Report"</a> <span class="cs1-format">(PDF)</span>. <i>BitSavers.Org</i>. MIT Project MAC.</cite></li>

<li><cite id="CITEREFSaltzer1965" class="citation web cs1">Saltzer, Jerome H. (1965). <a rel="nofollow" class="external text" href="http://bitsavers.org/pdf/mit/lcs/tr/MIT-LCS-TR-0016.pdf">"CTSS Technical Notes"</a> <span class="cs1-format">(PDF)</span>. <i>BitSavers.Org</i>. MIT Project MAC.</cite></li>

<li><cite id="CITEREFCorbató1963" class="citation web cs1">Corbató, Fernando J.; et al. (1963). <a rel="nofollow" class="external text" href="https://people.csail.mit.edu/saltzer/CTSS/CTSS-Documents/CTSS_ProgrammersGuide_1963.pdf">"The Compatible Time-Sharing System: A Programmer's Guide (first edition)"</a> <span class="cs1-format">(PDF)</span>. <i>People.CSAIL.MIT.Edu/Saltzer/</i>. MIT Computation Center (MIT Press).</cite></li>

<li><cite id="CITEREFCrisman1965" class="citation web cs1">Crisman, Patricia A., ed. (1965). <a rel="nofollow" class="external text" href="https://people.csail.mit.edu/saltzer/CTSS/CTSS-Documents/CTSS_ProgrammersGuide_1966.pdf">"The Compatible Time-Sharing System: A Programmer's Guide (second edition)"</a> <span class="cs1-format">(PDF)</span>. <i>People.CSAIL.MIT.Edu/Saltzer/</i>. MIT Computation Center (MIT Press).</cite></li>

<li><cite id="CITEREFSaltzer1964" class="citation web cs1">Saltzer, Jerome H. (1964). <a rel="nofollow" class="external text" href="http://web.mit.edu/Saltzer/www/publications/AH.9.01.html">"Manuscript Typing and Editing"</a>. <i>Web.MIT.edu</i>. MIT Computation Center.</cite></li></ul>

<div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2></div>

<ul><li><a rel="nofollow" class="external text" href="http://purl.umn.edu/107476">Oral history interview with John McCarthy</a>, <a href="Charles_Babbage_Institute" class="mw-redirect" title="Charles Babbage Institute">Charles Babbage Institute</a>, University of Minnesota. Discusses computer developments at MIT including time sharing.</li>

<li><a rel="nofollow" class="external text" href="http://purl.umn.edu/107230">Oral history interview with Fernando J. Corbató</a>, <a href="Charles_Babbage_Institute" class="mw-redirect" title="Charles Babbage Institute">Charles Babbage Institute</a>, University of Minnesota. Discusses many computer developments at MIT including CTSS.</li>

<li><a rel="nofollow" class="external text" href="http://purl.umn.edu/107281">Oral history interview with Robert M. Fano</a>, Charles Babbage Institute, University of Minnesota. Discusses computer developments at MIT including CTSS.</li>

<li><a rel="nofollow" class="external text" href="http://www.multicians.org/thvv/7094.html">The IBM 7094 and CTSS</a>: personal memoir of <a href="Tom_Van_Vleck" title="Tom Van Vleck">Tom Van Vleck</a>, a system programmer on CTSS</li>

<li><a rel="nofollow" class="external text" href="http://www.piercefuller.com/library/ctss.html">CTSS Source</a> version MIT8C0 in Paul Pierce's collection.</li>

<li><a rel="nofollow" class="external text" href="http://www.cozx.com/dpitts/ibm7090.html">Dave Pitts' IBM 7094 support</a> – Includes a <a href="License-free_software" title="License-free software">license-free</a> simulator, cross assembler and linker that can be used to build and run CTSS.</li>

<li><a rel="nofollow" class="external text" href="https://github.com/rcornwell/ctss">Richard Cornwell's CTSS sources and binaries</a>, which run on <a href="SIMH" title="SIMH">SIMH</a>. Includes <a href="License-free_software" title="License-free software">license-free</a> <a rel="nofollow" class="external text" href="https://github.com/rcornwell/I7000tools">tools</a></li>

<li><a rel="nofollow" class="external text" href="http://www.cio.com.au/article/325323/cio_blast_from_past:_40_years_multics,_1969-2009">CIO: 40 years of Multics, 1969-2009</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20180623090522/https://www.cio.com.au/article/325323/cio_blast_from_past:_40_years_multics,_1969-2009">Archived</a> 2018-06-23 at the <a href="Wayback_Machine" title="Wayback Machine">Wayback Machine</a>: Interview with CTSS and Multics developer Fernando J. Corbato.</li>

<li><a href="Jerome_Saltzer" class="mw-redirect" title="Jerome Saltzer">Jerome Saltzer</a>'s <a rel="nofollow" class="external text" href="https://people.csail.mit.edu/saltzer/CTSS/CTSS-Documents/">CTSS bookshelf</a> via <a href="CSAIL" class="mw-redirect" title="CSAIL">CSAIL</a>.</li></ul>

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<ul><li><a href="Time-sharing_system_evolution" title="Time-sharing system evolution">Time-sharing system evolution</a></li></ul>

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<ul><li><a href="BBN_Time-Sharing_System" title="BBN Time-Sharing System">BBN Time-Sharing System</a></li>

<li><a href="Berkeley_Timesharing_System" title="Berkeley Timesharing System">Berkeley Timesharing System</a></li>

<li><a href="Burroughs_MCP" title="Burroughs MCP">Burroughs MCP</a></li>

<li><a href="CDC_Kronos" title="CDC Kronos">CDC Kronos</a></li>

<li><a href="Cray_Time_Sharing_System" title="Cray Time Sharing System">Cray Time Sharing System (CTSS)</a></li>

<li><a href="Multiple_Console_Time_Sharing_System" title="Multiple Console Time Sharing System">MCTSS</a></li>

<li><a href="Multics" title="Multics">Multics</a></li>

<li><a href="MUSIC/SP" title="MUSIC/SP">MUSIC/SP</a></li>

<li><a href="NLTSS" title="NLTSS">NLTSS</a></li>

<li><a href="OpenVMS" title="OpenVMS">OpenVMS</a></li>

<li><a href="ORVYL_and_WYLBUR" title="ORVYL and WYLBUR">ORVYL and WYLBUR</a></li>

<li><a href="TENEX_(operating_system)" title="TENEX (operating system)">TENEX</a></li>

<li><a href="WAITS" title="WAITS">WAITS</a></li></ul>

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