37:
2900:
986:
972:
converting textbook information on teletypesetter tape to error-free Grade 2 Braille was successfully demonstrated. 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
856:, 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".
993:
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. A deployment of three
976:
to print the first braille edition of a book produced from teletypesetter input, only a few weeks after the ink-print version. 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
971:
translation software ran on CTSS and could output to a BRAILLEMBOSS braille page printer. 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
1333:
of "CTSS", as later the name "Unix" was a parody of "Multics". 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
1316:
wrote in 1977 that UNIX could be seen as a "modern implementation" of CTSS. 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
1114:
instead of the default configuration which provides only one. 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
879:
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
2335:
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
1209:
in later system. 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
954:; 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.
875:) connected to the computer, while another program was running in the computer at the same time. 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.
828:
until 1969 when the red machine was moved to the
Information Processing Center 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
2105:
1823:
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
1475:
Much of the early development in the time-sharing field took place on university campuses. Notable examples are the CTSS (Compatible Time-Sharing System) at MIT, which was the first general purpose time-sharing
770:
1329:(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
821:
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.
825:
63:
939:
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
927:, 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
931:
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
2618:
2664:
763:
2940:
864:
852:
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". Computers at that time, like
1741:"Final Report Development and Demonstration of Communication Systems for the Blind and Deaf/Blind. Braille Communication Terminals and Tactile Paging Systems"
1714:
2294:
1177:
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
1549:
2418:
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
912:
756:
2195:
1697:
1418:
1727:
The modular software program for braille translation and automatic management of input and output modes, subsequently called "DOTSYS" was underway...
1523:
586:
472:
1217:
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
591:
1606:
1054:, which executed a list of commands contained in a file. RUNCOM also provided for parameter substitution. He later created a design for the
2657:
1392:
1265:
614:
608:
602:
501:
240:
1458:(Report). St. Louis, MO: Washington University. p. 13. National Aeronautics and Space Administration Grant No. Y/NGL-26-008-054.
1651:
Progress Report Number 9 of the
Research and Educational Activities in Machine Computation by the Cooperating Colleges of New England
1570:
Progress Report Number 4 of the
Research and Educational Activities in Machine Computation by the Cooperating Colleges of New England
2085:
495:
950:
This became the initial version of the
Compatible Time-Sharing System. This was apparently the first ever public demonstration of
2945:
2935:
2904:
2650:
1488:
266:
1669:
1902:
1870:
2068:
2018:
824:
A second deployment of CTSS on a separate IBM 7094 that was received in October 1963 (the "red machine") was used early on in
2476:
2411:
2370:
2175:
2099:
1981:
1944:
1907:
1779:
1747:
1600:
1459:
973:
849:
2443:
888:
By July, 1961 a few time sharing commands had become operational on the Computation Center's IBM 709, and in November 1961,
2760:
2041:
998:
consoles for testing at the MIT Engineering Library showed that it was preferred over two other systems, ARDS and DATEL.
2615:
1127:. It also had some special memory-management hardware, a clock interrupt, and the ability to trap certain instructions.
2348:
900:. Robert C. Daley, Peter R. Bos and at least 6 other programmers implemented the operating system, partly based on the
876:
2725:
2228:
1997:
Since September 27, 1971, the BRISC has been available at the Engineering Library station on a two-hours a day basis.
728:
708:
2745:
1842:(Report). The Sensory Aids Evaluation and Development Center Massachusetts Institute of Technology. August 14, 1970
1778:(Report). The Sensory Aids Evaluation and Development Center Massachusetts Institute of Technology. April 3, 1967.
1692:
2285:
2266:
2244:
2141:
1813:(Report). The Sensory Aids Evaluation and Development Center Massachusetts Institute of Technology. April 30, 1969
2750:
2513:
2497:
1808:
Final Report to Social Rehabilitation Administration Department of Health, Education and Welfare Washington, D.C.
1326:
1258:
drum memory with 186K words that could load a 32K-word memory bank in one second (later upgraded to 0.25 seconds)
651:
1280:
2865:
2835:
2755:
2740:
2687:
2570:, Charles Babbage Institute, University of Minnesota. Discusses computer developments at MIT including CTSS.
2191:
1353:
1348:
1586:
F. J. CorbatĂł; M. M. Daggett; R. C. Daley; R. J. Creasy; J. D. Hellwig; R. H. Orenstein; L. K. Korn (1963).
1632:
1426:
1107:
2246:
IBM 7090 and 7094 Data Processing Systems Additional Core Storage - RPO E02120 (7090) Dr RPO E15724 (7094)
896:. On May 3, 1962, F. J. CorbatĂł, M. M. Daggett and R. C. Daley published a paper about that system at the
2815:
2705:
1182:
920:
645:
344:
1514:
384:
317:
79:
42:
1334:
names consisting of two names which are a maximum of six-characters long. Both support linked files.
2561:
2551:
1297:
1124:
897:
156:
2825:
2765:
2735:
2402:
2361:
1201:, and there were also shared directories for groups of people with the same "problem number". Each
1170:
741:
329:
1587:
1115:
modern operating systems. Causing memory-protection interrupts were used for software interrupts.
2930:
2925:
2700:
1385:
1343:
1283:. Some of the terminals were located remotely, and the system could be accessed using the public
1116:
830:
2850:
2785:
2397:
2356:
2117:
The basic concept of sending instantaneously messages to logged in users came with ... CTSS ...
1120:
901:
806:
447:
425:
419:
376:
323:
272:
177:
59:
1650:
1569:
889:
2870:
2810:
2607:
2593:
2319:
2091:
1307:
1198:
620:
596:
580:
439:
2632:
2377:
Sir Maurice, as he is known today, had been inspired by CTSS to create a time-sharing system
1746:. The Sensory Aids Evaluation and Development Center Massachusetts Institute of Technology.
941:
login, logout, input, edit, fap, mad, madtrn, load, use, start, skippm, listf, printf, xdump
2529:
928:
860:
834:
735:
715:
70:
2554:, University of Minnesota. Discusses computer developments at MIT including time sharing.
8:
2830:
2389:
1386:"Compatible Time-Sharing System (1961-1973): Fiftieth Anniversary Commemorative Overview"
2564:, University of Minnesota. Discusses many computer developments at MIT including CTSS.
1837:
Conversion Table, Inches to Millimeters a Braille Computer Generated Mathematical Table
1493:
1319:
1206:
916:
2472:
2407:
2366:
2224:
2219:
Silberschatz, Abraham; Peterson, James L. (June 1988). "13: Historical Perspective".
2171:
2095:
1706:
1665:
1596:
1085:
1073:
1058:
1036:
1022:
1021:
CTSS had one of the first computerized text editing and formatting utilities, called
549:
278:
192:
162:
2800:
2676:
2065:
2010:
1081:
1077:
1062:
995:
799:
795:
335:
184:
135:
130:
2434:
1970:
1933:
1894:
1862:
1836:
1807:
1772:
1740:
1452:
1106:
CTSS used a modified IBM 7090 mainframe computer that had two 32,768 (32K) 36-bit-
2642:
2622:
2163:
2072:
1585:
1029:
936:
2583:
1664:
CorbatĂł, Fernando J.; Merwin Daggett, Marjorie; Daley, Robert C. (May 3, 1962).
694:
688:
36:
2628:
2430:
2014:
1313:
1303:
721:
170:
2392:(2004). "An Historical Connection between Time-Sharing and Virtual Circuits".
2320:"An Integrated Hardware-Software System for Computer Graphics in Time Sharing"
2919:
2710:
2596:
simulator, cross assembler and linker that can be used to build and run CTSS.
2577:
2268:
IBM 7090-7094 Multiprogramming Package RPO E07291 (7090) or RPO 880287 (7094)
2087:
New Concepts for Presence and Availability in Ubiquitous and Mobile Computing
2061:
1971:
Project Intrex. Semiannual Activity Report, 15 September 1971 - 15 March 1972
1381:
1202:
798:. Compatible Time Sharing referred to time sharing which was compatible with
1174:
977:
inches to millimeters in braille via the BRAILLEMBOSS braille page printer.
2673:
2573:
2129:
1234:
1089:
1066:
1047:
1040:
1028:
CTSS had one of the first inter-user messaging implementations, pioneering
951:
792:
483:
75:
46:
2610:
2589:
1710:
1693:"Selected Perspectives on a Quarter Century of Rehabilitation Engineering"
218:
2471:(1st ed.). Sebastopol, California: O'Reilly Media. pp. 85–102.
1300:, and greatly influenced the design of other early time-sharing systems.
1269:
1111:
872:
845:
97:
2133:
2715:
1226:
682:
465:
254:
54:
802:; it could offer both time sharing and batch processing concurrently.
2469:
Hackers: Heroes of the Computer Revolution - 25th Anniversary Edition
1276:
932:
868:
675:
556:
2599:
1773:
Evaluation and Development of Sensory Aids and Devices. Final Report
2775:
1273:
1255:
1248:
1244:
1015:
908:
818:
814:
701:
356:
350:
149:
145:
2845:
2840:
2795:
2770:
1240:
1145:
DORMNT – Put the user into dormant status, with program in memory
1055:
985:
968:
924:
853:
810:
519:
413:
396:
311:
207:
2625:: Interview with CTSS and Multics developer Fernando J. Corbato.
2442:. Tenth Hawaii International Conference on the System Sciences.
2318:
Thornhill, D. E.; Stoz, R. H.; Ross, T. T.; Ward, J. E. (1968).
863:
published a paper "Time Sharing in Large Fast Computers" at the
2880:
2875:
2820:
2805:
2790:
2730:
2042:"Passwords Evolved: Authentication Guidance for the Modern Era"
1330:
1142:
DEAD – Put the user into dead status, with no program in memory
1051:
809:("Comp Center"). CTSS was first demonstrated on MIT's modified
574:
568:
559:
525:
513:
507:
459:
453:
407:
390:
1895:
Intrex Buffer-Controller Display System Operation and Software
1419:"An Interview with Brian Kernighan: Breeding Little Languages"
2885:
2855:
2780:
2636:
2567:
2557:
2547:
1284:
1186:
1178:
1008:
657:
565:
260:
1453:
Educational Computer Utilization and Computer Communications
813:
in November 1961. The hardware was replaced with a modified
2860:
2603:
2261:
2259:
671:
626:
531:
478:
20:
1795:
Demonstration on CTSS of teletypesetter-to-Grade 2 Braille
1663:
1268:
transmission control unit capable of supporting up to 112
2011:"The World's First Computer Password? It Was Useless Too"
1205:
had two names, the second indicating its type as did the
489:
2256:
1516:
The Compatible Time-Sharing System, A Programmer's Guide
1154:
TSSFIL – Get access to the CTSS system files on the disk
1589:
The Compatible Time-Sharing System A Programmer's Guide
41:
Preamble of two versions of the CTSS scheduler, one in
2293:. Special Systems Features Bulletin. IBM. L22-6554-1.
2317:
2274:. Special Systems Features Bulletin. IBM. L22-6641-3.
2252:. Special Systems Features Bulletin. IBM. L22-6636-1.
1559:
The first known description of computer time-sharing.
1160:
GETBRK – Get the instruction location counter at quit
1123:
with a quantum time unit 200 ms, was controlled by a
2218:
1296:
CTSS was described in a paper presented at the 1962
193:
883:
2672:
2287:Core Storage Clock and Interval Timer - RPO FB9349
1698:Journal of Rehabilitation Research and Development
1229:. These included six data channels connecting to:
1522:(Second ed.). The M.I.T Computation Center.
1451:Singh, Jai P.; Morgan, Robert P. (October 1971).
290:7040/7044 Operating System (16/32K) (7040-PR-150)
2917:
2192:"Documents describing special hardware for CTSS"
1014:CTSS was the first computer system to implement
2558:Oral history interview with Fernando J. CorbatĂł
1513:Crisman, Patricia A., ed. (December 31, 1969).
1489:"New Information Center Will Open at MIT Today"
1439:I was using CTSS, the first time-sharing system
1379:
2941:Massachusetts Institute of Technology software
1633:"Reminiscences on the History of Time Sharing"
1261:Two custom high-speed vector graphics displays
1225:Input-output hardware was mostly standard IBM
1151:SETMEM – Set the size of the memory allocation
1148:GETMEM – Get the size of the memory allocation
1072:CTSS had an implementation of the text editor
2658:
2436:The Unix Time-sharing System: A retrospective
1630:
764:
2600:Richard Cornwell's CTSS sources and binaries
1157:USRFIL – Change back to user's own directory
2586:version MIT8C0 in Paul Pierce's collection.
2467:Levy, Steven (2010). "Winners and Losers".
1932:Hurlburt, Charles E. (September 15, 1971).
1551:Digital Computer Advanced Coding Techniques
1450:
1025:(the successors of MEMO, MODIFY and DITTO).
2665:
2651:
2568:Oral history interview with Robert M. Fano
2325:. MIT Project MAC. ESL-R-356 and MAC-TR-56
2170:. Boston: Pearson Education. p. 234.
1739:Dalrymple, George F. (February 26, 1973).
1581:
1579:
1508:
1506:
1504:
962:
867:in Paris, where he envisaged a programmer
771:
757:
241:History of IBM mainframe operating systems
2548:Oral history interview with John McCarthy
2401:
2360:
1738:
1624:
1130:
2008:
1968:
1931:
1860:
1164:
1136:RDFLXA – Read an input line from console
984:
892:demonstrated at MIT what was called the
865:UNESCO Information Processing Conference
2527:
2511:
2429:
2347:
2162:
1969:Overhage, Carl F. J. (March 15, 1972).
1717:from the original on September 20, 2023
1576:
1512:
1501:
1139:WRFLX – Write an output line to console
2918:
2460:
2388:
2214:
2212:
2144:from the original on December 21, 2017
2083:
1672:from the original on September 6, 2009
1547:
1541:
1375:
1373:
1371:
1369:
2721:Compatible Time-Sharing System (CTSS)
2646:
2521:BitSavers.Informatik.Uni-Stuttgart.de
2505:BitSavers.Informatik.Uni-Stuttgart.de
1666:"An Experimental Time-Sharing System"
1416:
1306:witnessed CTSS and the design of the
1169:CTSS at first had only an assembler,
989:Diagram of the Intrex running on CTSS
974:American Printing House for the Blind
30:Compatible Time-Sharing System (CTSS)
2495:
2466:
2055:
2039:
2009:McMillan, Robert (27 January 2012).
1934:The Intrex Retrieval System Software
1892:
1863:Project Intrex - A Brief Description
1690:
1657:
1621:Describe the system and its commands
1398:from the original on October 9, 2022
1088:, with regular expressions added by
1046:MIT Computation Center staff member
2616:CIO: 40 years of Multics, 1969-2009
2498:"The MAC System: A Progress Report"
2209:
1465:from the original on March 19, 2023
1366:
1247:disk storage, later upgraded to an
848:said in the 1954 summer session at
13:
2489:
2128:
1987:from the original on June 25, 2024
1950:from the original on June 25, 2024
1913:from the original on June 25, 2024
1785:from the original on June 25, 2024
1753:from the original on June 25, 2024
1529:from the original on June 25, 2024
1050:created for CTSS a command called
14:
2957:
2541:
2021:from the original on 25 June 2024
1893:Kehr, James E. (September 1972).
1096:
89:Discontinued, simulator available
2899:
2898:
1298:Spring Joint Computer Conference
967:The first version of the DOTSYS
898:Spring Joint Computer Conference
894:Experimental Time-Sharing System
884:Experimental Time Sharing System
791:) was the first general purpose
35:
2736:Cray Time Sharing System (CTSS)
2530:"Manuscript Typing and Editing"
2449:from the original on 2022-10-09
2423:
2382:
2351:(2004). "The Titan Influence".
2341:
2311:
2300:from the original on 2023-04-08
2278:
2237:
2223:. Addison-Wesley. p. 514.
2198:from the original on 2024-06-25
2184:
2156:
2122:
2108:from the original on 2024-06-25
2077:
2033:
2002:
1962:
1925:
1886:
1854:
1829:
1800:
1765:
1732:
1691:Mann, Robert W (October 1986).
1684:
1643:
1612:from the original on 2012-05-27
1417:Noren, Allen (April 10, 2009).
1327:Incompatible Timesharing System
1251:, with 38 million word capacity
957:
919:for user consoles, and maybe a
871:a program at a console (like a
2946:Time-sharing operating systems
2936:Discontinued operating systems
2355:. Springer. pp. 103–108.
2066:The History of Electronic Mail
1562:
1481:
1444:
1410:
1220:
1192:
923:. Each of the 3 users had two
785:Compatible Time-Sharing System
1:
2688:Time-sharing system evolution
2580:, a system programmer on CTSS
1980:(Report). MIT. Intrex PR-13.
1861:Overhage, Carl F. J. (1971).
1359:
1354:Time-sharing system evolution
1349:Timeline of operating systems
1291:
1173:, and a compiler, MAD. Also,
817:in 1962 and later a modified
306:Miscellaneous S/360 line OSes
249:Early mainframe computer OSes
2590:Dave Pitts' IBM 7094 support
2396:. Springer. pp. 85–88.
1065:which in turn inspired Unix
492:(OS/VS2R2 and later) (1974)
7:
2706:Berkeley Timesharing System
2528:Saltzer, Jerome H. (1964).
2512:Saltzer, Jerome H. (1965).
2168:The Art of UNIX Programming
2040:Hunt, Troy (26 July 2017).
1337:
1001:
880:development of the system.
109:; 63 years ago
10:
2962:
1557:. MIT. pp. 16-2–16-3.
1035:CTSS had one of the first
840:
805:CTSS was developed at the
293:1410/7010 Operating System
18:
2894:
2696:
2683:
2562:Charles Babbage Institute
2552:Charles Babbage Institute
2536:. MIT Computation Center.
2221:Operating System Concepts
2134:"The Origin of the Shell"
1391:. IEEE Computer Society.
1125:multilevel feedback queue
1101:
980:
213:
203:
183:
169:
155:
141:
129:
125:Colleges and universities
121:
103:
93:
85:
69:
53:
34:
16:Computer operating system
2496:Fano, Robert M. (1964).
1572:(Report). December 1958.
1197:Each user had their own
1061:that was implemented by
19:Not to be confused with
2701:BBN Time-Sharing System
1344:PLATO (computer system)
963:DOTSYS and BRAILLEMBOSS
831:University of Edinburgh
2514:"CTSS Technical Notes"
2084:Fetter, Mirko (2019).
1631:John McCarthy (1983).
1310:was inspired by that.
1131:Supervisor subroutines
990:
902:Fortran Monitor System
807:MIT Computation Center
377:DOS/360 and successors
255:GM OS & GM-NAA I/O
178:Command-line interface
60:MIT Computation Center
2576:: personal memoir of
2574:The IBM 7094 and CTSS
2092:University of Bamberg
1548:Backus, John (1954).
1272:terminals, including
1165:Programming languages
1076:, the predecessor of
988:
440:OS/360 and successors
1653:(Report). July 1961.
1497:. November 11, 1968.
861:Christopher Strachey
835:University of Oxford
736:UNIX System Services
716:UNIX System Services
2592:– Includes a
2094:Press. p. 38.
1637:Stanford University
1237:readers and punches
1039:systems similar to
907:The system used an
890:Fernando J. CorbatĂł
31:
2621:2018-06-23 at the
2523:. MIT Project MAC.
2507:. MIT Project MAC.
2431:Ritchie, Dennis M.
2071:2017-12-02 at the
1494:The New York Times
1423:O'Reilly Community
991:
29:
2913:
2912:
2677:operating systems
2478:978-1-4493-8839-3
2413:978-0-387-21821-2
2372:978-0-387-21821-2
2177:978-0-13-246588-5
2101:978-3-86309-623-6
1602:978-0-262-03008-3
1185:and a version of
1037:instant messaging
1023:TYPSET and RUNOFF
913:Herbert M. Teager
781:
780:
235:
234:
2953:
2902:
2901:
2801:ORVYL and WYLBUR
2667:
2660:
2653:
2644:
2643:
2537:
2524:
2518:
2508:
2502:
2483:
2482:
2464:
2458:
2457:
2455:
2454:
2448:
2441:
2427:
2421:
2420:
2405:
2394:Computer Systems
2386:
2380:
2379:
2364:
2353:Computer Systems
2345:
2339:
2338:
2332:
2330:
2324:
2315:
2309:
2308:
2306:
2305:
2299:
2292:
2282:
2276:
2275:
2273:
2263:
2254:
2253:
2251:
2241:
2235:
2234:
2216:
2207:
2206:
2204:
2203:
2188:
2182:
2181:
2164:Raymond, Eric S.
2160:
2154:
2153:
2151:
2149:
2126:
2120:
2119:
2114:
2113:
2081:
2075:
2059:
2053:
2052:
2050:
2048:
2037:
2031:
2030:
2028:
2026:
2006:
2000:
1999:
1994:
1992:
1986:
1975:
1966:
1960:
1959:
1957:
1955:
1949:
1938:
1929:
1923:
1922:
1920:
1918:
1912:
1899:
1890:
1884:
1883:
1881:
1879:
1867:
1858:
1852:
1851:
1849:
1847:
1841:
1833:
1827:
1826:
1820:
1818:
1812:
1804:
1798:
1797:
1792:
1790:
1784:
1777:
1769:
1763:
1762:
1760:
1758:
1752:
1745:
1736:
1730:
1729:
1724:
1722:
1688:
1682:
1681:
1679:
1677:
1661:
1655:
1654:
1647:
1641:
1640:
1628:
1622:
1620:
1618:
1617:
1611:
1594:
1583:
1574:
1573:
1566:
1560:
1558:
1556:
1545:
1539:
1538:
1536:
1534:
1528:
1521:
1510:
1499:
1498:
1485:
1479:
1478:
1472:
1470:
1464:
1457:
1448:
1442:
1441:
1436:
1434:
1429:on June 30, 2017
1425:. Archived from
1414:
1408:
1407:
1405:
1403:
1397:
1390:
1377:
1308:Titan Supervisor
1243:tape drives, an
1063:Glenda Schroeder
937:return character
800:batch processing
796:operating system
773:
766:
759:
510:Version 1 (1980)
237:
236:
231:
228:
226:
224:
222:
220:
214:Official website
199:
195:
122:Marketing target
117:
115:
110:
39:
32:
28:
26:Operating system
2961:
2960:
2956:
2955:
2954:
2952:
2951:
2950:
2916:
2915:
2914:
2909:
2890:
2692:
2679:
2671:
2623:Wayback Machine
2602:, which run on
2544:
2516:
2500:
2492:
2490:Further reading
2487:
2486:
2479:
2465:
2461:
2452:
2450:
2446:
2439:
2428:
2424:
2414:
2387:
2383:
2373:
2346:
2342:
2328:
2326:
2322:
2316:
2312:
2303:
2301:
2297:
2290:
2284:
2283:
2279:
2271:
2265:
2264:
2257:
2249:
2243:
2242:
2238:
2231:
2217:
2210:
2201:
2199:
2190:
2189:
2185:
2178:
2161:
2157:
2147:
2145:
2127:
2123:
2111:
2109:
2102:
2082:
2078:
2073:Wayback Machine
2060:
2056:
2046:
2044:
2038:
2034:
2024:
2022:
2007:
2003:
1990:
1988:
1984:
1973:
1967:
1963:
1953:
1951:
1947:
1943:(Report). MIT.
1936:
1930:
1926:
1916:
1914:
1910:
1906:(Report). MIT.
1897:
1891:
1887:
1877:
1875:
1865:
1859:
1855:
1845:
1843:
1839:
1835:
1834:
1830:
1824:CTSS-dependent.
1816:
1814:
1810:
1806:
1805:
1801:
1788:
1786:
1782:
1775:
1771:
1770:
1766:
1756:
1754:
1750:
1743:
1737:
1733:
1720:
1718:
1689:
1685:
1675:
1673:
1662:
1658:
1649:
1648:
1644:
1629:
1625:
1615:
1613:
1609:
1603:
1592:
1584:
1577:
1568:
1567:
1563:
1554:
1546:
1542:
1532:
1530:
1526:
1519:
1511:
1502:
1487:
1486:
1482:
1468:
1466:
1462:
1455:
1449:
1445:
1432:
1430:
1415:
1411:
1401:
1399:
1395:
1388:
1384:, eds. (2011).
1380:Walden, David;
1378:
1367:
1362:
1340:
1294:
1223:
1218:
1195:
1167:
1133:
1104:
1099:
1030:electronic mail
1004:
983:
965:
960:
915:, with added 3
886:
843:
777:
748:
747:
678:
664:
663:
641:
633:
632:
552:
542:
541:
443:
432:
431:
380:
369:
368:
307:
299:
298:
294:
250:
217:
189:
172:
113:
111:
108:
104:Initial release
49:
27:
24:
17:
12:
11:
5:
2959:
2949:
2948:
2943:
2938:
2933:
2931:1970s software
2928:
2926:1960s software
2911:
2910:
2908:
2907:
2895:
2892:
2891:
2889:
2888:
2883:
2878:
2873:
2868:
2863:
2858:
2853:
2848:
2843:
2838:
2833:
2828:
2823:
2818:
2813:
2808:
2803:
2798:
2793:
2788:
2783:
2778:
2773:
2768:
2763:
2758:
2753:
2748:
2743:
2738:
2733:
2728:
2723:
2718:
2713:
2708:
2703:
2697:
2694:
2693:
2691:
2690:
2684:
2681:
2680:
2670:
2669:
2662:
2655:
2647:
2641:
2640:
2633:CTSS bookshelf
2629:Jerome Saltzer
2626:
2613:
2597:
2587:
2581:
2571:
2565:
2555:
2543:
2542:External links
2540:
2539:
2538:
2525:
2509:
2491:
2488:
2485:
2484:
2477:
2459:
2422:
2412:
2403:10.1.1.14.9546
2381:
2371:
2362:10.1.1.14.9546
2349:Hartley, David
2340:
2310:
2277:
2255:
2236:
2229:
2208:
2183:
2176:
2155:
2121:
2100:
2076:
2054:
2032:
2015:Wired magazine
2001:
1961:
1924:
1885:
1853:
1828:
1799:
1764:
1731:
1683:
1656:
1642:
1623:
1601:
1575:
1561:
1540:
1500:
1480:
1443:
1409:
1382:Van Vleck, Tom
1364:
1363:
1361:
1358:
1357:
1356:
1351:
1346:
1339:
1336:
1314:Dennis Ritchie
1304:Maurice Wilkes
1293:
1290:
1289:
1288:
1262:
1259:
1252:
1238:
1222:
1219:
1216:
1194:
1191:
1166:
1163:
1162:
1161:
1158:
1155:
1152:
1149:
1146:
1143:
1140:
1137:
1132:
1129:
1103:
1100:
1098:
1097:Implementation
1095:
1094:
1093:
1070:
1044:
1033:
1026:
1019:
1012:
1003:
1000:
982:
979:
964:
961:
959:
956:
911:, modified by
885:
882:
859:In June 1959,
842:
839:
779:
778:
776:
775:
768:
761:
753:
750:
749:
746:
745:
739:
732:
729:OpenExtensions
725:
719:
712:
705:
698:
692:
686:
679:
670:
669:
666:
665:
662:
661:
655:
649:
642:
639:
638:
635:
634:
631:
630:
624:
618:
612:
606:
600:
594:
589:
587:VM/BSE (BSEPP)
584:
578:
572:
563:
553:
548:
547:
544:
543:
540:
539:
538:
537:
536:
535:
529:
523:
517:
511:
505:
499:
487:
481:
470:
469:
468:
463:
451:
444:
438:
437:
434:
433:
430:
429:
423:
417:
411:
405:
404:
403:
394:
388:
381:
375:
374:
371:
370:
367:
366:
365:
364:
363:
362:
361:
360:
339:
333:
327:
321:
315:
308:
305:
304:
301:
300:
297:
296:
291:
288:
282:
276:
270:
264:
258:
251:
248:
247:
244:
243:
233:
232:
215:
211:
210:
205:
201:
200:
187:
181:
180:
175:
173:user interface
167:
166:
160:
153:
152:
143:
139:
138:
133:
127:
126:
123:
119:
118:
105:
101:
100:
95:
91:
90:
87:
83:
82:
73:
67:
66:
57:
51:
50:
40:
25:
15:
9:
6:
4:
3:
2:
2958:
2947:
2944:
2942:
2939:
2937:
2934:
2932:
2929:
2927:
2924:
2923:
2921:
2906:
2897:
2896:
2893:
2887:
2884:
2882:
2879:
2877:
2874:
2872:
2869:
2867:
2864:
2862:
2859:
2857:
2854:
2852:
2849:
2847:
2844:
2842:
2839:
2837:
2834:
2832:
2829:
2827:
2824:
2822:
2819:
2817:
2814:
2812:
2809:
2807:
2804:
2802:
2799:
2797:
2794:
2792:
2789:
2787:
2784:
2782:
2779:
2777:
2774:
2772:
2769:
2767:
2764:
2762:
2759:
2757:
2754:
2752:
2749:
2747:
2744:
2742:
2739:
2737:
2734:
2732:
2729:
2727:
2724:
2722:
2719:
2717:
2714:
2712:
2711:Burroughs MCP
2709:
2707:
2704:
2702:
2699:
2698:
2695:
2689:
2686:
2685:
2682:
2678:
2675:
2668:
2663:
2661:
2656:
2654:
2649:
2648:
2645:
2638:
2634:
2630:
2627:
2624:
2620:
2617:
2614:
2612:
2609:
2605:
2601:
2598:
2595:
2591:
2588:
2585:
2582:
2579:
2578:Tom Van Vleck
2575:
2572:
2569:
2566:
2563:
2559:
2556:
2553:
2549:
2546:
2545:
2535:
2531:
2526:
2522:
2515:
2510:
2506:
2499:
2494:
2493:
2480:
2474:
2470:
2463:
2445:
2438:
2437:
2432:
2426:
2419:
2415:
2409:
2404:
2399:
2395:
2391:
2390:Fraser, Sandy
2385:
2378:
2374:
2368:
2363:
2358:
2354:
2350:
2344:
2337:
2321:
2314:
2296:
2289:
2288:
2281:
2270:
2269:
2262:
2260:
2248:
2247:
2240:
2232:
2230:0-201-18760-4
2226:
2222:
2215:
2213:
2197:
2193:
2187:
2179:
2173:
2169:
2165:
2159:
2143:
2139:
2135:
2131:
2130:Pouzin, Louis
2125:
2118:
2107:
2103:
2097:
2093:
2089:
2088:
2080:
2074:
2070:
2067:
2064:'s memoir of
2063:
2062:Tom Van Vleck
2058:
2043:
2036:
2020:
2016:
2012:
2005:
1998:
1983:
1979:
1972:
1965:
1946:
1942:
1935:
1928:
1909:
1905:
1904:
1896:
1889:
1874:(Report). MIT
1873:
1872:
1864:
1857:
1838:
1832:
1825:
1809:
1803:
1796:
1781:
1774:
1768:
1749:
1742:
1735:
1728:
1716:
1712:
1708:
1704:
1700:
1699:
1694:
1687:
1671:
1667:
1660:
1652:
1646:
1638:
1634:
1627:
1608:
1604:
1598:
1595:. MIT Press.
1591:
1590:
1582:
1580:
1571:
1565:
1553:
1552:
1544:
1525:
1518:
1517:
1509:
1507:
1505:
1496:
1495:
1490:
1484:
1477:
1461:
1454:
1447:
1440:
1428:
1424:
1420:
1413:
1394:
1387:
1383:
1376:
1374:
1372:
1370:
1365:
1355:
1352:
1350:
1347:
1345:
1342:
1341:
1335:
1332:
1328:
1324:
1322:
1321:
1315:
1311:
1309:
1305:
1301:
1299:
1286:
1285:Telex and TWX
1282:
1278:
1275:
1271:
1267:
1263:
1260:
1257:
1253:
1250:
1246:
1242:
1239:
1236:
1232:
1231:
1230:
1228:
1215:
1213:
1208:
1204:
1200:
1190:
1188:
1184:
1180:
1176:
1172:
1159:
1156:
1153:
1150:
1147:
1144:
1141:
1138:
1135:
1134:
1128:
1126:
1122:
1118:
1113:
1109:
1091:
1087:
1083:
1079:
1075:
1071:
1068:
1067:shell scripts
1064:
1060:
1057:
1053:
1049:
1045:
1042:
1038:
1034:
1031:
1027:
1024:
1020:
1017:
1013:
1010:
1007:The original
1006:
1005:
999:
997:
987:
978:
975:
970:
955:
953:
948:
946:
942:
938:
935:, and when a
934:
930:
926:
922:
918:
914:
910:
905:
903:
899:
895:
891:
881:
878:
877:John McCarthy
874:
870:
866:
862:
857:
855:
851:
847:
838:
836:
832:
827:
822:
820:
816:
812:
808:
803:
801:
797:
794:
790:
786:
774:
769:
767:
762:
760:
755:
754:
752:
751:
743:
740:
737:
733:
730:
726:
723:
720:
717:
713:
710:
706:
703:
699:
696:
693:
690:
687:
684:
681:
680:
677:
673:
668:
667:
659:
656:
653:
650:
647:
644:
643:
637:
636:
628:
625:
622:
619:
616:
613:
610:
607:
604:
601:
598:
595:
593:
590:
588:
585:
582:
579:
576:
573:
570:
567:
564:
561:
558:
555:
554:
551:
546:
545:
533:
530:
527:
524:
521:
518:
515:
512:
509:
506:
503:
500:
497:
494:
493:
491:
488:
485:
482:
480:
477:
476:
474:
471:
467:
464:
461:
458:
457:
455:
452:
449:
446:
445:
441:
436:
435:
427:
424:
421:
418:
415:
412:
409:
406:
402:VSE/AF (1979)
401:
400:
398:
395:
392:
389:
386:
383:
382:
378:
373:
372:
358:
355:
354:
352:
349:
348:
346:
343:
342:
340:
337:
334:
331:
328:
325:
322:
319:
316:
313:
310:
309:
303:
302:
295:(1410-PR-155)
292:
289:
286:
283:
280:
277:
274:
271:
268:
265:
262:
259:
256:
253:
252:
246:
245:
242:
239:
238:
230:
216:
212:
209:
206:
202:
197:
196:
188:
186:
182:
179:
176:
174:
168:
164:
161:
158:
154:
151:
147:
144:
140:
137:
134:
132:
128:
124:
120:
106:
102:
99:
96:
92:
88:
86:Working state
84:
81:
77:
74:
72:
68:
65:
61:
58:
56:
52:
48:
44:
38:
33:
22:
2720:
2674:Time-sharing
2608:license-free
2594:license-free
2533:
2520:
2504:
2468:
2462:
2451:. Retrieved
2435:
2425:
2417:
2393:
2384:
2376:
2352:
2343:
2334:
2329:February 20,
2327:. Retrieved
2313:
2302:. Retrieved
2286:
2280:
2267:
2245:
2239:
2220:
2200:. Retrieved
2186:
2167:
2158:
2148:February 17,
2146:. Retrieved
2137:
2124:
2116:
2110:. Retrieved
2086:
2079:
2057:
2045:. Retrieved
2035:
2023:. Retrieved
2004:
1996:
1989:. Retrieved
1977:
1964:
1952:. Retrieved
1940:
1927:
1915:. Retrieved
1901:
1888:
1876:. Retrieved
1869:
1856:
1844:. Retrieved
1831:
1822:
1815:. Retrieved
1802:
1794:
1787:. Retrieved
1767:
1755:. Retrieved
1734:
1726:
1719:. Retrieved
1702:
1696:
1686:
1676:February 25,
1674:. Retrieved
1659:
1645:
1636:
1626:
1614:. Retrieved
1588:
1564:
1550:
1543:
1531:. Retrieved
1515:
1492:
1483:
1474:
1467:. Retrieved
1446:
1438:
1431:. Retrieved
1427:the original
1422:
1412:
1402:February 20,
1400:. Retrieved
1325:
1318:
1312:
1302:
1295:
1235:punched card
1224:
1211:
1196:
1168:
1105:
1090:Ken Thompson
1048:Louis Pouzin
1011:ran on CTSS.
992:
966:
958:Applications
952:time-sharing
949:
944:
940:
917:Flexowriters
906:
893:
887:
858:
844:
823:
804:
793:time-sharing
788:
784:
782:
592:VM/SE (SEPP)
486:(SVS) (1972)
410:(1983, 1985)
341:RACS (1965)
284:
204:Succeeded by
194:data missing
191:
131:Available in
94:Source model
76:FAP assembly
2606:. Includes
2584:CTSS Source
2534:Web.MIT.edu
1270:teleprinter
1227:peripherals
1221:Peripherals
1193:File system
1119:allocation
1112:core memory
846:John Backus
826:Project MAC
742:OpenSolaris
709:OpenEdition
702:OpenEdition
165:, protected
98:Open source
64:Project MAC
45:and one in
2920:Categories
2716:CDC Kronos
2453:2022-02-19
2304:2024-04-21
2202:2024-04-21
2138:Multicians
2112:2023-03-19
1705:(4): 1–6.
1616:2007-02-04
1360:References
1292:Influences
1277:Selectrics
1233:Printers,
1175:Fortran II
1121:scheduling
933:interrupts
925:tape units
466:OS/VS1 BPE
163:Monolithic
71:Written in
2398:CiteSeerX
2357:CiteSeerX
2336:Computer.
1991:March 17,
1846:March 13,
1817:March 13,
1789:March 13,
1757:March 13,
1721:March 13,
1533:March 10,
1476:system...
1287:networks.
1281:Model 35s
1207:extension
1199:directory
1117:Processor
1110:banks of
869:debugging
676:Unix-like
142:Platforms
55:Developer
2905:Category
2776:MUSIC/SP
2619:Archived
2444:Archived
2433:(1977).
2295:Archived
2196:Archived
2166:(2003).
2142:Archived
2106:Archived
2069:Archived
2047:22 March
2025:22 March
2019:Archived
1982:Archived
1954:March 8,
1945:Archived
1917:March 8,
1908:Archived
1878:March 8,
1780:Archived
1748:Archived
1715:Archived
1670:Archived
1607:Archived
1524:Archived
1469:March 8,
1460:Archived
1433:July 28,
1393:Archived
1338:See also
1274:IBM 1050
1266:IBM 7750
1256:IBM 7320
1249:IBM 1302
1245:IBM 1301
1183:LISP 1.5
1179:COMIT II
1016:password
1002:Features
909:IBM 7090
873:teletype
833:and the
819:IBM 7094
815:IBM 7090
700:MVS/ESA
640:TPF line
615:VM/XA SP
609:VM/XA SF
603:VM/XA MA
502:MVS/SE 2
484:OS/VS2R1
357:MUSIC/SP
285:MIT CTSS
227:/ibm7090
150:IBM 7094
146:IBM 7090
2846:TOPS-20
2841:TOPS-10
2796:OpenVMS
2771:Multics
1711:3820117
1241:IBM 729
1056:Multics
969:braille
945:xundump
854:IBM 704
841:History
811:IBM 709
714:OS/390
707:VM/ESA
695:AIX/ESA
689:AIX/370
550:VM line
520:MVS/ESA
475:(1967)
456:(1968)
414:VSE/ESA
399:(1979)
397:DOS/VSE
385:DOS/360
353:(1972)
347:(1966)
324:TSS/360
318:TOS/360
312:BOS/360
225:/dpitts
208:Multics
185:License
171:Default
136:English
112: (
2903:
2881:VPS/VM
2876:VP/CSS
2821:RSTS/E
2806:OS4000
2791:NOS/VE
2731:CP/CMS
2475:
2410:
2400:
2369:
2359:
2227:
2174:
2098:
1709:
1599:
1331:parody
1320:daemon
1102:Kernel
1084:, and
1052:RUNCOM
1018:login.
994:BRISC
981:Intrex
929:memory
744:(2008)
738:(2001)
731:(2000)
724:(1999)
718:(1996)
711:(1995)
704:(1993)
697:(1991)
691:(1990)
685:(1981)
660:(2005)
654:(1979)
648:(1967)
629:(2000)
623:(1990)
621:VM/ESA
617:(1988)
611:(1985)
605:(1984)
599:(1980)
583:(1972)
581:VM/370
577:(1968)
575:VP/CSS
571:(1967)
562:(1967)
534:(2000)
528:(1995)
526:OS/390
522:(1988)
516:(1983)
514:MVS/XA
508:MVS/SP
504:(1979)
498:(1978)
496:MVS/SE
462:(1972)
460:OS/VS1
454:MFT II
450:(1966)
442:(1966)
428:(2021)
422:(2005)
416:(1991)
408:VSE/SP
393:(1972)
391:DOS/VS
387:(1965)
379:(1966)
359:(1985)
338:(1967)
332:(1967)
326:(1967)
320:(1965)
314:(1965)
287:(1961)
281:(1960)
275:(1959)
269:(1958)
263:(1957)
257:(1955)
157:Kernel
2886:WAITS
2856:TSS/8
2826:TENEX
2781:NLTSS
2761:MCTSS
2637:CSAIL
2611:tools
2517:(PDF)
2501:(PDF)
2447:(PDF)
2440:(PDF)
2323:(PDF)
2298:(PDF)
2291:(PDF)
2272:(PDF)
2250:(PDF)
1985:(PDF)
1974:(PDF)
1948:(PDF)
1937:(PDF)
1911:(PDF)
1898:(PDF)
1866:(PDF)
1840:(PDF)
1811:(PDF)
1783:(PDF)
1776:(PDF)
1751:(PDF)
1744:(PDF)
1610:(PDF)
1593:(PDF)
1555:(PDF)
1527:(PDF)
1520:(PDF)
1463:(PDF)
1456:(PDF)
1396:(PDF)
1389:(PDF)
1212:listf
1187:ALGOL
1059:shell
1041:write
1009:ELIZA
921:timer
734:z/OS
727:z/VM
722:Linux
658:z/TPF
597:VM/SP
566:CP-67
557:CP-40
420:z/VSE
351:MUSIC
336:ORVYL
279:IBSYS
261:BESYS
229:.html
221:.cozx
198:]
190:[
2861:Unix
2836:TSOS
2811:Pick
2756:LTSS
2746:EMAS
2741:DTSS
2635:via
2604:SIMH
2473:ISBN
2408:ISBN
2367:ISBN
2331:2022
2225:ISBN
2172:ISBN
2150:2022
2096:ISBN
2049:2019
2027:2019
1993:2022
1978:ERIC
1956:2022
1941:ERIC
1919:2022
1903:ERIC
1880:2022
1871:ERIC
1848:2022
1819:2022
1791:2022
1759:2022
1723:2022
1707:PMID
1678:2022
1597:ISBN
1535:2022
1471:2022
1435:2023
1404:2022
1279:and
1203:file
1108:word
943:and
789:CTSS
783:The
674:and
672:UNIX
627:z/VM
569:/CMS
560:/CMS
532:z/OS
479:65MP
267:UMES
223:.com
159:type
114:1961
107:1961
21:CICS
2866:UTS
2851:TSS
2831:TSO
2816:RAX
2786:NOS
2766:MTS
2751:ITS
2726:COS
2631:'s
1264:An
1254:An
1171:FAP
1086:vim
1074:QED
996:CRT
850:MIT
683:UTS
652:TPF
646:ACP
490:MVS
473:MVT
448:MFT
426:VSE
345:RAX
330:MTS
273:SOS
219:www
80:MAD
47:FAP
43:MAD
2922::
2871:VM
2560:,
2550:,
2532:.
2519:.
2503:.
2416:.
2406:.
2375:.
2365:.
2333:.
2258:^
2211:^
2194:.
2140:.
2136:.
2132:.
2115:.
2104:.
2090:.
2017:.
2013:.
1995:.
1976:.
1939:.
1900:.
1868:.
1821:.
1793:.
1725:.
1713:.
1703:23
1701:.
1695:.
1668:.
1635:.
1605:.
1578:^
1503:^
1491:.
1473:.
1437:.
1421:.
1368:^
1323:.
1214::
1189:.
1181:,
1082:vi
1080:,
1078:ed
947:.
904:.
837:.
148:,
78:,
62:,
2666:e
2659:t
2652:v
2639:.
2481:.
2456:.
2307:.
2233:.
2205:.
2180:.
2152:.
2051:.
2029:.
1958:.
1921:.
1882:.
1850:.
1761:.
1680:.
1639:.
1619:.
1537:.
1406:.
1092:.
1069:.
1043:.
1032:.
787:(
772:e
765:t
758:v
116:)
23:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
