词条 | Compatible Time-Sharing System |
释义 |
| name = Compatible Time-Sharing System | logo = | screenshot = | caption = | developer = MIT Computation Center | source_model = | kernel_type = monolithic, protected | supported_platforms = IBM 7090, IBM 7094, GE 645 | ui = command line | family = | released = 1961 | latest_release_version = | latest_release_date = | latest_test_version = | latest_test_date = | marketing_target = MIT only | programmed_in = FAP assembly, MAD | prog_language = FAP assembly, MAD, Fortran, LISP | language = English | updatemodel = | package_manager = | working_state = Discontinued, simulator | license = open source | website = {{URL|www.cozx.com/dpitts/ibm7090.html}} }} The Compatible Time-Sharing System (CTSS), was one of the first time-sharing operating systems; it was developed at the MIT Computation Center. CTSS was first demonstrated in 1961 and was operated at MIT until 1973. During part of this time, MIT's influential Project MAC also ran CTSS, but the system did not spread beyond these two sites. CTSS was described in a paper presented at the 1962 Spring Joint Computer Conference and greatly influenced the design of other early time-sharing systems. {{History of IBM mainframe operating systems}}Experimental Time-Sharing SystemJohn Backus said in the 1954 summer session at MIT 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".[1] Computers at that time, like IBM 704, 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".[2]In June 1959, Christopher Strachey published a paper "Time Sharing in Large Fast Computers" at the UNESCO Information Processing Conference in Paris, where he envisaged a programmer debugging a program at a console (like a teletype) connected to the computer, while another program was running in the computer at the same time.[3][4] 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. John McCarthy 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. By July, 1961[5] a few time sharing commands had become operational on the Computation Center's IBM 709, and in November 1961, Fernando J. Corbató demonstrated at MIT what was called the "Experimental Time-Sharing System". On May 3, 1962, F. J. Corbató, M. M. Daggett and R. C. Daley published a paper about that system at the Spring Joint Computer Conference.[6] Robert C. Daley, Peter R. Bos and at least 6 other programmers implemented the operating system, partly based on the Fortran Monitor System. The system used an IBM 7090, modified by Herbert M. Teager, with added 3 Flexowriters for user consoles, and maybe a timer. Each of the 3 users had two tape units, 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 memory 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 interrupts, and when a return character 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 login, logout, input, edit, fap, mad, madtrn, load, use, start, skippm, listf, printf, xdump and xundump. This became the initial version of the Compatible Time-Sharing System. This was evidently the first ever demonstration of time-sharing; there are other claims, but about 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. Features
ImplementationKernelCTSS used a modified IBM 7090 mainframe computer that had two 32,768 (32K) 36-bit-word banks of core memory instead of the normal one.[10] 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 only be called by software interrupts, like in the modern operating systems. Causing memory-protection interrupts were used for software interrupts.[3] Processor allocation scheduling with a quantum time unit 200 ms, was controlled by a multilevel feedback queue.[10] It also had some special memory-management hardware, a clock interrupt and the ability to trap certain instructions. Supervisor subroutines
Programming languagesCTSS at first had only an assembler FAP and a compiler MAD. Also, Fortran II code could be translated into a MAD code. Later half of the system was written in MAD. Later there were other programming languages like LISP and a version of ALGOL. File systemEvery user had one's own directory, and there were also directories for groups of people, who had the same "problem number". Each file had two names, the second name was similar to extension today. At first, each file could have one of four modes: temporary, permanent, read-only class 1, and read-only class 2. Read-only class 2 differed in that the user couldn't change the mode of these files. Files could also be linked from other directories than the user's directory. A directory listing by listf: 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 Disk-control subroutines
Console commands
PeripheralsInput-output hardware was mostly standard IBM peripherals. These included six data channels connecting to:
InfluencesMultics, 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 technical terms inherited by these systems from CTSS is daemon. Incompatible Timesharing System (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 parody of CTSS, as later the name of Unix was a parody of Multics.[11]See also
References1. ^Backus, John, Computer Advanced Coding Techniques, MIT 1954, page 16-2. The first known description of computer time-sharing. 2. ^[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], December, 1958, 3. ^1 F. J. Corbató, et al., The Compatible Time-Sharing System A Programmer's Guide (MIT Press, 1963) {{ISBN|978-0-262-03008-3}}. Describe the system and its commands 4. ^John McCarthy, Reminiscences on the History of Time Sharing {{webarchive|url=https://web.archive.org/web/20071020032705/http://www-formal.stanford.edu/jmc/history/timesharing/timesharing.html |date=2007-10-20 }} (Stanford University 1983). 5. ^[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], July, 1961 6. ^F. J. Corbató, M. M. Daggett, R. C. Daley, An Experimental Time-Sharing System (IFIPS 1962). 7. ^Tom Van Vleck's memoir of The History of Electronic Mail 8. ^{{cite web |last1=McMillan |first1=Robert |title=The World's First Computer Password? It Was Useless Too |url=https://www.wired.com/2012/01/computer-password/ |publisher=Wired magazine |accessdate=22 March 2019 |date=27 January 2012}} 9. ^{{cite web |last1=Hunt |first1=Troy |title=Passwords Evolved: Authentication Guidance for the Modern Era |url=https://www.troyhunt.com/passwords-evolved-authentication-guidance-for-the-modern-era/ |accessdate=22 March 2019 |date=26 July 2017}} 10. ^1 {{cite book |title=Operating System Concepts |chapter=13: Historical Perspective |page=514 |first1=Abraham |last1=Silberschatz |first2=James L. |last2=Peterson |date=June 1988 |isbn=0-201-18760-4}} 11. ^{{cite book|title=Hackers: Heroes of the Computer Revolution - 25th Anniversary Edition|date=2010|publisher=O'Reilly Media|isbn=978-1449388393|edition=1st|location=Sebastopol, California|pages=85–102|chapter=Winners and Losers|last=Levy|first=Steven}} Further reading
External links
4 : 1960s software|Discontinued operating systems|Massachusetts Institute of Technology software|Time-sharing operating systems |
随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识,基本涵盖了大多数领域的百科知识,是一部内容自由、开放的电子版国际百科全书。