Berkeley Timesharing System
{{Short description|Time-sharing computer operating system}}
{{Infobox OS
| name = Berkeley Timesharing System
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| developer = University of California, Berkeley
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| kernel_type =
| supported_platforms = Scientific Data Systems' SDS 940
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| language = English
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| working_state = Discontinued
}}
The Berkeley Timesharing System was a pioneering time-sharing operating system implemented between 1964 and 1967 at the University of California, Berkeley. It was designed as part of Project Genie and marketed by Scientific Data Systems for the SDS 940 computer system.
It was the first commercial time-sharing which allowed general-purpose user programming, including machine language.
History
In the mid-1960s, most computers used batch processing: one user at a time with no interactivity. A few pioneering systems such as the Atlas Supervisor at the University of Manchester, Compatible Time-Sharing System at MIT, and the Dartmouth Time-Sharing System at Dartmouth College required large expensive machines.
Implementation started in 1964 with the arrival of the SDS 930 which was modified slightly, and an operating system was written from scratch.{{cite web |title= Project Genie: Berkeley's piece of the computer revolution |publisher= University of California, Berkeley Engineering |author= Paul Spinrad and Patti Meagher |url= http://coe.berkeley.edu/news-center/publications/forefront/archive/forefront-fall-2007/features/berkeley2019s-piece-of-the-computer-revolution |accessdate= April 17, 2011 |archive-url= https://web.archive.org/web/20110719144454/http://coe.berkeley.edu/news-center/publications/forefront/archive/forefront-fall-2007/features/berkeley2019s-piece-of-the-computer-revolution |archive-date= 2011-07-19 |url-status= dead }}
Students who worked on the Berkeley Timesharing System included undergraduates Chuck Thacker and L. Peter Deutsch and doctoral student Butler Lampson.[http://research.microsoft.com/lampson/Systems.html Butler Lampson - Systems]
The heart of the system was the Monitor (roughly what is now usually called a kernel) and the
Executive (roughly what is now usually called a command-line interface).
When the system was working, Max Palevsky, founder of Scientific Data Systems, was at first not interested in selling it as a product. He thought timesharing had no commercial demand. However, as other customers expressed interest, it was put on the SDS pricelist as an expensive variant of the 930.{{cite book |author = Michael A. Hiltzik |title= The Dealers of Lightning: Xerox PARC and the Dawn of the Computer Age |publisher = HarperCollins |date = April 4, 2000 |pages= 18–20 |isbn = 0-88730-989-5 |url= https://books.google.com/books?id=lzgOduibRJgC }}
By November 1967 it was being sold commercially as the SDS 940.{{cite book |title= SDS 940 Time-Sharing System Technical Manual |work= SDS 90 11 16A |date= November 1967 |publisher= Scientific Data Systems |location= Santa Monica, California |url= http://bitsavers.org/pdf/sds/9xx/940/901116A_940_TimesharingTechMan_Nov67.pdf |accessdate= April 17, 2011 }}
By August 1968 a version 2.0 was announced that was just called the "SDS 940 Time-Sharing System".{{cite book |title= SDS 940 Time-Sharing System (Version 2.0) Technical Manual |work= SDS 90 11 16B |date= August 1968 |publisher= Scientific Data Systems |location= Santa Monica, California |url= http://bitsavers.org/pdf/sds/9xx/940/901116B_940_TimesharingTechMan_Aug68.pdf |accessdate= April 17, 2011 }}
Other timesharing systems were generally one-of-a-kind systems, or limited to a single application (such as teaching Dartmouth BASIC). The 940 was the first to allow for general-purpose programming, and sold about 60 units: not large by today's standards, but it was a significant part of SDS' revenues.
One customer was Bolt, Beranek and Newman. The TENEX operating system for the PDP-10 mainframe computer used many features of the SDS 940 Time-Sharing System system, but extended the memory management to include demand paging.{{cite web |title= Origins and Development of TOPS-20 |year= 1996 |author= Dan Murphy |url= http://tenex.opost.com/hbook.html |accessdate= April 17, 2011 |author-link= Daniel Murphy (computer scientist) }}
Some concepts of the operating system also influenced the design of Unix, whose designer Ken Thompson worked on the SDS 940 while at Berkeley.
The QED text editor was first implemented by Butler Lampson and L. Peter Deutsch for the Berkeley Timesharing System in 1967.{{cite web |author= Dennis Ritchie |author-link= Dennis Ritchie |title=An incomplete history of the QED Text Editor |location=Murray Hill |publisher=Bell Labs |date=February 12, 2004 |url= http://plan9.bell-labs.com/who/dmr/qed.html |accessdate= April 17, 2011 }}
Another major customer was Tymshare, who used the system to become the USA's best known commercial timesharing service in the late 1960s. By 1972, Tymshare alone had 23 systems in operation.{{cite web |title= Timesharing as a Business |publisher= Computer History Museum |url= http://www.computerhistory.org/revolution/mainframe-computers/7/181 |accessdate= April 17, 2011 }} (includes pictures)
See also
References
{{Reflist}}
Further reading
- {{cite journal |title= A user machine in a time-sharing system |journal= Proceedings of the IEEE |volume= 54 |number= 12 |date=December 1966 |pages= 1766–1774 |author1= Butler Lampson |author-link= Butler Lampson |author2= W. Lichtenberger |author3= M. Pirtle |url= http://research.microsoft.com/en-us/um/people/blampson/02-UserMachine/WebPage.html |doi=10.1109/proc.1966.5260|archive-url= https://web.archive.org/web/20160214202544/http://research.microsoft.com/en-us/um/people/blampson/02-UserMachine/WebPage.html |archive-date= 2016-02-14 }} Reprinted in Computer Structures, ed. Bell and Newell, McGraw-Hill, 1971, pp 291–300
External links
- [http://simh.trailing-edge.com/sds940.html SDS-940 Simulator Configuration]
- {{cite web |title= Berkeley Hardware Prototypes |author= David Patterson |url= http://www.cs.berkeley.edu/~pattrsn/Arch/prototypes2.html |accessdate= April 17, 2011 |author-link= David Patterson (scientist) }}
{{Time-sharing operating systems}}