This article covers the evolution of time-sharing systems, providing links to major early time-sharing operating systems, showing their subsequent evolution.
The meaning of the term time-sharing has shifted from its original usage. From 1949 to 1960, time-sharing was used to refer to multiprogramming; it evolved to mean multi-user interactive computing.
Time-sharing was first proposed in the mid- to late-1950s and first implemented in the early 1960s. The concept was born out of the realization that a single expensive computer could be efficiently utilized by enabling multiprogramming, and, later, by allowing multiple users simultaneous interactive access.[1] In 1984, Christopher Strachey wrote he considered the change in the meaning of the term time-sharing to be a source of confusion and not what he meant when he wrote his original paper in 1959.[2][3]
Without time-sharing, an individual user would enter bursts of information followed by long pauses; but with a group of users working at the same time, the pauses of one user would be filled by the activity of the others. Similarly, small slices of time spent waiting for disk, tape, or network input could be granted to other users. Given an optimal group size, the overall process could be very efficient.[note 1]
See details and additional systems in the table below. Relationships shown here are for the purpose of grouping entries and do not reflect all influences. The Cambridge Multiple-Access System[6][7] was the first time-sharing system developed outside the United States.
Family tree of major time-sharing operating system families Influences: ⇶ derivation ⇉ strong influence → some influence/precedence
In computing, multitasking is the concurrent execution of multiple tasks over a certain period of time. New tasks can interrupt already started ones before they finish, instead of waiting for them to end. As a result, a computer executes segments of multiple tasks in an interleaved manner, while the tasks share common processing resources such as central processing units (CPUs) and main memory. Multitasking automatically interrupts the running program, saving its state and loading the saved state of another program and transferring control to it. This "context switch" may be initiated at fixed time intervals, or the running program may be coded to signal to the supervisory software when it can be interrupted.
In computing, time-sharing is the concurrent sharing of a computing resource among many tasks or users by giving each task or user a small slice of processing time. This quick switch between tasks or users gives the illusion of simultaneous execution. It enables multi-tasking by a single user or enables multiple-user sessions.
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This article presents a detailed timeline of events in the history of computing from 1950 to 1979. For narratives explaining the overall developments, see the history of computing.
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The Compatible Time-Sharing System (CTSS) was the first general purpose time-sharing operating system. Compatible Time Sharing referred to time sharing which was compatible with batch processing; it could offer both time sharing and batch processing concurrently.
Joseph Carl Robnett Licklider, known simply as J. C. R. or "Lick", was an American psychologist and computer scientist who is considered to be among the most prominent figures in computer science development and general computing history.
Donald Watts Davies, was a Welsh computer scientist and Internet pioneer who was employed at the UK National Physical Laboratory (NPL).
Christopher S. Strachey was a British computer scientist. He was one of the founders of denotational semantics, and a pioneer in programming language design and computer time-sharing. He has also been credited as possibly being the first developer of a video game and for coining terms such as polymorphism and referential transparency that are still widely used by developers today. He was a member of the Strachey family, prominent in government, arts, administration, and academia.
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A computer network is a set of computers sharing resources located on or provided by network nodes. Computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies.
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David Fielding Hartley FBCS is a computer scientist and Fellow of Clare College, Cambridge. He was Director of the University of Cambridge Computing Service from 1970–1994, Chief Executive of United Kingdom Joint Academic Network (JANET) 1994–1997, and Executive Director of Cambridge Crystallographic Data Centre (CCDC) 1997–2002. He is now much involved with the National Museum of Computing.
The NPL network, or NPL Data Communications Network, was a local area computer network operated by a team from the National Physical Laboratory (NPL) in London that pioneered the concept of packet switching.
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David Corydon Walden was an American computer scientist and Internet pioneer who contributed to the engineering development of the ARPANET, a precursor of the modern Internet. He specifically contributed to the Interface Message Processor, which was the packet switching node for the ARPANET. Walden was a contributor to IEEE Computer Society's Annals of the History of Computing and was a member of the TeX Users Group.
↑ Corbató, F. J.; Daggett, M. M.; Daley, R. C.; Creasy, R. J.; Hellwig, J. D.; Orenstein, R. H.; Korn, L. K. (1963). The Compatible Time-Sharing System A Programmer's Guide(PDF). MIT Press. ISBN978-0-262-03008-3. To establish the context of the present work, it is informative to trace the development of time-sharing at MIT. Shortly after the first paper on time-shared computers by C. Strachey at the June 1959 UNESCO Information Processing conference, H.M. Teager and J. McCarthy delivered an unpublished paper "Time-Shared Program Testing" at the August 1959 ACM Meeting.
↑ Roberts, Dr. Lawrence G. (November 1978). "The Evolution of Packet Switching". Archived from the original on March 24, 2016. Retrieved 5 September 2017. Almost immediately after the 1965 meeting, Donald Davies conceived of the details of a store-and-forward packet switching system
↑ Seibel, Peter (2009). Coders at work: reflections on the craft of programming. New York: Apress. p.463. ISBN9781430219491. The things that I [Ken Thompson] liked [about Multics] enough to actually take were the hierarchical file system and the shell
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