Time-sharing
Encyclopedia
Time-sharing is the sharing of a computing resource among many users by means of multiprogramming
and multi-tasking
. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major technological shift in the history of computing.
By allowing a large number of users to interact concurrently with a single computer, time-sharing dramatically lowered the cost of providing computing capability, made it possible for individuals and organizations to use a computer without owning one, and promoted the interactive use of computers and the development of new interactive application
s.
methodologies evolved to decrease these dead times, queuing up programs so that as soon as one completed, the next would start.
To support a batch processing operation, a number of card punch or paper tape writers would be used by programmers, who would use these inexpensive machines to write their programs "offline". When they completed typing them, they were submitted to the operations team, who would schedule them for running. Important programs would be run quickly, less important ones were unpredictable. When the program was finally run, the output, generally printed, would be returned to the programmer. The complete process might take days, during which the programmer might never see the computer.
The alternative, allowing the user to operate the computer directly, was generally far too expensive to consider. This was because the user had long delays where they were simply sitting there entering code. This limited developments in direct interactivity to organizations that could afford to waste computing cycles, large universities for the most part. Programmers at the universities decried the inhumanist behaviors that batch processing imposed, to the point that Stanford students made a short film humorously critiquing it. They experimented with new ways to directly interact with the computer, a field today known as human-computer interaction.
Implementing a system able to take advantage of this would be difficult. Batch processing was really a methodological development on top of the earliest systems; computers still ran single programs for single users at any time, all that batch processing changed was the time delay between one program and the next. Developing a system that supported multiple users at the same time was a completely different concept; the "state" of each user and their programs would have to be kept in the machine, and then switched between quickly. This would take up computer cycles, and on the slow machines of the era this was a concern. However, as computers rapidly improved in speed, and especially in size of core memory in which users' states were retained, the overhead of time-sharing continually decreased, relatively.
The concept was first described publicly in early 1957 by Bob Bemer
as part of an article in Automatic Control Magazine. The first project to implement a time-sharing system was initiated by John McCarthy
in late 1957, on a modified IBM 704
, and later on an additionally modified IBM 7090
computer. Although he left to work on Project MAC and other projects, one of the results of the project, known as the Compatible Time-Sharing System or CTSS, was demonstrated in November 1961. CTSS has a good claim to be the first time-sharing system and remained in use until 1973. Another contender for the first demonstrated time-sharing system was PLATO
II, created by Donald Bitzer
at a public demonstration at Robert Allerton Park
near the University of Illinois in early 1961. Bitzer has long said that the PLATO project would have gotten the patent on time-sharing if only the University of Illinois had known how to process patent applications faster, but at the time university patents were so few and far between, they took a long time to be submitted. The first commercially successful time-sharing system was the Dartmouth Time Sharing System
.
s (central computer systems), which in many implementations sequentially polled the terminals to see if there was any additional data or action requested by the computer user. Later technology in interconnections were interrupt
driven, and some of these used parallel data transfer technologies such as the IEEE 488 standard. Generally, computer terminals were utilized on college properties in much the same places as desktop computer
s or personal computer
s are found today. In the earliest days of personal computers, many were in fact used as particularly smart terminals for time-sharing systems.
With the rise of microcomputing in the early 1980s, time-sharing faded into the background because the individual microprocessors were sufficiently inexpensive that a single person could have all the CPU time
dedicated solely to their needs, even when idle.
The Internet has brought the general concept of time-sharing back into popularity. Expensive corporate server farms costing millions can host thousands of customers all sharing the same common resources. As with the early serial terminals, websites operate primarily in bursts of activity followed by periods of idle time. This bursting nature permits the service to be used by many website customers at once, and none of them notice any delays in communications until the servers start to get very busy.
s. Early systems used Teletype
Model 33 KSR or ASR or Model 35 KSR or ASR in ASCII
environments, and IBM
Selectric typewriter-based terminals in EBCDIC
environments. They would connect to the central computer by dial-up Bell 103A modem or acoustically coupled
modem
s operating at 10–15 characters per second. Later terminals and modems supported 30–120 characters per second. The time-sharing system would provide a complete operating environment, including a variety of programming language processors, various software packages, file storage, bulk printing, and off-line storage. Users were charged rent for the terminal, a charge for hours of connect time, a charge for seconds of CPU time, and a charge for kilobyte-months of disk storage.
Common systems used for time-sharing included the SDS 940
, the PDP-10
, and the IBM 360. Companies providing this service included GE
's GEISCO, IBM
subsidiary The Service Bureau Corporation, Tymshare
(founded in 1966), National CSS
(founded in 1967 and bought by Dun & Bradstreet in 1979), Dial Data (bought by Tymshare in 1968), and Bolt, Beranek, and Newman. By 1968, there were 32 such service bureaus serving the NIH alone. The Auerbach Guide to Timesharing 1973 edition
lists 125 different timesharing services using equipment from Burroughs, CDC
, DEC
, HP
, Honeywell
, IBM
, RCA
, Univac
and XDS
.The information was shared to help poor enterprise as small and medium.
's original "Xanadu
" hypertext repository was envisioned as such a service. It became clear as the computer industry grew that no such consolidation of computing resources would occur as timesharing systems. Some argue that the move through client-server computing to centralized server farms and virtualization presents a market for computing utilities again.
and with SaaS
products.
Multiprogramming
Computer multiprogramming is the allocation of a computer system and its resources to more than one concurrent application, job or user ....
and multi-tasking
Computer multitasking
In computing, multitasking is a method where multiple tasks, also known as processes, share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is actively executing instructions for...
. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major technological shift in the history of computing.
By allowing a large number of users to interact concurrently with a single computer, time-sharing dramatically lowered the cost of providing computing capability, made it possible for individuals and organizations to use a computer without owning one, and promoted the interactive use of computers and the development of new interactive application
Application software
Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...
s.
Batch processing
The earliest computers were extremely expensive devices, and very slow. Machines were typically dedicated to a particular set of tasks and operated by control panel, the operator manually entering small programs via switches in order to load and run other programs. These programs might take hours, even weeks, to run. As computers grew in speed, run times dropped, and suddenly the time taken to start up the next program became a concern. The batch processingBatch processing
Batch processing is execution of a series of programs on a computer without manual intervention.Batch jobs are set up so they can be run to completion without manual intervention, so all input data is preselected through scripts or command-line parameters...
methodologies evolved to decrease these dead times, queuing up programs so that as soon as one completed, the next would start.
To support a batch processing operation, a number of card punch or paper tape writers would be used by programmers, who would use these inexpensive machines to write their programs "offline". When they completed typing them, they were submitted to the operations team, who would schedule them for running. Important programs would be run quickly, less important ones were unpredictable. When the program was finally run, the output, generally printed, would be returned to the programmer. The complete process might take days, during which the programmer might never see the computer.
The alternative, allowing the user to operate the computer directly, was generally far too expensive to consider. This was because the user had long delays where they were simply sitting there entering code. This limited developments in direct interactivity to organizations that could afford to waste computing cycles, large universities for the most part. Programmers at the universities decried the inhumanist behaviors that batch processing imposed, to the point that Stanford students made a short film humorously critiquing it. They experimented with new ways to directly interact with the computer, a field today known as human-computer interaction.
Time-sharing
Time-sharing was developed out of the realization that while any single user was inefficient, a large group of users together were not. This was due to the pattern of interaction; in most cases users entered bursts of information followed by long pause, but a group of users working at the same time would mean that the pauses of one user would be used up by the activity of the others. Given an optimal group size, the overall process could be very efficient. Similarly, small slices of time spent waiting for disk, tape, or network input could be granted to other users.Implementing a system able to take advantage of this would be difficult. Batch processing was really a methodological development on top of the earliest systems; computers still ran single programs for single users at any time, all that batch processing changed was the time delay between one program and the next. Developing a system that supported multiple users at the same time was a completely different concept; the "state" of each user and their programs would have to be kept in the machine, and then switched between quickly. This would take up computer cycles, and on the slow machines of the era this was a concern. However, as computers rapidly improved in speed, and especially in size of core memory in which users' states were retained, the overhead of time-sharing continually decreased, relatively.
The concept was first described publicly in early 1957 by Bob Bemer
Bob Bemer
Robert William Bemer was a computer scientist best known for his work at IBM during the late 1950s and early 1960s.-Biography:...
as part of an article in Automatic Control Magazine. The first project to implement a time-sharing system was initiated by John McCarthy
John McCarthy (computer scientist)
John McCarthy was an American computer scientist and cognitive scientist. He coined the term "artificial intelligence" , invented the Lisp programming language and was highly influential in the early development of AI.McCarthy also influenced other areas of computing such as time sharing systems...
in late 1957, on a modified IBM 704
IBM 704
The IBM 704, the first mass-produced computer with floating point arithmetic hardware, was introduced by IBM in 1954. The 704 was significantly improved over the IBM 701 in terms of architecture as well as implementations which were not compatible with its predecessor.Changes from the 701 included...
, and later on an additionally modified IBM 7090
IBM 7090
The IBM 7090 was a second-generation transistorized version of the earlier IBM 709 vacuum tube mainframe computers and was designed for "large-scale scientific and technological applications". The 7090 was the third member of the IBM 700/7000 series scientific computers. The first 7090 installation...
computer. Although he left to work on Project MAC and other projects, one of the results of the project, known as the Compatible Time-Sharing System or CTSS, was demonstrated in November 1961. CTSS has a good claim to be the first time-sharing system and remained in use until 1973. Another contender for the first demonstrated time-sharing system was PLATO
PLATO
PLATO was the first generalized computer assisted instruction system, and, by the late 1970s, comprised several thousand terminals worldwide on nearly a dozen different networked mainframe computers...
II, created by Donald Bitzer
Donald Bitzer
Donald L. Bitzer is an American electrical engineer and computer scientist. He was the co-inventor of the plasma display, is largely regarded as the "father of PLATO", and has made a career of improving classroom productivity by using computer and telecommunications technologies.The creation of...
at a public demonstration at Robert Allerton Park
Robert Allerton Park
The Robert Allerton Park is a 1,517 acre park, nature center, and conference center located near Monticello, Illinois on the upper Sangamon River...
near the University of Illinois in early 1961. Bitzer has long said that the PLATO project would have gotten the patent on time-sharing if only the University of Illinois had known how to process patent applications faster, but at the time university patents were so few and far between, they took a long time to be submitted. The first commercially successful time-sharing system was the Dartmouth Time Sharing System
Dartmouth Time Sharing System
The Dartmouth Time-Sharing System, or DTSS for short, was the first large-scale time-sharing system to be implemented successfully. DTSS was inspired by a PDP-1-based time-sharing system at Bolt, Beranek and Newman. In 1962, John Kemeny and Thomas Kurtz at Dartmouth College submitted a grant for...
.
Development
Throughout the late 1960s and the 1970s, computer terminals were multiplexed onto large institutional mainframe computerMainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
s (central computer systems), which in many implementations sequentially polled the terminals to see if there was any additional data or action requested by the computer user. Later technology in interconnections were interrupt
Interrupt
In computing, an interrupt is an asynchronous signal indicating the need for attention or a synchronous event in software indicating the need for a change in execution....
driven, and some of these used parallel data transfer technologies such as the IEEE 488 standard. Generally, computer terminals were utilized on college properties in much the same places as desktop computer
Desktop computer
A desktop computer is a personal computer in a form intended for regular use at a single location, as opposed to a mobile laptop or portable computer. Early desktop computers are designed to lay flat on the desk, while modern towers stand upright...
s or personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
s are found today. In the earliest days of personal computers, many were in fact used as particularly smart terminals for time-sharing systems.
With the rise of microcomputing in the early 1980s, time-sharing faded into the background because the individual microprocessors were sufficiently inexpensive that a single person could have all the CPU time
CPU time
CPU time is the amount of time for which a central processing unit was used for processing instructions of a computer program, as opposed to, for example, waiting for input/output operations. The CPU time is often measured in clock ticks or as a percentage of the CPU's capacity...
dedicated solely to their needs, even when idle.
The Internet has brought the general concept of time-sharing back into popularity. Expensive corporate server farms costing millions can host thousands of customers all sharing the same common resources. As with the early serial terminals, websites operate primarily in bursts of activity followed by periods of idle time. This bursting nature permits the service to be used by many website customers at once, and none of them notice any delays in communications until the servers start to get very busy.
Time-sharing business
In the 1960s, several companies started providing time-sharing services as service bureauService bureau
A service bureau is a company which provides business services for a fee. The term has been extensively used to describe technology based services to financial services companies, particularly banks. Customers of service bureaus typically do not have the scale or expertise to incorporate these...
s. Early systems used Teletype
Teletype Corporation
The Teletype Corporation, a part of American Telephone and Telegraph Company's Western Electric manufacturing arm since 1930, came into being in 1928 when the Morkrum-Kleinschmidt Company changed its name to the name of its trademark equipment...
Model 33 KSR or ASR or Model 35 KSR or ASR in ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
environments, and IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
Selectric typewriter-based terminals in EBCDIC
EBCDIC
Extended Binary Coded Decimal Interchange Code is an 8-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems....
environments. They would connect to the central computer by dial-up Bell 103A modem or acoustically coupled
Acoustic coupler
In telecommunications, the term acoustic coupler has the following meanings:# An interface device for coupling electrical signals by acoustical means—usually into and out of a telephone instrument....
modem
Modem
A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
s operating at 10–15 characters per second. Later terminals and modems supported 30–120 characters per second. The time-sharing system would provide a complete operating environment, including a variety of programming language processors, various software packages, file storage, bulk printing, and off-line storage. Users were charged rent for the terminal, a charge for hours of connect time, a charge for seconds of CPU time, and a charge for kilobyte-months of disk storage.
Common systems used for time-sharing included the SDS 940
SDS 940
The SDS 940 was Scientific Data Systems' first machine designed to support time sharing directly, and was based on the SDS 930's 24-bit CPU built primarily of integrated circuits. It was announced in February 1966 and shipped in April, becoming a major part of Tymshare's expansion during the 1960s...
, the PDP-10
PDP-10
The PDP-10 was a mainframe computer family manufactured by Digital Equipment Corporation from the late 1960s on; the name stands for "Programmed Data Processor model 10". The first model was delivered in 1966...
, and the IBM 360. Companies providing this service included GE
Gê
Gê are the people who spoke Ge languages of the northern South American Caribbean coast and Brazil. In Brazil the Gê were found in Rio de Janeiro, Minas Gerais, Bahia, Piaui, Mato Grosso, Goias, Tocantins, Maranhão, and as far south as Paraguay....
's GEISCO, IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
subsidiary The Service Bureau Corporation, Tymshare
Tymnet
Tymnet was an international data communications network headquartered in San Jose, California that used virtual call packet switched technology and X.25, SNA/SDLC, ASCII and BSC interfaces to connect host computers at thousands of large companies, educational institutions, and government agencies....
(founded in 1966), National CSS
National CSS
National CSS, Inc. was a time-sharing firm in the 1960-80s, until its acquisition by Dun & Bradstreet in 1979. NCSS was originally headquartered in Norwalk, Connecticut, but relocated to Wilton in 1978. Sales offices, data centers, and development facilities were located at various sites...
(founded in 1967 and bought by Dun & Bradstreet in 1979), Dial Data (bought by Tymshare in 1968), and Bolt, Beranek, and Newman. By 1968, there were 32 such service bureaus serving the NIH alone. The Auerbach Guide to Timesharing 1973 edition
lists 125 different timesharing services using equipment from Burroughs, CDC
Control Data Corporation
Control Data Corporation was a supercomputer firm. For most of the 1960s, it built the fastest computers in the world by far, only losing that crown in the 1970s after Seymour Cray left the company to found Cray Research, Inc....
, DEC
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
, HP
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
, Honeywell
Honeywell
Honeywell International, Inc. is a major conglomerate company that produces a variety of consumer products, engineering services, and aerospace systems for a wide variety of customers, from private consumers to major corporations and governments....
, IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
, RCA
RCA
RCA Corporation, founded as the Radio Corporation of America, was an American electronics company in existence from 1919 to 1986. The RCA trademark is currently owned by the French conglomerate Technicolor SA through RCA Trademark Management S.A., a company owned by Technicolor...
, Univac
UNIVAC
UNIVAC is the name of a business unit and division of the Remington Rand company formed by the 1950 purchase of the Eckert-Mauchly Computer Corporation, founded four years earlier by ENIAC inventors J. Presper Eckert and John Mauchly, and the associated line of computers which continues to this day...
and XDS
Scientific Data Systems
Scientific Data Systems, or SDS, was an American computer company founded in September 1961 by Max Palevsky, a veteran of Packard Bell and Bendix, along with eleven other computer scientists. SDS was an early adopter of integrated circuits in computer design and the first to employ silicon...
.The information was shared to help poor enterprise as small and medium.
The computer utility
A great deal of thought was given in the 1970s to centralized computer resources being offered as computing utilities, the same as the electrical or telephone utilities. Ted NelsonTed Nelson
Theodor Holm Nelson is an American sociologist, philosopher, and pioneer of information technology. He coined the terms "hypertext" and "hypermedia" in 1963 and published it in 1965...
's original "Xanadu
Project Xanadu
Project Xanadu was the first hypertext project, founded in 1960 by Ted Nelson. Administrators of Project Xanadu have declared it an improvement over the World Wide Web, with mission statement: "Today's popular software simulates paper...
" hypertext repository was envisioned as such a service. It became clear as the computer industry grew that no such consolidation of computing resources would occur as timesharing systems. Some argue that the move through client-server computing to centralized server farms and virtualization presents a market for computing utilities again.
Security
Security had not been a major issue for the centralized batch processing systems that were common when the time-sharing paradigm emerged. Neither was much more than username security required on many campuses. Commercial users, especially those in the financial and retail categories, demanded much higher security and also raised the issues that are being addressed today as companies consider the outsourcing of services. The first international conference on computer security in London in 1971 was primarily driven by the time-sharing industry and its customers. The same issues are still being tackled today on the WebWorld Wide Web
The World Wide Web is a system of interlinked hypertext documents accessed via the Internet...
and with SaaS
Software as a Service
Software as a service , sometimes referred to as "on-demand software," is a software delivery model in which software and its associated data are hosted centrally and are typically accessed by users using a thin client, normally using a web browser over the Internet.SaaS has become a common...
products.
Time-sharing systems
Significant early timesharing systems:- Also see: Time-sharing system evolutionTime-sharing system evolutionAs of the middle 1960's, all computer systems were single program systems known as "batch processing": One job in and one job out. Some very large and powerful mainframes had been built, and most all of them were powered by vacuum tubes...
- Allen-BabcockAllen-BabcockAllen-Babcock Computing"Allen-Babcock Computing was founded in Los Angeles in 1964. The company was established by James Babcock and Michael Jane Allen Babcock to take advantage of the fast-growing market for computer time-sharing services."...
RUSH Time-sharing System - BBN PDP-1PDP-1The PDP-1 was the first computer in Digital Equipment Corporation's PDP series and was first produced in 1960. It is famous for being the computer most important in the creation of hacker culture at MIT, BBN and elsewhere...
Time-sharing System -> Massachusetts General Hospital PDP-1D -> MUMPS - BBN TENEXTOPS-20The TOPS-20 operating system by Digital Equipment Corporation was the second proprietary OS for the PDP-10 mainframe computer. TOPS-20 began in 1969 as the TENEX operating system of Bolt, Beranek and Newman...
-> DEC TOPS-20TOPS-20The TOPS-20 operating system by Digital Equipment Corporation was the second proprietary OS for the PDP-10 mainframe computer. TOPS-20 began in 1969 as the TENEX operating system of Bolt, Beranek and Newman...
, Foonly FOONEX, MAXC OS at PARC, Stanford LOTS - Burroughs Time-sharing MCP -> HP 3000HP 3000The HP 3000 series is a family of minicomputers released by Hewlett-Packard in 1973. It was designed to be the first minicomputer delivered with a full featured operating system with time-sharing. The first models were withdrawn from the market until speed improvements could be made. It ultimately...
MPE - Berkeley Timesharing SystemBerkeley Timesharing SystemThe Berkeley Timesharing System was a pioneering time-sharing operating system implemented between 1964 and 1967 at the University of California, Berkeley...
at UC Berkeley Project GenieProject GenieProject Genie was a computer research project started in 1964 at the University of California, Berkeley.It produced an early time-sharing system including the Berkeley Timesharing System, which was then commercialized as the SDS 940.-History:...
-> Scientific Data SystemsScientific Data SystemsScientific Data Systems, or SDS, was an American computer company founded in September 1961 by Max Palevsky, a veteran of Packard Bell and Bendix, along with eleven other computer scientists. SDS was an early adopter of integrated circuits in computer design and the first to employ silicon...
SDS 940SDS 940The SDS 940 was Scientific Data Systems' first machine designed to support time sharing directly, and was based on the SDS 930's 24-bit CPU built primarily of integrated circuits. It was announced in February 1966 and shipped in April, becoming a major part of Tymshare's expansion during the 1960s...
(TymshareTymshareTymshare, Inc. was headquartered in Cupertino, California from 1964 to 1984.It was a well-known timesharing service and third-party hardware maintenance company throughout its history and competed with companies such as Four Phase, Compuserve, and Digital Equipment Corporation...
, BBNBBNBBN might refer to:* BBN Technologies, formerly Bolt, Beranek and Newman, a technology company in Cambridge, Massachusetts, best known for its work on packet switching technology and its construction of the Interface Message Processor - the first router...
, SRI, Community Memory) -> BCC 500 -> MAXC at PARC - UC Berkeley CAL-TSS (ran on CDC 6400CDC 6000 seriesThe CDC 6000 series was a family of mainframe computers manufactured by Control Data Corporation in the 1960s. It consisted of CDC 6400, CDC 6500, CDC 6600 and CDC 6700 computers, which all were extremely rapid and efficient for their time...
) - UC Berkeley BSD UNIXUnixUnix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
- CDC Kronos
- Compu-Time, Inc (Ran on a Honeywell 400/4000) Started 1968 in Ft Lauderdale, FL, moved to Daytona Beach in 1970.
- Dartmouth Time Sharing SystemDartmouth Time Sharing SystemThe Dartmouth Time-Sharing System, or DTSS for short, was the first large-scale time-sharing system to be implemented successfully. DTSS was inspired by a PDP-1-based time-sharing system at Bolt, Beranek and Newman. In 1962, John Kemeny and Thomas Kurtz at Dartmouth College submitted a grant for...
(DTSS) -> GE Time-sharing -> GEnieGEnieGEnie was an online service created by a General Electric business - GEIS that ran from 1985 through the end of 1999. In 1994, GEnie claimed around 350,000 users. Peak simultaneous usage was around 10,000 users... - DEC PDP-6PDP-6The PDP-6 was a computer model developed by Digital Equipment Corporation in 1963. It was influential primarily as the prototype for the later PDP-10; the instruction sets of the two machines are almost identical.The PDP-6 was DEC's first "big" machine...
Time-sharing Monitor -> TOPS-10TOPS-10The TOPS-10 System was a computer operating system from Digital Equipment Corporation for the PDP-10 mainframe computer launched in 1967...
-> TSS-8TSS-8TSS-8 was a little time-sharing operating system co-written by Don Witcraft and John Everett at Digital Equipment Corporation in 1967. The operating system ran on the 12-bit PDP-8 computer and was released in 1968....
, RSTS-11RSTS/ERSTS is a multi-user time-sharing operating system, developed by Digital Equipment Corporation , for the PDP-11 series of 16-bit minicomputers. The first version of RSTS was implemented in 1970 by DEC software engineers that developed the TSS-8 time-sharing operating system for the PDP-8...
, RSX-11RSX-11RSX-11 is a family of real-time operating systems mainly for PDP-11 computers created by Digital Equipment Corporation , common in the late 1970s and early 1980s. RSX-11D first appeared on the PDP-11/40 in 1972...
-> VAX/VMS - HP-2000 Timeshared BASICBASICBASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use - the name is an acronym from Beginner's All-purpose Symbolic Instruction Code....
- IBMIBMInternational Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
TSS/360TSS/360The IBM Time Sharing System TSS/360 was an early time-sharing operating system designed exclusively for a special model of the System/360 line of mainframes, the Model 67. Made available on a trial basis to a limited set of customers in 1967, it was never officially released as a supported product... - IBMIBMInternational Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
CP-67CP-67CP-67 was the control program portion of CP/CMS, a virtual machine operating system developed for the IBM System/360-67 by IBM's Cambridge Scientific Center. It was a reimplementation of their earlier research system CP-40, which ran on a one-off customized S/360-40...
-> VM/CMS - IBMIBMInternational Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
CALL/360, CALL/OS - using IBM 360/50 - International Timesharing Corporation
- Michigan Terminal SystemMichigan Terminal SystemThe Michigan Terminal System is one of the first time-sharing computer operating systems. Initially developed in 1967 at the University of Michigan for use on IBM S/360-67, S/370 and compatible mainframe computers, it was developed and used by a consortium of eight universities in the United...
- Michigan State University CDC SCOPE/HUSTLER System
- MIT CTSS -> MULTICSMulticsMultics was an influential early time-sharing operating system. The project was started in 1964 in Cambridge, Massachusetts...
(MIT/GE/Bell Labs) -> UNIXUnixUnix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
, PRIMOSPRIMOSPRIMOS was an operating system developed during the 1970s by Prime Computer for its minicomputer systems. It rapidly gained popularity and by the mid-1980s was a serious contender as a mainline minicomputer operating system... - MIT PDP-1 Time-sharing System -> ITSIncompatible Timesharing SystemITS, the Incompatible Timesharing System , was an early, revolutionary, and influential time-sharing operating system from MIT; it was developed principally by the Artificial Intelligence Laboratory at MIT, with some help from Project MAC.In addition to being technically influential ITS, the...
- MUSIC/SPMUSIC/SPMUSIC/SP was developed at McGill University in the 1970s from an early IBM time-sharing system called RAX...
-> McGill University System for Interactive Computing - National CSSNational CSSNational CSS, Inc. was a time-sharing firm in the 1960-80s, until its acquisition by Dun & Bradstreet in 1979. NCSS was originally headquartered in Norwalk, Connecticut, but relocated to Wilton in 1978. Sales offices, data centers, and development facilities were located at various sites...
-> VP/CSSVP/CSSVP/CSS was a time-sharing operating system developed by National CSS. It began life in 1968 as a copy of IBM's CP/CMS, which at the time was distributed to IBM customers at no charge, in source code form, without support, as part of the IBM Type-III Library...
(ran on IBM 360 series; originally based on IBM's CP/CMSCP/CMSCP/CMS was a time-sharing operating system of the late 60s and early 70s, known for its excellent performance and advanced features... - Oregon State University OS-3 (ran on CDC 3000CDC 3000The CDC 3000 series computers from Control Data Corporation were mid-1960s follow-ons to the CDC 1604 and CDC 924 systems. Over time, a range of machines were produced - divided into the 'upper 3000 series' and the 'lower 3000 series'. CDC phased out production of the 3000 series in the early 1970s...
series) - RANDRANDRAND Corporation is a nonprofit global policy think tank first formed to offer research and analysis to the United States armed forces by Douglas Aircraft Company. It is currently financed by the U.S. government and private endowment, corporations including the healthcare industry, universities...
JOSSJOSSJOSS was one of the very first interactive, time sharing programming languages.JOSS I, developed by J. Clifford Shaw at RAND was first implemented, in beta form, on the JOHNNIAC computer in May 1963...
-> JOSS-2 -> JOSS-3 - RCA Time Sharing Operating SystemTime Sharing Operating SystemTime Sharing Operating System, or TSOS, was an operating system for RCA mainframe computers of the Spectra 70 series.RCA was in the computer business until 1971. Then it sold its computer business to Sperry Corporation; Sperry offered TSOS renaming it to VS/9...
- Service in Informatics and Analysis (SIA)Service in Informatics and AnalysisService in Informatics and Analysis , was one of the pioneering time-sharing service bureau companies in the late 1960s, Later known as SIA Computer Services. Its head office was located at Lower Belgrave Street, close to Victoria Station in London, and the company had branch offices in Edinburgh,...
(ran on CDC 6600CDC 6600The CDC 6600 was a mainframe computer from Control Data Corporation, first delivered in 1964. It is generally considered to be the first successful supercomputer, outperforming its fastest predecessor, IBM 7030 Stretch, by about three times...
KronosKronosKronos can refer to:*Cronus, a Titan, the father of Zeus, Poseidon, Hades, Hestia, Demeter, Hera, and Chiron.In business*Kronos Foods, the world's largest manufacturer of gyrosIn computing...
system) - System Development CorporationSystem Development CorporationSystem Development Corporation , based in Santa Monica, California, was considered the world's first computer software company.SDC started in 1955 as the systems engineering group for the SAGE air defense ground system at the RAND Corporation...
Time-sharing System on the AN/FSQ-32AN/FSQ-32The AN/FSQ-32 was a computer made by IBM in 1960 and 1961 for the United States Air Force Strategic Air Command . IBM called it the 4020 Military Computer, but it was more commonly known as the Q-32. Only one unit was ever built.-History:The Q-32 was installed at System Development Corporation ... - Stanford PDP-1 Time-sharing System -> SAIL -> WAITSWAITSWAITS was a heavily-modified variant of Digital Equipment Corporation's Monitor operating system for the PDP-6 and PDP-10 mainframe computers, used at the Stanford Artificial Intelligence Laboratory up until 1990; the mainframe computer it ran on also went by the name of "SAIL".There was never an...
- Time Sharing Ltd. First commercial Time-sharing system in Europe and first dual (fault tolerant) Time-sharing system.
- TymshareTymshareTymshare, Inc. was headquartered in Cupertino, California from 1964 to 1984.It was a well-known timesharing service and third-party hardware maintenance company throughout its history and competed with companies such as Four Phase, Compuserve, and Digital Equipment Corporation...
SDS-940 -> Tymcom X -> Tymcom XX - XDSScientific Data SystemsScientific Data Systems, or SDS, was an American computer company founded in September 1961 by Max Palevsky, a veteran of Packard Bell and Bendix, along with eleven other computer scientists. SDS was an early adopter of integrated circuits in computer design and the first to employ silicon...
CP-V -> Honeywell CP-6CP-6This article is about the satellite. For the operating system, see CP-6 operating systemCP-6, also known as PolySat-6, PolySat CP-6 or CalPoly 6 is a single-unit CubeSat which was built and is operated by the California Polytechnic State University. It is primarily intended to perform a technology... - Univac/Unisys VMOS, VS/9VS/9VS/9 was a computer operating system available for the Univac 90/60, 90/70 and 90/80 mainframe during the late 1960s through 1980s. The 90/60 and 90/70 were repackaged Univac 9700 computers...
See also
- Multiseat
- Linux Terminal Server ProjectLinux Terminal Server ProjectLinux Terminal Server Project is a free and open source terminal server for Linux that allows many people to simultaneously use the same computer. Applications run on the server with a terminal known as a thin client handling input and output...
- Thin clientThin clientA thin client is a computer or a computer program which depends heavily on some other computer to fulfill its traditional computational roles. This stands in contrast to the traditional fat client, a computer designed to take on these roles by itself...
- Centralized computingCentralized computingCentralized computing is computing done at a central location, using terminals that are attached to a central computer. The computer itself may control all the peripherals directly , or they may be attached via a terminal server...
- TELCOMPTELCOMPTELCOMP was a programming language developed at Bolt, Beranek and Newman in about 1965 and in use until at least 1974.It was an interactive, conversational language based on JOSS, developed by BBN after Cliff Shaw from RAND visited the labs in 1964 as part of the NIH survey...
Computer utilities
- Robert Frankston "The Computer Utility As A Marketplace For Computer Services" 1973
- Ted Nelson "Dream Machines" pp. 56,57
Time-sharing systems
- The Multics History Web Site
- DTSS Web site
- Time-sharing System Surveys (1965-67) at bitsavers.org
- BBN TENEX Documentation at bitsavers.org
- UCB Project Genie Documentation at bitsavers.org
- CAL TSS Documentation at bitsavers.org
- CAL TSS Archives at mcjones.org
- SDS-940 Documentation at bitsavers.org
- Berkeley Computer Corporation BCC-500 Documentation at bitsavers.org
- CDC Kronos Documentation at bitsavers.org
- Dartmouth DTSS Documentation at bitsavers.org
- TOPS-10 Documentation at bitsavers.org
- TOPS-20 Documentation at bitsavers.org
- GE Mark I Timesharing Documentation at bitsavers.org
- MULTICS Documentation at bitsavers.org
- Honeywell CP-6 Documentation at bitsavers.org
- HP-2000 Timeshared BASIC System Documentation at bitsavers.org
- IBM TSS-360 Documentation at bitsavers.org
- MIT CTSS - Compatible Time-Sharing System
- MIT PDP-1 Time-sharing System Documentation at bitsavers.org
- Oregon State OS-3 Documentation at bitsavers.org
- Rand JOSS Documentation at bitsavers.org
- Stanford PDP-1 Documentation at bitsavers.org
- Tymshare Documentation at bitsavers.org
- XDS Sigma CP-V Documentation at bitsavers.org
External links
- Reminiscences of the history of time sharing by John McCarthyJohn McCarthy (computer scientist)John McCarthy was an American computer scientist and cognitive scientist. He coined the term "artificial intelligence" , invented the Lisp programming language and was highly influential in the early development of AI.McCarthy also influenced other areas of computing such as time sharing systems...
- Origins of timesharing by Bob BemerBob BemerRobert William Bemer was a computer scientist best known for his work at IBM during the late 1950s and early 1960s.-Biography:...
- Interview with Professor Fernando J. Corbato on the history of Multics and origins of time-sharing