This article covers the evolution of time-sharing systems, providing links to major early

time-sharing In computing, time-sharing is the sharing of a computing resource among many users at the same time by means of multiprogramming and multi-tasking.DEC Timesharing (1965), by Peter Clark, The DEC Professional, Volume 1, Number 1 Its emergence a ...

operating systems, showing their subsequent evolution.

Time-sharing

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 if a multitasking, multiprogramming operating system allowed multiple users simultaneous interactive access. Typically 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. Each user would use their own computer terminal, initially electromechanical

teleprinter A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point and point-to-multipoint configurations. Initia ...

s such as the

Teletype Model 33 The Teletype Model 33 is an electromechanical teleprinter designed for light-duty office use. It is less rugged and cost less than earlier Teletype machines. The Teletype Corporation introduced the Model 33 as a commercial product in 1963 after ...

ASR or the Friden Flexowriter; from about 1970 these were progressively superseded by

CRT CRT or Crt may refer to: Science, technology, and mathematics Medicine and biology * Calreticulin, a protein *Capillary refill time, for blood to refill capillaries *Cardiac resynchronization therapy and CRT defibrillator (CRT-D) * Catheter-re ...

–based units such as the DEC

VT05 :''"VT-05" can also refer to .'' The VT05 is the first free-standing CRT computer terminal from Digital Equipment Corporation introduced in 1970. Famous for its futuristic styling, the VT05 presents the user with an upper-case-only ASCII charac ...

, Datapoint 2200 and Lear Siegler ADM-3A. Terminals were initially linked to a nearby computer via current loop or serial cables, by conventional telegraph circuits provided by PTTs and over specialist digital

leased line A leased line is a private telecommunications circuit between two or more locations provided according to a commercial contract. It is sometimes also known as a private circuit, and as a data line in the UK. Typically, leased lines are used by ...

s such T1.

Modem A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by Modulation#Digital modulati ...

s such as the

Bell 103 The Bell 103 modem or Bell 103 dataset was the second commercial modem for computers, released by AT&T Corporation in 1962. It allowed digital data to be transmitted over regular unconditioned telephone lines at a speed of 300 bits per second. It ...

and successors, allowed remote and higher-speed use over the analogue voice telephone network.

Family tree of major systems

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 was the first time-sharing system developed outside the United States.

System descriptions and relationships

References

{{Time-sharing operating systems History of software Time-sharing system evolution

Time-sharing

Family tree of major systems

System descriptions and relationships

See also

References