Donald Davies
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Donald Davies
Donald Watts Davies, (7 June 1924 – 28 May 2000) was a Welsh computer scientist who was employed at the UK National Physical Laboratory (NPL). In 1965 he conceived of packet switching, which is today the dominant basis for data communications in computer networks worldwide. Davies proposed a commercial national data network in the United Kingdom and designed and built the local-area NPL network to demonstrate the technology. Many of the wide-area packet-switched networks built in the 1970s were similar "in nearly all respects" to his original 1965 design. The ARPANET project credited Davies for his influence, which was key to the development of the Internet. Davies' work was independent of the work of Paul Baran in the United States who had a similar idea in the early 1960s, and who also provided input to the ARPANET project, after his work was highlighted by Davies' team. Early life Davies was born in Treorchy in the Rhondda Valley, Wales. His father, a clerk at a coal ...
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NPL Network
The NPL network, or NPL Data Communications Network, was a local area computer network operated by a team from the National Physical Laboratory in London that pioneered the concept of packet switching. Based on designs first conceived by Donald Davies in 1965, development work began in 1968. Elements of the first version of the network, the Mark I, became operational during 1969 then fully operational in January 1970, and the Mark II version operated from 1973 until 1986. The NPL network and the ARPANET in the United States were the first two computer networks that implemented packet switching and the NPL network was the first to use high-speed links. Origins In 1965, Donald Davies, who was later appointed to head of the NPL Division of Computer Science, proposed a commercial national data network based on packet switching in ''Proposal for the Development of a National Communications Service for On-line Data Processing''. After the proposal was not taken up nationally, during ...
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Treorchy
Treorchy ( cy, Treorci; ) is a town and community (and electoral ward) in Wales. Once a mining town, it retains such characteristics. Situated in the county borough of Rhondda Cynon Taf in the Rhondda Fawr valley. Treorchy is also one of the 16 communities of the Rhondda. It includes the villages of Cwmparc and Ynyswen. History Prior to industrialisation, most of the land was owned by one of the great families of Glamorgan with Treorchy coming under the domain of the Marquess of Bute Estate. The discovery of coal transformed the area. The period following 1851 saw Treorchy becoming an industrial town. The town grew around the coal mining industry during the late 19th and early 20th century, but by the end of the 20th century all the local pits had closed, creating an economic downturn in the community. Treorchy had been established when the Abergorki Colliery, situated in Cwm Orci to the north, was opened as a level in 1859 by a Mr Huxham, a former manager of the Bute Merthyr Co ...
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Portsmouth
Portsmouth ( ) is a port and city in the ceremonial county of Hampshire in southern England. The city of Portsmouth has been a unitary authority since 1 April 1997 and is administered by Portsmouth City Council. Portsmouth is the most densely populated city in the United Kingdom, with a population last recorded at 208,100. Portsmouth is located south-west of London and south-east of Southampton. Portsmouth is mostly located on Portsea Island; the only English city not on the mainland of Great Britain. Portsea Island has the third highest population in the British Isles after the islands of Great Britain and Ireland. Portsmouth also forms part of the regional South Hampshire conurbation, which includes the city of Southampton and the boroughs of Eastleigh, Fareham, Gosport, Havant and Waterlooville. Portsmouth is one of the world's best known ports, its history can be traced to Roman times and has been a significant Royal Navy dockyard and base for centuries. Portsm ...
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Router (computing)
A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions between networks and on the global Internet. Data sent through a network, such as a web page or email, is in the form of data packets. A packet is typically forwarded from one router to another router through the networks that constitute an internetwork (e.g. the Internet) until it reaches its destination node. A router is connected to two or more data lines from different IP networks. When a data packet comes in on one of the lines, the router reads the network address information in the packet header to determine the ultimate destination. Then, using information in its routing table or routing policy, it directs the packet to the next network on its journey. The most familiar type of IP routers are home and small office routers that simply forward IP packets between the home computers and the Internet. More sophisticated routers, ...
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Massachusetts Institute Of Technology
The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the most prestigious and highly ranked academic institutions in the world. Founded in response to the increasing industrialization of the United States, MIT adopted a European polytechnic university model and stressed laboratory instruction in applied science and engineering. MIT is one of three private land grant universities in the United States, the others being Cornell University and Tuskegee University. The institute has an urban campus that extends more than a mile (1.6 km) alongside the Charles River, and encompasses a number of major off-campus facilities such as the MIT Lincoln Laboratory, the Bates Center, and the Haystack Observatory, as well as affiliated laboratories such as the Broad and Whitehead Institutes. , 98 ...
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Teddington
Teddington is a suburb in south-west London in the London Borough of Richmond upon Thames. In 2021, Teddington was named as the best place to live in London by ''The Sunday Times''. Historically in Middlesex, Teddington is situated on a long meander of the Thames between Hampton Wick and Strawberry Hill, Twickenham. Mostly residential, it stretches from the river to Bushy Park with a long high street of shops, restaurants and pubs. There is a suspension bridge over the lowest non-tidal lock on the Thames, Teddington Lock. At Teddington's centre is a mid-rise urban development, containing offices and apartments. Economy Teddington is bisected by an almost continuous road of shops, offices and other facilities running from the river to Bushy Park. There are two clusters of offices on this route; on the edge of Bushy Park the National Physical Laboratory, National Measurement Office and LGC form a scientific centre. Around Teddington station and the town centre are a number o ...
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English Electric Computers
English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national identity, an identity and common culture ** English language in England, a variant of the English language spoken in England * English languages (other) * English studies, the study of English language and literature * ''English'', an Amish term for non-Amish, regardless of ethnicity Individuals * English (surname), a list of notable people with the surname ''English'' * People with the given name ** English McConnell (1882–1928), Irish footballer ** English Fisher (1928–2011), American boxing coach ** English Gardner (b. 1992), American track and field sprinter Places United States * English, Indiana, a town * English, Kentucky, an unincorporated community * English, Brazoria County, Texas, an unincorporated community * Englis ...
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English Electric DEUCE
The DEUCE (''Digital Electronic Universal Computing Engine'') was one of the earliest United Kingdom, British commercially available computers, built by English Electric from 1955. It was the production version of the Pilot ACE, itself a cut-down version of Alan Turing's Automatic Computing Engine, ACE. Hardware description The DEUCE had 1450 thermionic valves, and used mercury (element), mercury delay-line memory, delay lines for its main memory; each of the 12 delay lines could store 32 instructions or data words of 32 bits each. It adopted the then high 1 megahertz clock rate of the Pilot ACE. Input/output was via Hollerith 80-column punch-card equipment. The reader read cards at the rate of 200 per minute, while the card punch rate was 100 cards per minute. The DEUCE also had an 8192-word magnetic drum for main storage. To access any of the 256 tracks of 32 words, the drum had one group of 16 read and one group of 16 write heads, each group on indepen ...
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Pilot ACE
The Pilot ACE (Automatic Computing Engine) was one of the first computers built in the United Kingdom. Built at the National Physical Laboratory (NPL) in the early 1950s, it was also one of the earliest general-purpose, stored-program computers – joining other UK designs like the Manchester Mark 1 and EDSAC of the same era. It was a preliminary version of the full ACE, which was designed by Alan Turing, who left NPL before the construction was completed. History Pilot ACE was built to a cut down version of Turing's full ACE design. After Turing left NPL (in part because he was disillusioned by the lack of progress on building the ACE), James H. Wilkinson took over the project. Donald Davies, Harry Huskey and Mike Woodger were involved with the design. The Pilot ACE ran its first program on 10 May 1950, and was demonstrated to the press in November 1950. Although originally intended as a prototype, it became clear that the machine was a potentially useful resource, especiall ...
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Universal Turing Machine
In computer science, a universal Turing machine (UTM) is a Turing machine that can simulate an arbitrary Turing machine on arbitrary input. The universal machine essentially achieves this by reading both the description of the machine to be simulated as well as the input to that machine from its own tape. Alan Turing introduced the idea of such a machine in 1936–1937. This principle is considered to be the origin of the idea of a stored-program computer used by John von Neumann in 1946 for the "Electronic Computing Instrument" that now bears von Neumann's name: the von Neumann architecture. Martin Davis, ''The universal computer : the road from Leibniz to Turing'' (2017) In terms of computational complexity, a multi-tape universal Turing machine need only be slower by logarithmic factor compared to the machines it simulates. Introduction Every Turing machine computes a certain fixed partial computable function from the input strings over its alphabet. In that sense it be ...
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Software Bug
A software bug is an error, flaw or fault in the design, development, or operation of computer software that causes it to produce an incorrect or unexpected result, or to behave in unintended ways. The process of finding and correcting bugs is termed " debugging" and often uses formal techniques or tools to pinpoint bugs. Since the 1950s, some computer systems have been designed to deter, detect or auto-correct various computer bugs during operations. Bugs in software can arise from mistakes and errors made in interpreting and extracting users' requirements, planning a program's design, writing its source code, and from interaction with humans, hardware and programs, such as operating systems or libraries. A program with many, or serious, bugs is often described as ''buggy''. Bugs can trigger errors that may have ripple effects. The effects of bugs may be subtle, such as unintended text formatting, through to more obvious effects such as causing a program to crash, freezing th ...
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Automatic Computing Engine
The Automatic Computing Engine (ACE) was a British early electronic serial stored-program computer designed by Alan Turing. It was based on the earlier Pilot ACE. It led to the MOSAIC computer, the Bendix G-15, and other computers. Background The project was managed by John R. Womersley, superintendent of the Mathematics Division of the National Physical Laboratory (NPL). The use of the word ''Engine'' was in homage to Charles Babbage and his Difference Engine and Analytical Engine. Turing's technical design ''Proposed Electronic Calculator'' was the product of his theoretical work in 1936 "On Computable Numbers" (and ) and his wartime experience at Bletchley Park where the Colossus computers had been successful in breaking German military codes. In his 1936 paper, Turing described his idea as a "universal computing machine", but it is now known as the Universal Turing machine. Turing was sought by Womersley to work in the NPL on the ACE project; he accepted and beg ...
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