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Williams Tube
The Williams tube, or the Williams–Kilburn tube named after inventors Freddie Williams and Tom Kilburn, is an early form of computer memory. It was the first random-access digital storage device, and was used successfully in several early computers. The Williams tube works by displaying a grid of dots on a cathode-ray tube (CRT). Due to the way CRTs work, this creates a small charge of static electricity over each dot. The charge at the location of each of the dots is read by a thin metal sheet just in front of the display. Since the display faded over time, it was periodically refreshed. It operates faster than earlier acoustic delay-line memory, at the speed of the electrons inside the vacuum tube, rather than at the speed of sound. The system was adversely affected by nearby electrical fields, and required frequent adjustment to remain operational. Williams–Kilburn tubes were used primarily on high-speed computer designs. Williams and Kilburn applied for British patents ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Williams Tube
The Williams tube, or the Williams–Kilburn tube named after inventors Freddie Williams and Tom Kilburn, is an early form of computer memory. It was the first random-access digital storage device, and was used successfully in several early computers. The Williams tube works by displaying a grid of dots on a cathode-ray tube (CRT). Due to the way CRTs work, this creates a small charge of static electricity over each dot. The charge at the location of each of the dots is read by a thin metal sheet just in front of the display. Since the display faded over time, it was periodically refreshed. It operates faster than earlier acoustic delay-line memory, at the speed of the electrons inside the vacuum tube, rather than at the speed of sound. The system was adversely affected by nearby electrical fields, and required frequent adjustment to remain operational. Williams–Kilburn tubes were used primarily on high-speed computer designs. Williams and Kilburn applied for British patents ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flip-flop (electronics)
In electronics, a flip-flop or latch is a circuit that has two stable states and can be used to store state information – a bistable multivibrator. The circuit can be made to change state by signals applied to one or more control inputs and will have one or two outputs. It is the basic storage element in sequential logic. Flip-flops and latches are fundamental building blocks of digital electronics systems used in computers, communications, and many other types of systems. Flip-flops and latches are used as data storage elements. A flip-flop is a device which stores a single '' bit'' (binary digit) of data; one of its two states represents a "one" and the other represents a "zero". Such data storage can be used for storage of ''state'', and such a circuit is described as sequential logic in electronics. When used in a finite-state machine, the output and next state depend not only on its current input, but also on its current state (and hence, previous inputs). It can also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNIVAC 1103
The UNIVAC 1103 or ERA 1103, a successor to the UNIVAC 1101, was a computer system designed by Engineering Research Associates and built by the Remington Rand corporation in October 1953. It was the first computer for which Seymour Cray was credited with design work. History Even before the completion of the ''Atlas'' (UNIVAC 1101), the Navy asked Engineering Research Associates to design a more powerful machine. This project became Task 29, and the computer was designated ''Atlas II''. In 1952, Engineering Research Associates asked the Armed Forces Security Agency (the predecessor of the NSA) for approval to sell the ''Atlas II'' commercially. Permission was given, on the condition that several specialized instructions would be removed. The commercial version then became the UNIVAC 1103. Because of security classification, Remington Rand management was unaware of this machine before this. The first commercially sold UNIVAC 1103 was sold to the aircraft manufacturer Convair, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selectron Tube
The Selectron was an early form of digital computer memory developed by Jan A. Rajchman and his group at the Radio Corporation of America (RCA) under the direction of Vladimir K. Zworykin. It was a vacuum tube that stored digital data as electrostatic charges using technology similar to the Williams tube storage device. The team was never able to produce a commercially viable form of Selectron before magnetic-core memory became almost universal. Development Development of Selectron started in 1946 at the behest of John von Neumann of the Institute for Advanced Study, who was in the midst of designing the IAS machine and was looking for a new form of high-speed memory. RCA's original design concept had a capacity of 4096 bits, with a planned production of 200 by the end of 1946. They found the device to be much more difficult to build than expected, and they were still not available by the middle of 1948. As development dragged on, the IAS machine was forced to switch to Wil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IAS Machine
The IAS machine was the first electronic computer built at the Institute for Advanced Study (IAS) in Princeton, New Jersey. It is sometimes called the von Neumann machine, since the paper describing its design was edited by John von Neumann, a mathematics professor at both Princeton University and IAS. The computer was built from late 1945 until 1951 under his direction. The general organization is called von Neumann architecture, even though it was both conceived and implemented by others. The computer is in the collection of the Smithsonian National Museum of American History but is not currently on display. History Julian Bigelow was hired as chief engineer in May 1946. Hewitt Crane, Herman Goldstine, Gerald Estrin, Arthur Burks, George W. Brown and Willis Ware also worked on the project. The machine was in limited operation in the summer of 1951 and fully operational on June 10, 1952. It was in operation until July 15, 1958. Description The IAS machine was a binary co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferranti Mark 1
The Ferranti Mark 1, also known as the Manchester Electronic Computer in its sales literature, and thus sometimes called the Manchester Ferranti, was produced by British electrical engineering firm Ferranti Ltd. It was the world's first commercially available general-purpose digital computer. It was "the tidied up and commercialised version of the Manchester Mark I". The first machine was delivered to the Victoria University of Manchester in February 1951 (publicly demonstrated in July) ahead of the UNIVAC I, which was sold to the United States Census Bureau on 31 March 1951, although not delivered until late December the following year. History and specifications Based on the Manchester Mark 1, which was designed at the University of Manchester by Freddie Williams and Tom Kilburn, the machine was built by Ferranti of the United Kingdom. The main improvements over it were in the size of the primary and secondary storage, a faster multiplier, and additional instructions. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manchester Mark 1
The Manchester Mark 1 was one of the earliest stored-program computers, developed at the Victoria University of Manchester, England from the Manchester Baby (operational in June 1948). Work began in August 1948, and the first version was operational by April 1949; a program written to search for Mersenne primes ran error-free for nine hours on the night of 16/17 June 1949. The machine's successful operation was widely reported in the British press, which used the phrase "electronic brain" in describing it to their readers. That description provoked a reaction from the head of the University of Manchester's Department of Neurosurgery, the start of a long-running debate as to whether an electronic computer could ever be truly creative. The Mark 1 was to provide a computing resource within the university, to allow researchers to gain experience in the practical use of computers, but it very quickly also became a prototype on which the design of Ferranti's commercial version cou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proper Factor
In mathematics, a divisor of an integer n, also called a factor of n, is an integer m that may be multiplied by some integer to produce n. In this case, one also says that n is a multiple of m. An integer n is divisible or evenly divisible by another integer m if m is a divisor of n; this implies dividing n by m leaves no remainder. Definition An integer is divisible by a nonzero integer if there exists an integer such that n=km. This is written as :m\mid n. Other ways of saying the same thing are that divides , is a divisor of , is a factor of , and is a multiple of . If does not divide , then the notation is m\not\mid n. Usually, is required to be nonzero, but is allowed to be zero. With this convention, m \mid 0 for every nonzero integer . Some definitions omit the requirement that m be nonzero. General Divisors can be negative as well as positive, although sometimes the term is restricted to positive divisors. For example, there are six divisors of 4; they ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testbed
A testbed (also spelled test bed) is a platform for conducting rigorous, transparent, and replicable testing of scientific theories, computational tools, and new technologies. The term is used across many disciplines to describe experimental research and new product development platforms and environments. They may vary from hands-on prototype development in manufacturing industries such as automobiles (known as " mules"), aircraft engines or systems and to intellectual property refinement in such fields as computer software development shielded from the hazards of testing live. Software development In software development, testbedding is a method of testing a particular module (function, class, or library) in an isolated fashion. It may be used as a proof of concept or when a new module is tested apart from the program/system it will later be added to. A skeleton framework is implemented around the module so that the module behaves as if already part of the larger program. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manchester Baby
The Manchester Baby, also called the Small-Scale Experimental Machine (SSEM), was the first electronic stored-program computer. It was built at the University of Manchester by Frederic C. Williams, Tom Kilburn, and Geoff Tootill, and ran its first program on 21 June 1948. The Baby was not intended to be a practical computing engine, but was instead designed as a testbed for the Williams tube, the first truly random-access memory. Described as "small and primitive" 50 years after its creation, it was the first working machine to contain all the elements essential to a modern electronic digital computer. As soon as the Baby had demonstrated the feasibility of its design, a project was initiated at the university to develop it into a full scale operational machine, the . The Mark 1 in turn quickly became the prototype for the Ferranti Mark 1, the world's first commercially available general-purpose computer. The Baby had a 32- bit word length and a memory of 32 words (1 k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Victoria University Of Manchester
The Victoria University of Manchester, usually referred to as simply the University of Manchester, was a university in Manchester, England. It was founded in 1851 as Owens College. In 1880, the college joined the federal Victoria University. After the demerger of the Victoria University, it gained an independent university charter in 1904 as the Victoria University of Manchester. On 1 October 2004, the Victoria University of Manchester merged with the University of Manchester Institute of Science and Technology (UMIST) to form a new, larger entity named the University of Manchester. History 1851–1951 Owens College was founded in 1851, named after John Owens, a textile merchant, who left a bequest of £96,942 for the purpose. Its first accommodation was at Cobden House on Quay Street, Manchester, in a house which had been the residence of Richard Cobden. In 1859, Owens College was approved as a provincial examination centre for matriculation candidates of the University of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
