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EDSAC 2
EDSAC 2 was an early computer (operational in 1958), the successor to the Electronic Delay Storage Automatic Calculator (EDSAC). It was the first computer to have a microprogrammed control unit and a bit-slice hardware architecture. First calculations were performed on incomplete machine in 1957. Calculations about elliptic curves performed on EDSAC-2 in the early 1960s led to the Birch and Swinnerton-Dyer conjecture, a Millennium Prize Problem, unsolved as of 2022. And in 1963, Frederick Vine and Drummond Matthews Drummond Hoyle Matthews FRS (5 February 1931 – 20 July 1997), known as "Drum", was a British marine geologist and geophysicist and a key contributor to the theory of plate tectonics. His work, along with that of fellow Briton Fred Vine a ... used EDSAC 2 to generate a seafloor magnetic anomaly map from data collected in the Indian Ocean by H.M.S. Owen, key evidence that helped support Plate Tectonic theory. References Early British computers On ...
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Two-out-of-five Code
A two-out-of-five code is a constant-weight code that provides exactly ten possible combinations of two bits, and is thus used for representing the decimal digits using five bits. Each bit is assigned a weight, such that the set bits sum to the desired value, with an exception for zero. According to Federal Standard 1037C: * each decimal digit is represented by a binary numeral consisting of five bits of which two are of one kind, called ''ones'', and three are of the other kind, called ''zeros'', and * the usual weights assigned to the bit positions are 0-1-2-3-6. However, in this scheme, zero is encoded as binary ''01100''; strictly speaking the 0-1-2-3-6 previously claimed is just a mnemonic device. The weights give a unique encoding for most digits, but allow two encodings for 3: 0+3 or 10010 and 1+2 or 01100. The former is used to encode the digit 3, and the latter is used to represent the otherwise unrepresentable zero. The IBM 7070, IBM 7072, and IBM 7074 computers ...
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EDSAC
The Electronic Delay Storage Automatic Calculator (EDSAC) was an early British computer. Inspired by John von Neumann's seminal ''First Draft of a Report on the EDVAC'', the machine was constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England. EDSAC was the second electronic digital stored-program computer to go into regular service. Later the project was supported by J. Lyons & Co. Ltd., intending to develop a commercially applied computer and succeeding in Lyons' development of LEO I, based on the EDSAC design. Work on EDSAC started during 1947, and it ran its first programs on 6 May 1949, when it calculated a table of square numbers and a list of prime numbers. EDSAC was finally shut down on 11 July 1958, having been superseded by EDSAC 2, which remained in use until 1965. Technical overview Physical components As soon as EDSAC was operational, it began serving the university's research needs. It us ...
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Computer
A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as Computer program, programs. These programs enable computers to perform a wide range of tasks. A computer system is a nominally complete computer that includes the Computer hardware, hardware, operating system (main software), and peripheral equipment needed and used for full operation. This term may also refer to a group of computers that are linked and function together, such as a computer network or computer cluster. A broad range of Programmable logic controller, industrial and Consumer electronics, consumer products use computers as control systems. Simple special-purpose devices like microwave ovens and remote controls are included, as are factory devices like industrial robots and computer-aided design, as well as general-purpose devi ...
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Electronic Delay Storage Automatic Calculator
The Electronic Delay Storage Automatic Calculator (EDSAC) was an early British computer. Inspired by John von Neumann's seminal ''First Draft of a Report on the EDVAC'', the machine was constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England. EDSAC was the second electronic digital stored-program computer to go into regular service. Later the project was supported by J. Lyons & Co. Ltd., intending to develop a commercially applied computer and succeeding in Lyons' development of LEO I, based on the EDSAC design. Work on EDSAC started during 1947, and it ran its first programs on 6 May 1949, when it calculated a table of square numbers and a list of prime numbers. EDSAC was finally shut down on 11 July 1958, having been superseded by EDSAC 2, which remained in use until 1965. Technical overview Physical components As soon as EDSAC was operational, it began serving the university's research needs. It u ...
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Microcode
In processor design, microcode (μcode) is a technique that interposes a layer of computer organization between the central processing unit (CPU) hardware and the programmer-visible instruction set architecture of a computer. Microcode is a layer of hardware-level instructions that implement higher-level machine code instructions or internal finite-state machine sequencing in many digital processing elements. Microcode is used in general-purpose central processing units, although in current desktop CPUs, it is only a fallback path for cases that the faster hardwired control unit cannot handle. Microcode typically resides in special high-speed memory and translates machine instructions, state machine data, or other input into sequences of detailed circuit-level operations. It separates the machine instructions from the underlying electronics so that instructions can be designed and altered more freely. It also facilitates the building of complex multi-step instructions, while red ...
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Control Unit
The control unit (CU) is a component of a computer's central processing unit (CPU) that directs the operation of the processor. A CU typically uses a binary decoder to convert coded instructions into timing and control signals that direct the operation of the other units (memory, arithmetic logic unit and input and output devices, etc.). Most computer resources are managed by the CU. It directs the flow of data between the CPU and the other devices. John von Neumann included the control unit as part of the von Neumann architecture. In modern computer designs, the control unit is typically an internal part of the CPU with its overall role and operation unchanged since its introduction. Multicycle control units The simplest computers use a multicycle microarchitecture. These were the earliest designs. They are still popular in the very smallest computers, such as the embedded systems that operate machinery. In a multicycle computer, the control unit often steps through the i ...
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Bit-slice
Bit slicing is a technique for constructing a processor from modules of processors of smaller bit width, for the purpose of increasing the word length; in theory to make an arbitrary ''n''-bit central processing unit (CPU). Each of these component modules processes one bit field or "slice" of an operand. The grouped processing components would then have the capability to process the chosen full word-length of a given software design. Bit slicing more or less died out due to the advent of the microprocessor. Recently it has been used in arithmetic logic units (ALUs) for quantum computers and as a software technique, e.g. for cryptography in x86 CPUs. Operational details Bit-slice processors (BSPs) usually include 1-, 2-, 4-, 8- or 16-bit arithmetic logic unit (ALU) and control lines (including carry or overflow signals that are internal to the processor in non-bitsliced CPU designs). For example, two 4-bit ALU chips could be arranged side by side, with control lines ...
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EDSAC II Chassis Construction
The Electronic Delay Storage Automatic Calculator (EDSAC) was an early British computer. Inspired by John von Neumann's seminal ''First Draft of a Report on the EDVAC'', the machine was constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England. EDSAC was the second electronic digital stored-program computer to go into regular service. Later the project was supported by J. Lyons & Co. Ltd., intending to develop a commercially applied computer and succeeding in Lyons' development of LEO I, based on the EDSAC design. Work on EDSAC started during 1947, and it ran its first programs on 6 May 1949, when it calculated a table of square numbers and a list of prime numbers. EDSAC was finally shut down on 11 July 1958, having been superseded by EDSAC 2, which remained in use until 1965. Technical overview Physical components As soon as EDSAC was operational, it began serving the university's research needs. It u ...
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Birch And Swinnerton-Dyer Conjecture
In mathematics, the Birch and Swinnerton-Dyer conjecture (often called the Birch–Swinnerton-Dyer conjecture) describes the set of rational solutions to equations defining an elliptic curve. It is an open problem in the field of number theory and is widely recognized as one of the most challenging mathematical problems. It is named after mathematicians Bryan John Birch and Peter Swinnerton-Dyer, who developed the conjecture during the first half of the 1960s with the help of machine computation. , only special cases of the conjecture have been proven. The modern formulation of the conjecture relates arithmetic data associated with an elliptic curve ''E'' over a number field ''K'' to the behaviour of the Hasse–Weil ''L''-function ''L''(''E'', ''s'') of ''E'' at ''s'' = 1. More specifically, it is conjectured that the rank of the abelian group ''E''(''K'') of points of ''E'' is the order of the zero of ''L''(''E'', ''s'') at ''s'' = 1, and the first non-zero ...
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Millennium Prize Problem
The Millennium Prize Problems are seven well-known complex mathematical problems selected by the Clay Mathematics Institute in 2000. The Clay Institute has pledged a US$1 million prize for the first correct solution to each problem. According to the official website of the Clay Mathematics Institute, the Millennium Prize Problems are officially also called the Millennium Problems. To date, the only Millennium Prize problem to have been solved is the Poincaré conjecture. The Clay Institute awarded the monetary prize to Russian mathematician Grigori Perelman in 2010. However, he declined the award as it was not also offered to Richard S. Hamilton, upon whose work Perelman built. The remaining six unsolved problems are the Birch and Swinnerton-Dyer conjecture, Hodge conjecture, Navier–Stokes existence and smoothness, P versus NP problem, Riemann hypothesis, and Yang–Mills existence and mass gap. Overview The Clay Institute was inspired by a set of twenty-three problems ...
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Frederick Vine
Frederick John Vine FRS (born 17 June 1939) is an English marine geologist and geophysicist. He made key contributions to the theory of plate tectonics, helping to show that the seafloor spreads from mid-ocean ridges with a symmetrical pattern of magnetic reversals in the basalt rocks on either side. Early life Vine was born in Chiswick, London, and educated at Latymer Upper School and St John's College, Cambridge where he studied Natural Sciences (BA, 1962) and marine geophysics (PhD, 1965). He married Susan 'Sue' Vine (née McCall), who worked as a research assistant for Drummond Matthews in the Department of Geodesy and Geophysics, University of Cambridge, contributing to the development of the sea-floor spreading hypothesis associated with Matthews and her husband. Plate Tectonics Vine's PhD thesis was on 'Magnetism in the Seafloor' and supervised by Drummond Matthews. Having met Harry Hess he was aware of sea floor spreading, where the ocean bed acts as a 'conveyor belt ...
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Drummond Matthews
Drummond Hoyle Matthews FRS (5 February 1931 – 20 July 1997), known as "Drum", was a British marine geologist and geophysicist and a key contributor to the theory of plate tectonics. His work, along with that of fellow Briton Fred Vine and Canadian Lawrence Morley, showed how variations in the magnetic properties of rocks forming the ocean floor could be consistent with, and ultimately help confirm, Harry Hammond Hess's 1962 theory of seafloor spreading. In 1989 he was awarded the Geological Society of London's highest honour, the Wollaston Medal. Early life During World War II he went to school at The Downs in Malvern, and then Bryanston School in Dorset. He became head boy at both. Career Alfred Wegener's theory of continental drift had never gained much scientific support due to its lack of any satisfactory mechanism to drive the process. During the 1950s, however, extensive surveys of the ocean floor revealed a global, linked system of mid-ocean ridges, all of which ...
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