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Accumulator (computing)
In a computer's central processing unit (CPU), the accumulator is a register in which intermediate arithmetic logic unit results are stored. Without a register like an accumulator, it would be necessary to write the result of each calculation (addition, multiplication, shift, etc.) to cache or main memory, perhaps only to be read right back again for use in the next operation. Accessing memory is slower than accessing a register like an accumulator because the technology used for the large main memory is slower (but cheaper) than that used for a register. Early electronic computer systems were often split into two groups, those with accumulators and those without. Modern computer systems often have multiple general-purpose registers that can operate as accumulators, and the term is no longer as common as it once was. However, to simplify their design, a number of special-purpose processors still use a single accumulator. Basic concept Mathematical operations often take ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Walther WSR-16 Inside The Machine
Walther () is a masculine given name and a surname. It is a German form of Walter, which is derived from the Old High German ''Walthari'', containing the elements ''wald'' -"power", "brightness" or "forest" and ''hari'' -"warrior". The name was first popularized by the famous epic German hero Walther von Aquitaine and later with the Minnesänger Walther von der Vogelweide. Given name * Walther Bauersfeld (1879–1959), German engineer who built the first projection planetarium * Walther Bothe (1891–1957), German nuclear physicist and Nobel laureate * Walther von Brauchitsch (1881–1948), German World War II field marshal * Walther Dahl (1916–1985), German World War II flying ace * Walther von Dyck (1856–1934), German mathematician * Walther Flemming (1843–1905), German biologist and a founder of cytogenetics * Walther Funk (1890–1960), economist and Nazi official convicted of war crimes in the Nuremberg Trials * Walther Hahm (1894–1951), German World War II genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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PIC Microcontrollers
PIC (usually pronounced as /pɪk/) is a family of microcontrollers made by Microchip Technology, derived from the PIC1640 originally developed by General Instrument's Microelectronics Division. The name PIC initially referred to ''Peripheral Interface Controller'',"MOS DATA 1976", General Instrument 1976 Databook and was subsequently expanded for a short time to include ''Programmable Intelligent Computer'', though the name PIC is no longer used as an acronym for any term. The first parts of the family were available in 1976; by 2013 the company had shipped more than twelve billion individual parts, used in a wide variety of embedded systems. The PIC was originally designed as a peripheral for the General Instrument CP1600, the first commercially available single-chip 16-bit computing, 16-bit microprocessor. To limit the number of pins required, the CP1600 had a complex highly-Multiplexed bus#Bus multiplexing, multiplexed bus which was difficult to interface with, so in ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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MIX (abstract Machine)
MIX is a hypothetical computer used in Donald Knuth's monograph, ''The Art of Computer Programming'' (''TAOCP''). MIX's model number is 1009, which was derived by combining the model numbers and names of several contemporaneous, commercial machines deemed significant by the author. Also, "MIX" read as a Roman numeral is 1009. The 1960s-era MIX has since been superseded by a new (also hypothetical) computer architecture, MMIX, to be incorporated in forthcoming editions of ''TAOCP''. Software implementations for both the MIX and MMIX architectures have been developed by Knuth and made freely available (named "MIXware" and "MMIXware", respectively). Several derivatives of Knuth's MIX/MMIX emulators also exist. GNU MDK is one such software package; it is free and runs on a wide variety of platforms. Their purpose for education is quite similar to John L. Hennessy's and David A. Patterson's DLX architecture, from ''Computer Organization and Design - The Hardware Software Inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Donald Knuth
Donald Ervin Knuth ( ; born January 10, 1938) is an American computer scientist and mathematician. He is a professor emeritus at Stanford University. He is the 1974 recipient of the ACM Turing Award, informally considered the Nobel Prize of computer science. Knuth has been called the "father of the analysis of algorithms". Knuth is the author of the multi-volume work '' The Art of Computer Programming''. He contributed to the development of the rigorous analysis of the computational complexity of algorithms and systematized formal mathematical techniques for it. In the process, he also popularized the asymptotic notation. In addition to fundamental contributions in several branches of theoretical computer science, Knuth is the creator of the TeX computer typesetting system, the related METAFONT font definition language and rendering system, and the Computer Modern family of typefaces. As a writer and scholar, Knuth created the WEB and CWEB computer programming systems des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Percy Ludgate
Percy Edwin Ludgate (2 August 1883 – 16 October 1922) was an Ireland, Irish amateur scientist who designed the second analytical engine (general-purpose Turing-complete computer) in history. Life Ludgate was born on 2 August 1883 in Skibbereen, County Cork, to Michael Ludgate and Mary McMahon. In the 1901 census, he is listed as Civil Servant National Education (Boy Copyist) in Dublin. In the 1911 census, he is also in Dublin, as a Commercial Clerk (Corn Merchant). He studied accountancy at Rathmines College of Commerce, earning a gold medal based on the results of his final examinations in 1917. At some date before or after then, he joined Kevans & Son, accountants. Work on analytical engine It seems that Ludgate worked as a clerk for an unknown corn merchant, in Dublin, and pursued his interest in calculating machines at night. Charles Babbage in 1843 and Ludgate in 1909 designed the only two mechanical analytical engines before the electromechanical analytical engine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Blaise Pascal
Blaise Pascal (19June 162319August 1662) was a French mathematician, physicist, inventor, philosopher, and Catholic Church, Catholic writer. Pascal was a child prodigy who was educated by his father, a tax collector in Rouen. His earliest mathematical work was on projective geometry; he wrote a significant treatise on the subject of conic sections at the age of 16. He later corresponded with Pierre de Fermat on probability theory, strongly influencing the development of modern economics and social sciences, social science. In 1642, he started some pioneering work on calculating machines (called Pascal's calculators and later Pascalines), establishing him as one of the first two inventors of the mechanical calculator. Like his contemporary René Descartes, Pascal was also a pioneer in the natural and applied sciences. Pascal wrote in defense of the scientific method and produced several controversial results. He made important contributions to the study of fluids, and clari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Gottfried Leibniz
Gottfried Wilhelm Leibniz (or Leibnitz; – 14 November 1716) was a German polymath active as a mathematician, philosopher, scientist and diplomat who is credited, alongside Isaac Newton, Sir Isaac Newton, with the creation of calculus in addition to many other branches of mathematics, such as binary arithmetic and statistics. Leibniz has been called the "last universal genius" due to his vast expertise across fields, which became a rarity after his lifetime with the coming of the Industrial Revolution and the spread of specialized labor. He is a prominent figure in both the history of philosophy and the history of mathematics. He wrote works on philosophy, theology, ethics, politics, law, history, philology, games, music, and other studies. Leibniz also made major contributions to physics and technology, and anticipated notions that surfaced much later in probability theory, biology, medicine, geology, psychology, linguistics and computer science. Leibniz contributed to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Adding Machine
An adding machine is a class of mechanical calculator, usually specialized for bookkeeping calculations. Consequently, the earliest adding machines were often designed to read in particular currencies. Adding machines were ubiquitous office equipment in developed countries for most of the twentieth century. They were phased out in favor of electronic calculators in the 1970s and by personal computers beginning in about 1985. Blaise Pascal and Wilhelm Schickard were the two original inventors of the mechanical calculator in 1642. For Pascal, this was an adding machine that could perform additions and subtractions directly and multiplication and divisions by repetitions, while Schickard's machine, invented several decades earlier, was less functionally efficient but was supported by a mechanised form of multiplication tables. These two were followed by a series of inventors and inventions leading to those of Thomas de Colmar, who launched the mechanical calculator indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Addressing Mode
Addressing modes are an aspect of the instruction set architecture in most central processing unit (CPU) designs. The various addressing modes that are defined in a given instruction set architecture define how the machine language instructions in that architecture identify the operand(s) of each instruction. An addressing mode specifies how to calculate the effective memory address of an operand by using information held in registers and/or constants contained within a machine instruction or elsewhere. In computer programming, addressing modes are primarily of interest to those who write in assembly languages and to compiler writers. For a related concept see orthogonal instruction set which deals with the ability of any instruction to use any addressing mode. Caveats There are no generally accepted names for addressing modes: different authors and computer manufacturers may give different names to the same addressing mode, or the same names to different addressing modes. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Memory Address
In computing, a memory address is a reference to a specific memory location in memory used by both software and hardware. These addresses are fixed-length sequences of digits, typically displayed and handled as unsigned integers. This numerical representation is based on the features of CPU (such as the instruction pointer and incremental address registers). Programming language constructs often treat the memory like an array. Types Physical addresses A digital computer's main memory consists of many memory locations, each identified by a unique physical address (a specific code). The CPU or other devices can use these codes to access the corresponding memory locations. Generally, only system software (such as the BIOS, operating systems, and specialized utility programs like memory testers) directly addresses physical memory using machine code instructions or processor registers. These instructions tell the CPU to interact with a hardware component called the memory c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Instruction (computer Science)
In computer science, an instruction set architecture (ISA) is an abstract model that generally defines how software controls the CPU in a computer or a family of computers. A device or program that executes instructions described by that ISA, such as a central processing unit (CPU), is called an ''implementation'' of that ISA. In general, an ISA defines the supported Machine code, instructions, data types, Register (computer), registers, the hardware support for managing Computer memory, main memory, fundamental features (such as the memory consistency, addressing modes, virtual memory), and the input/output model of implementations of the ISA. An ISA specifies the behavior of machine code running on implementations of that ISA in a fashion that does not depend on the characteristics of that implementation, providing binary compatibility between implementations. This enables multiple implementations of an ISA that differ in characteristics such as Computer performance, performa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Operand
In mathematics, an operand is the object of a mathematical operation, i.e., it is the object or quantity that is operated on. Unknown operands in equalities of expressions can be found by equation solving. Example The following arithmetic expression shows an example of operators and operands: :3 + 6 = 9 In the above example, '+' is the symbol for the operation called addition. The operand '3' is one of the inputs (quantities) followed by the addition operator, and the operand '6' is the other input necessary for the operation. The result of the operation is 9. (The number '9' is also called the sum of the augend 3 and the addend 6.) An operand, then, is also referred to as "one of the inputs (quantities) for an operation". Notation Expressions as operands Operands may be nested, and may consist of expressions also made up of operators with operands. :(3 + 5) \times 2 In the above expression '(3 + 5)' is the first operand for the multiplication operator and '2' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |