The NASA Columbia Supercomputer.

A computer is a machine for manipulating data according to a list of instructions. Computer is an IEEE Computer Society practitioner-oriented magazine issued to all members of the society. ... Image File history File links Download high-resolution version (2100x1524, 3508 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Supercomputer NASA Advanced Supercomputing facility Computer/Temp ... Image File history File links Download high-resolution version (2100x1524, 3508 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Supercomputer NASA Advanced Supercomputing facility Computer/Temp ... The National Aeronautics and Space Administration (NASA) is an agency of the United States federal government, responsible for the nations public space program. ... NASAs 10,240-processor Columbia supercomputer is built from 20 SGI Altix systems, each powered by 512 Intel Itanium 2 processors. ... Wind turbines The scientific definition of a machine is any device that transmits or modifies energy. ...

Computers take numerous physical forms. Early electronic computers were the size of a large room, consuming as much power as several hundred modern personal computers. ^[1] Today, computers can be made small enough to fit into a wrist watch and be powered from a watch battery. Society has come to recognize personal computers and their portable equivalent, the laptop computer, as icons of the information age; they are what most people think of as "a computer". However, the most common form of computer in use today is by far the embedded computer. Embedded computers are small, simple devices that are often used to control other devices—for example, they may be found in machines ranging from fighter aircraft to industrial robots, digital cameras, and even children's toys. A watch is a timepiece or clock that displays the time and sometimes the day, date, month and year. ... Type CR2032 watch battery (lithium anode, 3 V, 20. ... Laptop with touchpad. ... It has been suggested that Digital Age be merged into this article or section. ... An embedded system is a special-purpose computer system, which is completely encapsulated by the device it controls. ... This article or section does not adequately cite its references or sources. ... An industrial robot is officially defined by ISO[1] as an automatically controlled, reprogrammable, multipurpose manipulator programmable in three or more axes. ... This article or section does not cite its references or sources. ... A teddy bear A Toy is an object used in play. ...

A computer in a wristwatch.

The ability to store and execute programs makes computers extremely versatile and distinguishes them from calculators. The Church–Turing thesis is a mathematical statement of this versatility: Any computer with a certain minimum capability is, in principle, capable of performing the same tasks that any other computer can perform. Therefore, computers with capability and complexity ranging from that of a personal digital assistant to a supercomputer are all able to perform the same computational tasks as long as time and storage capacity are not considerations. Download high resolution version (1024x1539, 87 KB)wristwatch computer from http://wearcam. ... Download high resolution version (1024x1539, 87 KB)wristwatch computer from http://wearcam. ... A watch is a timepiece or clock that displays the time and sometimes the day, date, month and year. ... A calculator is a device for performing calculations. ... In computability theory the Church–Turing thesis (also known as Churchs thesis, Churchs conjecture and Turings thesis) is a hypothesis about the nature of mathematical functions that can be computed by a digital computer or a human with a pencil and paper following a set of rules. ... Personal digital assistants (PDAs) are handheld computers that were originally designed as personal organizers, but became much more versatile over the years. ... A supercomputer is a computer that leads the world in terms of processing capacity, particularly speed of calculation, at the time of its introduction. ...

History of computing

Main article: History of computing

The Jacquard loom was one of the first programmable devices.

It is difficult to define any one device as the earliest computer. The very definition of a computer has changed and it is therefore impossible to identify the first computer. Many devices once called "computers" would no longer qualify as such by today's standards. The history of computing is longer than the history of computing hardware and modern computing technology and includes the history of methods intended for pen and paper or for chalk and slate, with or without the aid of tables. ... Jacquard loom on display at the museum of science and industry. ... Jacquard loom on display at the museum of science and industry. ... Jacquard loom on display at Museum of Science and Industry in Manchester, England The Jacquard loom is a mechanical loom, invented by Joseph Marie Jacquard in 1801, which used the holes punched in pasteboard punch cards to control the weaving of patterns in fabric. ...

Originally, the term "computer" referred to a person who performed numerical calculations (a human computer), often with the aid of a mechanical calculating device. Examples of early mechanical computing devices included the abacus, the slide rule and arguably the astrolabe and the Antikythera mechanism (which dates from about 150-100 BC). The end of the Middle Ages saw a re-invigoration of European mathematics and engineering, and Wilhelm Schickard's 1623 device was the first of a number of mechanical calculators constructed by European engineers. Before mechanical and electronic computers, the term computer, in use from the mid 17th century, meant a human undertaking mathematical calculations. ... A basic arithmetic calculator. ... For the finite element analysis software, see ABAQUS. An abacus (plurals abacuses or abaci) is a calculating tool, often constructed as a wooden frame with beads sliding on wires. ... A typical 10 inch student slide rule (Pickett N902-T simplex trig). ... A 16th century astrolabe. ... The Antikythera mechanism (main fragment). ... The Middle Ages formed the middle period in a traditional schematic division of European history into three ages: the classical civilization of Antiquity, the Middle Ages, and modern times, beginning with the Renaissance. ... Wilhelm Schickard Wilhelm Schickard (April 22, 1592 – October 23, 1635) was a German polymath who built the first computer in 1623. ...

However, none of those devices fit the modern definition of a computer because they could not be programmed. In 1801, Joseph Marie Jacquard made an improvement to the textile loom that used a series of punched paper cards as a template to allow his loom to weave intricate patterns automatically. The resulting Jacquard loom was an important step in the development of computers because the use of punched cards to define woven patterns can be viewed as an early, albeit limited, form of programmability. This does not adequately cite its references or sources. ... A Turkish woman in Konya works at a traditional loom. ... Punched cards (or Hollerith cards, or IBM cards), are pieces of stiff paper that contain digital information represented by the presence or absence of holes in predefined positions. ...

In 1837, Charles Babbage was the first to conceptualize and design a fully programmable mechanical computer that he called "The Analytical Engine".^[2] Due to limited finance, and an inability to resist tinkering with the design, Babbage never actually built his Analytical Engine. Charles Babbage (26 December 1791 – 18 October 1871) was an English mathematician, philosopher, mechanical engineer and (proto-) computer scientist who originated the idea of a programmable computer. ... The analytical engine, an important step in the history of computers, is the design of a mechanical modern general-purpose computer by the British professor of mathematics Charles Babbage. ...

Large-scale automated data processing of punched cards was performed for the US Census in 1890 by tabulating machines designed by Herman Hollerith and manufactured by the Computing Tabulating Recording Corporation, which later became IBM. By the end of the 19th century a number of technologies that would later prove useful in the realization of practical computers had begun to appear: the punched card, boolean algebra, the vacuum tube (thermionic valve) and the teleprinter. The Eleventh United States Census was taken June 1, 1890. ... Tabulating machine constructed by Hollerith The tabulating machine was a machine designed to assist in tabulations. ... Herman Hollerith (February 29, 1860 – November 17, 1929) was an American statistician who developed a mechanical tabulator based on punched cards to rapidly tabulate statistics from millions of pieces of data. ... The Computing Tabulating Recording Corporation (CTR)[1] was incorporated on June 15, 1911 in Endicott, New York a few miles west of Binghamton. ... International Business Machines Corporation (known as IBM or Big Blue; NYSE: IBM) is a multinational computer technology and consulting corporation headquartered in Armonk, New York, USA. The company is one of the few information technology companies with a continuous history dating back to the 19th century. ... Punched cards (or Hollerith cards, or IBM cards), are pieces of stiff paper that contain digital information represented by the presence or absence of holes in predefined positions. ... In abstract algebra, a Boolean algebra is an algebraic structure (a collection of elements and operations on them obeying defining axioms) that captures essential properties of both set operations and logic operations. ... In electronics, a vacuum tube or (outside North America) thermionic valve or just valve, is a device generally used to amplify, switch or otherwise modify, a signal by controlling the movement of electrons in an evacuated space. ... Teletype machines in World War II A teleprinter (teletypewriter, teletype or TTY for TeleTYpe/TeleTYpewriter) is a now largely obsolete electro-mechanical typewriter which can be used to communicate typed messages from point to point through a simple electrical communications channel, often just a pair of wires. ...

During the first half of the 20th century, many scientific computing needs were met by increasingly sophisticated analog computers, which used a direct mechanical or electrical model of the problem as a basis for computation. However, these were not programmable and generally lacked the versatility and accuracy of modern digital computers. A page from the Bombardiers Information File (BIF) that describes the components and controls of the Norden bombsight. ... Lightning strikes during a night-time thunderstorm. ... Look up computation in Wiktionary, the free dictionary. ...

A succession of steadily more powerful and flexible computing devices were constructed in the 1930s and 1940s, gradually adding the key features that are seen in modern computers. The use of digital electronics (largely invented by Claude Shannon in 1937) and more flexible programmability were vitally important steps, but defining one point along this road as "the first digital electronic computer" is difficult (Shannon 1940). Notable achievements include: The binary numeral system, or base-2 number system, is a numeral system that represents numeric values using two symbols, usually 0 and 1. ... Electronics is the study of the flow of charge through various materials and devices such as, semiconductors, resistors, inductors, capacitors, nano-structures, and vacuum tubes. ... A computer program is a collection of instructions that describe a task, or set of tasks, to be carried out by a computer. ... In computability theory, an abstract machine or programming language is called Turing complete, Turing equivalent, or (computationally) universal if it has a computational power equivalent to a universal Turing machine (a simplified model of a programmable computer). ... Konrad Zuse (1992) Statue in Bad Hersfeld Konrad Zuse (June 22, 1910 – December 18, 1995) was a German engineer and computer pioneer. ... Konrad Zuses Z3 was the first working programmable, fully automatic machine, whose attributes, with the addition of conditional branching, have often been the ones used as criteria in defining a computer. ... Film stock is the term for photographic film on which films are recorded. ... Konrad Zuses Z3 was the first working programmable, fully automatic machine, whose attributes, with the addition of conditional branching, have often been the ones used as criteria in defining a computer. ... Atanasoff-Berry Computer replica at 1st floor of Durham Center, Iowa State University The Atanasoff-Berry Computer (ABC) was one of the first electronic digital computing device. ... A Colossus Mark II computer. ... Portion of the Harvard-IBM Mark 1, left side. ... ENIAC ENIAC, short for Electronic Numerical Integrator and Computer,[1] was the first large-scale, electronic, digital computer capable of being reprogrammed to solve a full range of computing problems,[2] although earlier computers had been built with some of these properties. ... Read-only memory (usually known by its acronym, ROM) is a class of storage media used in computers and other electronic devices. ... Claude Elwood Shannon (April 30, 1916 _ February 24, 2001) has been called the father of information theory, and was the founder of practical digital circuit design theory. ...

EDSAC was one of the first computers to implement the stored program (von Neumann) architecture.

• Konrad Zuse's electromechanical "Z machines". The Z3 (1941) was the first working machine featuring binary arithmetic, including floating point arithmetic and a measure of programmability. In 1998 the Z3 was proved to be Turing complete, therefore being the world's first operational computer.
• The Atanasoff-Berry Computer (1941) which used vacuum tube based computation, binary numbers, and regenerative capacitor memory.
• The secret British Colossus computer (1944), which had limited programmability but demonstrated that a device using thousands of tubes could be reasonably reliable and electronically reprogrammable. It was used for breaking German wartime codes.
• The Harvard Mark I (1944), a large-scale electromechanical computer with limited programmability.
• The US Army's Ballistics Research Laboratory ENIAC (1946), which used decimal arithmetic and was the first general purpose electronic computer, although it initially had an inflexible architecture which essentially required rewiring to change its programming.

Several developers of ENIAC, recognizing its flaws, came up with a far more flexible and elegant design, which came to be known as the stored program architecture or von Neumann architecture. This design was first formally described by John von Neumann in the paper "First Draft of a Report on the EDVAC", published in 1945. A number of projects to develop computers based on the stored program architecture commenced around this time, the first of these being completed in Great Britain. The first to be demonstrated working was the Manchester Small-Scale Experimental Machine (SSEM) or "Baby". However, the EDSAC, completed a year after SSEM, was perhaps the first practical implementation of the stored program design. Shortly thereafter, the machine originally described by von Neumann's paper—EDVAC—was completed but didn't see full-time use for an additional two years. Image File history File links EDSAC_(10). ... Image File history File links EDSAC_(10). ... EDSAC EDSAC (Electronic Delay Storage Automatic Calculator) was an early British computer (one of the first computers to be created). ... Design of the Von Neumann architecture For the robotic architecture also named after Von Neumann, see Von Neumann machine The von Neumann architecture is a computer design model that uses a single storage structure to hold both instructions and data. ... Konrad Zuse (1992) Statue in Bad Hersfeld Konrad Zuse (June 22, 1910 – December 18, 1995) was a German engineer and computer pioneer. ... In engineering, electromechanics combines the sciences of electromagnetism of electrical engineering and mechanics. ... Konrad Zuses Z3 was the first working programmable, fully automatic machine, whose attributes, with the addition of conditional branching, have often been the ones used as criteria in defining a computer. ... The binary numeral system, or base-2 number system, is a numeral system that represents numeric values using two symbols, usually 0 and 1. ... In computability theory, an abstract machine or programming language is called Turing complete, Turing equivalent, or (computationally) universal if it has a computational power equivalent to a universal Turing machine (a simplified model of a programmable computer). ... Atanasoff-Berry Computer replica at 1st floor of Durham Center, Iowa State University The Atanasoff-Berry Computer (ABC) was one of the first electronic digital computing device. ... Look up computation in Wiktionary, the free dictionary. ... Regenerative capacitor memory is a type of computer memory that uses the electrical property of capacitance to store the data. ... A Colossus Mark II computer. ... Cryptanalysis (from the Greek kryptós, hidden, and analýein, to loosen or to untie) is the study of methods for obtaining the meaning of encrypted information, without access to the secret information which is normally required to do so. ... Portion of the Harvard-IBM Mark 1, left side. ... The US Army Ballistics Research Labatory is at Aberdeen Proving Ground, Aberdeen, Maryland. ... ENIAC ENIAC, short for Electronic Numerical Integrator and Computer,[1] was the first large-scale, electronic, digital computer capable of being reprogrammed to solve a full range of computing problems,[2] although earlier computers had been built with some of these properties. ... The decimal (base ten or occasionally denary) numeral system has ten as its base. ... Design of the Von Neumann architecture For the robotic architecture also named after Von Neumann, see Von Neumann machine The von Neumann architecture is a computer design model that uses a single storage structure to hold both instructions and data. ... John von Neumann (Hungarian Margittai Neumann János Lajos) (born December 28, 1903 in Budapest, Austria-Hungary; died February 8, 1957 in Washington D.C., United States) was a Hungarian-born American mathematician and polymath who made contributions to quantum physics, functional analysis, set theory, topology, economics, computer science, numerical... The First Draft of a Report on the EDVAC (or First Draft) was an incomplete 101-page document written by John von Neumann and distributed on June 30, 1945 by Herman Goldstine, security officer on the classified ENIAC project. ... Replica of the SSEM The Manchester Small-Scale Experimental Machine (SSEM), nicknamed Baby, was the first stored-program computer to run a program, on June 21, 1948. ... EDSAC EDSAC (Electronic Delay Storage Automatic Calculator) was an early British computer (one of the first computers to be created). ... The EDVAC as installed in Building 328 at the Ballistics Research Laboratory. ...

Nearly all modern computers implement some form of the stored program architecture, making it the single trait by which the word "computer" is now defined. By this standard, many earlier devices would no longer be called computers by today's definition, but are usually referred to as such in their historical context. While the technologies used in computers have changed dramatically since the first electronic, general-purpose computers of the 1940s, most still use the von Neumann architecture. The design made the universal computer a practical reality. Design of the Von Neumann architecture For the robotic architecture also named after Von Neumann, see Von Neumann machine The von Neumann architecture is a computer design model that uses a single storage structure to hold both instructions and data. ...

Microprocessors are miniaturized devices that often implement stored program CPUs.

Vacuum tube-based computers were in use throughout the 1950s, but were largely replaced in the 1960s by transistor-based devices, which were smaller, faster, cheaper, used less power and were more reliable. These factors allowed computers to be produced on an unprecedented commercial scale. By the 1970s, the adoption of integrated circuit technology and the subsequent creation of microprocessors such as the Intel 4004 caused another leap in size, speed, cost and reliability. By the 1980s, computers had become sufficiently small and cheap to replace simple mechanical controls in domestic appliances such as washing machines. Around the same time, computers became widely accessible for personal use by individuals in the form of home computers and the now ubiquitous personal computer. In conjunction with the widespread growth of the Internet since the 1990s, personal computers are becoming as common as the television and the telephone and almost all modern electronic devices contain a computer of some kind.
Image File history File links Download high resolution version (1341x1002, 803 KB) Summary Macro shot of an Intel 80486DX2 die in its packaging. ... Image File history File links Download high resolution version (1341x1002, 803 KB) Summary Macro shot of an Intel 80486DX2 die in its packaging. ... Microprocessors, including an Intel 80486DX2 and an Intel 80386 A microprocessor (abbreviated as µP or uP) is an electronic computer central processing unit (CPU) made from miniaturized transistors and other circuit elements on a single semiconductor integrated circuit (IC) (aka microchip or just chip). ... CPU can stand for: in computing: Central processing unit in journalism: Commonwealth Press Union in law enforcement: Crime prevention unit in software: Critical patch update, a type of software patch distributed by Oracle Corporation in Macleans College is often known as Ash Lim. ... In electronics, a vacuum tube or (outside North America) thermionic valve or just valve, is a device generally used to amplify, switch or otherwise modify, a signal by controlling the movement of electrons in an evacuated space. ... Assorted discrete transistors A transistor is a semiconductor device, commonly used as an amplifier. ... Integrated circuit showing memory blocks, logic and input/output pads around the periphery Microchips with a transparent window, showing the integrated circuit inside. ... A microprocessor is a programmable digital electronic component that incorporates the functions of a central processing unit (CPU) on a single semiconducting integrated circuit (IC). ... The Intel 4004, a 4-bit central processing unit (CPU) released by Intel Corp. ... Front-loading washing machine. ... Children playing on a Amstrad CPC 464 in the 1980s. ... The telephone is a telecommunications device which is used to transmit and receive sound (most commonly speech) across distance. ...

Stored program architecture

Main articles: Computer program and Computer programming

The defining feature of modern computers which distinguishes them from all other machines is that they can be programmed. That is to say that a list of instructions (the program) can be given to the computer and it will store them and carry them out at some time in the future. A computer program is a collection of instructions that describe a task, or set of tasks, to be carried out by a computer. ... Computer programming (often shortened to programming or coding) is the process of writing, testing, and maintaining the source code of computer programs. ... Computer programming (often shortened to programming or coding) is the process of writing, testing, and maintaining the source code of computer programs. ... In computer science, an instruction typically refers to a single operation of a processor within a computer architecture. ... A computer program is a collection of instructions that describe a task, or set of tasks, to be carried out by a computer. ...

In most cases, computer instructions are simple: add one number to another, move some data from one location to another, send a message to some external device, etc. These instructions are read from the computer's memory and are generally carried out (executed) in the order they were given. However, there are usually specialized instructions to tell the computer to jump ahead or backwards to some other place in the program and to carry on executing from there. These are called "jump" instructions (or branches). Furthermore, jump instructions may be made to happen conditionally so that different sequences of instructions may be used depending on the result of some previous calculation or some external event. Many computers directly support subroutines by providing a type of jump that "remembers" the location it jumped from and another instruction to return to that point. This article or section does not adequately cite its references or sources. ... In computer science, conditional statements are a vital part of a programming language. ... In computer science, a subroutine (function, method, procedure, or subprogram) is a portion of code within a larger program, which performs a specific task and is relatively independent of the remaining code. ...

Program execution might be likened to reading a book. While a person will normally read each word and line in sequence, they may at times jump back to an earlier place in the text or skip sections that are not of interest. Similarly, a computer may sometimes go back and repeat the instructions in some section of the program over and over again until some internal condition is met. This is called the flow of control within the program and it is what allows the computer to perform tasks repeatedly without human intervention. In computer science control flow (or alternatively, flow of control) refers to the order in which the individual statements or instructions of an imperative program are performed or executed. ...

Comparatively, a person using a pocket calculator can perform a basic arithmetic operation such as adding two numbers with just a few button presses. But to add together all of the numbers from 1 to 1,000 would take thousands of button presses and a lot of time—with a near certainty of making a mistake. On the other hand, a computer may be programmed to do this with just a few simple instructions. For example: A calculator is a device for performing calculations. ...

 mov #0,sum ; set sum to 0 mov #1,num ; set num to 1 loop: add num,sum ; add num to sum add #1,num ; add 1 to num cmp num,#1000 ; compare num to 1000 ble loop ; if num <= 1000, go back to 'loop' halt ; end of program. stop running 

Once told to run this program, the computer will perform the repetitive addition task without further human intervention. It will almost never make a mistake and a modern PC can complete the task in about a millionth of a second.^[3]

However, computers cannot "think" for themselves in the sense that they only solve problems in exactly the way they are programmed to. An intelligent human faced with the above addition task might soon realize that instead of actually adding up all the numbers one can simply use the equation

and arrive at the correct answer (500,500) with little work. ^[4] In other words, a computer programmed to add up the numbers one by one as in the example above would do exactly that without regard to efficiency or alternative solutions.

Programs

A 1970s punched card containing one line from a FORTRAN program. The card reads: "Z(1) = Y + W(1)" and is labelled "PROJ039" for identification purposes.

In practical terms, a computer program might include anywhere from a dozen instructions to many millions of instructions for something like a word processor or a web browser. A typical modern computer can execute billions of instructions every second and nearly never make a mistake over years of operation. Image File history File links Download high-resolution version (1687x809, 475 KB) Summary Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Punch card ... Image File history File links Download high-resolution version (1687x809, 475 KB) Summary Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Punch card ... A CTR census machine, utilizing a punched card system. ... Fortran (previously FORTRAN[1]) is a general-purpose[2], procedural,[3] imperative programming language that is especially suited to numeric computation and scientific computing. ... A computer program is a collection of instructions that describe a task, or set of tasks, to be carried out by a computer. ... A word processor (also more formally known as a document preparation system) is a computer application used for the production (including composition, editing, formatting, and possibly printing) of any sort of viewable or printed material. ... An example of a web browser (Internet Explorer), displaying the English Wikipedia main page. ...

Large computer programs may take teams of computer programmers years to write and the probability of the entire program having been written completely in the manner intended is unlikely. Errors in computer programs are called bugs. Sometimes bugs are benign and do not affect the usefulness of the program, in other cases they might cause the program to completely fail (crash), in yet other cases there may be subtle problems. Sometimes otherwise benign bugs may be used for malicious intent, creating a security exploit. Bugs are usually not the fault of the computer. Since computers merely execute the instructions they are given, bugs are nearly always the result of programmer error or an oversight made in the program's design. ^[5] In computing, a programmer is someone who does computer programming and develops computer software. ... A software bug is an error, flaw, mistake, failure, or fault in a computer program that prevents it from behaving as intended (e. ... A crash in computing is a condition where a program (either an application or part of the operating system) stops performing its expected function and also stops responding to other parts of the system. ... In computer security, an exploit is a piece of software, a chunk of data, or sequence of commands that take advantage of a bug, glitch or vulnerability in order to get unintended or unanticipated behavior out of computer software, hardware, or something electronic (usually computerized). ...

In most computers, individual instructions are stored as machine code with each instruction being given a unique number (its operation code or opcode for short). The command to add two numbers together would have one opcode, the command to multiply them would have a different opcode and so on. The simplest computers are able to perform any of a handful of different instructions, the more complex computers have several hundred to choose from—each with a unique numerical code. Since the computer's memory is able to store numbers, it can also store the instruction codes. This leads to the important fact that entire programs (which are just lists of instructions) can be represented as lists of numbers and can themselves be manipulated inside the computer just as if they were numeric data. The fundamental concept of storing programs in the computer's memory alongside the data they operate on is the crux of the von Neumann, or stored program, architecture. In some cases, a computer might store some or all of its program in memory that is kept separate from the data it operates on. This is called the Harvard architecture after the Harvard Mark I computer. Modern von Neumann computers display some traits of the Harvard architecture in their designs, such as in CPU caches. Machine code or machine language is a system of instructions and data directly understandable by a computers central processing unit. ... Microprocessors perform operations using binary bits (on/off/1or0). ... The term Harvard architecture originally referred to computer architectures that used physically separate storage and signal pathways for their instructions and data (in contrast to the von Neumann architecture). ... Portion of the Harvard-IBM Mark 1, left side. ... Diagram of a CPU memory cache A CPU cache is a cache used by the central processing unit of a computer to reduce the average time to access memory. ...

While it is possible to write computer programs as long lists of numbers (machine language) and this technique was used with many early computers,^[6] it is extremely tedious to do so in practice, especially for complicated programs. Instead, each basic instruction can be given a short name that is indicative of its function and easy to remember—a mnemonic such as ADD, SUB, MULT or JUMP. These mnemonics are collectively known as a computer's assembly language. Converting programs written in assembly language into something the computer can actually understand (machine language) is usually done by a computer program called an assembler. Machine languages and the assembly languages that represent them (collectively termed low-level programming languages) tend to be unique to a particular type of computer. This means that an ARM architecture computer (such as may be found in a PDA or a hand-held videogame) cannot understand the machine language of an Intel Pentium or the AMD Athlon 64 computer that might be in a PC.^[7] A system of codes directly understandable by a computers CPU is termed this CPUs native or machine language. ... Wikiquote has a collection of quotations related to: English mnemonics A mnemonic (pronounced in RP, [nɪmÉ‘nɪk] in GA) is a memory aid, and most serve an educational purpose. ... An assembly language is a low-level language used in the writing of computer programs. ... In computer science, a low-level programming language is a language that provides little or no abstraction from a computers microprocessor. ... The ARM architecture (previously, the Advanced RISC Machine, and prior to that Acorn RISC Machine) is a 32-bit RISC processor architecture that is widely used in a number of embedded designs. ... Personal digital assistants (PDAs) are handheld computers that were originally designed as personal organizers, but became much more versatile over the years. ... A handheld video game is a video game designed primarily for handheld game consoles such as Nintendos Game Boy line. ... The Pentium is a fifth-generation x86 architecture microprocessor from Intel. ... The Athlon 64 is an eighth-generation, AMD64 architecture microprocessor produced by AMD, released on September 23, 2003[1]. It is the third processor to bear the name Athlon, and the immediate successor to the Athlon XP[2]. The second processor (after the Opteron) to implement AMD64 architecture and the... While being one of the first personal computers, the Altair 8800 was considered a mere toy due its lack of abilities. ...

Though considerably easier than in machine language, writing long programs in assembly language is often difficult and error prone. Therefore, most complicated programs are written in more abstract high-level programming languages that are able to express the needs of the computer programmer more conveniently (and thereby help reduce programmer error). High level languages are usually "compiled" into machine language (or sometimes into assembly language and then into machine language) using another computer program called a compiler.^[8] Since high level languages are more abstract than assembly language, it is possible to use different compilers to translate the same high level language program into the machine language of many different types of computer. This is part of the means by which software like video games may be made available for different computer architectures such as personal computers and various video game consoles. A high-level programming language is a programming language that, in comparison to low-level programming languages, may be more abstract, easier to use, or more portable across platforms. ... In computing, a programmer is someone who does computer programming and develops computer software. ... This article is about the computing term. ... Four different video game consoles from different generations. ...

The task of developing large software systems is an immense intellectual effort. It has proven, historically, to be very difficult to produce software with an acceptably high reliability, on a predictable schedule and budget. The academic and professional discipline of software engineering concentrates specifically on this problem. e. ...

Example

A traffic light showing red.

Suppose a computer is being employed to drive a traffic light. A simple stored program might say: Image File history File linksMetadata Download high-resolution version (2048x1536, 1138 KB)y bib y invntea the trafic File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File linksMetadata Download high-resolution version (2048x1536, 1138 KB)y bib y invntea the trafic File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Traffic lights can have several additional lights for filter turns or bus lanes. ...

1. Turn off all of the lights
2. Turn on the red light
3. Wait for sixty seconds
4. Turn off the red light
5. Turn on the green light
6. Wait for sixty seconds
7. Turn off the green light
8. Turn on the yellow light
9. Wait for two seconds
10. Turn off the yellow light
11. Jump to instruction number (2)

With this set of instructions, the computer would cycle the light continually through red, green, yellow and back to red again until told to stop running the program.

However, suppose there is a simple on/off switch connected to the computer that is intended be used to make the light flash red while some maintenance operation is being performed. The program might then instruct the computer to: Electrical switches. ...

1. Turn off all of the lights
2. Turn on the red light
3. Wait for sixty seconds
4. Turn off the red light
5. Turn on the green light
6. Wait for sixty seconds
7. Turn off the green light
8. Turn on the yellow light
9. Wait for two seconds
10. Turn off the yellow light
11. If the maintenance switch is NOT turned on then jump to instruction number 2
12. Turn on the red light
13. Wait for one second
14. Turn off the red light
15. Wait for one second
16. Jump to instruction number 11

In this manner, the computer is either running the instructions from number (2) to (11) over and over or it's running the instructions from (11) down to (16) over and over, depending on the position of the switch.^[9]

How computers work

Main articles: Central processing unit and Microprocessor

A general purpose computer has four main sections: the arithmetic and logic unit (ALU), the control unit, the memory, and the input and output devices (collectively termed I/O). These parts are interconnected by busses, often made of groups of wires. Die of an Intel 80486DX2 microprocessor (actual size: 12×6. ... A microprocessor is a programmable digital electronic component that incorporates the functions of a central processing unit (CPU) on a single semiconducting integrated circuit (IC). ... ALU redirects here. ... A control unit is the part of a CPU or other device that directs its operation. ... This article or section does not adequately cite its references or sources. ... In computer architecture, a bus is a subsystem that transfers data or power between computer components inside a computer or between computers and typically is controlled by device driver software. ... This article or section does not adequately cite its references or sources. ...

The control unit, ALU, registers, and basic I/O (and often other hardware closely linked with these) are collectively known as a central processing unit (CPU). Early CPUs were comprised of many separate components but since the mid-1970s CPUs have typically been constructed on a single integrated circuit called a microprocessor. Die of an Intel 80486DX2 microprocessor (actual size: 12×6. ... Integrated circuit showing memory blocks, logic and input/output pads around the periphery Microchips with a transparent window, showing the integrated circuit inside. ... A microprocessor is a programmable digital electronic component that incorporates the functions of a central processing unit (CPU) on a single semiconducting integrated circuit (IC). ...

Control unit

Main articles: CPU design and Control unit

The control unit (often called a control system or central controller) directs the various components of a computer. It reads and interprets (decodes) instructions in the program one by one. The control system decodes each instruction and turns it into a series of control signals that operate the other parts of the computer.^[10] Control systems in advanced computers may change the order of some instructions so as to improve performance. CPU design is the hardware design of a central processing unit. ... A control unit is the part of a CPU or other device that directs its operation. ...

A key component common to all CPUs is the program counter, a special memory cell (a register) that keeps track of which location in memory the next instruction is to be read from.^[11] The program counter (also called the instruction pointer in some computers) is a register in a computer processor which indicates where the computer is in its instruction sequence. ... Register or registration may mean: Registration (or licensing) is required of a number of occupations and professions where maintenance of standards is required to protect public safety. ...

Diagram showing how a particular MIPS architecture instruction would be decoded by the control system.

The control system's function is as follows—note that this is a simplified description and some of these steps may be performed concurrently or in a different order depending on the type of CPU: Image File history File links Mips32_addi. ... Image File history File links Mips32_addi. ... A MIPS R4400 microprocessor made by Toshiba. ...

1. Read the code for the next instruction from the cell indicated by the program counter.
2. Decode the numerical code for the instruction into a set of commands or signals for each of the other systems.
3. Increment the program counter so it points to the next instruction.
4. Read whatever data the instruction requires from cells in memory (or perhaps from an input device). The location of this required data is typically stored within the instruction code.
5. Provide the necessary data to an ALU or register.
6. If the instruction requires an ALU or specialized hardware to complete, instruct the hardware to perform the requested operation.
7. Write the result from the ALU back to a memory location or to a register or perhaps an output device.
8. Jump back to step (1).

Since the program counter is (conceptually) just another set of memory cells, it can be changed by calculations done in the ALU. Adding 100 to the program counter would cause the next instruction to be read from a place 100 locations further down the program. Instructions that modify the program counter are often known as "jumps" and allow for loops (instructions that are repeated by the computer) and often conditional instruction execution (both examples of control flow). In computer science control flow (or alternatively, flow of control) refers to the order in which the individual statements or instructions of an imperative program are performed or executed. ...

It is noticeable that the sequence of operations that the control unit goes through to process an instruction is in itself like a short computer program - and indeed, in some more complex CPU designs, there is another yet smaller computer called a microsequencer that runs a microcode program that causes all of these events to happen. In the field of computer architecture and engineering, a sequencer or microsequencer, is a part of a control unit of a CPU. It generates the addresses used to step through the microprogram of a control store. ... A microprogram is a program consisting of microcode that controls the different parts of a computers central processing unit (CPU). ...

Arithmetic/logic unit (ALU)

Main article: Arithmetic logic unit

The ALU is capable of performing two classes of operations: arithmetic and logic. The arithmetic logic unit/arithmetic-logic unit (ALU) of a computers CPU is a part of the execution unit, a core component of all CPUs. ...

The set of arithmetic operations that a particular ALU supports may be limited to adding and subtracting or might include multiplying or dividing, trigonometry functions (sine, cosine, etc) and square roots. Some can only operate on whole numbers (integers) whilst others use floating point to represent real numbers—albeit with limited precision. However, any computer that is capable of performing just the simplest operations can be programmed to break down the more complex operations into simple steps that it can perform. Therefore, any computer can be programmed to perform any arithmetic operation—although it will take more time to do so if its ALU does not directly support the operation. An ALU may also compare numbers and return boolean truth values (true or false) depending on whether one is equal to, greater than or less than the other ("is 64 greater than 65?"). Wikibooks has a book on the topic of Trigonometry Trigonometry (from the Greek Trigona = three angles and metron = measure[1]) is a branch of mathematics which deals with triangles, particularly triangles in a plane where one angle of the triangle is 90 degrees (right angled triangles). ... In mathematics, a square root of a number x is a number r such that , or in words, a number r whose square (the result of multiplying the number by itself) is x. ... The integers are commonly denoted by the above symbol. ... A floating-point number is a digital representation for a number in a certain subset of the rational numbers, and is often used to approximate an arbitrary real number on a computer. ... In mathematics, the real numbers may be described informally as numbers that can be given by an infinite decimal representation, such as 2. ... In logic and mathematics, a logical value, also called a truth value, is a value indicating to what extent a proposition is true. ...

Logic operations involve boolean logic: AND, OR, XOR and NOT. These can be useful both for creating complicated conditional statements and processing boolean logic. In abstract algebra, a Boolean algebra is an algebraic structure (a collection of elements and operations on them obeying defining axioms) that captures essential properties of both set operations and logic operations. ... AND Logic Gate In logic and mathematics, logical conjunction (usual symbol and) is a two-place logical operation that results in a value of true if both of its operands are true, otherwise a value of false. ... OR logic gate. ... Exclusive disjunction, also known as exclusive or and symbolized by XOR or EOR, is a logical operation on two operands that results in a logical value of true if and only if one of the operands, but not both, has a value of true. ... Negation, in its most basic sense, changes the truth value of a statement to its opposite. ... In computer science, conditional statements are a vital part of a programming language. ... Boolean logic is a complete system for logical operations. ...

Superscalar computers contain multiple ALUs so that they can process several instructions at the same time. Graphics processors and computers with SIMD and MIMD features often provide ALUs that can perform arithmetic on vectors and matrices. Simple superscalar pipeline. ... It has been suggested that this article be split into multiple articles. ... -1... Multiple Instruction Multiple Data (MIMD) is a type of parallel computing architecture where many functional units perform different operations on different data. ... A vector going from A to B. In physics and in vector calculus, a spatial vector, or simply vector, is a concept characterized by a magnitude and a direction. ... In mathematics, a matrix (plural matrices) is a rectangular table of numbers or, more generally, a table consisting of abstract quantities that can be added and multiplied. ...

Memory

Main article: Computer storage

Magnetic core memory was popular main memory for computers through the 1960s until it was completely replaced by semiconductor memory.

A computer's memory may be viewed as a list of cells into which numbers may be placed or read. Each cell has a numbered "address" and can store a single number. The computer may be instructed to "put the number 123 into the cell numbered 1357" or to "add the number that is in cell 1357 to the number that is in cell 2468 and put the answer into cell 1595". The information stored in memory may represent practically anything. Letters, numbers, even computer instructions may be placed into memory with equal ease. Since the CPU does not differentiate between different types of information, it is up to the software to give significance to what the memory sees as nothing but a series of numbers. This article or section does not adequately cite its references or sources. ... Image File history File linksMetadata Download high-resolution version (1280x960, 259 KB) This is a 50x photograph of magnetic core random access memory from a 4 KiB memory plane. ... Image File history File linksMetadata Download high-resolution version (1280x960, 259 KB) This is a 50x photograph of magnetic core random access memory from a 4 KiB memory plane. ... A 16×16 cm area core memory plane of 128×128 bits, i. ...

In almost all modern computers, each memory cell is set up to store binary numbers in groups of eight bits (called a byte). Each byte is able to represent 256 different numbers; either from 0 to 255 or -128 to +127. To store larger numbers, several consecutive bytes may be used (typically, two, four or eight). When negative numbers are required, they are usually stored in two's complement notation. Other arrangements are possible, but are usually not seen outside of specialized applications or historical contexts. A computer may store any kind of information in memory as long as it can be somehow represented in numerical form. Modern computers have billions or even trillions of bytes of memory. The binary or base-two numeral system is a system for representing numbers in which a radix of two is used; that is, each digit in a binary numeral may have either of two different values. ... This article is about the unit of information. ... In computer science a byte is a unit of measurement of information storage, most often consisting of eight bits. ... The twos complement of a binary number is the value obtained by subtracting the number from a large power of two (specifically, from 2N for an N-bit twos complement). ...

The CPU contains a special set of memory cells called registers that can be read and written to much more rapidly than the main memory area. There are typically between two and one hundred registers depending on the type of CPU. Registers are used for the most frequently needed data items to avoid having to access main memory every time data is needed. Since data is constantly being worked on, reducing the need to access main memory (which is often slow compared to the ALU and control units) greatly increases the computer's speed. In computer architecture, a processor register is a small amount of very fast computer memory used to speed the execution of computer programs by providing quick access to commonly used values—typically, the values being in the midst of a calculation at a given point in time. ...

Computer main memory comes in two principal varieties: random access memory or RAM and read-only memory or ROM. RAM can be read and written to anytime the CPU commands it, but ROM is pre-loaded with data and software that never changes, so the CPU can only read from it. ROM is typically used to store the computer's initial start-up instructions. In general, the contents of RAM is erased when the power to the computer is turned off while ROM retains its data indefinitely. In a PC, the ROM contains a specialized program called the BIOS that orchestrates loading the computer's operating system from the hard disk drive into RAM whenever the computer is turned on or reset. In embedded computers, which frequently do not have disk drives, all of the software required to perform the task may be stored in ROM. Software that is stored in ROM is often called firmware because it is notionally more like hardware than software. Flash memory blurs the distinction between ROM and RAM by retaining data when turned off but being rewritable like RAM. However, flash memory is typically much slower than conventional ROM and RAM so its use is restricted to applications where high speeds are not required. ^[12] Random access memory (usually known by its acronym, RAM) is a type of magnetic storage data storage used in computers. ... Read-only memory (usually known by its acronym, ROM) is a class of storage media used in computers and other electronic devices. ... This article or section does not adequately cite its references or sources. ... An operating system (OS) is a set of computer programs that manage the hardware and software resources of a computer. ... An embedded system is a special-purpose computer system, which is completely encapsulated by the device it controls. ... In computing, firmware is software that is embedded in a hardware device. ... A USB flash drive. ...

In more sophisticated computers there may be one or more RAM cache memories which are slower than registers but faster than main memory. Generally computers with this sort of cache are designed to move frequently needed data into the cache automatically, often without the need for any intervention on the programmer's part. Diagram of a CPU memory cache A CPU cache is a cache used by the central processing unit of a computer to reduce the average time to access memory. ...

Input/output (I/O)

Main article: Input/output

Hard disks are common I/O devices used with computers.

I/O is the means by which a computer receives information from the outside world and sends results back. Devices that provide input or output to the computer are called peripherals. On a typical personal computer, peripherals include inputs like the keyboard and mouse, and outputs such as the display and printer. Hard disks, floppy disks and optical discs serve as both inputs and outputs. Computer networking is another form of I/O. Energy Input: The energy placed into a reaction. ... Image File history File links Download high resolution version (1024x683, 323 KB) Summary Alpha six, http://www. ... Image File history File links Download high resolution version (1024x683, 323 KB) Summary Alpha six, http://www. ... Typical hard drives of the mid-1990s. ... A peripheral is a type of computer hardware that is added to a host computer in order to expand its abilities. ... Operating a mechanical 1: Pulling the mouse turns the ball. ... Nineteen inch (48 cm) CRT computer monitor A computer display, monitor or screen is a computer peripheral device capable of showing still or moving images generated by a computer and processed by a graphics card. ... This does not cite any references or sources. ... Typical hard drives of the mid-1990s. ... A floppy disk is a data storage device that is composed of a disk of thin, flexible (floppy) magnetic storage medium encased in a square or rectangular plastic shell. ... The optical lens of a compact disc drive. ... This article or section is in need of attention from an expert on the subject. ...

Practically any device that can be made to interface digitally may be used as I/O. The computer in the Engine Control Unit of a modern automobile might read the position of the pedals and steering wheel, the output of the oxygen sensor and devices that monitor the speed of each wheel. The output devices include the various lights and gauges that the driver sees as well as the engine controls such as the spark ignition circuits and fuel injection systems. In a digital wristwatch, the computer reads the buttons and causes numbers and symbols to be shown on the liquid crystal display. An Engine Control Unit (ECU) also know as Engine Management System (EMS) is an electronic system which controls various aspects of an internal combustion engines operation. ... Karl Benzs Velo (vélo means bicycle in French) model (1894) - entered into the first automobile race 2005 MINI Cooper S. An automobile (also motor car or simply car) is a wheeled passenger vehicle that carries its own motor. ... // An oxygen sensor is an electronic device that measures the proportion of oxygen (O2) in the gas or liquid being analyzed. ... Reflective twisted nematic liquid crystal display. ...

Often, I/O devices are complex computers in their own right with their own CPU and memory. A graphics processing unit might contain fifty or more tiny computers that perform the calculations necessary to display 3D graphics. Modern desktop computers contain many smaller computers that assist the main CPU in performing I/O. It has been suggested that this article be split into multiple articles. ... 3D computer graphics are different from 2D computer graphics in that a three-dimensional representation of geometric data is stored in the computer for the purposes of performing calculations and rendering 2D images. ... Desktop computer with several common peripherals (Monitor, keyboard, mouse, speakers, microphone and a printer) A desktop computer is a personal computer made for use on a desk in an office or home and is distinguished from portable computers such as laptops or PDAs. ...

Multitasking

Main article: Computer multitasking

While a computer may be viewed as running one gigantic program stored in its main memory, in some systems it is necessary to give the appearance of running several programs simultaneously. This is achieved by having the computer switch rapidly between running each program in turn. One means by which this is done is with a special signal called an interrupt which can periodically cause the computer to stop executing instructions where it was and do something else instead. By remembering where it was executing prior to the interrupt, the computer may return to that task later. If several programs are running "at the same time", then the interrupt generator may be causing several hundred interrupts per second, causing a program switch each time. Since modern computers typically execute instructions several orders of magnitude faster than human perception, many programs may seem to be running at the same time even though only one is ever executing in any given instant. This method of multitasking is sometimes termed "time-sharing" since each program is allocated a "slice" of time in turn. In computing, multitasking is a method by which multiple tasks, also known as processes, share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is... In computing, an interrupt is an asynchronous signal from hardware or software indicating the need for attention. ...

Before the era of cheap computers, the principle use for multitasking was to allow many people to share the same computer.

Seemingly, multitasking would cause a computer that is switching between several programs to run more slowly - in direct proportion to the number of programs it is running. However, most programs spend much of their time waiting for slow input/output devices to complete their tasks. If a program is waiting for the user to click on the mouse or press a key on the keyboard, then it will not take a "time slice" until the event it is waiting for has occurred. This frees up time for other programs to execute so that many programs may be run at the same time without unacceptable speed loss.

Multiprocessing

Main article: Multiprocessing

Cray designed many supercomputers that used multiprocessing heavily.

Some computers may divide their work between one or more separate CPUs, creating a multiprocessing configuration. Traditionally, this technique was utilized only in large and powerful computers such as supercomputers, mainframe computers and servers. However, multiprocessor and multi-core (multiple CPUs on a single integrated circuit) personal and laptop computers have become widely available and are beginning to see increased usage in lower-end markets as a result. Multiprocessing is traditionally known as the use of multiple concurrent processes in a system as opposed to a single process at any one instant. ... ImageMetadata File history File links Download high resolution version (2592x1944, 2110 KB) File links The following pages link to this file: Supercomputer Cray-2 ... ImageMetadata File history File links Download high resolution version (2592x1944, 2110 KB) File links The following pages link to this file: Supercomputer Cray-2 ... For alternate meanings, see Cray (disambiguation). ... A supercomputer is a computer that leads the world in terms of processing capacity, particularly speed of calculation, at the time of its introduction. ... This article or section does not adequately cite its references or sources. ... This article or section does not cite its references or sources. ... This article or section does not adequately cite its references or sources. ...

Supercomputers in particular often have highly unique architectures that differ significantly from the basic stored-program architecture and from general purpose computers.^[13] They often feature thousands of CPUs, customized high-speed interconnects, and specialized computing hardware. Such designs tend to be useful only for specialized tasks due to the large scale of program organization required to successfully utilize most of a the available resources at once. Supercomputers usually see usage in large-scale simulation, graphics rendering, and cryptography applications, as well as with other so-called "embarrassingly parallel" tasks. A computer simulation or a computer model is a computer program that attempts to simulate an abstract model of a particular system. ... This article or section does not adequately cite its references or sources. ... The German Lorenz cipher machine, used in World War II for encryption of very high-level general staff messages Cryptography (or cryptology; derived from Greek κρυπτός kryptós hidden, and the verb γράφω gráfo write) is the study of message secrecy. ... In the jargon of parallel computing, an embarrassingly parallel workload (or embarrassingly parallel problem) is one for which no particular effort is needed to segment the problem into a very large number of parallel tasks, and there is no essential dependency (or communication) between those parallel tasks. ...

Networking and the Internet

Main articles: Computer networking and Internet

Visualization of a portion of the routes on the Internet.

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The image above is proposed for deletion. See images and media for deletion to help reach a consensus on what to do.

Computers have been used to coordinate information in multiple locations since the 1950s, with the US military's SAGE system the first large-scale example of such a system, which led to a number of special-purpose commercial systems like Sabre. This article or section is in need of attention from an expert on the subject. ... Image File history File links Download high-resolution version (1024x1024, 510 KB) I created this small partial map of the Internet from the 2005-01-15 data found here using a slightly different rendering technique than was used to generate the maps there. ... Image File history File links Download high-resolution version (1024x1024, 510 KB) I created this small partial map of the Internet from the 2005-01-15 data found here using a slightly different rendering technique than was used to generate the maps there. ... Routing Schemes anycast broadcast multicast unicast In computer networking the term routing (or routeing) refers to selecting paths in a computer network along which to send data. ... SAGE Sector Control Room. ... Sabre Logo Sabre is a computer reservations system/global distribution system (GDS) used by airlines, railways, hotels, travel agents and other travel companies. ...

In the 1970s, computer engineers at research institutions throughout the US began to link their computers together using telecommunications technology. This effort was funded by ARPA (now DARPA), and the computer network that it produced was called the ARPANET. The technologies that made the Arpanet possible spread and evolved. In time, the network spread beyond academic and military institutions and became known as the Internet. The emergence of networking involved a redefinition of the nature and boundaries of the computer. Computer operating systems and applications were modified to include the ability to define and access the resources of other computers on the network, such as peripheral devices, stored information, and the like, as extensions of the resources of an individual computer. Initially these facilities were available primarily to people working in high-tech environments, but in the 1990s the spread of applications like e-mail and the World Wide Web, combined with the development of cheap, fast networking technologies like Ethernet and ADSL saw computer networking become almost ubiquitous. In fact, the number of computers that are networked is growing phenomenally. A very large proportion of personal computers regularly connect to the Internet to communicate and receive information. "Wireless" networking, often utilizing mobile phone networks, has meant networking is becoming increasingly ubiquitous even in mobile computing environments. The Defense Advanced Research Projects Agency (DARPA) is an agency of the United States Department of Defense responsible for the development of new technology for use by the military. ... Computer networks redirects here. ... ARPANET logical map, March 1977. ... Wikipedia does not yet have an article with this exact name. ... WWWs historical logo designed by Robert Cailliau The World Wide Web (or the Web) is a system of interlinked, hypertext documents that runs over the Internet. ... Ethernet is a large, diverse family of frame-based computer networking technologies that operates at many speeds for local area networks (LANs). ... Asymmetric Digital Subscriber Line (ADSL) is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional modem can provide. ...

Further topics

Hardware

The term hardware covers all of those parts of a computer that are tangible objects. Circuits, displays, power supplies, cables, keyboards, printers and mice are all hardware.

Computing hardware has been an important component of the process of calculation and data storage since it became useful for numerical values to be processed and shared. ... The Antikythera mechanism (main fragment). ... Part of Babbages Difference engine, assembled after his death by Babbages son, using parts found in his laboratory. ... The Norden bombsight A page from the Bombardiers Information File (BIF) that describes the components and controls of the Norden Bombsight. ... Jacquard loom on display at Museum of Science and Industry in Manchester, England The Jacquard loom is a mechanical loom, invented by Joseph Marie Jacquard in 1801, which used the holes punched in pasteboard punch cards to control the weaving of patterns in fabric. ... The analytical engine, an important step in the history of computers, is the design of a mechanical modern general-purpose computer by the British professor of mathematics Charles Babbage. ... Portion of the Harvard-IBM Mark 1, left side. ... Konrad Zuses Z3 was the first working programmable, fully automatic machine, whose attributes, with the addition of conditional branching, have often been the ones used as criteria in defining a computer. ... Atanasoff-Berry Computer replica at 1st floor of Durham Center, Iowa State University The Atanasoff-Berry Computer (ABC) was one of the first electronic digital computing device. ... ENIAC ENIAC, short for Electronic Numerical Integrator and Computer,[1] was the first large-scale, electronic, digital computer capable of being reprogrammed to solve a full range of computing problems,[2] although earlier computers had been built with some of these properties. ... EDSAC EDSAC (Electronic Delay Storage Automatic Calculator) was an early British computer (one of the first computers to be created). ... The EDVAC as installed in Building 328 at the Ballistics Research Laboratory. ... UNIVAC I Central Complex, containing the central processor and main memory unit. ... An integrated circuit (IC) is a thin chip consisting of at least two interconnected semiconductor devices, mainly transistors, as well as passive components like resistors. ... This article or section does not adequately cite its references or sources. ... System/360 Model 65 operators console, with register value lamps and toggle switches (middle of picture) and emergency pull switch (upper right). ... The group of competitors (mainframe computer manufacturers) to IBM in the 1960s became known as the BUNCH: Burroughs, UNIVAC, NCR, Control Data Corporation, and Honeywell. ... Minicomputer (colloquially, mini) is a largely obsolete term for a class of multi-user computers which make up the middle range of the computing spectrum, in between the largest multi-user systems (traditionally, mainframe computers) and the smallest single-user systems (microcomputers or personal computers). ... A PDP-8 on display at the Smithsonians National Museum of American History in Washington, D.C.. This example is from the first generation of PDP-8s, built with discrete transistors and later known as the Straight 8. ... The PDP-11 was a 16-bit minicomputer sold by Digital Equipment Corp. ... The System/32 (IBM 5320) is a single user minicomputer marketed by IBM in the mid- to late 1970s. ... The System/36 was a minicomputer marketed by IBM from 1983 to 2000. ... VAX is a 32-bit computing architecture that supports an orthogonal instruction set (machine language) and virtual addressing (i. ... i5 Model 570 (2006) The Application System/400 (also known as AS/400), now System i (also known as iSeries), is a type of computer produced by IBM. It was first produced in 1988. ... In computer science, 4-bit is an adjective used to describe integers, memory addresses or other data units that are at most 4 bits wide, or to describe CPU and ALU architectures based on registers, address buses, or data buses of that size. ... The Intel 4004, a 4-bit central processing unit (CPU) released by Intel Corp. ... Intel D4040 Microprocessor The Intel 4040 microprocessor was the successor to the Intel 4004. ... 8-bit refers to the number of bits used in the data bus of a computer. ... Intel 8008 The Intel 8008 was an early microprocessor designed and manufactured by Intel and introduced in April, 1972. ... Intel C8080A processor. ... Motorola 6800 Microprocessor The 6800 is a microprocessor produced by Motorola and released shortly after the Intel 8080 in 1975. ... 1 MHz Motorola 6809E processor, manufactured in 1983. ... The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle for MOS Technology in 1975. ... One of the first Z80 microprocessors manufactured; the date stamp says well before July 1976. ... In computer science, 16-bit is an adjective used to describe integers that are at most two bytes wide, or to describe CPU architectures based on registers, address buses, or data buses of that size. ... The Intel 8088 is an Intel microprocessor based on the 8086, with 16-bit registers and an 8-bit external data bus. ... The Z8000 was a 16-bit microprocessor introduced by ZiLOG in 1979. ... W65C816S microprocessor in a DIP40 package. ... 32-bit is a term applied to processors, and computer architectures which manipulate the address and data in 32-bit chunks. ... The Intel 80386 is a microprocessor which was used as the central processing unit (CPU) of many personal computers from 1986 until 1994 and later. ... The Pentium is a fifth-generation x86 architecture microprocessor from Intel. ... The Motorola 68000 is a CISC microprocessor, the first member of a successful family of microprocessors from Motorola, which were all mostly software compatible. ... The ARM architecture (previously, the Advanced RISC Machine, and prior to that Acorn RISC Machine) is a 32-bit RISC processor architecture that is widely used in a number of embedded designs. ... In computing, a 64-bit component is one in which data are processed or stored in 64-bit units (words). ... The AMD64 or x86-64 is a 64-bit processor architecture invented by AMD. It is a superset of the x86 architecture, which it natively supports. ... PowerPC is a RISC microprocessor architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM. Originally intended for personal computers, PowerPC CPUs have since become popular embedded and high-performance processors as well. ... A MIPS R4400 microprocessor made by Toshiba. ... Sun UltraSPARC II Microprocessor Sun UltraSPARC T1 (Niagara 8 Core) SPARC (Scalable Processor Architecture) is a RISC microprocessor instruction set architecture originally designed in 1985 by Sun Microsystems. ... It has been suggested that Embedded System Design in an FPGA be merged into this article or section. ... The Intel 8048 microcontroller, Intels first µC, was used in the Magnavox Odyssey² video game console and (in its 8042 variant) in the original IBM PC keyboard. ... The Intel 8051 is a microcontroller developed by Intel in 1980 for use in embedded products and still (2003) one of the most popular microcontrollers. ... Desktop computer with several common peripherals (Monitor, keyboard, mouse, speakers, microphone and a printer) A desktop computer is a personal computer made for use on a desk in an office or home and is distinguished from portable computers such as laptops or PDAs. ... Children playing on a Amstrad CPC 464 in the 1980s. ... Laptop with touchpad. ... Personal digital assistants (PDAs) are handheld computers that were originally designed as personal organizers, but became much more versatile over the years. ... A Portable computer is a computer that is designed to be moved from one place to another (in other words, it is a computer that is portable). ... Toshiba Portege 3500 tablet PC, in tablet configuration. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... This article or section does not cite its references or sources. ... The Bloch sphere is a representation of a qubit, the fundamental building block of quantum computers. ... A chemical computer, also called reaction-diffusion computer, BZ computer or gooware computer is an unconventional computer based on a semi-solid chemical soup where data is represented by varying concentrations of chemicals. ... DNA computing is a form of computing which uses DNA and molecular biology, instead of the traditional silicon-based computer technologies. ... An optical computer is a computer that uses light instead of electricity (i. ... A peripheral is a type of computer hardware that is added to a host computer in order to expand its abilities. ... Energy Input: The energy placed into a reaction. ... A contemporary computer mouse, with the most common standard features — two buttons and a scroll-wheel. ... A computer keyboard is a peripheral partially modeled after the typewriter keyboard. ... Joystick elements: 1. ... In computing, a scanner is a device that analyzes an image (such as a photograph, printed text, or handwriting) or an object (such as an ornament) and converts it to a digital image. ... Look up monitor in Wiktionary, the free dictionary. ... This does not cite any references or sources. ... A floppy disk is a data storage device that comprises a circular piece of thin, flexible (hence floppy) magnetic storage medium encased in a square or rectangular plastic wallet. ... Typical hard drives of the mid-1990s. ... The optical lens of a compact disc drive. ... Teletype machines in World War II A teleprinter (teletypewriter, teletype or TTY for TeleTYpe/TeleTYpewriter) is a now largely obsolete electro-mechanical typewriter which can be used to communicate typed messages from point to point through a simple electrical communications channel, often just a pair of wires. ... In computer architecture, a bus is a subsystem that transfers data or power between computer components inside a computer or between computers and typically is controlled by device driver software. ... RS-232 (also referred to as EIA RS-232C or V.24) is a standard for serial binary data interchange between a DTE (Data terminal equipment) and a DCE (Data communication equipment). ... This article or section does not cite any references or sources. ... This article or section does not cite its references or sources. ... Note: USB may also mean upper sideband in radio. ... This article or section is in need of attention from an expert on the subject. ... Ethernet is a large, diverse family of frame-based computer networking technologies that operates at many speeds for local area networks (LANs). ... This article or section is not written in the formal tone expected of an encyclopedia article. ... In computer networking, fiber-distributed data interface (FDDI) is a standard for data transmission in a local area network that can extend in range up to 200 km (124 miles). ...

Software

Software refers to parts of the computer that have no material form; programs, data, protocols, etc are all software. When software is stored in hardware that cannot easily be modified (such as BIOS ROM in an IBM PC compatible), it is sometimes termed firmware to indicate that it falls into an area of uncertainty between hardware and software. This article or section does not adequately cite its references or sources. ... Look up ROM in Wiktionary, the free dictionary. ... This article or section does not cite its references or sources. ...

It has been suggested that this article or section be merged with Computer program. ... An operating system (OS) is a set of computer programs that manage the hardware and software resources of a computer. ... Filiation of Unix and Unix-like systems Unix (officially trademarked as UNIX®) is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy. ... Berkeley Software Distribution (BSD, sometimes called Berkeley Unix) is the Unix derivative distributed by the University of California, Berkeley, starting in the 1970s. ... It has been suggested that Traditional Unix be merged into this article or section. ... AIX (Advanced Interactive eXecutive) is a proprietary operating system developed by IBM based on UNIX System V. Before the product was ever marketed, the acronym AIX originally stood for Advanced IBM UNIX. AIX has pioneered numerous network operating system enhancements, introducing new innovations later adopted by Unix-like operating systems... HP-UX (Hewlett Packard UniX) is Hewlett-Packards proprietary implementation of the Unix operating system, based on System V (initially System III). ... Solaris is a computer operating system developed by Sun Microsystems. ... SunOS was the version of the UNIX operating system developed by Sun Microsystems for their workstations and server systems until the early 1990s. ... FreeBSD is a Unix-like free operating system descended from AT&T UNIX via the Berkeley Software Distribution (BSD) branch through the 386BSD and 4. ... NetBSD is a freely redistributable, open source version of the Unix-like BSD computer operating system. ... IRIX is a computer operating system developed by Silicon Graphics, Inc. ... GNU (pronounced ) is a computer operating system - consisting of a kernel, libraries, system utilities, compilers, and end-user application software - composed entirely of free software. ... Linux (IPA pronunciation: ) is a Unix-like computer operating system family. ... This page provides general information about each of the notable Linux distributions in the form of a categorized list. ... The many Linux distributions differ for various reasons including technical, organizational, and philosophical. ... Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... Windows 9x is a term used to describe the DOS-based operating systems Windows 95 and Windows 98, similar versions of Microsoft Windows which were produced in the 1990s. ... Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. ... This article or section does not cite its references or sources. ... Instructions on how to use the directory command. ... QDOS (Quick and Dirty Operating System) was the working title for 86-DOS, an operating system developed and marketed by Seattle Computer Products for its Intel 8086-based computer kit. ... IBM PC-DOS was one of the three major operating systems that dominated the personal computer market from about 1985 to 1995. ... Microsofts disk operating system, MS-DOS, was Microsofts implementation of DOS, which was the first popular operating system for the IBM PC, and until recently, was widely used on the PC compatible platform. ... FreeDOS (formerly Free-DOS and PD-DOS) is an operating system for IBM PC compatible computers. ... This article or section does not adequately cite its references or sources. ... This article or section does not adequately cite its references or sources. ... Mac OS X (official IPA pronunciation: ) is a line of proprietary, graphical operating systems developed, marketed, and sold by Apple Inc. ... An embedded operating system is an operating system for embedded computer systems. ... A real-time operating system (RTOS) is a class of operating system intended for real-time applications. ... Operating systems can be categorized by technology (Unix-like or others such as Windows), ownership and license (proprietary or open source), working state (historic like MS-DOS and OS/2 or current like Linux and Windows), application (general like Linux, Windows), desktop only (MS-DOS, MacOS), mainframe only (VM), real... The Amoeba distributed operating system is a microkernel-based research operating system written by Andrew S. Tanenbaum at Vrije Universiteit. ... Tiled window arrangement of Oberon Oberon is an operating system, originally developed as part of the NS32032-based Ceres workstation project; it is written entirely in the Oberon programming language. ... Bluebottle, also known as AOS, is the name of the next generation Native Oberon, the Oberon operating system for bare PC hardware. ... Plan 9 from Bell Labs is a distributed operating system, primarily used as a research vehicle. ... Illustration of an application which may use libvorbisfile. ... ... Microsoft DirectX is a collection of APIs for handling tasks related to multimedia, especially game programming, on Microsoft platforms. ... OpenGL (Open Graphics Library) is a standard specification defining a cross-language cross-platform API for writing applications that produce 3D computer graphics (and 2D computer graphics as well). ... OpenAL (Open Audio Library) is a cross-platform audio API. It is designed for efficient rendering of multichannel three dimensional positional audio. ... The C standard library is a now-standardised collection of header files and library routines used to implement common operations, such as input/output and string handling, in the C programming language. ... In Computer Science, data is often distinguished from code, though both are represented in modern computers as binary strings. ... For other senses of this word, see protocol. ... The Internet protocol suite is the set of communications protocols that implement the protocol stack on which the Internet runs. ... Kermit is a computer file transfer/management protocol and a set of communications software tools; it provides a consistent approach to file transfer, terminal emulation, script programming, and character set conversion across many different computer hardware and OS platforms. ... The abbreviation FTP can refer to: The File Transfer Protocol used on the Internet. ... HTTP (for HyperText Transfer Protocol) is the primary method used to convey information on the World Wide Web. ... Simple Mail Transfer Protocol (SMTP) is the de facto standard for email transmission across the Internet. ... A file format is a particular way to encode information for storage in a computer file. ... HTML, short for Hypertext Markup Language, is the predominant markup language for the creation of web pages. ... The Extensible Markup Language (XML) is a general-purpose markup language. ... In computing, JPEG (pronounced JAY-peg; IPA: ) is a commonly used standard method of compression for photographic images. ... The Moving Picture Experts Group or MPEG is a working group of ISO/IEC charged with the development of video and audio encoding standards. ... PNG (Portable Network Graphics) is a bitmapped image format that employs lossless data compression. ... The user interface is the part of a system exposed to users. ... A graphical user interface (GUI, often pronounced gooey) is a type of user interface which allows people to interact with a computer and computer-controlled devices which employ graphical icons, visual indicators or special graphical elements called widgets, along with text labels or text navigation to represent the information and... In human–computer interaction, WIMP stands for window, icon, menu, pointing device, denoting a style of interaction using these elements. ... Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... This article or section does not cite any references or sources. ... QNX (pronounced either Q-N-X or Q-nix) is a commercial POSIX-compliant Unix-like real-time operating system, aimed primarily at the embedded systems market. ... CDE on Unix (Solaris 8) DECwindows CDE on OpenVMS 7. ... GEM (Graphical Environment Manager) was a windowing system created by Digital Research, Inc. ... TUI (Text User Interface) is a retronym that was coined sometime after the invention of graphical user interfaces, to distinguish them from text based user interfaces. ... This article or section does not adequately cite its references or sources. ... In computing, a shell is a piece of software that provides an interface for users (command line interpreter). ... This article or section does not cite any references or sources. ... In computing, an office suite, sometimes called an office application suite or productivity suite is a software suite intended to be used by typical clerical and knowledge workers. ... Word processing, in its now-usual meaning, is the use of a word processor to create documents using computers. ... Adobe InDesign CS2, one of many popular desktop publishing applications. ... A presentation program is a computer software package used to display information, normally in the form of a slide show. ... A database management system (DBMS) is computer software designed for the purpose of managing databases. ... Screenshot of a spreadsheet made with OpenOffice. ... Accounting software is computer software that records and processes accounting transactions within functional modules such as accounts payable, accounts receivable, payroll and trial balance. ... Browsing redirects here Browser can refer to: Browser - a type of herbivore whose nutrition generally comes from high growing plants, like trees, rather than a grazer that eats from the ground. ... {{ #REDIRECT [[ --216. ... The inside/front of a Dell PowerEdge web server The term Web server can mean one of two things: A computer that is responsible for accepting HTTP requests from clients, which are known as Web browsers, and serving them HTTP responses along with optional data contents, which usually are Web... A mail transfer agent or MTA (also called a mail transport agent, mail server, or a mail exchanger in the context of the Domain Name System) is a computer program or software agent that transfers electronic mail messages from one computer to another. ... A screenshot of PowWow, one of the first instant messengers with a graphical user interface // Instant messaging or IM is a form of real-time communication between two or more people based on typed text. ... “CAD” redirects here. ... Computer-aided manufacturing (CAM) refers to the software used to generate the instruction codes for a CNC machine in order for it to cut out a shape designed in a computer-aided design (CAD) system. ... Computer graphics is a sub-field of computer science and is concerned with digitally synthesizing and manipulating visual content. ... A screenshot from the KDE raster graphics editor KolourPaint A screenshot from the GIMP raster graphics editor A raster graphics editor is a computer program that allows users to paint and edit pictures interactively on the computer screen and save them in one of many popular bitmap or raster formats... A screenshot of the xfig vector graphics editor A screenshot of the modern vector graphics editor Xara Xtreme A vector graphics editor is a computer program that allows users to compose and edit vector graphics images interactively on the computer screen (compare with MetaPost) and save them in one of... It has been suggested that this article or section be merged into 3D computer graphics software. ... Animation software is software that is used either for computer animation or to assist animators with the considerable work needed to create more traditional pieces of animation. ... 3D computer graphics are different from 2D computer graphics in that a three-dimensional representation of geometric data is stored in the computer for the purposes of performing calculations and rendering 2D images. ... The term video editing can refer to: non-linear editing system, using computers with video editing software linear video editing, using videotape Video editing is the process of re-arranging or modifying segments of video to form another piece of video. ... UPIICSA IPN - Binary image Image processing is any form of information processing for which the input is an image, such as photographs or frames of video; the output is not necessarily an image, but can be for instance a set of features of the image. ... Digital audio comprises audio signals stored in a digital format. ... This article should be merged with Digital Audio Workstation. ... An audio player is a kind of media player for playing back digital audio, including optical discs such as CDs, SACDs, DVD-Audio, HDCD, and audio files. ... A software synthesizer, also known as a softsynth or virtual instrument is a computer program for digital audio generation. ... Computer music is music generated with, or composed with the aid of, computers. ... e. ... This article is about the computing term. ... An assembly language is a low-level language used in the writing of computer programs. ... An interpreter is a computer program that executes other programs. ... A debugger is a computer program that is used to test and debug other programs. ... Notepad is the standard text editor for Microsoft Windows A text editor is a piece of computer software for editing plain text. ... It has been suggested that IDE-style interface be merged into this article or section. ... In software engineering, performance analysis (a field of dynamic program analysis) is the investigation of a programs behavior using information gathered as the program runs, as opposed to static code analysis. ... Revision control (also known as version control, source control or (source) code management (SCM)) is the management of multiple revisions of the same unit of information. ... Software Configuration Management (SCM) is part of configuration management (CM). ... Edutainment (also educational entertainment or entertainment-education) is a form of entertainment designed to educate as well as to amuse. ... Educational games are games; board and card games, including video games that are designed to teach people, typically children, about a certain subject, expand concepts, reinforce development, understand an historical event or culture, or assit them in learning a skill as they play. ... Serious games (SGs) or persuasive games are computer and video games used as persuasion technology or educational technology. ... Interior cockpit of a modern flight simulator A flight simulator is a system that tries to replicate, or simulate, the experience of flying an aircraft as closely and realistically as possible. ... It has been suggested that Multiplayer game be merged into this article or section. ... Chess, one of the most well-known and played strategy games ever. ... Minesweeper, a popular computer puzzle game found on many machines. ... First-person shooter (FPS) is a genre of video games which is characterized by an on-screen view that simulates the in-game characters point of view and a focus on the use of handheld ranged weapons. ... A simple platform sequence from the game Wonder Boy Platform game, or platformer, is a video game genre characterized by jumping to and from suspended platforms or over obstacles. ... World of Warcraft, a popular MMORPG A Massively Multiplayer Online Game (also called MMOG or MMO) is a computer game which is capable of supporting hundreds or thousands of players simultaneously. ... Zork I is one of the first interactive fiction games, as well as being one of the first commercially sold. ... Hondas humanoid robot, ASIMO The term Artificial Intelligence (AI) was first used by John McCarthy who used it to mean the science and engineering of making intelligent machines.[1] It can also refer to intelligence as exhibited by an artificial (man-made, non-natural, manufactured) entity. ... Antivirus software consists of computer programs that attempt to identify, thwart and eliminate computer viruses and other malicious software (malware). ... A malware scanner is a program, akin to virus scanners, which detects malicious software in a computers RAM or hard drive. ... An installation program or installer is a computer program that installs files, such as applications, drivers, or other software, onto a computer. ... Illustration of a package management system being used to download new software. ... A file manager is a computer program that provides a user interface to work with file systems. ...

Programming languages

Programming languages provide various ways of specifying programs for computers to run. Unlike natural languages, programming languages are designed to permit no ambiguity and to be concise. They are purely written languages and are often difficult to read aloud. They are generally either translated into machine language by a compiler or an assembler before being run, or translated directly at run time by an interpreter. Sometimes programs are executed by a hybrid method of the two techniques. There are thousands of different programming languages—some intended to be general purpose, others useful only for highly specialized applications. The term natural language is used to distinguish languages spoken and signed (by hand signals and facial expressions) by humans for general-purpose communication from constructs such as writing, computer-programming languages or the languages used in the study of formal logic, especially mathematical logic. ... A system of codes directly understandable by a computers CPU is termed this CPUs native or machine language. ... This article is about the computing term. ... An assembly language is a low-level language used in the writing of computer programs. ... Interpreter can mean one of the following: In communication, an interpreter is a person whose role is to facilitate dialogue between two parties that do not use the same language. ...

Other listings of programming languages are: Categorical list of programming languages Generational list of programming languages Chronological list of programming languages Note: Esoteric programming languages have been moved to the separate List of esoteric programming languages. ... There are a lot of kinds of listing. ... This is a timeline, i. ... This is a list of programming languages grouped by category. ... Here, a genealogy of programming languages is shown. ... The list of programming languages consists of all notable programming languages in existence, currently or since the dawn of computing, in alphabetical order. ... Non-English-based programming languages are computer programming languages that, unlike most well-known programming languages, do not use keywords taken from, or inspired by, the English vocabulary. ... An assembly language is a low-level language used in the writing of computer programs. ... The ARM architecture (previously, the Advanced RISC Machine, and prior to that Acorn RISC Machine) is a 32-bit RISC processor architecture that is widely used in a number of embedded designs. ... A MIPS R4400 microprocessor made by Toshiba. ... Wikibooks has more about this subject: Programming:x86 assembly x86 assembly language is the assembly language for the x86 class of processors, which includes Intels Pentium series and AMDs Athlon series. ... A high-level programming language is a programming language that is more user-friendly, to some extent platform-independent, and abstract from low-level computer processor operations such as memory accesses. ... Screenshot of Atari BASIC, an early BASIC language for small computers. ... C is a general-purpose, procedural, imperative computer programming language developed in 1972 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system. ... C++ (pronounced see plus plus, IPA: ) is a general-purpose, high-level programming language with low-level facilities. ... The title given to this article is incorrect due to technical limitations. ... COBOL is a third-generation programming language, and one of the oldest programming languages still in active use. ... Fortran (previously FORTRAN[1]) is a general-purpose[2], procedural,[3] imperative programming language that is especially suited to numeric computation and scientific computing. ... Java is an object-oriented applications programming language developed by Sun Microsystems in the early 1990s. ... Lisp is a family of computer programming languages with a long history and a distinctive fully-parenthesized syntax. ... Pascal is an imperative computer programming language, developed in 1970 by Niklaus Wirth as a language particularly suitable for structured programming. ... Scripting languages (commonly called scripting programming languages or script languages) are computer programming languages that are typically interpreted and can be typed directly from a keyboard. ... JavaScript is the name of Netscape Communications Corporations and now the Mozilla Foundations implementation of the ECMAScript standard, a scripting language based on the concept of prototype-based programming. ... Python is a high-level programming language first released by Guido van Rossum in 1991. ... Ruby is a reflective, dynamic, object-oriented programming language. ... PHP (PHP:Hypertext Preprocessor) is a reflective programming language originally designed for producing dynamic web pages. ... Perl is a dynamic programming language created by Larry Wall and first released in 1987. ...

Professions and organizations

As the use of computers has spread throughout society, there are an increasing number of careers involving computers. Following the theme of hardware, software and firmware, the brains of people who work in the industry are sometimes known irreverently as wetware or "meatware".

The need for computers to work well together and to be able to exchange information has spawned the need for many standards organizations, clubs and societies of both a formal and informal nature. Electrical Engineers design power systems… … and complex electronic circuits. ... It has been suggested that this article or section be merged with electrical and electronics engineering. ... Computer engineering (also called electronic and computer engineering) is a discipline that combines elements of both electrical engineering and computer science. ... Telecommunications engineering focuses on the transmission of information across a channel such as a coax cable, optical fibre or free space. ... Optical engineering is the field of study which focuses on applications of optics. ... // Human–computer interaction (HCI), alternatively man–machine interaction (MMI) or computer–human interaction (CHI), is the study of interaction between people (users) and computers. ... Information technology (IT), as defined by the Information Technology Association of America (ITAA)is: the study, design, development, implementation, support or management of computer-based information systems, particularly software applications and computer hardware. ... e. ... Scientific computing (or computational science) is the field of study concerned with constructing mathematical models and numerical solution techniques and using computers to analyze and solve scientific and engineering problems. ... Web design is the designing and graphical presentation of content shown on the Internet in the form of Web sites and other Web applications using many different forms of media. ... Adobe InDesign CS2, one of many popular desktop publishing applications. ... Sound recorder redirects here. ...

The American National Standards Institute or ANSI (pronounced an-see) is a nonprofit organization that oversees the development of standards for products, services, processes and systems in the United States. ... The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ... The Institute of Electrical and Electronics Engineers or IEEE (pronounced as eye-triple-e) is an international non-profit, professional organization for the advancement of technology related to electricity. ... The Internet Engineering Task Force (IETF) develops and promotes Internet standards, cooperating closely with the W3C and ISO/IEC standard bodies; and dealing in particular with standards of the TCP/IP and Internet protocol suite. ... The International Organization for Standardization (ISO) is an international standard-setting body composed of representatives from various national standards bodies. ... The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web (W3). ... The Association for Computing Machinery, or ACM, was founded in 1947 as the worlds first scientific and educational computing society. ... IET logo The Institution of Engineering and Technology (IET) is the professional institution for engineering and technology in the United Kingdom. ... The International Federation for Information Processing, usually known as IFIP, is an umbrella organization for national societies working in the field of information technology. ... Clockwise from top: The logo of the GNU Project (the GNU head), the Linux kernel mascot Tux the Penguin, and the FreeBSD daemon Free software is a term coined by Richard Stallman and the Free Software Foundation[1] to refer to software that can be used, studied, and modified without... Open source software is an antonym for closed source software and refers to any computer software whose source code is available under a license (or arrangement such as the public domain) that permits users to study, change, and improve the software, and to redistribute it in modified or unmodified form. ... The Free Software Foundation (FSF) is a non-profit corporation founded in October 1985 by Richard Stallman to support the free software movement (free as in freedom), and in particular the GNU project. ... The Mozilla Foundation (abbreviated MF or MoFo) is a non-profit organization that exists to support and provide leadership for the open source Mozilla project. ... Apache Software Foundation Logo The Apache Softwares Foundation (ASF) is a non-profit corporation (classified as 501(c)(3) in the United States) to support Apache software projects, including the Apache HTTP Server. ...

See also

• Computability theory
• Computer science
• Computing
• Computers in fiction
• Computer security and Computer insecurity
• List of computer term etymologies
• Virtualization

Wikipedia does not have an article with this exact name. ... Wiktionary (from wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 150 languages. ... Image File history File links This is a lossless scalable vector image. ... Wikiquote is a sister project of Wikipedia, using the same MediaWiki software. ... Image File history File links Commons-logo. ... The Wikimedia Commons (also called Wikicommons) is a repository of free content images, sound and other multimedia files. ... In computer science, computability theory is the branch of the theory of computation that studies which problems are computationally solvable using different models of computation. ... Computer science, or computing science, is the study of the theoretical foundations of information and computation and their implementation and application in computer systems. ... Memory (Random Access Memory) Look up computing in Wiktionary, the free dictionary. ... This page is intended to be a list of computers in fiction and science fiction. ... This article describes how security can be achieved through design and engineering. ... Many current computer systems have limited security precautions in place. ... This is a list of the origins of computer-related terms (i. ... In computing, virtualization is a broad term that refers to the abstraction of computer resources. ...

Notes

ENIAC ENIAC, short for Electronic Numerical Integrator and Computer,[1] was the first large-scale, electronic, digital computer capable of being reprogrammed to solve a full range of computing problems,[2] although earlier computers had been built with some of these properties. ... Part of Babbages Difference engine, assembled after his death by Babbages son, using parts found in his laboratory. ... The PDP-11 was a 16-bit minicomputer sold by Digital Equipment Corp. ... Minicomputer (colloquially, mini) is a largely obsolete term for a class of multi-user computers which make up the middle range of the computing spectrum, in between the largest multi-user systems (traditionally, mainframe computers) and the smallest single-user systems (microcomputers or personal computers). ... In computer programming, a comment is a programming language construct that provides a mechanism for embedding information in the source code that is (generally) ignored by compilers and interpreters but may be of use to people reading the program source, or other programming tools that process the source such as... Hondas humanoid robot, ASIMO The term Artificial Intelligence (AI) was first used by John McCarthy who used it to mean the science and engineering of making intelligent machines.[1] It can also refer to intelligence as exhibited by an artificial (man-made, non-natural, manufactured) entity. ... On October 30, 1994, Professor Thomas Nicely who was then at Lynchburg College reported a bug in the Pentium floating point unit. ... Intel Corporation (NASDAQ: INTC, SEHK: 4335), founded in 1968 as Integrated Electronics Corporation, is an American multinational corporation that is best known for designing and manufacturing microprocessors and specialized integrated circuits. ... A microprocessor is a programmable digital electronic component that incorporates the functions of a central processing unit (CPU) on a single semiconducting integrated circuit (IC). ... A floating-point number is a digital representation for a number in a certain subset of the rational numbers, and is often used to approximate an arbitrary real number on a computer. ... Minicomputer (colloquially, mini) is a largely obsolete term for a class of multi-user computers which make up the middle range of the computing spectrum, in between the largest multi-user systems (traditionally, mainframe computers) and the smallest single-user systems (microcomputers or personal computers). ... The DEC logo Digital Equipment Corporation was a pioneering American company in the computer industry. ... A PDP-8 on display at the Smithsonians National Museum of American History in Washington, D.C.. This example is from the first generation of PDP-8s, built with discrete transistors and later known as the Straight 8. ... In computing, booting (booting up) is a bootstrapping process that starts operating systems when the user turns on a computer system. ... Non-volatile memory, or non-volatile storage, is computer memory that can retain the stored information even when not powered. ... The AMD64 or x86-64 is a 64-bit processor architecture invented by AMD. It is a superset of the x86 architecture, which it natively supports. ... “AMD” redirects here. ... The Athlon 64 is an eighth-generation, AMD64 architecture microprocessor produced by AMD, released on September 23, 2003[1]. It is the third processor to bear the name Athlon, and the immediate successor to the Athlon XP[2]. The second processor (after the Opteron) to implement AMD64 architecture and the... Core 2 is an eighth-generation x86 architecture microprocessor produced by Intel and based on the Intel Core microarchitecture. ... The Pentium is a fifth-generation x86 architecture microprocessor from Intel. ... // Overview The exposed die of an Intel 80486DX2 microprocessor. ... In computer programming, an interpreted language is a programming language whose programs may be executed from source form, by an interpreter. ... An interpreter is a computer program that executes other programs. ... A software bug is an error, flaw, mistake, failure, or fault in a computer program that prevents it from behaving as intended (e. ... The EDVAC as installed in Building 328 at the Ballistics Research Laboratory. ... An example of a Computer cluster A computer cluster is a group of loosely coupled computers that work together closely so that in many respects they can be viewed as though they are a single computer. ... An instruction set, or instruction set architecture (ISA), describes the aspects of a computer architecture visible to a programmer, including the native datatypes, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O (if any). ...

References

Aberdeen Proving Ground is a United States Army facility located at Aberdeen, Maryland (in Harford county). ... The United States Army is one of the armed forces of the United States and has primary responsibility for land-based military operations. ... For the Manfred Mann album, see 2006 (album). ... April 5 is the 95th day of the year in the Gregorian calendar (96th in leap years). ... The DEC logo Digital Equipment Corporation was a pioneering American company in the computer industry. ...   Maynard is a town in Middlesex County, Massachusetts, United States. ... Hans Meuer is a Professor of Computer Science at the University of Mannheim, general manager of Prometeus GmbH and general chairman of the International Supercomputing Conference[1]. In 1986, he became co-founder and organizer of the first Mannheim Supercomputer Conference[2], which has been held annually ever since. ... Jack Dongarra is a University Distinguished Professor of Computer Science in the Computer Science Department [1] at the University of Tennessee. ... For the Manfred Mann album, see 2006 (album). ... November 13 is the 317th day of the year (318th in leap years) in the Gregorian calendar, with 48 days remaining. ... The TOP500 project ranks and details the 500 most powerful publicly-known computer systems in the world. ... For the Manfred Mann album, see 2006 (album). ... November 27 is the 331st day (332nd in leap years) of the year in the Gregorian calendar. ...