An embedded system is a controller programmed and controlled by a real-time operating system with a dedicated function within a larger mechanical or electrical system with real-time computing constraints. It is embedded as part of a complete device including hardware and mechanical parts. Embedded systems control many devices in common use today. Ninety-eight percent of all microprocessors manufactured are used in embedded systems. Examples of properties of typical embedded computers when compared with general-purpose counterparts are low power consumption, small size, rugged operating ranges, low per-unit cost; this comes at the price of limited processing resources, which make them more difficult to program and to interact with. However, by building intelligence mechanisms on top of the hardware, taking advantage of possible existing sensors and the existence of a network of embedded units, one can both optimally manage available resources at the unit and network levels as well as provide augmented functions, well beyond those available.
For example, intelligent techniques can be designed to manage power consumption of embedded systems. Modern embedded systems are based on microcontrollers, but ordinary microprocessors are common in more complex systems. In either case, the processor used may be types ranging from general purpose to those specialized in certain class of computations, or custom designed for the application at hand. A common standard class of dedicated processors is the digital signal processor. Since the embedded system is dedicated to specific tasks, design engineers can optimize it to reduce the size and cost of the product and increase the reliability and performance; some embedded systems are mass-produced. Embedded systems range from portable devices such as digital watches and MP3 players, to large stationary installations like traffic lights, factory controllers, complex systems like hybrid vehicles, MRI, avionics. Complexity varies from low, with a single microcontroller chip, to high with multiple units and networks mounted inside a large chassis or enclosure.
One of the first recognizably modern embedded systems was the Apollo Guidance Computer, developed ca. 1965 by Charles Stark Draper at the MIT Instrumentation Laboratory. At the project's inception, the Apollo guidance computer was considered the riskiest item in the Apollo project as it employed the newly developed monolithic integrated circuits to reduce the size and weight. An early mass-produced embedded system was the Autonetics D-17 guidance computer for the Minuteman missile, released in 1961; when the Minuteman II went into production in 1966, the D-17 was replaced with a new computer, the first high-volume use of integrated circuits. Since these early applications in the 1960s, embedded systems have come down in price and there has been a dramatic rise in processing power and functionality. An early microprocessor for example, the Intel 4004, was designed for calculators and other small systems but still required external memory and support chips. In 1978 National Engineering Manufacturers Association released a "standard" for programmable microcontrollers, including any computer-based controllers, such as single board computers and event-based controllers.
As the cost of microprocessors and microcontrollers fell it became feasible to replace expensive knob-based analog components such as potentiometers and variable capacitors with up/down buttons or knobs read out by a microprocessor in consumer products. By the early 1980s, memory and output system components had been integrated into the same chip as the processor forming a microcontroller. Microcontrollers find applications. A comparatively low-cost microcontroller may be programmed to fulfill the same role as a large number of separate components. Although in this context an embedded system is more complex than a traditional solution, most of the complexity is contained within the microcontroller itself. Few additional components may be needed and most of the design effort is in the software. Software prototype and test can be quicker compared with the design and construction of a new circuit not using an embedded processor. Embedded systems are found in consumer, automotive, medical and military applications.
Telecommunications systems employ numerous embedded systems from telephone switches for the network to cell phones at the end user. Computer networking uses dedicated routers and network bridges to route data. Consumer electronics include MP3 players, mobile phones, video game consoles, digital cameras, GPS receivers, printers. Household appliances, such as microwave ovens, washing machines and dishwashers, include embedded systems to provide flexibility and features. Advanced HVAC systems use networked thermostats to more and efficiently control temperature that can change by time of day and season. Home automation uses wired- and wireless-networking that can be used to control lights, security, audio/visual, etc. all of which use embedded devices for sensing and controlling. Transportation systems from flight to automobiles use embedded systems. New airplanes contain advanced avionics such as inertial guidance systems and GPS receivers that have considerable safety requirements. Various electric motors — brushless DC motors, induction motors and DC motors — use electric/electronic motor controllers.
Automobiles, electric vehicles, hy
The Sega Saturn is a 32-bit fifth-generation home video game console developed by Sega and released on November 22, 1994 in Japan, May 11, 1995 in North America, July 8, 1995 in Europe. The successor to the successful Sega Genesis, the Saturn has a dual-CPU architecture and eight processors, its games are in CD-ROM format, its game library contains several arcade ports as well as original games. Development of the Saturn began in 1992, the same year Sega's groundbreaking 3D Model 1 arcade hardware debuted. Designed around a new CPU from Japanese electronics company Hitachi, another video display processor was incorporated into the system's design in early 1994 to better compete with Sony's forthcoming PlayStation; the Saturn was successful in Japan, but failed to sell in large numbers in the United States after its surprise May 1995 launch, four months before its scheduled release date. After the debut of the Nintendo 64 in late 1996, the Saturn lost market share in the U. S. where it was discontinued in 1998.
Having sold 9.26 million units worldwide, the Saturn is considered a commercial failure. The failure of Sega's development teams to release a game in the Sonic the Hedgehog series, known in development as Sonic X-treme, has been considered a factor in the console's poor performance. Although the Saturn is remembered for several well-regarded games, including Nights into Dreams, the Panzer Dragoon series, the Virtua Fighter series, its reputation is mixed due to its complex hardware design and limited third-party support. Sega's management has been criticized for its decisions during the system's development and discontinuation. Released in 1988, the Genesis was Sega's entry into the fourth generation of video game consoles. In mid-1990, Sega CEO Hayao Nakayama hired Tom Kalinske as CEO of Sega of America. Kalinske developed a four-point plan for sales of the Genesis: lower the price of the console, create a U. S.-based team to develop games targeted at the American market, continue aggressive advertising campaigns, sell Sonic the Hedgehog with the console.
The Japanese board of directors disapproved of the plan, but all four points were approved by Nakayama, who told Kalinske, "I hired you to make the decisions for Europe and the Americas, so go ahead and do it." Magazines praised Sonic as one of the greatest games made, Sega's console took off as customers, waiting for the Super Nintendo Entertainment System decided to purchase a Genesis instead. However, the release of a CD-based add-on for the Genesis, the Sega CD, was commercially disappointing. Sega experienced success with arcade games. In 1992 and 1993, the new Sega Model 1 arcade system board showcased Sega AM2's Virtua Racing and Virtua Fighter, which played a crucial role in popularizing 3D polygonal graphics. In particular, Virtua Fighter garnered praise for its simple three-button control scheme, with strategy coming from the intuitively observed differences between characters that felt and acted differently rather than the more ornate combos of two-dimensional competitors. Despite its crude visuals—with characters composed of fewer than 1,200 polygons—Virtua Fighter's fluid animation and realistic depiction of distinct fighting styles gave its combatants a lifelike presence considered impossible to replicate with sprites.
The Model 1 was an expensive system board, bringing home releases of its games to the Genesis required more than its hardware could handle. Several alternatives helped to bring Sega's newest arcade games to the console, such as the Sega Virtua Processor chip used for Virtua Racing, the Sega 32X add-on. Development of the Saturn was supervised by Hideki Sato, Sega's director and deputy general manager of research and development. According to Sega project manager Hideki Okamura, the Saturn project started over two years before the system was showcased at the Tokyo Toy Show in June 1994; the name "Saturn" was the system's codename during development in Japan, but was chosen as the official product name. Computer Gaming World in March 1994 reported a rumor that "the Sega Saturn... will release in Japan before the end of the year" for $250–300. In 1993, Sega and Japanese electronics company Hitachi formed a joint venture to develop a new CPU for the Saturn, which resulted in the creation of the "SuperH RISC Engine" that year.
The Saturn was designed around a dual-SH2 configuration. According to Kazuhiro Hamada, Sega's section chief for Saturn development during the system's conception, "the SH-2 was chosen for reasons of cost and efficiency; the chip has a calculation system similar to a DSP, but we realized that a single CPU would not be enough to calculate a 3D world." Although the Saturn's design was finished before the end of 1993, reports in early 1994 of the technical capabilities of Sony's upcoming PlayStation console prompted Sega to include another video display processor to improve the system's 2D performance and texture-mapping. CD-ROM-based and cartridge-only versions of the Saturn hardware were considered for simultaneous release during the system's development, but this idea was discarded due to concerns over the lower quality and higher price of cartridge-based games. According to Kalinske, Sega of America "fought against the architecture of Saturn for quite some time". Seeking an alternative graphics chip for the Saturn, Kalinske attempted to broker a deal with Silicon Graphics, but Sega of Japan rejected the proposal.
Silicon Graphics subsequently collaborated with Nintendo on the Nintendo 64. Kalinske, Sony Electronic Publishing's Olaf Olafsson, Sony America's Micky Schulhof h
A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single integrated circuit, or at most a few integrated circuits. The microprocessor is a multipurpose, clock driven, register based, digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory, provides results as output. Microprocessors contain sequential digital logic. Microprocessors operate on symbols represented in the binary number system; the integration of a whole CPU onto a single or a few integrated circuits reduced the cost of processing power. Integrated circuit processors are produced in large numbers by automated processes, resulting in a low unit price. Single-chip processors increase reliability because there are many fewer electrical connections that could fail; as microprocessor designs improve, the cost of manufacturing a chip stays the same according to Rock's law. Before microprocessors, small computers had been built using racks of circuit boards with many medium- and small-scale integrated circuits.
Microprocessors combined this into a few large-scale ICs. Continued increases in microprocessor capacity have since rendered other forms of computers completely obsolete, with one or more microprocessors used in everything from the smallest embedded systems and handheld devices to the largest mainframes and supercomputers; the complexity of an integrated circuit is bounded by physical limitations on the number of transistors that can be put onto one chip, the number of package terminations that can connect the processor to other parts of the system, the number of interconnections it is possible to make on the chip, the heat that the chip can dissipate. Advancing technology makes more powerful chips feasible to manufacture. A minimal hypothetical microprocessor might include only an arithmetic logic unit, a control logic section; the ALU performs addition and operations such as AND or OR. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation.
The control logic retrieves instruction codes from memory and initiates the sequence of operations required for the ALU to carry out the instruction. A single operation code might affect many individual data paths and other elements of the processor; as integrated circuit technology advanced, it was feasible to manufacture more and more complex processors on a single chip. The size of data objects became larger. Additional features were added to the processor architecture. Floating-point arithmetic, for example, was not available on 8-bit microprocessors, but had to be carried out in software. Integration of the floating point unit first as a separate integrated circuit and as part of the same microprocessor chip sped up floating point calculations. Physical limitations of integrated circuits made such practices as a bit slice approach necessary. Instead of processing all of a long word on one integrated circuit, multiple circuits in parallel processed subsets of each data word. While this required extra logic to handle, for example and overflow within each slice, the result was a system that could handle, for example, 32-bit words using integrated circuits with a capacity for only four bits each.
The ability to put large numbers of transistors on one chip makes it feasible to integrate memory on the same die as the processor. This CPU cache has the advantage of faster access than off-chip memory and increases the processing speed of the system for many applications. Processor clock frequency has increased more than external memory speed, so cache memory is necessary if the processor is not delayed by slower external memory. A microprocessor is a general-purpose entity. Several specialized processing devices have followed: A digital signal processor is specialized for signal processing. Graphics processing units are processors designed for realtime rendering of images. Other specialized units exist for video machine vision. Microcontrollers integrate a microprocessor with peripheral devices in embedded systems. Systems on chip integrate one or more microprocessor or microcontroller cores. Microprocessors can be selected for differing applications based on their word size, a measure of their complexity.
Longer word sizes allow each clock cycle of a processor to carry out more computation, but correspond to physically larger integrated circuit dies with higher standby and operating power consumption. 4, 8 or 12 bit processors are integrated into microcontrollers operating embedded systems. Where a system is expected to handle larger volumes of data or require a more flexible user interface, 16, 32 or 64 bit processors are used. An 8- or 16-bit processor may be selected over a 32-bit processor for system on a chip or microcontroller applications that require low-power electronics, or are part of a mixed-signal integrated circuit with noise-sensitive on-chip analog electronics such as high-resolution analog to digital converters, or both. Running 32-bit arithmetic on an 8-bit chip could end up using more power, as the chip must execute software with multiple instructions. Thousands of items that were traditionally not computer-related inc
The Nintendo GameCube is a home video game console released by Nintendo in Japan and North America in 2001 and Europe and Australia in 2002. The sixth-generation console is the successor to the Nintendo 64, designed to compete with Sony's PlayStation 2 and Microsoft's Xbox; the GameCube is the first Nintendo console to use optical discs as its primary storage medium. The discs are in the miniDVD format and the system was not designed to play full-sized DVDs or audio CDs, unlike its competitors, focused on gaming instead; the console supports online gaming for a small number of games via a GameCube broadband or modem adapter and can connect to a Game Boy Advance with a link cable, which allows players to access exclusive in-game features using the handheld as a second screen and controller. The GameCube uses composite video cables to display games on the television; the models produced before May 2004 had the ability to use digital component AV cables and progressive scan and a second serial port.
The nameplate on the top of the console with the words "Nintendo GameCube" could be removed. This model was known as DOL-001. All those features were removed in GameCube consoles produced between 2004-2007; the newer model had firmware that disabled Action Replay cheats and cheat codes and the disc-reading laser was improved in many ways, though it did not last as long. The newer model came with a 48-watt AC adapter to power the console, while the original was 46 watts. Reception of the GameCube at the time was positive; the console was praised for its controller, extensive software library and high-quality games, but was criticized for its exterior design and lack of features. Nintendo sold 21.74 million GameCube units worldwide before the console was discontinued in 2007. Its successor, the seventh-generation Wii, was released in November 2006. In 1997, a graphics hardware design company called ArtX was launched, staffed by twenty engineers who had worked at SGI on the design of the Nintendo 64's graphics hardware.
The team was led by Dr. Wei Yen, SGI's head of Nintendo Operations, the department responsible for the Nintendo 64's fundamental architectural design. Partnering with Nintendo in 1998, ArtX began the complete design of the system logic and of the graphics processor of Nintendo's sixth-generation video game console bearing the early internal code name of "N2000". At Nintendo's press conference in May 1999, the console was first publicly announced as "Project Dolphin", the successor to the Nintendo 64. Subsequently, Nintendo began providing development kits to game developers such as Rare and Retro Studios. Nintendo formed a strategic partnership with IBM, who created the Dolphin's CPU, named "Gekko". ArtX was acquired by ATI in April 2000, whereupon the Flipper graphics processor design had been completed by ArtX and was not overtly influenced by ATI. In total, ArtX team cofounder Greg Buchner recalled that their portion of the console's hardware design timeline had arced from inception in 1998 to completion in 2000.
Of ATI's acquisition of ArtX, an ATI spokesperson said, "ATI now becomes a major supplier to the game console market via Nintendo. The Dolphin platform is reputed to be king of the hill in terms of graphics and video performance with 128-bit architecture."The console was announced as the GameCube at a press conference in Japan on August 24, 2000, abbreviated as "NGC" in Japan and "GCN" in North America. Nintendo unveiled its software lineup for the sixth-generation console at E3 2001, focusing on fifteen launch games, including Luigi's Mansion and Star Wars Rogue Squadron II: Rogue Leader. Several games scheduled to launch with the console were delayed, it is the first console in the company's history not to accompany a Super Mario platform game at launch. Long before the console's launch, Nintendo had developed and patented an early prototype of motion controls for the GameCube, with which developer Factor 5 had experimented for its launch games. An interview quoted Greg Thomas, Sega of America's VP of Development as saying, "What does worry me is Dolphin's sensory controllers because there's an example of someone thinking about something different."
These motion control concepts would not be deployed to consumers for several years, until the Wii Remote. Prior to the GameCube's release, Nintendo focused resources on the launch of the Game Boy Advance, a handheld game console and successor to the original Game Boy and Game Boy Color; as a result, several games destined for the Nintendo 64 console were postponed in favor of becoming early releases on the GameCube. The last first-party game in 2001 for the Nintendo 64 was released in May, a month before the Game Boy Advance's launch and six months before the GameCube's, emphasizing the company's shift in resources. Concurrently, Nintendo was developing software for the GameCube which would provision future connectivity between it and the Game Boy Advance. Certain games, such as The Legend of Zelda: Four Swords Adventures and Final Fantasy Crystal Chronicles, can use the handheld as a secondary screen and controller when connected to the console via a link cable. Nintendo began its marketing campaign with the catchphrase "The Nintendo Difference" at its E3 2001 reveal.
The goal was to distinguish itself from the competition as an entertainment company. Advertisements push the slogan, "Born to Play", video game commercials feature a rotating cube animation that morphs into a GameCube logo and ends with a voice whisperin
A dividend is a payment made by a corporation to its shareholders as a distribution of profits. When a corporation earns a profit or surplus, the corporation is able to re-invest the profit in the business and pay a proportion of the profit as a dividend to shareholders. Distribution to shareholders may be in cash or, if the corporation has a dividend reinvestment plan, the amount can be paid by the issue of further shares or share repurchase; when dividends are paid, shareholders must pay income taxes, the corporation does not receive a corporate income tax deduction for the dividend payments. A dividend is allocated as a fixed amount per share with shareholders receiving a dividend in proportion to their shareholding. For the joint-stock company, paying dividends is not an expense. Retained earnings are shown in the shareholders' equity section on the company's balance sheet – the same as its issued share capital. Public companies pay dividends on a fixed schedule, but may declare a dividend at any time, sometimes called a special dividend to distinguish it from the fixed schedule dividends.
Cooperatives, on the other hand, allocate dividends according to members' activity, so their dividends are considered to be a pre-tax expense. The word "dividend" comes from the Latin word "dividendum". In financial history of the world, the Dutch East India Company was the first recorded company to pay regular dividends; the VOC paid annual dividends worth around 18 percent of the value of the shares for 200 years of existence. Cash dividends are the most common form of payment and are paid out in currency via electronic funds transfer or a printed paper check; such dividends are a form of investment income and are taxable to the recipient in the year they are paid. This is the most common method of sharing corporate profits with the shareholders of the company. For each share owned, a declared amount of money is distributed. Thus, if a person owns 100 shares and the cash dividend is 50 cents per share, the holder of the stock will be paid $50. Dividends paid are not classified as an expense, but rather a deduction of retained earnings.
Dividends paid does appear on the balance sheet. Stock or scrip dividends are those paid out in the form of additional stock shares of the issuing corporation, or another corporation, they are issued in proportion to shares owned. Nothing tangible will be gained if the stock is split because the total number of shares increases, lowering the price of each share, without changing the market capitalization, or total value, of the shares held. Stock dividend distributions do not affect the market capitalization of a company. Stock dividends are not includable in the gross income of the shareholder for US income tax purposes; because the shares are issued for proceeds equal to the pre-existing market price of the shares. Property dividends or dividends in specie are those paid out in the form of assets from the issuing corporation or another corporation, such as a subsidiary corporation, they are rare and most are securities of other companies owned by the issuer, however they can take other forms, such as products and services.
Interim dividends are dividend payments made before a company's Annual General Meeting and final financial statements. This declared dividend accompanies the company's interim financial statements. Other dividends can be used in structured finance. Financial assets with a known market value can be distributed as dividends. For large companies with subsidiaries, dividends can take the form of shares in a subsidiary company. A common technique for "spinning off" a company from its parent is to distribute shares in the new company to the old company's shareholders; the new shares can be traded independently. The most popular metric to determine the dividend coverage is the payout ratio. Most the payout ratio is calculated based on earnings per share: Payout ratio = x 100A payout ratio greater than 1 means the company is paying out more in dividends for the year than it earned. Dividends are paid in cash. On the other hand, earnings are an accountancy measure and do not represent the actual cash-flow of a company.
Hence, a more liquidity-driven way to determine the dividend’s safety is to replace earnings by free cash flow. The free cash flow represents the company’s available cash based on its operating business after investments: Payout Ratio = x 100 A dividend, declared must be approved by a company's board of directors before it is paid. For public companies, four dates are relevant regarding dividends:Declaration date — the day the board of directors announces its intention to pay a dividend. On that day, a liability is created and the company records that liability on its books. In-dividend date — the last day, one trading day before the ex-dividend date, where the stock is said to be cum dividend. In other words, existing holders of the stock and anyone who buys it on this day will receive the dividend, whereas any holders selling the stock lose their right to t
In many national currencies, the cent represented by the cent sign is a monetary unit that equals 1⁄100 of the basic monetary unit. Etymologically, the word cent derives from the Latin word "centum" meaning hundred. Cent refers to a coin worth one cent. In the United States, the 1¢ coin is known by the nickname penny, alluding to the British coin and unit of that name. In the European Union, coins designs are chosen nationally, while the reverse and the currency as a whole is managed by the European Central Bank. In Canada, production of the 1¢ coin was ended in 2012. A cent is represented by the cent sign, a minuscule letter "c" crossed by a diagonal stroke or a vertical line: ¢. Cent amounts from 1 cent to 99 cents can be represented as one or two digits followed by the appropriate abbreviation, or as a subdivision of the base unit. Back in the days of typewriters, the cent sign appeared as the shift of the 6 key; the cent sign has not survived the changeover from typewriters to computer keyboards.
There are alternative ways, however, to create the character in most common code pages, including Unicode and Windows-1252: On DOS- or Windows-based computers, hold Alt while typing 0162 or 155 on the numeric keypad. If there is no numeric keypad, as on many laptops, type A2 in Windows Wordpad followed by Alt+X and copy/paste the resulting ¢ into the target document. For the US International keyboard: <Right Alt> <Shift> c. On Macintosh systems, hold ⌥ Option and press 4 on the number row. On Unix/Linux systems with a compose key, Compose+|+C and Compose+/+C are typical sequences; the cent sign has Unicode code point: U+00A2 ¢ CENT SIGN, U+FFE0 ￠ FULLWIDTH CENT SIGN. When written in English, the cent sign follows the amount, in contrast with a larger currency symbol, placed before the amount. For example, 2¢ and $0.02, or 2c and €0.02. Examples of currencies around the world featuring centesimal units called cent, or related words from the same root such as céntimo, centésimo, centavo or sen, are: Argentine peso Aruban florin Australian dollar Barbadian dollar Bahamian dollar Belize dollar Bermudian dollar Bolivian boliviano Brazilian real Brunei dollar Canadian dollar Cayman Islands dollar Chilean peso.
Centavos exist and are considered in financial transactions. Cook Islands dollar Cuban peso East Caribbean dollar Eritrean nakfa Estonian kroon European Union's euro – the coins bear the text "EURO CENT". Greek coins have ΛΕΠΤΑ on the obverse of the others; the actual usage varies depending on the language. Fijian dollar Guyanese dollar Indonesian rupiah Jamaican dollar Kenyan shilling Lesotho loti Liberian dollar Malaysian ringgit Mauritian rupee Mexican peso Moroccan dirham Namibian dollar Netherlands Antillean gulden New Zealand dollar Panamanian balboa Peruvian nuevo sol Philippine peso Seychellois rupee Sierra Leonean leone Singapore dollar South African rand Sri Lankan rupee Surinamese dollar Swazi lilangeni New Taiwan dollar Tanzanian shilling Tongan paʻanga Trinidad and Tobago dollar Ugandan shilling United States dollar Uruguayan peso Zimbabwean dollarExamples of currencies featuring centesimal units not called cent British pound – divided into 100 pence since 1971 Bulgarian lev (as stotinka, Bulgarian: стотинка Chinese Yuan/Renminbi – divided into 100 fēn.
Croatian kuna – divided into 100 lipa Danish krone – divided into 100 øre Estonian mark – divided into 100 penni Indian rupee – divided into 100 paise Israeli new shekel – divided into 100 agorot Macao pataca – divided into 100 avos Macedonian denar – divided into 100 deni Norwegian krone – divided into 100 øre Pakistani rupee – divided into 100 paise Polish złoty – divided into 100 groszy Romanian and Moldovan leu – divided into 100 bani Russian ruble – divided into 100 kopeks Saudi riyal. Examples of currencies which do not feature centesimal units: Costa Rican colón – no fractional denomination in circulation since the 1980s divided into 100 céntimos. Czech koruna – no fractional denomination in circulation divided into 100 hellers Japanese yen – no fractional denomination in circulation divided into 100 sen and 1000 rin. South Korean Won no fractional denomination in circulation divided into 100 jeon. Icelandic króna – no fractional denomination in circulation divided into 100 eyrir. Kuwaiti dinar – divided into 1000 fils Omani rial – divided into 1000 baisa Mauritanian ouguiya – divided into 5 khoums Malagasy ariary – divided into 5 iraimbilanjaExamples of currencies which use the cent symbol for other purpose: Costa Rican colón – The common symbol'¢' is used locally to represent'₡', the proper
Computing is any activity that uses computers. It includes developing hardware and software, using computers to manage and process information and entertain. Computing is a critically important, integral component of modern industrial technology. Major computing disciplines include computer engineering, software engineering, computer science, information systems, information technology; the ACM Computing Curricula 2005 defined "computing" as follows: "In a general way, we can define computing to mean any goal-oriented activity requiring, benefiting from, or creating computers. Thus, computing includes designing and building hardware and software systems for a wide range of purposes; the list is endless, the possibilities are vast." and it defines five sub-disciplines of the computing field: computer science, computer engineering, information systems, information technology, software engineering. However, Computing Curricula 2005 recognizes that the meaning of "computing" depends on the context: Computing has other meanings that are more specific, based on the context in which the term is used.
For example, an information systems specialist will view computing somewhat differently from a software engineer. Regardless of the context, doing computing well can be complicated and difficult; because society needs people to do computing well, we must think of computing not only as a profession but as a discipline. The term "computing" has sometimes been narrowly defined, as in a 1989 ACM report on Computing as a Discipline: The discipline of computing is the systematic study of algorithmic processes that describe and transform information: their theory, design, efficiency and application; the fundamental question underlying all computing is "What can be automated?" The term "computing" is synonymous with counting and calculating. In earlier times, it was used in reference to the action performed by mechanical computing machines, before that, to human computers; 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.
Computing is intimately tied to the representation of numbers. But long before abstractions like the number arose, there were mathematical concepts to serve the purposes of civilization; these concepts include one-to-one correspondence, comparison to a standard, the 3-4-5 right triangle. The earliest known tool for use in computation was the abacus, it was thought to have been invented in Babylon circa 2400 BC, its original style of usage was by lines drawn in sand with pebbles. Abaci, of a more modern design, are still used as calculation tools today; this was the first known calculation aid - preceding Greek methods by 2,000 years. The first recorded idea of using digital electronics for computing was the 1931 paper "The Use of Thyratrons for High Speed Automatic Counting of Physical Phenomena" by C. E. Wynn-Williams. Claude Shannon's 1938 paper "A Symbolic Analysis of Relay and Switching Circuits" introduced the idea of using electronics for Boolean algebraic operations. A computer is a machine that manipulates data according to a set of instructions called a computer program.
The program has an executable form. The same program in its human-readable source code form, enables a programmer to study and develop a sequence of steps known as an algorithm; because the instructions can be carried out in different types of computers, a single set of source instructions converts to machine instructions according to the central processing unit type. The execution process carries out the instructions in a computer program. Instructions express, they trigger sequences of simple actions on the executing machine. Those actions produce effects according to the semantics of the instructions. Computer software or just "software", is a collection of computer programs and related data that provides the instructions for telling a computer what to do and how to do it. Software refers to one or more computer programs and data held in the storage of the computer for some purposes. In other words, software is a set of programs, procedures and its documentation concerned with the operation of a data processing system.
Program software performs the function of the program it implements, either by directly providing instructions to the computer hardware or by serving as input to another piece of software. The term was coined to contrast with the old term hardware. In contrast to hardware, software is intangible. Software is sometimes used in a more narrow sense, meaning application software only. Application software known as an "application" or an "app", is a computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with documents. Apps may be published separately; some users need never install one. Application software is contrasted with system software and middleware, which manage and integrate a computer's capabilities, but