1.
Programmable calculator
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Programmable calculators are calculators that can automatically carry out a sequence of operations under control of a stored program, much like a computer. The first programmable calculators such as the IBM CPC used punched cards or other media for program storage, hand-held electronic calculators store programs on magnetic strips, removable read-only memory cartridges, or in battery-backed read/write memory. Since the early 1990s, most of these flexible handheld units belong to the class of graphing calculators, before the mass-manufacture of inexpensive dot-matrix LCDs however, programmable calculators usually featured a one-line numeric or alphanumeric display. The Big Four manufacturers of programmable calculators are Casio, Hewlett-Packard, Sharp, all of the above have also made pocket computers in the past, especially Casio and Sharp. As they are used for graphing functions, the screens of these machines are pixel-addressable, programming capability appears most commonly in graphing calculators, as the larger screen allows multiple lines of source code to be viewed simultaneously. Many programs written for calculators can be found on the internet, users can download the programs to a personal computer, and then upload them to the calculator using a specialized link cable, infrared wireless link or through a memory card. Sometimes these programs can also be run through emulators on the PC, programming these machines can be done on the machine, on the PC side and uploaded as source code, or compiled on the PC side and uploaded as with Flash and some C/C++ implementations. Programmes, data, and so forth can also be exchanged amongst similar machines via the ports on the calculator used for PC connectivity. On-board programming tools which use non-native language implementations include the On-Board C Compiler for fx series Casio calculators, commonly available programs for calculators include everything from math/science related problem solvers to video games, as well as so-called demos. The companies themselves also have such as TIEducation. com with information. In the early days most programmable calculators used a simplified programming language. Calculators supporting such programming were Turing-complete if they supported both conditional statements and indirect addressing of memory, notable examples of Turing complete calculators were Casio FX-602P series, the HP-41 and the TI-59. Keystroke programming is used in mid-range calculators like the HP 35s. BASIC is a programming language commonly adapted to desktop computers. The most common languages now used in high range calculators are proprietary BASIC-style dialects as used by CASIO and these BASIC dialects are optimised for calculator use, combining the advantages of BASIC and keystroke programming. They have little in common with mainstream BASIC, the version for the Ti-89 and subsequent is more fully featured, including the full set of string and character manipulation functions and statements in standard Basic. A complete port of BBC Basic to the TI-83 subfamily of calculators is now available and it is installed via a cable or IrDA connection with a computer. RPL is a special Forth-like programming language used by Hewlett Packard in its high range devices, the first device with RPL calculator was the HP-28C released in 1987
2.
Graphing calculator
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A graphing calculator is a handheld calculator that is capable of plotting graphs, solving simultaneous equations, and performing other tasks with variables. Most popular graphing calculators are also programmable, allowing the user to create customized programs, typically for scientific/engineering, because they have large displays, graphing calculators also typically display several lines of text and calculations at the same time. Casio produced the first commercially available graphing calculator, the fx-7000G, sharp produced its first graphing calculator, the EL-5200, in 1986. Since then Sharps innovations include models with a touchscreen, Equation Editor, hewlett Packard followed in the form of the HP-28C. This was followed by the HP-28S, HP-48SX, HP-48S, models like the HP 50g or the HP Prime feature a computer algebra system capable of manipulating symbolic expressions and analytic solving. An unusual and powerful CAS calculator is the now obsolete year 2001 Casio Cassiopeia A-10 and A-11 stylus-operated PDAs, the HP series of graphing calculators is best known for its Reverse Polish notation / Reverse Polish Lisp interface, although the HP-49G introduced a standard expression entry interface as well. Texas Instruments has produced graphing calculators since 1990, the oldest of which was the TI-81, some of the newer calculators are similar, with the addition of more memory, faster processors, and USB connection such as the TI-82, TI-83 series, and TI-84 series. Other models, designed to be appropriate for students 10–14 years of age, are the TI-80, other TI graphing calculators have been designed to be appropriate for calculus, namely the TI-85, TI-86, TI-89 series, and TI-92 series. TI offers a CAS on the TI-89, TI-Nspire CAS and TI-92 series of calculators, TI calculators are targeted specifically to the educational market, but are also widely available to the general public. Some graphing calculators have a computer system, which means that they are capable of producing symbolic results. These calculators can manipulate algebraic expressions, performing such as factor, expand. In addition, they can give answers in exact form without numerical approximations, Calculators that have a computer algebra system are called symbolic or CAS calculators. Examples of symbolic calculators include the HP 50g, the HP Prime, the TI-89, the TI-Nspire CAS, student laboratory exercises with data from such devices enhances learning of math, especially statistics and mechanics. Some of the most notable and extensive community-driven graphing calculator archives are ticalc. org and it is simple to download games to a graphing calculator, as nearly all calculator program archives are free and open source. Even though handheld gaming devices fall in a price range. Nowadays graduate students and researchers have turned to advanced Computer Aided Math software for learning as well as experimenting, north America – high school mathematics teachers allow and even encourage their students to use graphing calculators in class. In some cases they are required, some of them are disallowed in certain classes such as chemistry or physics due to their capacity to contain full periodic tables. United Kingdom – a graphing calculator is allowed for A-level maths courses, however they are not required, similarly, at GCSE, all current courses include one paper where no calculator of any kind can be used, but students are permitted to use graphical calculators for other papers
3.
Texas Instruments
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Texas Instruments Inc. is an American technology company that designs and manufactures semiconductors, which it sells to electronics designers and manufacturers globally. Headquartered in Dallas, Texas, United States, TI is one of the top ten semiconductor companies worldwide, Texas Instrumentss focus is on developing analog chips and embedded processors, which accounts for more than 85% of their revenue. TI also produces TI digital light processing technology and education technology products including calculators, microcontrollers, to date, TI has more than 43,000 patents worldwide. TI produced the worlds first commercial silicon transistor in 1950, Jack Kilby invented the integrated circuit in 1958 while working at TIs Central Research Labs. TI also invented the hand-held calculator in 1967, and introduced the first single-chip microcontroller in 1970, in 1987, TI invented the digital light processing device, which serves as the foundation for the companys award-winning DLP technology and DLP Cinema. In 1990, TI came out with the popular TI-81 calculator which made them a leader in the calculator industry. In 1997, its business was sold to Raytheon, which allowed TI to strengthen its focus on digital solutions. Texas Instruments was founded by Cecil H. Green, J. Erik Jonsson, Eugene McDermott, McDermott was one of the original founders of Geophysical Service Inc. in 1930. McDermott, Green, and Jonsson were GSI employees who purchased the company in 1941, in November,1945, Patrick Haggerty was hired as general manager of the Laboratory and Manufacturing division, which focused on electronic equipment. By 1951, the L&M division, with its contracts, was growing faster than GSIs Geophysical division. The company was reorganized and initially renamed General Instruments Inc, because there already existed a firm named General Instrument, the company was renamed Texas Instruments that same year. From 1956 to 1961, Fred Agnich of Dallas, later a Republican member of the Texas House of Representatives, was the Texas Instruments president, Geophysical Service, Inc. became a subsidiary of Texas Instruments. Early in 1988 most of GSI was sold to the Halliburton Company, in 1930, J. Clarence Karcher and Eugene McDermott founded Geophysical Service, an early provider of seismic exploration services to the petroleum industry. In 1939, the company reorganized as Coronado Corp. an oil company with Geophysical Service Inc, on December 6,1941, McDermott along with three other GSI employees, J. Erik Jonsson, Cecil H. Green, and H. B. During World War II, GSI expanded their services to include electronics for the U. S. Army, Signal Corps, in 1951, the company changed its name to Texas Instruments, GSI becoming a wholly owned subsidiary of the new company. Texas Instruments also continued to manufacture equipment for use in the seismic industry, after selling GSI, TI finally sold the company to Halliburton in 1988, at which point GSI ceased to exist as a separate entity. Texas Instruments entered the electronics market in 1942 with submarine detection equipment. During the early 1980s, Texas Instruments instituted a quality program which included Juran training, as well as promoting statistical process control, Taguchi methods and Design for Six Sigma
4.
Calculator input methods
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There are various ways in which calculators interpret keystrokes. One can categorize calculators into two types, 1) single-step or immediate execution calculators and 2) expression or formula calculators. On a formula calculator one types in an expression and then presses Enter to evaluate the expression, there are various systems for typing in an expression, infix, postfix, natural display, etc. On an immediate execution calculator, the user presses a key for each operation, by pressing keys to all the intermediate results. Scientific calculators have buttons for brackets and these calculators can take order of operation into account, also for unary operations like √ or x2 the number is entered first then the operator. Simple four-function calculators, such as included with most operating systems. The first example has been given twice, the first version is for simple calculators, showing how it is necessary to rearrange operands in order to get the correct result. The second version is for scientific calculators, where operator precedence is observed, the immediate execution calculators are based on a mixture of infix and postfix notation, binary operations are infix but unary operations are postfix. Because operators are applied one at a time, the user must work out which button to use at each stage. Use memory buttons to ensure that operations are applied in the correct order, use the special buttons +/− and 1/x, that do not correspond to operations in the formula, for non-commutative operators. Mistakes can be hard to spot because, For the above reasons, the operation carried out when a button is pressed is not always the same as the button, but a previously entered operation. The simplest example of a problem when using an immediate execution calculator given by Professor Thimbleby is 4*. On an immediate execution calculator, depending on which keys are used, and the order in which they are pressed, also, among the calculators, there are differences in the way a given sequence of button presses is interpreted. The result can be, −1, If the subtraction button, −, is pressed after the multiplication, *, it is interpreted as a correction of the *, rather than a minus sign, so that 4 −5 is calculated. 20, If the change-sign button, +/−, is pressed before the 5, it interpreted as −5. −20, To get the answer, +/− must be pressed last. So +/− and addition have to be used rather than subtraction, when + is pressed, the multiplication is performed. 4×, The addition must be done first, so the calculation carried out is ×4, when * is pressed, the addition is performed
5.
Liquid-crystal display
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A liquid-crystal display is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals. Liquid crystals do not emit light directly, instead using a backlight or reflector to produce images in color or monochrome and they use the same basic technology, except that arbitrary images are made up of a large number of small pixels, while other displays have larger elements. LCDs are used in a range of applications including computer monitors, televisions, instrument panels, aircraft cockpit displays. Small LCD screens are common in consumer devices such as digital cameras, watches, calculators. LCD screens are used on consumer electronics products such as DVD players, video game devices. LCD screens have replaced heavy, bulky cathode ray tube displays in all applications. LCD screens are available in a range of screen sizes than CRT and plasma displays, with LCD screens available in sizes ranging from tiny digital watches to huge. Since LCD screens do not use phosphors, they do not suffer image burn-in when an image is displayed on a screen for a long time. LCDs are, however, susceptible to image persistence, the LCD screen is more energy-efficient and can be disposed of more safely than a CRT can. Its low electrical power consumption enables it to be used in battery-powered electronic equipment more efficiently than CRTs can be, by 2008, annual sales of televisions with LCD screens exceeded sales of CRT units worldwide, and the CRT became obsolete for most purposes. Without the liquid crystal between the filters, light passing through the first filter would be blocked by the second polarizer. Before an electric field is applied, the orientation of the molecules is determined by the alignment at the surfaces of electrodes. In a twisted nematic device, the surface alignment directions at the two electrodes are perpendicular to other, and so the molecules arrange themselves in a helical structure. This induces the rotation of the polarization of the incident light, and this light will then be mainly polarized perpendicular to the second filter, and thus be blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, color LCD systems use the same technique, with color filters used to generate red, green, and blue pixels. The optical effect of a TN device in the state is far less dependent on variations in the device thickness than that in the voltage-off state. Because of this, TN displays with low content and no backlighting are usually operated between crossed polarizers such that they appear bright with no voltage. When no image is displayed, different arrangements are used, for this purpose, TN LCDs are operated between parallel polarizers, whereas IPS LCDs feature crossed polarizers
6.
Dot matrix
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A dot matrix is a 2-dimensional patterned array, used to represent characters, symbols and images. Every type of modern technology uses dot matrices for display of information, including phones, televisions. They are also used in textiles with sewing, knitting, in printers, the dots are usually the darkened areas of the paper. In displays, the dots may light up, as in an LED, CRT, or plasma display, or darken, as in an LCD. As an impact printer, the term refers to low-resolution impact printers, with a column of 8,9 or 24 pins hitting an ink-impregnated fabric ribbon, like a typewriter ribbon. It was originally contrasted with both daisy wheel printers and line printers that used fixed-shape embossed metal or plastic stamps to mark paper. Impact printers survive where multi-part forms are needed, as the pins can impress dots through multiple layers of paper to make a carbonless copy, all types of electronic printers typically generate image data as a two-step process. External raster image processing was possible such as to print a graphical image, depending on the printer technology the dot size or grid shape may not be uniform. Some printers are capable of producing smaller dots and will intermesh the small dots within the larger ones for antialiasing. A dot matrix is useful for marking materials other than paper, in manufacturing industry, many product marking applications use dot matrix inkjet or impact methods. This can also be used to print 2D matrix codes, e. g. Datamatrix. Although the output of modern computers is generally all in the form of dot matrices, vector data encoding requires less memory and less data storage, in situations where the shapes may need to be resized, as with font typefaces. For maximum image quality using only dot matrix fonts, it would be necessary to store a separate dot matrix pattern for the different potential point sizes that might be used. Instead, a group of vector shapes is used to render all the specific dot matrix patterns needed for the current display or printing task. An LED matrix or LED display is a large, low-resolution form of dot-matrix display and it consists of a 2-D diode matrix with their cathodes joined in rows and their anodes joined in columns. By controlling the flow of electricity through each row and column pair it is possible to control each LED individually, by multiplexing, scanning across rows, quickly flashing the LEDs on and off, it is possible to create characters or pictures to display information to the user. By varying the rate per LED, the display can approximate levels of brightness. Multi-colored LEDs or RGB-colored LEDs permit use as an image display
7.
Motorola 68000
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The Motorola 68000 is a 32-bit CISC microprocessor with a 16-bit external data bus, designed and marketed by Motorola Semiconductor Products Sector. After 38 years in production, the 68000 architecture is still in use, the 68000 grew out of the MACSS project, begun in 1976 to develop an entirely new architecture without backward compatibility. It would be a higher-power sibling complementing the existing 8-bit 6800 line rather than a compatible successor, in the end, the 68000 did retain a bus protocol compatibility mode for existing 6800 peripheral devices, and a version with an 8-bit data bus was produced. However, the designers focused on the future, or forward compatibility. For instance, the CPU registers are 32 bits wide, though few self-contained structures in the processor itself operate on 32 bits at a time. The MACSS team drew heavily on the influence of minicomputer processor design, such as the PDP-11 and VAX systems, in the mid 1970s, the 8-bit microprocessor manufacturers raced to introduce the 16-bit generation. National Semiconductor had been first with its IMP-16 and PACE processors in 1973–1975, Intel had worked on their advanced 16/32-bit Intel iAPX432 since 1975 and their Intel 8086 since 1976. Arriving late to the 16-bit arena afforded the new processor more transistors, 32-bit macroinstructions, the original MC68000 was fabricated using an HMOS process with a 3.5 µm feature size. Formally introduced in September 1979, Initial samples were released in February 1980, Initial speed grades were 4,6, and 8 MHz.10 MHz chips became available during 1981, and 12.5 MHz chips by June 1982. The 16.67 MHz 12F version of the MC68000, the fastest version of the original HMOS chip, was not produced until the late 1980s, tom Gunter, retired Corporate Vice President at Motorola, is known as the Father of the 68000. The 68000 was used in Microsoft Xenix systems as well as an early NetWare Unix-based Server, the 68000 was used in the first generation of desktop laser printers including the original Apple Inc. In 1982, the 68000 received an update to its ISA allowing it to virtual memory and to conform to the Popek. The updated chip was called the 68010, a further extended version which exposed 31 bits of the address bus was also produced, in small quantities, as the 68012. To support lower-cost systems and control applications with smaller sizes, Motorola introduced the 8-bit compatible MC68008. This was a 68000 with an 8-bit data bus and an address bus. After 1982, Motorola devoted more attention to the 68020 and 88000 projects, several other companies were second-source manufacturers of the HMOS68000. These included Hitachi, who shrank the size to 2.7 µm for their 12.5 MHz version, Mostek, Rockwell, Signetics, Thomson/SGS-Thomson. Toshiba was also a maker of the CMOS 68HC000
8.
AAA battery
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An AAA or triple-A battery is a standard size of dry cell battery commonly used in low-drain portable electronic devices. A triple-A battery is a cell and measures 10.5 mm in diameter and 44.5 mm in length, including the positive terminal button. The positive terminal has a diameter of 3.8 mm. Alkaline AAA batteries weigh around 11.5 grams, while primary lithium AAA batteries weigh about 7.6 g, rechargeable nickel–metal hydride AAA batteries typically weigh 14–15 g. AAA batteries are most often used in electronic devices, such as TV remote controls, MP3 players. Devices that require the same voltage, but have a current draw, are often designed to use larger batteries such as the AA battery type. AA batteries have about three times the capacity of AAA batteries, with the increasing efficiency and miniaturization of modern electronics, many devices which previously were designed for AA batteries are being replaced by models that accept AAA Battery cells. As of 2007, AAA batteries accounted for 24% of alkaline battery sales in the United States. In Japan as of 2011, 28% of alkaline batteries sold were AAA. In Switzerland as of 2008, AAA batteries totaled 30% of primary battery sales and 32% of secondary battery sales
9.
TI-83 series
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The TI-83 series of graphing calculators is manufactured by Texas Instruments. The original TI-83 is itself a version of the TI-82. Released in 1996, it was one of the most popular graphing calculators for students, although it does not include as many calculus functions, applications and programs can be downloaded from certain websites, or written on the calculator. The Flash memory can also be used to store user programs, the TI-83 was redesigned twice, first in 1999 and again in 2001. The 1999 redesign introduced a very similar to the TI-73 and TI-83 Plus. The 2001 redesign introduced a different shape to the calculator itself, eliminated the glossy grey screen border. The TI-83 was the first calculator in the TI series to have built in assembly language support, the TI-92, TI-85, and TI-82 were capable of running assembly language programs, but only after sending a specially constructed memory backup. The support on the TI-83 could be accessed through a feature of the calculator. Users would write their assembly program on their computer, assemble it, the user would then execute the command Send (9prgmXXX, and it would execute the program. Successors of the TI-83 replaced the Send backdoor with a less-hidden Asm command, the TI-83 Plus is a graphing calculator made by Texas Instruments, designed in 1999 as an upgrade to the TI-83. The TI-83 Plus is one of TIs most popular calculators and it uses a Zilog Z80 microprocessor running at 6 MHz, a 96×64 monochrome LCD screen, and 4 AAA batteries as well as backup CR1616 or CR1620 battery. A link port is built into the calculator in the form of a 2. 5mm jack. The main improvement over the TI-83, however, is the addition of 512 kB of Flash ROM, most of the Flash memory is used by the operating system, with 160 kB available for user files and applications. Another development is the ability to install Flash Applications, which allows the user to add functionality to the calculator, such applications have been made for math and science, text editing, organizers and day planners, editing spread sheets, games, and many other uses. Symbolic manipulation is not built into the TI-83 Plus and it can be programmed using a language called TI-BASIC, which is similar to the BASIC computer language. Programming may also be done in TI Assembly, made up of Z80 assembly, Assembly programs run much faster, but are more difficult to write. Thus, the writing of Assembly programs is often done on a computer and it uses 4 Triple A Batteries. The TI-83 Plus Silver Edition is a version of the TI-83 Plus calculator
10.
TI-84 Plus series
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The TI-84 Plus is a graphing calculator made by Texas Instruments which was released in early 2004. There is no original TI-84, only the TI-84 Plus and TI-84 Plus Silver Edition models, the TI-84 Plus is an enhanced version of the TI-83 Plus. The key-by-key correspondence is relatively the same, but the 84 features some improved hardware, the Archive is about 3 times as large, and CPU about 2.5 times as fast. A USB port and built-in clock functionality were also added, the TI-84 Plus Silver Edition was released in 2004 as an upgrade to the TI-83 Plus Silver Edition. Like the TI-83 Plus Silver Edition, it features a 15 MHz Zilog Z80 processor and 24 kB user available RAM, the chip has 128 kB, but TI has not made an OS that uses all of it. Newer calculators have a RAM chip that is only 48 kB, all calculators with the letter H or later as the last letter in the serial code have fewer ram pages, causing some programs to not run correctly. There is 1.5 MB of user-accessible Flash ROM, like the standard TI-84 Plus, the Silver Edition includes a built-in USB port, a built-in clock, and assembly support. It uses 4 AAA batteries and a button cell battery. The TI-84 Plus Silver Edition comes preloaded with a variety of applications and these programs are also available for the TI-84 Plus, but some must be downloaded separately from TIs website. It is manufactured by Kinpo Electronics, TI offers a special yellow version of the TI-84 Plus, inscribed with the words School Property, for schools to loan out to students. This special design was produced in effort to combat theft, owners can buy other interchangeable colored face-plates and slide-cases online. A kickstand-style slide case and other accessories are also available, although graphing calculators have been called inexpensive in education reform research, the TI-84 Plus Silver Edition costs $139.00 as of 2013 on the TI online store. This calculator has been discontinued in favor of the TI-84 Plus C Silver Edition, in 2011, TI launched for the French market a miniaturized version of the TI-84 Plus, the TI-84 Pocket. fr. In 2012, TI launched for the Asian market a version of the TI-84 Plus Silver Edition. The TI-84 Plus C Silver Edition was first publicly referenced in October 2012 in a tweet from TI and it has a high-resolution 320x240-pixel color screen, a modified version of the 2. 55MP operating system, a rechargeable battery and keystroke compatibility with existing math and programming tools. It has the standard 2. 5mm I/O linkport and a mini-USB port, more details about the calculators math and programming features were published when TI began distributing review models in February 2013, and even more when the calculator was released in 2013. The TI-84 Plus CE was publicly previewed by TI Education in January 2015, the calculators OS5. x is incompatible with the TI-84 Plus C Silver Editions hardware. The calculator has 154KB of user-accessible RAM and 3. 0MB of Archive memory and it uses the eZ80 processor from Zilog, making all Z80 assembly programs from previous 84 Plus series calculators incompatible
11.
Pixel
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The address of a pixel corresponds to its physical coordinates. LCD pixels are manufactured in a grid, and are often represented using dots or squares. Each pixel is a sample of an image, more samples typically provide more accurate representations of the original. The intensity of each pixel is variable, in color imaging systems, a color is typically represented by three or four component intensities such as red, green, and blue, or cyan, magenta, yellow, and black. The word pixel is based on a contraction of pix and el, the word pixel was first published in 1965 by Frederic C. Billingsley of JPL, to describe the elements of video images from space probes to the Moon. Billingsley had learned the word from Keith E. McFarland, at the Link Division of General Precision in Palo Alto, McFarland said simply it was in use at the time. The word is a combination of pix, for picture, the word pix appeared in Variety magazine headlines in 1932, as an abbreviation for the word pictures, in reference to movies. By 1938, pix was being used in reference to pictures by photojournalists. The concept of a picture element dates to the earliest days of television, some authors explain pixel as picture cell, as early as 1972. In graphics and in image and video processing, pel is often used instead of pixel, for example, IBM used it in their Technical Reference for the original PC. A pixel is generally thought of as the smallest single component of a digital image, however, the definition is highly context-sensitive. For example, there can be printed pixels in a page, or pixels carried by electronic signals, or represented by digital values, or pixels on a display device, or pixels in a digital camera. This list is not exhaustive and, depending on context, synonyms include pel, sample, byte, bit, dot, Pixels can be used as a unit of measure such as,2400 pixels per inch,640 pixels per line, or spaced 10 pixels apart. For example, a high-quality photographic image may be printed with 600 ppi on a 1200 dpi inkjet printer, even higher dpi numbers, such as the 4800 dpi quoted by printer manufacturers since 2002, do not mean much in terms of achievable resolution. The more pixels used to represent an image, the closer the result can resemble the original, the number of pixels in an image is sometimes called the resolution, though resolution has a more specific definition.3 megapixels. The pixels, or color samples, that form an image may or may not be in one-to-one correspondence with screen pixels. In computing, a composed of pixels is known as a bitmapped image or a raster image
12.
Flash memory
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Flash memory is electronic non-volatile computer storage medium that can be electrically erased and reprogrammed. Toshiba developed flash memory from EEPROM in the early 1980s and introduced it to the market in 1984, the two main types of flash memory are named after the NAND and NOR logic gates. The individual flash memory cells exhibit internal characteristics similar to those of the corresponding gates, where EPROMs had to be completely erased before being rewritten, NAND-type flash memory may be written and read in blocks which are generally much smaller than the entire device. NOR-type flash allows a machine word to be written—to an erased location—or read independently. The NAND type operates primarily in memory cards, USB flash drives, solid-state drives, NAND or NOR flash memory is also often used to store configuration data in numerous digital products, a task previously made possible by EEPROM or battery-powered static RAM. One key disadvantage of flash memory is that it can endure a relatively small number of write cycles in a specific block. In addition to being non-volatile, flash memory offers fast read access times, although flash memory is technically a type of EEPROM, the term EEPROM is generally used to refer specifically to non-flash EEPROM which is erasable in small blocks, typically bytes. Because erase cycles are slow, the block sizes used in flash memory erasing give it a significant speed advantage over non-flash EEPROM when writing large amounts of data. As of 2013, flash memory costs much less than byte-programmable EEPROM and had become the dominant memory type wherever a system required a significant amount of non-volatile solid-state storage, Flash memory was invented by Fujio Masuoka while working for Toshiba circa 1980. According to Toshiba, the flash was suggested by Masuokas colleague, Shōji Ariizumi. Masuoka and colleagues presented the invention at the IEEE1984 International Electron Devices Meeting held in San Francisco, Intel Corporation saw the massive potential of the invention and introduced the first commercial NOR type flash chip in 1988. NOR-based flash has long erase and write times, but provides full address and data buses, allowing random access to any memory location. This makes it a replacement for older read-only memory chips. Its endurance may be from as little as 100 erase cycles for a flash memory, to a more typical 10,000 or 100,000 erase cycles. NOR-based flash was the basis of early flash-based removable media, CompactFlash was originally based on it, however, the I/O interface of NAND flash does not provide a random-access external address bus. Rather, data must be read on a basis, with typical block sizes of hundreds to thousands of bits. This makes NAND flash unsuitable as a replacement for program ROM. In this regard, NAND flash is similar to other data storage devices, such as hard disks and optical media
13.
TI-Nspire series
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The TI-Nspire product line is a series of graphing calculators developed by Texas Instruments. This line currently includes the TI-Nspire, TI-Nspire CAS, TI-Nspire CX, there are also models aimed for the Chinese market, named the TI-Nspire CM-C, TI-Nspire CX-C, TI-Nspire CM-C CAS, TI-Nspire CX-C CAS. There is also available for Windows and Mac OS X that act in similar ways to the calculators. This software either requires a license or can only be used for a limited time, however, Texas Instruments also provides separate software that can be used for an unlimited time without a license but only allows file transfers and not emulation of the calculator. In 2010, Texas Instruments updated the calculators to the Touchpad versions which come with the Nspire or Nspire CAS computer software, in 2011, TI announced two new models of the TI-Nspire series, Nspire CX and Nspire CX CAS. The main new features are the screen, rechargeable battery. The TI-Nspire series is different from the previous versions of the Texas Instrumentss calculators. Because TI wanted the calculator to feel more familiar for new users and it also handles documents in a similar way to PCs. The TI-Nspire was the first to be released in two models, a numeric and CAS version, the numeric is similar in features to the TI-84, except with a bigger and higher resolution screen and a full keyboard. The higher resolution makes it possible to draw graphs that are more detailed. The feature that the numeric lacks is the ability to solve algebraic equations such as indefinite integrals, to fill in the gap of needing an algebraic calculator, Texas Instruments introduced the second model with the name TI-Nspire CAS, where CAS stands for Computer Algebra System. The CAS is designed for college and university students, giving them the feature of calculating many algebraic equations like the Voyage 200, C and assembly are only possible through the jailbreaking program Ndless. Both the Nspire and Nspire CAS calculators have 16 MB of NAND Flash,20 MB of SDRAM, the NAND Flash contains the operating system and saved documents and is not executable. The SDRAM likely contains a version of the OS. The NOR Flash contains boot instructions for loading the operating system, much like all other TI graphing calculators, Nspire family models do not contain a backup battery, so when a battery is removed, the SDRAM content is deleted. This necessitates that the load the operating system and file structure from the NAND Flash to the SDRAM. The standard TI-Nspire calculator is comparable to the TI-84 Plus in features and it features a TI-84 mode by way of a replaceable snap-in keypad and contains a TI-84 Plus emulator. Because the TI-Nspire lacks a QWERTY keyboard, it is acceptable for use on the PSAT, SAT, SAT II, ACT, AP and it should be noted, however, that the CAS version is NOT allowed on the ACT or IB
14.
Hertz
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The hertz is the unit of frequency in the International System of Units and is defined as one cycle per second. It is named for Heinrich Rudolf Hertz, the first person to provide proof of the existence of electromagnetic waves. Hertz are commonly expressed in SI multiples kilohertz, megahertz, gigahertz, kilo means thousand, mega meaning million, giga meaning billion and tera for trillion. Some of the units most common uses are in the description of waves and musical tones, particularly those used in radio-. It is also used to describe the speeds at which computers, the hertz is equivalent to cycles per second, i. e. 1/second or s −1. In English, hertz is also used as the plural form, as an SI unit, Hz can be prefixed, commonly used multiples are kHz, MHz, GHz and THz. One hertz simply means one cycle per second,100 Hz means one hundred cycles per second, and so on. The unit may be applied to any periodic event—for example, a clock might be said to tick at 1 Hz, the rate of aperiodic or stochastic events occur is expressed in reciprocal second or inverse second in general or, the specific case of radioactive decay, becquerels. Whereas 1 Hz is 1 cycle per second,1 Bq is 1 aperiodic radionuclide event per second, the conversion between a frequency f measured in hertz and an angular velocity ω measured in radians per second is ω =2 π f and f = ω2 π. This SI unit is named after Heinrich Hertz, as with every International System of Units unit named for a person, the first letter of its symbol is upper case. Note that degree Celsius conforms to this rule because the d is lowercase. — Based on The International System of Units, the hertz is named after the German physicist Heinrich Hertz, who made important scientific contributions to the study of electromagnetism. The name was established by the International Electrotechnical Commission in 1930, the term cycles per second was largely replaced by hertz by the 1970s. One hobby magazine, Electronics Illustrated, declared their intention to stick with the traditional kc. Mc. etc. units, sound is a traveling longitudinal wave which is an oscillation of pressure. Humans perceive frequency of waves as pitch. Each musical note corresponds to a frequency which can be measured in hertz. An infants ear is able to perceive frequencies ranging from 20 Hz to 20,000 Hz, the range of ultrasound, infrasound and other physical vibrations such as molecular and atomic vibrations extends from a few femtoHz into the terahertz range and beyond. Electromagnetic radiation is described by its frequency—the number of oscillations of the perpendicular electric and magnetic fields per second—expressed in hertz. Radio frequency radiation is measured in kilohertz, megahertz, or gigahertz
15.
Random-access memory
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Random-access memory is a form of computer data storage which stores frequently used program instructions to increase the general speed of a system. A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the location of data inside the memory. RAM contains multiplexing and demultiplexing circuitry, to connect the lines to the addressed storage for reading or writing the entry. Usually more than one bit of storage is accessed by the same address, in todays technology, random-access memory takes the form of integrated circuits. RAM is normally associated with types of memory, where stored information is lost if power is removed. Other types of non-volatile memories exist that allow access for read operations. These include most types of ROM and a type of memory called NOR-Flash. Integrated-circuit RAM chips came into the market in the early 1970s, with the first commercially available DRAM chip, early computers used relays, mechanical counters or delay lines for main memory functions. Ultrasonic delay lines could only reproduce data in the order it was written, drum memory could be expanded at relatively low cost but efficient retrieval of memory items required knowledge of the physical layout of the drum to optimize speed. Latches built out of vacuum tube triodes, and later, out of transistors, were used for smaller and faster memories such as registers. Such registers were relatively large and too costly to use for large amounts of data, the first practical form of random-access memory was the Williams tube starting in 1947. It stored data as electrically charged spots on the face of a cathode ray tube, since the electron beam of the CRT could read and write the spots on the tube in any order, memory was random access. The capacity of the Williams tube was a few hundred to around a thousand bits, but it was smaller, faster. In fact, rather than the Williams tube memory being designed for the SSEM, magnetic-core memory was invented in 1947 and developed up until the mid-1970s. It became a form of random-access memory, relying on an array of magnetized rings. By changing the sense of each rings magnetization, data could be stored with one bit stored per ring, since every ring had a combination of address wires to select and read or write it, access to any memory location in any sequence was possible. Magnetic core memory was the form of memory system until displaced by solid-state memory in integrated circuits. Data was stored in the capacitance of each transistor, and had to be periodically refreshed every few milliseconds before the charge could leak away
16.
Computer program
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A computer program is a collection of instructions that performs a specific task when executed by a computer. A computer requires programs to function, and typically executes the programs instructions in a processing unit. A computer program is written by a computer programmer in a programming language. From the program in its form of source code, a compiler can derive machine code—a form consisting of instructions that the computer can directly execute. Alternatively, a program may be executed with the aid of an interpreter. A part of a program that performs a well-defined task is known as an algorithm. A collection of programs, libraries and related data are referred to as software. Computer programs may be categorized along functional lines, such as software or system software. The earliest programmable machines preceded the invention of the digital computer, in 1801, Joseph-Marie Jacquard devised a loom that would weave a pattern by following a series of perforated cards. Patterns could be weaved and repeated by arranging the cards, in 1837, Charles Babbage was inspired by Jacquards loom to attempt to build the Analytical Engine. The names of the components of the device were borrowed from the textile industry. In the textile industry, yarn was brought from the store to be milled, the device would have had a store—memory to hold 1,000 numbers of 40 decimal digits each. Numbers from the store would then have then transferred to the mill. It was programmed using two sets of perforated cards—one to direct the operation and the other for the input variables, however, after more than 17,000 pounds of the British governments money, the thousands of cogged wheels and gears never fully worked together. During a nine-month period in 1842–43, Ada Lovelace translated the memoir of Italian mathematician Luigi Menabrea, the memoir covered the Analytical Engine. The translation contained Note G which completely detailed a method for calculating Bernoulli numbers using the Analytical Engine and this note is recognized by some historians as the worlds first written computer program. In 1936, Alan Turing introduced the Universal Turing machine—a theoretical device that can model every computation that can be performed on a Turing complete computing machine and it is a finite-state machine that has an infinitely long read/write tape. The machine can move the back and forth, changing its contents as it performs an algorithm
17.
Text file
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A text file is a kind of computer file that is structured as a sequence of lines of electronic text. A text file exists within a file system. The end of a file is often denoted by placing one or more special characters. Such markers were required under the CP/M and MS-DOS operating systems, on modern operating systems such as Windows and Unix-like systems, text files do not contain any special EOF character. Text file refers to a type of container, while plain text refers to a type of content, Text files can contain plain text, but they are not limited to such. At a generic level of description, there are two kinds of files, text files and binary files. Because of their simplicity, text files are used for storage of information. They avoid some of the problems encountered with other formats, such as endianness, padding bytes. Further, when data corruption occurs in a file, it is often easier to recover. A disadvantage of text files is that usually have a low entropy. A simple text file needs no additional metadata to assist the reader in interpretation, and therefore may contain no data at all, the ASCII character set is the most common format for English-language text files, and is generally assumed to be the default file format in many situations. For accented and other characters, it is necessary to choose a character encoding. In many systems, this is chosen on the basis of the locale setting on the computer it is read on. Common character encodings include ISO 8859-1 for many European languages, because many encodings have only a limited repertoire of characters, they are often only usable to represent text in a limited subset of human languages. Unicode is an attempt to create a standard for representing all known languages. On most operating systems the name text file refers to file format that only plain text content with very little formatting. Such files can be viewed and edited on text terminals or in text editors. Text files usually have the MIME type text/plain, usually with additional information indicating an encoding, MS-DOS and Windows use a common text file format, with each line of text separated by a two-character combination, carriage return and line feed
18.
TI-92 series
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The TI-92 series of graphing calculators are a line of calculators produced by Texas Instruments. They include, the TI-92, the TI-92 Plus, and the Voyage 200, the design of these relatively large calculators includes a QWERTY keyboard. The TI-92 was originally released in 1995, and was the first symbolic calculator made by Texas Instruments and it came with a computer algebra system based on Derive, and was one of the first calculators to offer 3D graphing. The TI-92 was not allowed on most standardized tests due mostly to its QWERTY keyboard and its larger size was also rather cumbersome compared to other graphing calculators. The TI-92 was then replaced by the TI-92 Plus, which was essentially a TI-89 with the larger QWERTY keyboard design of the TI-92, eventually, TI released the Voyage 200, which is a smaller, lighter version of the TI-92 Plus with more Flash ROM. The TI-92 is no longer sold through TI or its dealers, the TI-92 Plus was released in 1998, slightly after the creation of the almost-identical TI-89, while physically looking exactly as its predecessor, the TI-92. Besides increased memory over its predecessor, the TI-92 Plus also featured a black screen, which had first appeared on the TI-89. A stand-alone TI-92 Plus calculator was functionally similar to the HW2 TI-89, both versions could run the same releases of operating system software. As of 2002, the TI-92 Plus was succeeded by the Voyage 200 and is no longer sold through TI or its dealers. Voyage 200 was released in 2002, being the replacement for the TI-92 Plus and it also features a somewhat smaller and more rounded case design. Its symbolic calculation system is based on a version of the calculation software Derive. The calculator can also run most programs written for the TI-89, a large number of applications, ranging from games to interactive periodic tables can be found online. The TI-89 Titanium offers exactly the same functionality in a format that is also legal on the SAT test. Official page specifies user-available ROM amount for TI-92 Plus as 702K and this is due to the TI-92+ coming with Cabri Geometry pre-installed, which uses the 314 KB difference. Comparison of Texas Instruments graphing calculators Official documentation, features of the Voyage 200
19.
Computer keyboard
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In computing, a computer keyboard is a typewriter-style device which uses an arrangement of buttons or keys to act as a mechanical lever or electronic switch. Following the decline of punch cards and paper tape, interaction via teleprinter-style keyboards became the input device for computers. A keyboard typically has characters engraved or printed on the keys, however, to produce some symbols requires pressing and holding several keys simultaneously or in sequence. While most keyboard keys produce letters, numbers or signs, other keys or simultaneous key presses can produce actions or execute computer commands. In normal usage, the keyboard is used as a text entry interface to type text and numbers into a word processor, in a modern computer, the interpretation of key presses is generally left to the software. A computer keyboard distinguishes each physical key from every other and reports all key presses to the controlling software, Keyboards are also used for computer gaming, either with regular keyboards or by using keyboards with special gaming features, which can expedite frequently used keystroke combinations. A keyboard is used to give commands to the operating system of a computer, such as Windows Control-Alt-Delete combination. A command-line interface is a type of user interface operated entirely through a keyboard and it was through such devices that modern computer keyboards inherited their layouts. Earlier models were developed separately by individuals such as Royal Earl House, earlier, Herman Hollerith developed the first keypunch devices, which soon evolved to include keys for text and number entry akin to normal typewriters by the 1930s. From the 1940s until the late 1960s, typewriters were the means of data entry. The keyboard remained the primary, most integrated computer peripheral well into the era of personal computing until the introduction of the mouse as a device in 1984. By this time, text-only user interfaces with sparse graphics gave way to comparatively graphics-rich icons on screen, One factor determining the size of a keyboard is the presence of duplicate keys, such as a separate numeric keyboard, for convenience. A keyboard with few keys is called a keypad, another factor determining the size of a keyboard is the size and spacing of the keys. Reduction is limited by the consideration that the keys must be large enough to be easily pressed by fingers. Alternatively a tool is used for pressing small keys, standard alphanumeric keyboards have keys that are on three-quarter inch centers, and have a key travel of at least 0.150 inches. Desktop computer keyboards, such as the 101-key US traditional keyboards or the 104-key Windows keyboards, include characters, punctuation symbols, numbers. The internationally common 102/104 key keyboards have a left shift key. Also the enter key is usually shaped differently, computer keyboards are similar to electric-typewriter keyboards but contain additional keys, such as the command or Windows keys
20.
Calculator
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An electronic calculator is a small, portable electronic device used to perform operations ranging from basic arithmetic to complex mathematics. The first solid state electronic calculator was created in the 1960s, building on the history of tools such as the abacus. It was developed in parallel with the computers of the day. The pocket sized devices became available in the 1970s, especially after the first microprocessor and they later became used commonly within the petroleum industry. Modern electronic calculators vary, from cheap, give-away, credit-card-sized models to sturdy desktop models with built-in printers and they became popular in the mid-1970s. By the end of decade, calculator prices had reduced to a point where a basic calculator was affordable to most. In addition to general purpose calculators, there are designed for specific markets. For example, there are scientific calculators which include trigonometric and statistical calculations, some calculators even have the ability to do computer algebra. Graphing calculators can be used to graph functions defined on the real line, as of 2016, basic calculators cost little, but the scientific and graphing models tend to cost more. In 1986, calculators still represented an estimated 41% of the worlds general-purpose hardware capacity to compute information, by 2007, this diminished to less than 0. 05%. Modern 2016 electronic calculators contain a keyboard with buttons for digits and arithmetical operations, most basic calculators assign only one digit or operation on each button, however, in more specific calculators, a button can perform multi-function working with key combinations. Large-sized figures and comma separators are used to improve readability. Various symbols for function commands may also be shown on the display, fractions such as 1⁄3 are displayed as decimal approximations, for example rounded to 0.33333333. Also, some fractions can be difficult to recognize in decimal form, as a result, Calculators also have the ability to store numbers into computer memory. Basic types of these only one number at a time. The variables can also be used for constructing formulas, some models have the ability to extend memory capacity to store more numbers, the extended memory address is termed an array index. Power sources of calculators are, batteries, solar cells or mains electricity, some models even have no turn-off button but they provide some way to put off. Crank-powered calculators were also common in the computer era
21.
QWERTY
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QWERTY is a keyboard layout for Latin script. The name comes from the order of the first six keys on the top left letter row of the keyboard, the QWERTY design is based on a layout created for the Sholes and Glidden typewriter and sold to Remington in 1873. It became popular with the success of the Remington No, the QWERTY layout was devised and created in the early 1870s by Christopher Latham Sholes, a newspaper editor and printer who lived in Milwaukee, Wisconsin. In October 1867, Sholes filed a patent application for his writing machine he developed with the assistance of his friends Carlos Glidden. Firstly, characters were mounted on arms or typebars, which would clash. Secondly, its point was located beneath the paper carriage, invisible to the operator. Consequently, jams were especially serious, because the typist could only discover the mishap by raising the carriage to inspect what had been typed, the solution was to place commonly used letter-pairs so that their typebars were not neighboring, avoiding jams. Sholes struggled for the five years to perfect his invention. The study of bigram frequency by educator Amos Densmore, brother of the financial backer James Densmore, is believed to have influenced the arrangement of letters, others suggest instead that the letter arrangement evolved from telegraph operators feedback. In November 1868 he changed the arrangement of the half of the alphabet, O to Z. These adjustments included placing the R key in the previously allotted to the period key. Apocryphal claims that change was made to let salesmen impress customers by pecking out the brand name TYPE WRITER QUOTE from one keyboard row are not formally substantiated. Vestiges of the original layout remained in the home row sequence DFGHJKL. The modern layout is, The QWERTY layout became popular with the success of the Remington No.2 of 1878, the first typewriter to include both upper and lower case letters, using a shift key. 0 and 1 were omitted to simplify the design and reduce the manufacturing and maintenance costs, they were chosen specifically because they were redundant and could be recreated using other keys. Typists who learned on these machines learned the habit of using the uppercase letter I for the one. In early designs, some characters were produced by printing two symbols with the carriage in the same position. For instance, the point, which shares a key with the numeral 1 on modern keyboards, could be reproduced by using a three-stroke combination of an apostrophe, a backspace
22.
Prettyprint
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Prettyprint is the application of any of various stylistic formatting conventions to text files, such as source code, markup, and similar kinds of content. Prettyprinters for programming language source code are called code beautifiers. Pretty-printing usually refers to displaying mathematical expressions similar to the way they would be typeset professionally, for example, in computer algebra systems such as Maxima or Mathematica the system may write output like x ^2 +3 * x as x 2 +3 x. Many text formatting programs can also typeset mathematics, TeX was developed specifically for high-quality mathematical typesetting, pretty-printing in markup language instances is most typically associated with indentation of tags and string content to visually determine hierarchy and nesting. In MathML, whitespace characters do not reflect data, meaning, in HTML, whitespace characters between tags are considered text and are parsed as text nodes into the parsed result. Programmers often use tools to format programming language source code in a particular manner, proper code formatting makes it easier to read and understand. Different programmers often prefer different styles of formatting, such as the use of code indentation, a code formatter converts source code from one format style to another. This is relatively straightforward because of the syntax of programming languages. Code beautifiers exist as standalone applications and built into text editors, for example, Emacs various language modes can correctly indent blocks of code attractively. An early example of pretty-printing was Bill Gospers GRINDEF program, which used combinatorial search with pruning to format LISP programs, Early versions operated on the executable form of the Lisp program and were oblivious to the special meanings of various functions. Later versions had special read conventions for incorporating non-executable comments and also for preserving read macros in unexpanded form and they also allowed special indentation conventions for special functions such as if. The term grind was used in some Lisp circles as a synonym for pretty-printing, many open source projects have established rules for code layout. The most typical are the GNU style and the BSD style, the biggest difference between the two is the location of the braces, in the GNU style, opening and closing braces are on lines by themselves, with the same indent. BSD style places an opening brace at the end of the line. The size of indent and location of whitespace also differs, the following example shows some typical C structures and how various indentation style rules format them. ACM8, 667-668 lgrind, Comprehensive TEX Archive Network NEATER2, ACM13, 669-675 SOAP - A Program which Documents and Edits ALGOL60 Programs. R. S. Scowen, D. Allin, A. L. Hillman, M. Shimell, J.14, 133-135 PRETTYP. PAS Early pascal prettyprinter. Pascal With Style style FreeBSD style guidelines vgrind, The Heirloom Project Formatting your source code GNU style guidelines
23.
Fraction (mathematics)
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A fraction represents a part of a whole or, more generally, any number of equal parts. When spoken in everyday English, a fraction describes how many parts of a certain size there are, for example, one-half, eight-fifths, three-quarters. A common, vulgar, or simple fraction consists of an integer numerator displayed above a line, numerators and denominators are also used in fractions that are not common, including compound fractions, complex fractions, and mixed numerals. The numerator represents a number of parts, and the denominator. For example, in the fraction 3/4, the numerator,3, tells us that the fraction represents 3 equal parts, the picture to the right illustrates 34 or ¾ of a cake. Fractional numbers can also be written without using explicit numerators or denominators, by using decimals, percent signs, an integer such as the number 7 can be thought of as having an implicit denominator of one,7 equals 7/1. Other uses for fractions are to represent ratios and to represent division, thus the fraction ¾ is also used to represent the ratio 3,4 and the division 3 ÷4. The test for a number being a number is that it can be written in that form. In a fraction, the number of parts being described is the numerator. Informally, they may be distinguished by placement alone but in formal contexts they are separated by a fraction bar. The fraction bar may be horizontal, oblique, or diagonal and these marks are respectively known as the horizontal bar, the slash or stroke, the division slash, and the fraction slash. In typography, horizontal fractions are known as en or nut fractions and diagonal fractions as em fractions. The denominators of English fractions are expressed as ordinal numbers. When the denominator is 1, it may be expressed in terms of wholes but is commonly ignored. When the numerator is one, it may be omitted, a fraction may be expressed as a single composition, in which case it is hyphenated, or as a number of fractions with a numerator of one, in which case they are not. Fractions should always be hyphenated when used as adjectives, alternatively, a fraction may be described by reading it out as the numerator over the denominator, with the denominator expressed as a cardinal number. The term over is used even in the case of solidus fractions, Fractions with large denominators that are not powers of ten are often rendered in this fashion while those with denominators divisible by ten are typically read in the normal ordinal fashion. A simple fraction is a number written as a/b or a b
24.
Derivative
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The derivative of a function of a real variable measures the sensitivity to change of the function value with respect to a change in its argument. Derivatives are a tool of calculus. For example, the derivative of the position of an object with respect to time is the objects velocity. The derivative of a function of a variable at a chosen input value. The tangent line is the best linear approximation of the function near that input value, for this reason, the derivative is often described as the instantaneous rate of change, the ratio of the instantaneous change in the dependent variable to that of the independent variable. Derivatives may be generalized to functions of real variables. In this generalization, the derivative is reinterpreted as a transformation whose graph is the best linear approximation to the graph of the original function. The Jacobian matrix is the matrix that represents this linear transformation with respect to the basis given by the choice of independent and dependent variables and it can be calculated in terms of the partial derivatives with respect to the independent variables. For a real-valued function of variables, the Jacobian matrix reduces to the gradient vector. The process of finding a derivative is called differentiation, the reverse process is called antidifferentiation. The fundamental theorem of calculus states that antidifferentiation is the same as integration, differentiation and integration constitute the two fundamental operations in single-variable calculus. Differentiation is the action of computing a derivative, the derivative of a function y = f of a variable x is a measure of the rate at which the value y of the function changes with respect to the change of the variable x. It is called the derivative of f with respect to x, If x and y are real numbers, and if the graph of f is plotted against x, the derivative is the slope of this graph at each point. The simplest case, apart from the case of a constant function, is when y is a linear function of x. This formula is true because y + Δ y = f = m + b = m x + m Δ x + b = y + m Δ x. Thus, since y + Δ y = y + m Δ x and this gives an exact value for the slope of a line. If the function f is not linear, however, then the change in y divided by the change in x varies, differentiation is a method to find an exact value for this rate of change at any given value of x. The idea, illustrated by Figures 1 to 3, is to compute the rate of change as the value of the ratio of the differences Δy / Δx as Δx becomes infinitely small
25.
Antiderivative
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In calculus, an antiderivative, primitive function, primitive integral or indefinite integral of a function f is a differentiable function F whose derivative is equal to the original function f. This can be stated symbolically as F ′ = f, the process of solving for antiderivatives is called antidifferentiation and its opposite operation is called differentiation, which is the process of finding a derivative. The discrete equivalent of the notion of antiderivative is antidifference, the function F = x3/3 is an antiderivative of f = x2, as the derivative of x3/3 is x2. As the derivative of a constant is zero, x2 will have a number of antiderivatives, such as x3/3, x3/3 +1, x3/3 -2. Thus, all the antiderivatives of x2 can be obtained by changing the value of C in F = x3/3 + C, essentially, the graphs of antiderivatives of a given function are vertical translations of each other, each graphs vertical location depending upon the value of C. In physics, the integration of acceleration yields velocity plus a constant, the constant is the initial velocity term that would be lost upon taking the derivative of velocity because the derivative of a constant term is zero. This same pattern applies to further integrations and derivatives of motion, C is called the arbitrary constant of integration. If the domain of F is a disjoint union of two or more intervals, then a different constant of integration may be chosen for each of the intervals. For instance F = { −1 x + C1 x <0 −1 x + C2 x >0 is the most general antiderivative of f =1 / x 2 on its natural domain ∪. Every continuous function f has an antiderivative, and one antiderivative F is given by the integral of f with variable upper boundary. Varying the lower boundary produces other antiderivatives and this is another formulation of the fundamental theorem of calculus. There are many functions whose antiderivatives, even though they exist, cannot be expressed in terms of elementary functions. Examples of these are ∫ e − x 2 d x, ∫ sin x 2 d x, ∫ sin x x d x, ∫1 ln x d x, ∫ x x d x. From left to right, the first four are the function, the Fresnel function, the trigonometric integral. See also Differential Galois theory for a detailed discussion. Finding antiderivatives of elementary functions is often harder than finding their derivatives. For some elementary functions, it is impossible to find an antiderivative in terms of elementary functions. See the articles on elementary functions and nonelementary integral for further information, integrals which have already been derived can be looked up in a table of integrals
26.
Integral
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In mathematics, an integral assigns numbers to functions in a way that can describe displacement, area, volume, and other concepts that arise by combining infinitesimal data. Integration is one of the two operations of calculus, with its inverse, differentiation, being the other. The area above the x-axis adds to the total and that below the x-axis subtracts from the total, roughly speaking, the operation of integration is the reverse of differentiation. For this reason, the integral may also refer to the related notion of the antiderivative. In this case, it is called an integral and is written. The integrals discussed in this article are those termed definite integrals, a rigorous mathematical definition of the integral was given by Bernhard Riemann. It is based on a procedure which approximates the area of a curvilinear region by breaking the region into thin vertical slabs. A line integral is defined for functions of two or three variables, and the interval of integration is replaced by a curve connecting two points on the plane or in the space. In a surface integral, the curve is replaced by a piece of a surface in the three-dimensional space and this method was further developed and employed by Archimedes in the 3rd century BC and used to calculate areas for parabolas and an approximation to the area of a circle. A similar method was developed in China around the 3rd century AD by Liu Hui. This method was used in the 5th century by Chinese father-and-son mathematicians Zu Chongzhi. The next significant advances in integral calculus did not begin to appear until the 17th century, further steps were made in the early 17th century by Barrow and Torricelli, who provided the first hints of a connection between integration and differentiation. Barrow provided the first proof of the theorem of calculus. Wallis generalized Cavalieris method, computing integrals of x to a power, including negative powers. The major advance in integration came in the 17th century with the independent discovery of the theorem of calculus by Newton. The theorem demonstrates a connection between integration and differentiation and this connection, combined with the comparative ease of differentiation, can be exploited to calculate integrals. In particular, the theorem of calculus allows one to solve a much broader class of problems. Equal in importance is the mathematical framework that both Newton and Leibniz developed
27.
Function (mathematics)
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In mathematics, a function is a relation between a set of inputs and a set of permissible outputs with the property that each input is related to exactly one output. An example is the function that each real number x to its square x2. The output of a function f corresponding to a x is denoted by f. In this example, if the input is −3, then the output is 9, likewise, if the input is 3, then the output is also 9, and we may write f =9. The input variable are sometimes referred to as the argument of the function, Functions of various kinds are the central objects of investigation in most fields of modern mathematics. There are many ways to describe or represent a function, some functions may be defined by a formula or algorithm that tells how to compute the output for a given input. Others are given by a picture, called the graph of the function, in science, functions are sometimes defined by a table that gives the outputs for selected inputs. A function could be described implicitly, for example as the inverse to another function or as a solution of a differential equation, sometimes the codomain is called the functions range, but more commonly the word range is used to mean, instead, specifically the set of outputs. For example, we could define a function using the rule f = x2 by saying that the domain and codomain are the numbers. The image of this function is the set of real numbers. In analogy with arithmetic, it is possible to define addition, subtraction, multiplication, another important operation defined on functions is function composition, where the output from one function becomes the input to another function. Linking each shape to its color is a function from X to Y, each shape is linked to a color, there is no shape that lacks a color and no shape that has more than one color. This function will be referred to as the color-of-the-shape function, the input to a function is called the argument and the output is called the value. The set of all permitted inputs to a function is called the domain of the function. Thus, the domain of the function is the set of the four shapes. The concept of a function does not require that every possible output is the value of some argument, a second example of a function is the following, the domain is chosen to be the set of natural numbers, and the codomain is the set of integers. The function associates to any number n the number 4−n. For example, to 1 it associates 3 and to 10 it associates −6, a third example of a function has the set of polygons as domain and the set of natural numbers as codomain
28.
Parametric equation
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In mathematics, parametric equations define a group of quantities as functions of one or more independent variables called parameters. For example, the equations x = cos t y = sin t form a representation of the unit circle. Parametric equations are used in kinematics, where the trajectory of an object is represented by equations depending on time as the parameter. Because of this application, a parameter is often labeled t, however. Parameterizations are non-unique, more than one set of equations can specify the same curve. In kinematics, objects paths through space are described as parametric curves. Used in this way, the set of equations for the objects coordinates collectively constitute a vector-valued function for position. Such parametric curves can then be integrated and differentiated termwise, thus, if a particles position is described parametrically as r = then its velocity can be found as v = r ′ = and its acceleration as a = r ″ =. Another important use of equations is in the field of computer-aided design. For example, consider the three representations, all of which are commonly used to describe planar curves. These problems can be addressed by rewriting the non-parametric equations in parametric form, numerous problems in integer geometry can be solved using parametric equations. A classical such solution is Euclids parametrization of right triangles such that the lengths of their sides a, b, by multiplying a, b and c by an arbitrary positive integer, one gets a parametrization of all right triangles whose three sides have integer lengths. Converting a set of equations to a single equation involves eliminating the variable t from the simultaneous equations x = x, y = y. If one of these equations can be solved for t, the expression obtained can be substituted into the equation to obtain an equation involving x and y only. If the parametrization is given by rational functions x = p r, y = q r, where p, q, r are set-wise coprime polynomials, in some cases there is no single equation in closed form that is equivalent to the parametric equations. The simplest equation for a parabola, y = x 2 can be parameterized by using a free parameter t, and setting x = t, y = t 2 f o r − ∞ < t < ∞. More generally, any given by an explicit equation y = f can be parameterized by using a free parameter t. A more sophisticated example is the following, consider the unit circle which is described by the ordinary equation x 2 + y 2 =1
29.
Polar coordinate systems
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The reference point is called the pole, and the ray from the pole in the reference direction is the polar axis. The distance from the pole is called the radial coordinate or radius, the concepts of angle and radius were already used by ancient peoples of the first millennium BC. In On Spirals, Archimedes describes the Archimedean spiral, a function whose radius depends on the angle, the Greek work, however, did not extend to a full coordinate system. From the 8th century AD onward, astronomers developed methods for approximating and calculating the direction to Mecca —and its distance—from any location on the Earth, from the 9th century onward they were using spherical trigonometry and map projection methods to determine these quantities accurately. There are various accounts of the introduction of polar coordinates as part of a coordinate system. The full history of the subject is described in Harvard professor Julian Lowell Coolidges Origin of Polar Coordinates, grégoire de Saint-Vincent and Bonaventura Cavalieri independently introduced the concepts in the mid-seventeenth century. Saint-Vincent wrote about them privately in 1625 and published his work in 1647, Cavalieri first used polar coordinates to solve a problem relating to the area within an Archimedean spiral. Blaise Pascal subsequently used polar coordinates to calculate the length of parabolic arcs, in Method of Fluxions, Sir Isaac Newton examined the transformations between polar coordinates, which he referred to as the Seventh Manner, For Spirals, and nine other coordinate systems. In the journal Acta Eruditorum, Jacob Bernoulli used a system with a point on a line, called the pole, Coordinates were specified by the distance from the pole and the angle from the polar axis. Bernoullis work extended to finding the radius of curvature of curves expressed in these coordinates, the actual term polar coordinates has been attributed to Gregorio Fontana and was used by 18th-century Italian writers. The term appeared in English in George Peacocks 1816 translation of Lacroixs Differential and Integral Calculus, alexis Clairaut was the first to think of polar coordinates in three dimensions, and Leonhard Euler was the first to actually develop them. The radial coordinate is often denoted by r or ρ, the angular coordinate is specified as ϕ by ISO standard 31-11. Angles in polar notation are generally expressed in degrees or radians. Degrees are traditionally used in navigation, surveying, and many applied disciplines, while radians are more common in mathematics, in many contexts, a positive angular coordinate means that the angle ϕ is measured counterclockwise from the axis. In mathematical literature, the axis is often drawn horizontal. Adding any number of turns to the angular coordinate does not change the corresponding direction. Also, a radial coordinate is best interpreted as the corresponding positive distance measured in the opposite direction. Therefore, the point can be expressed with an infinite number of different polar coordinates or
30.
Differential equation
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A differential equation is a mathematical equation that relates some function with its derivatives. In applications, the functions usually represent physical quantities, the derivatives represent their rates of change, because such relations are extremely common, differential equations play a prominent role in many disciplines including engineering, physics, economics, and biology. In pure mathematics, differential equations are studied from different perspectives. Only the simplest differential equations are solvable by explicit formulas, however, if a self-contained formula for the solution is not available, the solution may be numerically approximated using computers. Differential equations first came into existence with the invention of calculus by Newton, jacob Bernoulli proposed the Bernoulli differential equation in 1695. This is a differential equation of the form y ′ + P y = Q y n for which the following year Leibniz obtained solutions by simplifying it. Historically, the problem of a string such as that of a musical instrument was studied by Jean le Rond dAlembert, Leonhard Euler, Daniel Bernoulli. In 1746, d’Alembert discovered the wave equation, and within ten years Euler discovered the three-dimensional wave equation. The Euler–Lagrange equation was developed in the 1750s by Euler and Lagrange in connection with their studies of the tautochrone problem. This is the problem of determining a curve on which a particle will fall to a fixed point in a fixed amount of time. Lagrange solved this problem in 1755 and sent the solution to Euler, both further developed Lagranges method and applied it to mechanics, which led to the formulation of Lagrangian mechanics. Contained in this book was Fouriers proposal of his heat equation for conductive diffusion of heat and this partial differential equation is now taught to every student of mathematical physics. For example, in mechanics, the motion of a body is described by its position. Newtons laws allow one to express these variables dynamically as an equation for the unknown position of the body as a function of time. In some cases, this equation may be solved explicitly. An example of modelling a real world problem using differential equations is the determination of the velocity of a ball falling through the air, considering only gravity, the balls acceleration towards the ground is the acceleration due to gravity minus the acceleration due to air resistance. Gravity is considered constant, and air resistance may be modeled as proportional to the balls velocity and this means that the balls acceleration, which is a derivative of its velocity, depends on the velocity. Finding the velocity as a function of time involves solving a differential equation, Differential equations can be divided into several types
31.
BASIC
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BASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use. In 1964, John G. Kemeny and Thomas E. Kurtz designed the original BASIC language at Dartmouth College in the U. S. state of New Hampshire and they wanted to enable students in fields other than science and mathematics to use computers. At the time, nearly all use of computers required writing custom software, versions of BASIC became widespread on microcomputers in the mid-1970s and 1980s. Microcomputers usually shipped with BASIC, often in the machines firmware, having an easy-to-learn language on these early personal computers allowed small business owners, professionals, hobbyists, and consultants to develop custom software on computers they could afford. In the 2010s, BASIC remains popular in many computing dialects and in new languages influenced by BASIC, before the mid-1960s, the only computers were huge mainframe computers. Users submitted jobs on punched cards or similar media to specialist computer operators, the computer stored these, then used a batch processing system to run this queue of jobs one after another, allowing very high levels of utilization of these expensive machines. As the performance of computing hardware rose through the 1960s, multi-processing was developed and this allowed a mix of batch jobs to be run together, but the real revolution was the development of time-sharing. The original BASIC language was released on May 1,1964 by John G. Kemeny and Thomas E. Kurtz, the acronym BASIC comes from the name of an unpublished paper by Thomas Kurtz. BASIC was designed to allow students to write computer programs for the Dartmouth Time-Sharing System. It was intended specifically for technical users who did not have or want the mathematical background previously expected. Being able to use a computer to support teaching and research was quite novel at the time, the language was based on FORTRAN II, with some influences from ALGOL60 and with additions to make it suitable for timesharing. Wanting use of the language to become widespread, its designers made the available free of charge. They also made it available to schools in the Hanover area. In the following years, as dialects of BASIC appeared, Kemeny. A version was a part of the Pick operating system from 1973 onward. During this period a number of computer games were written in BASIC. A number of these were collected by DEC employee David H. Ahl and he later collected a number of these into book form,101 BASIC Computer Games, published in 1973. During the same period, Ahl was involved in the creation of a computer for education use
32.
IBM PC compatible
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IBM PC compatible computers are those similar to the original IBM PC, XT, and AT, able to run the same software and support the same expansion cards as those. Such computers used to be referred to as PC clones, or IBM clones, Columbia Data Products built the first clone of the IBM personal computer by a clean room implementation of its BIOS. Early IBM PC compatibles used the computer bus as the original PC. The IBM AT compatible bus was named the Industry Standard Architecture bus by manufacturers of compatible computers. The term IBM PC compatible is now a historical description only, only the Apple Macintosh classic Mac OS and macOS kept significant market share without compatibility with the IBM personal computer, so consumers are typically identified as being a PC or Mac user. IBM decided in 1980 to market a low-cost single-user computer as quickly as possible in response to Apple Computers success in the microcomputer market. On 12 August 1981, the first IBM PC went on sale, there were three operating systems available for it. The least expensive and most popular was PC DOS made by Microsoft, in a crucial concession, IBMs agreement allowed Microsoft to sell its own version, MS-DOS, for non-IBM computers. The only component of the original PC architecture exclusive to IBM was the BIOS and this software would run on any machine using MS-DOS or PC-DOS. Software that directly addressed the hardware instead of making standard calls was faster, however, software addressing IBM PC hardware in this way would not run on MS-DOS machines with different hardware. The 808x computer marketplace rapidly excluded all machines which were not hardware-, the 640 KB barrier on conventional system memory available to MS-DOS is a legacy of that period, other non-clone machines, while subject to a limit, could exceed 640 kB. Rumors of lookalike, compatible computers, created without IBMs approval, by June 1983 PC Magazine defined PC clone as a computer accommodate the user who takes a disk home from an IBM PC, walks across the room, and plugs it into the foreign machine. Because of a shortage of IBM PCs that year, many customers purchased clones instead, Columbia Data Products produced the first computer more or less compatible to the IBM PC standard during June 1982, soon followed by Eagle Computer. Compaq announced its first IBM PC compatible in November 1982, the Compaq Portable, the Compaq was the first sewing machine-sized portable computer that was essentially 100% PC-compatible. The company could not copy the BIOS directly as a result of the decision in Apple v. Franklin. Each computer would have its own Original Equipment Manufacturer version of MS-DOS, any software written for MS-DOS would operate on any MS-DOS computer, despite variations in hardware design. This expectation seemed reasonable in the marketplace of the time. Until then Microsoft was based primarily on computer languages such as BASIC, the established small system operating software was CP/M from Digital Research which was in use both at the hobbyist level and by the more professional of those using microcomputers
33.
Assembly language
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Each assembly language is specific to a particular computer architecture. In contrast, most high-level programming languages are generally portable across multiple architectures, Assembly language may also be called symbolic machine code. Assembly language is converted into machine code by a utility program referred to as an assembler. The conversion process is referred to as assembly, or assembling the source code, Assembly time is the computational step where an assembler is run. Assembly language uses a mnemonic to represent each low-level machine instruction or opcode, typically also each architectural register, flag, depending on the architecture, these elements may also be combined for specific instructions or addressing modes using offsets or other data as well as fixed addresses. Many assemblers offer additional mechanisms to facilitate development, to control the assembly process. A macro assembler includes a facility so that assembly language text can be represented by a name. A cross assembler is an assembler that is run on a computer or operating system of a different type from the system on which the code is to run. Cross-assembling facilitates the development of programs for systems that do not have the resources to support software development, a microassembler is a program that helps prepare a microprogram, called firmware, to control the low level operation of a computer. A meta-assembler is a used in some circles for a program that accepts the syntactic and semantic description of an assembly language. An assembler program creates object code by translating combinations of mnemonics and syntax for operations and this representation typically includes an operation code as well as other control bits and data. The assembler also calculates constant expressions and resolves symbolic names for memory locations, the use of symbolic references is a key feature of assemblers, saving tedious calculations and manual address updates after program modifications. Most assemblers also include facilities for performing textual substitution – e. g. to generate common short sequences of instructions as inline. Some assemblers may also be able to some simple types of instruction set-specific optimizations. One concrete example of this may be the ubiquitous x86 assemblers from various vendors, most of them are able to perform jump-instruction replacements in any number of passes, on request. Like early programming languages such as Fortran, Algol, Cobol and Lisp, assemblers have been available since the 1950s, however, assemblers came first as they are far simpler to write than compilers for high-level languages. There may be several assemblers with different syntax for a particular CPU or instruction set architecture, despite different appearances, different syntactic forms generally generate the same numeric machine code, see further below. A single assembler may also have different modes in order to support variations in syntactic forms as well as their exact semantic interpretations, there are two types of assemblers based on how many passes through the source are needed to produce the executable program
34.
C (programming language)
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C was originally developed by Dennis Ritchie between 1969 and 1973 at Bell Labs, and used to re-implement the Unix operating system. C has been standardized by the American National Standards Institute since 1989, C is an imperative procedural language. Therefore, C was useful for applications that had formerly been coded in assembly language. Despite its low-level capabilities, the language was designed to encourage cross-platform programming, a standards-compliant and portably written C program can be compiled for a very wide variety of computer platforms and operating systems with few changes to its source code. The language has become available on a wide range of platforms. In C, all code is contained within subroutines, which are called functions. Function parameters are passed by value. Pass-by-reference is simulated in C by explicitly passing pointer values, C program source text is free-format, using the semicolon as a statement terminator and curly braces for grouping blocks of statements. The C language also exhibits the characteristics, There is a small, fixed number of keywords, including a full set of flow of control primitives, for, if/else, while, switch. User-defined names are not distinguished from keywords by any kind of sigil, There are a large number of arithmetical and logical operators, such as +, +=, ++, &, ~, etc. More than one assignment may be performed in a single statement, function return values can be ignored when not needed. Typing is static, but weakly enforced, all data has a type, C has no define keyword, instead, a statement beginning with the name of a type is taken as a declaration. There is no function keyword, instead, a function is indicated by the parentheses of an argument list, user-defined and compound types are possible. Heterogeneous aggregate data types allow related data elements to be accessed and assigned as a unit, array indexing is a secondary notation, defined in terms of pointer arithmetic. Unlike structs, arrays are not first-class objects, they cannot be assigned or compared using single built-in operators, There is no array keyword, in use or definition, instead, square brackets indicate arrays syntactically, for example month. Enumerated types are possible with the enum keyword and they are not tagged, and are freely interconvertible with integers. Strings are not a data type, but are conventionally implemented as null-terminated arrays of characters. Low-level access to memory is possible by converting machine addresses to typed pointers
35.
Compiler
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A compiler is a computer program that transforms source code written in a programming language into another computer language, with the latter often having a binary form known as object code. The most common reason for converting source code is to create an executable program, the name compiler is primarily used for programs that translate source code from a high-level programming language to a lower level language. If the compiled program can run on a computer whose CPU or operating system is different from the one on which the compiler runs, more generally, compilers are a specific type of translator. While all programs that take a set of programming specifications and translate them, a program that translates from a low-level language to a higher level one is a decompiler. A program that translates between high-level languages is called a source-to-source compiler or transpiler. A language rewriter is usually a program that translates the form of expressions without a change of language, the term compiler-compiler is sometimes used to refer to a parser generator, a tool often used to help create the lexer and parser. A compiler is likely to many or all of the following operations, lexical analysis, preprocessing, parsing, semantic analysis, code generation. Program faults caused by incorrect compiler behavior can be difficult to track down and work around, therefore. Software for early computers was written in assembly language. The notion of a high level programming language dates back to 1943, no actual implementation occurred until the 1970s, however. The first actual compilers date from the 1950s, identifying the very first is hard, because there is subjectivity in deciding when programs become advanced enough to count as the full concept rather than a precursor. 1952 saw two important advances. Grace Hopper wrote the compiler for the A-0 programming language, though the A-0 functioned more as a loader or linker than the notion of a full compiler. Also in 1952, the first autocode compiler was developed by Alick Glennie for the Mark 1 computer at the University of Manchester and this is considered by some to be the first compiled programming language. The FORTRAN team led by John Backus at IBM is generally credited as having introduced the first unambiguously complete compiler, COBOL was an early language to be compiled on multiple architectures, in 1960. In many application domains the idea of using a higher level language quickly caught on, because of the expanding functionality supported by newer programming languages and the increasing complexity of computer architectures, compilers have become more complex. Early compilers were written in assembly language, the first self-hosting compiler – capable of compiling its own source code in a high-level language – was created in 1962 for the Lisp programming language by Tim Hart and Mike Levin at MIT. Since the 1970s, it has become practice to implement a compiler in the language it compiles
36.
TIGCC
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TIGCC is a software development environment which allows developers to program and compile A68K assembly, GNU assembly, and C code for the Motorola 68000 series Texas Instruments graphing calculators. TIGCC is licensed under the GNU General Public License, the TIGCC project includes many things that help developers create and manage projects. TIGCC IDE - an integrated development environment with the TIGCC compiler and it includes syntax editing and is also a project manager that helps to keep projects together. As of version 0. 96-beta8 the Windows IDE supports the latest version of TiEmu 3 for debugging via OLE Automation, KTIGCC - the Linux IDE, KTIGCC is similar to the Windows IDE. It runs under X11 using the KDE libraries and has a few new such as linking to real calculators with the latest libticables2. Documentation - The TIGCC manual contains detailed documentation on how to use the TIGCC IDE and compiler, Compiler - The TIGCC compiler is a patched version of GCC that allows developers to compile C and assembly code for the m68k Texas Instruments graphing calculators. Development of the TIGCC project has decreased drastically due to the departure of many team members. While TIGCC is still active, it is not growing as fast as it once was. Nevertheless, it is stable and complete. KTIGCC - KTIGCC is complete, i. e. all the features of the TIGCC IDE are also available in KTIGCC, additional features may be added in the future. The compiler - TIGCCs compiler is based on the GNU Compiler Collection, the latest released version of TIGCCs compiler is based on the GCC4.1. 2-20060728 snapshot. Due to disputes between a group of users and the current maintainer, a fork named GCC4TI was announced on January 3,2009. It currently has 2 active committers, the TIGCC project was originally developed by an international team of developers, most of whom have since resigned due to lack of time and/or interest. It is currently being maintained by Kevin Kofler, xavier Vassor, from the Doors Team. He was the creator of the TIGCC project and he made the original linker, which has since been replaced. Jean Canazzi, was the first maintainer of the compiler and made changes which were necessary to interface with the TIOS properly, niklas Brunlid, who fixed some bugs in the old linker. Zeljko Juric, made the first version of TIGCC library and his documentation constitutes a large portion of TIGCCs current documentation. Sebastian Reichelt, is the developer of the TIGCC IDE written in Delphi, philipp Winkler, made the HTML version of the documentation
37.
GNU Compiler Collection
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The GNU Compiler Collection is a compiler system produced by the GNU Project supporting various programming languages. GCC is a key component of the GNU toolchain and the compiler for most Unix-like Operating Systems. The Free Software Foundation distributes GCC under the GNU General Public License, GCC has played an important role in the growth of free software, as both a tool and an example. Originally named the GNU C Compiler, when it handled the C programming language. It was extended to compile C++ in December of that year, front ends were later developed for Objective-C, Objective-C++, Fortran, Java, Ada, and Go among others. Version 4.5 of the OpenMP specification is now supported in the C and C++ compilers, by default, the current version supports gnu++14, a superset of C++14 and gnu11, a superset of C11, with strict standard support also available. It also provides support for C++17 and later. GCC has been ported to a variety of instruction set architectures. GCC is also available for most embedded systems, including ARM-based, AMCC, the compiler can target a wide variety of platforms. Versions are also available for Microsoft Windows and other operating systems, GCC can compile code for Android and iOS. In an effort to bootstrap the GNU operating system, Richard Stallman asked Andrew S. Tanenbaum, when Tanenbaum told him that while the Free University was free, the compiler was not, Stallman decided to write his own. Stallmans initial plan was to rewrite an existing compiler from Lawrence Livermore Laboratory from Pastel to C with some help from Len Tower, none of the Pastel compiler code ended up in GCC, though Stallman did use the C front end he had written. GCC was first released March 22,1987, available by FTP from MIT, multiple forks proved inefficient and unwieldy, however, and the difficulty in getting work accepted by the official GCC project was greatly frustrating for many. In 1997, a group of developers formed Experimental/Enhanced GNU Compiler System to merge several experimental forks into a single project, the basis of the merger was a GCC development snapshot taken between the 2.7 and 2.81 releases. Projects merged included g77, PGCC, many C++ improvements, and many new architectures, with the release of GCC2.95 in July 1999 the two projects were once again united. GCC has since been maintained by a group of programmers from around the world under the direction of a steering committee. It has been ported to more kinds of processors and operating systems than any other compiler, GCC has been ported to a wide variety of instruction set architectures, and is widely deployed as a tool in the development of both free and proprietary software. GCC is also available for most embedded systems, including Symbian, ARM-based, AMCC, the compiler can target a wide variety of platforms, including video game consoles such as the PlayStation 2, Cell SPE of PlayStation 3 and Dreamcast
38.
Mathematics
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Mathematics is the study of topics such as quantity, structure, space, and change. There is a range of views among mathematicians and philosophers as to the exact scope, Mathematicians seek out patterns and use them to formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proof, when mathematical structures are good models of real phenomena, then mathematical reasoning can provide insight or predictions about nature. Through the use of abstraction and logic, mathematics developed from counting, calculation, measurement, practical mathematics has been a human activity from as far back as written records exist. The research required to solve mathematical problems can take years or even centuries of sustained inquiry, rigorous arguments first appeared in Greek mathematics, most notably in Euclids Elements. Galileo Galilei said, The universe cannot be read until we have learned the language and it is written in mathematical language, and the letters are triangles, circles and other geometrical figures, without which means it is humanly impossible to comprehend a single word. Without these, one is wandering about in a dark labyrinth, carl Friedrich Gauss referred to mathematics as the Queen of the Sciences. Benjamin Peirce called mathematics the science that draws necessary conclusions, David Hilbert said of mathematics, We are not speaking here of arbitrariness in any sense. Mathematics is not like a game whose tasks are determined by arbitrarily stipulated rules, rather, it is a conceptual system possessing internal necessity that can only be so and by no means otherwise. Albert Einstein stated that as far as the laws of mathematics refer to reality, they are not certain, Mathematics is essential in many fields, including natural science, engineering, medicine, finance and the social sciences. Applied mathematics has led to entirely new mathematical disciplines, such as statistics, Mathematicians also engage in pure mathematics, or mathematics for its own sake, without having any application in mind. There is no clear line separating pure and applied mathematics, the history of mathematics can be seen as an ever-increasing series of abstractions. The earliest uses of mathematics were in trading, land measurement, painting and weaving patterns, in Babylonian mathematics elementary arithmetic first appears in the archaeological record. Numeracy pre-dated writing and numeral systems have many and diverse. Between 600 and 300 BC the Ancient Greeks began a study of mathematics in its own right with Greek mathematics. Mathematics has since been extended, and there has been a fruitful interaction between mathematics and science, to the benefit of both. Mathematical discoveries continue to be made today, the overwhelming majority of works in this ocean contain new mathematical theorems and their proofs. The word máthēma is derived from μανθάνω, while the modern Greek equivalent is μαθαίνω, in Greece, the word for mathematics came to have the narrower and more technical meaning mathematical study even in Classical times
39.
Science
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Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe. The formal sciences are often excluded as they do not depend on empirical observations, disciplines which use science, like engineering and medicine, may also be considered to be applied sciences. However, during the Islamic Golden Age foundations for the method were laid by Ibn al-Haytham in his Book of Optics. In the 17th and 18th centuries, scientists increasingly sought to formulate knowledge in terms of physical laws, over the course of the 19th century, the word science became increasingly associated with the scientific method itself as a disciplined way to study the natural world. It was during this time that scientific disciplines such as biology, chemistry, Science in a broad sense existed before the modern era and in many historical civilizations. Modern science is distinct in its approach and successful in its results, Science in its original sense was a word for a type of knowledge rather than a specialized word for the pursuit of such knowledge. In particular, it was the type of knowledge which people can communicate to each other, for example, knowledge about the working of natural things was gathered long before recorded history and led to the development of complex abstract thought. This is shown by the construction of calendars, techniques for making poisonous plants edible. For this reason, it is claimed these men were the first philosophers in the strict sense and they were mainly speculators or theorists, particularly interested in astronomy. In contrast, trying to use knowledge of nature to imitate nature was seen by scientists as a more appropriate interest for lower class artisans. A clear-cut distinction between formal and empirical science was made by the pre-Socratic philosopher Parmenides, although his work Peri Physeos is a poem, it may be viewed as an epistemological essay on method in natural science. Parmenides ἐὸν may refer to a system or calculus which can describe nature more precisely than natural languages. Physis may be identical to ἐὸν and he criticized the older type of study of physics as too purely speculative and lacking in self-criticism. He was particularly concerned that some of the early physicists treated nature as if it could be assumed that it had no intelligent order, explaining things merely in terms of motion and matter. The study of things had been the realm of mythology and tradition, however. Aristotle later created a less controversial systematic programme of Socratic philosophy which was teleological and he rejected many of the conclusions of earlier scientists. For example, in his physics, the sun goes around the earth, each thing has a formal cause and final cause and a role in the rational cosmic order. Motion and change is described as the actualization of potentials already in things, while the Socratics insisted that philosophy should be used to consider the practical question of the best way to live for a human being, they did not argue for any other types of applied science
40.
Tetris
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Tetris is a tile-matching puzzle video game, originally designed and programmed by Russian game designer Alexey Pajitnov. It was released on June 6,1984, while he was working for the Dorodnitsyn Computing Centre of the Academy of Science of the USSR in Moscow and he derived its name from the Greek numerical prefix tetra- and tennis, Pajitnovs favorite sport. Tetris was the first entertainment software to be exported from the USSR to the US, the Tetris game is a popular use of tetrominoes, the four-element special case of polyominoes. Polyominoes have been used in popular puzzles since at least 1907, however, even the enumeration of pentominoes is dated to antiquity. It has even inspired Tetris serving dishes and been played on the sides of various buildings, electronic Gaming Monthlys 100th issue had Tetris in first place as Greatest Game of All Time. In 2007, Tetris came in place in IGNs 100 Greatest Video Games of All Time. Tetriminos are game pieces shaped like tetrominoes, geometric shapes composed of four blocks each. A random sequence of Tetriminos fall down the playing field, the objective of the game is to manipulate these Tetriminos, by moving each one sideways and rotating it by 90 degree units, with the aim of creating a horizontal line of ten units without gaps. When such a line is created, it disappears, and any block above the line will fall. When a certain number of lines are cleared, the game enters a new level. As the game progresses, each level causes the Tetriminos to fall faster, some games also end after a finite number of levels or lines. All of the Tetriminos are capable of single and double clears, I, J, and L are able to clear triples. Only the I Tetrimino has the capacity to four lines simultaneously. Pajitnovs original version for the Electronika 60 computer used green brackets to represent blocks, prior to The Tetris Companys standardization in the early 2000s, those colors varied widely from implementation to implementation. The scoring formula for the majority of Tetris products is built on the idea that more difficult line clears should be awarded more points. For example, a line clear in Tetris Zone is worth 100 points, clearing four lines at once is worth 800. Nearly all Tetris games allow the player to press a button to increase the speed of the current pieces descent, rather than waiting for it to fall. The player can stop the pieces increased speed before the piece reaches the floor by letting go of the button
41.
Minesweeper (video game)
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Minesweeper is a single-player puzzle video game. The objective of the game is to clear a rectangular board containing hidden mines without detonating any of them, the game originates from the 1960s, and has been written for many computing platforms in use today. It has many variations and offshoots, the player is initially presented with a grid of undifferentiated squares. Some randomly selected squares, unknown to the player, are designated to contain mines. Typically, the size of the grid and the number of mines are set in advance by the user, either by entering the numbers or selecting from defined skill levels, the game is played by revealing squares of the grid by clicking or otherwise indicating each square. If a square containing a mine is revealed, the player loses the game, the player uses this information to deduce the contents of other squares, and may either safely reveal each square or mark the square as containing a mine. In some versions, a question mark may be placed in a square to serve as an aid to logical deduction. Implementations may also allow players to quickly clear around a revealed square once the number of mines have been flagged around it. The game is won when all squares are revealed, because all mines have been located. Some versions of Minesweeper will set up the board by never placing a mine on the first square revealed, or by arranging the board so that the solution does not require guessing. Minesweeper for versions of Windows protects the first square revealed, in Windows 7, players may elect to replay a board, Minesweeper has its origins in the earliest mainframe games of the 1960s and 1970s. The earliest ancestor of Minesweeper was Jerimac Ratliffs Cube, the basic gameplay style became a popular segment of the puzzle game genre during the 1980s, with such titles as Mined-Out, Yomp, and Cube. S. It is not necessary to clear all non-mine squares, also, there is no mechanism for marking mines or counting the number of mines found. The number of steps taken is counted, although no high score functionality is included, players could attempt to beat their personal best score for a given number of mines. Unlike Minesweeper, the size of the minefield is fixed, however, the player may still specify the number of mines. Because the player must navigate through the minefield, it is impossible to win — namely. This allows for a game of Minesweeper where the skill is awarded assessed in points rather than game completion. The PC game Mole Control, in game, the minesweeper mechanic is integrated into a puzzle adventure game based in a village called Molar Creek
42.
ZX Spectrum
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The ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research Ltd. It was manufactured in Dundee, Scotland, in the now closed Timex factory, the Spectrum was among the first mainstream-audience home computers in the UK, similar in significance to the Commodore 64 in the USA. Licensing deals and clones followed, and earned Clive Sinclair a knighthood for services to British industry, the Commodore 64, Dragon 32, Oric-1 and Atmos, BBC Microcomputer and later the Amstrad CPC range were rivals to the Spectrum in the UK market during the early 1980s. Over 24,000 software titles have been released since the Spectrums launch, in 2014, a Bluetooth keyboard modelled on the Spectrum was announced. The Spectrum is based on a Zilog Z80 A CPU running at 3.5 MHz, the original model has 16 KB of ROM and either 16 KB or 48 KB of RAM. Hardware design was by Richard Altwasser of Sinclair Research, and the appearance was designed by Sinclairs industrial designer Rick Dickinson. Video output is through an RF modulator and was designed for use with contemporary portable television sets, the image resolution is 256×192 with the same colour limitations. To conserve memory, colour is stored separate from the bitmap in a low resolution, 32×24 grid overlay. In practice, this means that all pixels of an 8x8 character block share one foreground colour, Altwasser received a patent for this design. An attribute consists of a foreground and a colour, a brightness level and a flashing flag which. This scheme leads to what was dubbed colour clash or attribute clash and this became a distinctive feature of the Spectrum, meaning programs, particularly games, had to be designed around this limitation. Other machines available around the time, for example the Amstrad CPC or the Commodore 64. The Commodore 64 used colour attributes in a way, but a special multicolour mode, hardware sprites. Sound output is through a beeper on the machine itself, capable of producing one channel with 10 octaves, software was later available that could play two channel sound. The machine includes an expansion bus edge connector and 3.5 mm audio in/out ports for the connection of a recorder for loading and saving programs. The ear port can drive headphones and the mic port provides line level audio out which could be amplified, the machines Sinclair BASIC interpreter is stored in ROM and was written by Steve Vickers on contract from Nine Tiles Ltd. The Spectrums chiclet keyboard is marked with BASIC keywords, for example, pressing G when in programming mode would insert the BASIC command GO TO. The ZX Spectrum character set was expanded from that of the ZX81, Spectrum BASIC included extra keywords for the more advanced display and sound, and supported multi-statement lines
43.
Chess
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Chess is a two-player strategy board game played on a chessboard, a checkered gameboard with 64 squares arranged in an eight-by-eight grid. Chess is played by millions of people worldwide, both amateurs and professionals, each player begins the game with 16 pieces, one king, one queen, two rooks, two knights, two bishops, and eight pawns. Each of the six piece types moves differently, with the most powerful being the queen, the objective is to checkmate the opponents king by placing it under an inescapable threat of capture. To this end, a players pieces are used to attack and capture the opponents pieces, in addition to checkmate, the game can be won by voluntary resignation by the opponent, which typically occurs when too much material is lost, or if checkmate appears unavoidable. A game may result in a draw in several ways. Chess is believed to have originated in India, some time before the 7th century, chaturanga is also the likely ancestor of the Eastern strategy games xiangqi, janggi and shogi. The pieces took on their current powers in Spain in the late 15th century, the first generally recognized World Chess Champion, Wilhelm Steinitz, claimed his title in 1886. Since 1948, the World Championship has been controlled by FIDE, the international governing body. There is also a Correspondence Chess World Championship and a World Computer Chess Championship, online chess has opened amateur and professional competition to a wide and varied group of players. There are also many variants, with different rules, different pieces. FIDE awards titles to skilled players, the highest of which is grandmaster, many national chess organizations also have a title system. However, these are not recognised by FIDE, the term master may refer to a formal title or may be used more loosely for any skilled player. Until recently, chess was a sport of the International Olympic Committee. Chess was included in the 2006 and 2010 Asian Games, since the 1990s, computer analysis has contributed significantly to chess theory, particularly in the endgame. The computer IBM Deep Blue was the first machine to overcome a reigning World Chess Champion in a match when it defeated Garry Kasparov in 1997, the rise of strong computer programs that can be run on hand-held devices has led to increasing concerns about cheating during tournaments. The official rules of chess are maintained by FIDE, chesss international governing body, along with information on official chess tournaments, the rules are described in the FIDE Handbook, Laws of Chess section. Chess is played on a board of eight rows and eight columns. The colors of the 64 squares alternate and are referred to as light, the chessboard is placed with a light square at the right-hand end of the rank nearest to each player
44.
Link's Awakening
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The Legend of Zelda, Links Awakening is a 1993 action-adventure video game developed by Nintendo Entertainment Analysis & Development and published by Nintendo for the Game Boy. It is the installment in the The Legend of Zelda series. Links Awakening began as a port of the Super NES title The Legend of Zelda, A Link to the Past and it grew into an original project under the direction of Takashi Tezuka, with a story and script created by Yoshiaki Koizumi and Kensuke Tanabe. It is one of the few Zelda games not to place in the land of Hyrule. Instead, protagonist Link begins the game stranded on Koholint Island, assuming the role of Link, the player fights monsters and solves puzzles while searching for eight musical instruments that will awaken the sleeping Wind Fish and allow him to escape from the island. Links Awakening was critically and commercially successful, critics praised the games depth and number of features, complaints focused on its control scheme and monochrome graphics. Together, the two versions of the game have more than six million units worldwide, and have appeared on multiple game publications lists of the best games of all time. Unlike most The Legend of Zelda titles, Links Awakening is set outside the kingdom of Hyrule and it omits locations and characters from previous games, aside from protagonist Link and a passing mention of Princess Zelda. Instead, the takes place entirely on Koholint Island, an isolated landmass cut off from the rest of the world. The island, though small, contains a number of secrets. In Links Awakening, the player is given advice and directions by non-player characters such as Ulrira, chomp, an enemy from the Mario series, was included after a programmer gave Link the ability to grab the creature and take it for a walk. Director Takashi Tezuka said that the games freewheeling development made Links Awakening seem like a parody of The Legend of Zelda series, after the events of Oracle of Ages and Oracle of Seasons, the hero Link travels abroad to train for further threats. A storm destroys his boat at sea, and he washes ashore on Koholint Island and she is fascinated by Link and the outside world, and tells Link wistfully that, if she were a seagull, she would leave and travel across the sea. After Link recovers his sword, a mysterious owl tells him that he must wake the Wind Fish, Koholints guardian, the Wind Fish lies dreaming in a giant egg on top of Mt. Tamaranch, and can only be awakened by the eight Instruments of the Sirens. Link proceeds to explore a series of dungeons in order to recover the eight instruments, during his search for the sixth instrument, Link goes to the Ancient Ruins. There he finds a mural that details the reality of the island, after this revelation, the owl tells Link that this is only a rumor, and only the Wind Fish knows for certain whether it is true. Throughout Koholint Island, nightmare creatures attempt to obstruct Links quest for the instruments, after collecting all eight instruments from the eight dungeons across Koholint, Link climbs to the top of Mt. Tamaranch and plays the Ballad of the Wind Fish. This breaks open the egg in which the Wind Fish sleeps, Link enters and confronts the last evil being and its final transformation is DethI, a cyclopean, dual-tentacled Shadow
