1.
Shift key
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The shift key is a modifier key on a keyboard, used to type capital letters and other alternate upper characters. There are typically two shift keys, on the left and right sides of the row below the home row,2 Type-Writer of 1878, the No.1 model was capital-only. On the US layout and similar layouts, characters that typically require the use of the shift key include the parentheses, the question mark, the exclamation point. When the caps lock key is engaged, the key can be used to type lowercase letters on many operating systems. The keyboard symbol for the Shift key is given in ISO/IEC 9995-7 as symbol 1, in Unicode 6.1, the character approximating this symbol best is U+21E7 upwards white arrow. This symbol is used to denote the Shift key on modern keyboards. This symbol also is used in texts to denote the shift key, on computer keyboards, as opposed to typewriter keyboards, the shift key can have many more uses, It is sometimes used to modify the function keys. Modern Microsoft Windows keyboards typically have only 12 function keys, Shift+F1 must be used to type F13, Shift+F2 for F14 and it can modify various control and alt keys. For example, if Alt-Tab is used to cycle through open windows, holding shift while in a word processor will anchor the insertion point, such that moving the pointer and clicking the mouse to a new point will select the range of text in between. The shift key can also be used to modify the behavior on a computer. For example, holding shift while clicking on a link in a web browser might cause the page to open in a new window, in some web browsers, holding shift while scrolling will scan through previously viewed web pages. In macOS, holding shift while performing actions, such as minimising a window or enabling/disabling Dashboard or Mission Control. For some animations, holding control will make the move just slightly slower. On some keyboards, if both shift keys are held down only some letters can be typed. For example, on the Dell keyboard Model RT7D20 only 16 letters can be typed and this phenomenon is known as masking and is a fundamental limitation of the way the keyboard electronics are designed. The following is a list of actions involving the shift key for the Microsoft Windows operating system, altGr key Command key Option key StickyKeys
2.
Computer
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A computer is a device that can be instructed to carry out an arbitrary set of arithmetic or logical operations automatically. The ability of computers to follow a sequence of operations, called a program, such computers are used as control systems for a very wide variety of industrial and consumer devices. The Internet is run on computers and it millions of other computers. Since ancient times, simple manual devices like the abacus aided people in doing calculations, early in the Industrial Revolution, some mechanical devices were built to automate long tedious tasks, such as guiding patterns for looms. More sophisticated electrical machines did specialized analog calculations in the early 20th century, the first digital electronic calculating machines were developed during World War II. The speed, power, and versatility of computers has increased continuously and dramatically since then, conventionally, a modern computer consists of at least one processing element, typically a central processing unit, and some form of memory. The processing element carries out arithmetic and logical operations, and a sequencing, peripheral devices include input devices, output devices, and input/output devices that perform both functions. Peripheral devices allow information to be retrieved from an external source and this usage of the term referred to a person who carried out calculations or computations. The word continued with the same meaning until the middle of the 20th century, from the end of the 19th century the word began to take on its more familiar meaning, a machine that carries out computations. The Online Etymology Dictionary gives the first attested use of computer in the 1640s, one who calculates, the Online Etymology Dictionary states that the use of the term to mean calculating machine is from 1897. The Online Etymology Dictionary indicates that the use of the term. 1945 under this name, theoretical from 1937, as Turing machine, devices have been used to aid computation for thousands of years, mostly using one-to-one correspondence with fingers. The earliest counting device was probably a form of tally stick, later record keeping aids throughout the Fertile Crescent included calculi which represented counts of items, probably livestock or grains, sealed in hollow unbaked clay containers. The use of counting rods is one example, the abacus was initially used for arithmetic tasks. The Roman abacus was developed from used in Babylonia as early as 2400 BC. Since then, many forms of reckoning boards or tables have been invented. In a medieval European counting house, a checkered cloth would be placed on a table, the Antikythera mechanism is believed to be the earliest mechanical analog computer, according to Derek J. de Solla Price. It was designed to calculate astronomical positions and it was discovered in 1901 in the Antikythera wreck off the Greek island of Antikythera, between Kythera and Crete, and has been dated to circa 100 BC
3.
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
4.
ISO/IEC 9995
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ISO/IEC9995 Information technology — Keyboard layouts for text and office systems is an ISO standard series defining layout principles for computer keyboards. It does not define specific layouts but provides the base for national, the project of this standard was adopted at ISO in Berlin in 1985 under the proposition of Dr Yves Neuville. The ISO/IEC9995 standard series dates to 1994 and has undergone several updates over the years, the figure shows the division of a keyboard into sections, which are subdivided into zones. Also, the standard does not prevent a section to be placed left of the alphanumeric section. By means of the grid, each key can be identified by a unique combination of a letter. E. g. the key containing the digit one on several layouts is identified as “Key E01”, rows above of the alphanumeric section are to be labeled from K on, and rows below the space key are to be labeled from Z downwards. The grid may be angled, or squared, the standard does not constrain the numbers of rows and columns in the alphanumeric section. The characters which can be input by the keys in the section usually are organized in levels. For two-cased scripts like Latin, the level contains lower-case letters. For characters which are not letters, no rules are given regarding their distribution among the levels, while digits are commonly in Level 1, there are exceptions. The standard allows for a third level, usually, characters in such a level are selected by the means of an AltGr key. Thus, each such group usually is subdivided into levels, common examples are layouts allowing the input of characters of different scripts, like e. g. the Japanese keyboard layout. According to ISO/IEC 9995-1, the level is indicated by the row where the character is depicted on the keytop, Level 2 above of Level 1 Level 3 below Level 1. The group is indicated by the column on the keytop, The first or “primary group” at the left keytop border The second or “secondary group” at the right keytop border Additional groups in between. Thus, on the key of the German T2 layout, in the primary group are the characters “#” in Level 1, “” in Level 2. In the secondary group, there is the lowercase letter “ə” in Level 1, for layouts containing only one group, characters in Level 3 may be depicted in the lower right corner of a keytop, to allow larger depictions for ergonomic reasons. For instance, on the key of the German T1 layout. In fact, on such layouts, the AltGr key is a “group selector” as defined in ISO/IEC 9995-2, the selection of level and group during the input of a character is specified in ISO/IEC 9995-2
5.
AltGr key
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AltGr is a modifier key found on some computer keyboards and is primarily used to type characters that are unusual for the locale of the keyboard layout, such as currency symbols and accented letters. On a typical, IBM-compatible PC keyboard, the AltGr key, in macOS, the Option key has functions similar to the AltGr key. AltGr is used similarly to the Shift key, it is held down when another key is struck in order to obtain a character other than the one that the latter normally produces, AltGr and Shift can also sometimes be combined to obtain yet another character. However, IBM states that AltGr is an abbreviation for alternate graphic, AltGr was originally introduced as a means to produce box-drawing characters, also known as pseudographics, in text user interfaces. These characters are, however, much less useful in graphical user interfaces, originally, US PC keyboards did not have an AltGr key because that was relevant to only non-US markets, they simply had left and right Alt keys. The right Alt key is usually an equivalent of the AltGr key because both the right Alt key and the AltGr key share the same scancode and are indistinguishable by software. However, on some keyboards it may not be the case, on compact keyboards like those of netbooks, the right Alt key may be missing altogether. For comparison, the US-International keyboard layout follows, note that the /~ key has been omitted, it doesnt produce any characters together with the AltGr key with or without Shift. It generally produces a \, although, applications receive a different keycode and can instead use the key to, for example. In UK & Ireland keyboard layouts, the two symbols printed on most keyboards which require the AltGr key are, € the Euro currency symbol. Either |, the bar or ¦, the broken vertical bar. Located on the /¬ key, to the left of 1. The other bar symbol is the symbol on the \ key immediately to the left of the Z key. The two latter symbols interchange places in UK keyboards according to the system in use. Using the AltGr key on Linux produces many foreign characters and international symbols, details are to be found at QWERTY § United Kingdom Layout. On South Slavic Latin keyboards, the letters and special characters are created using AltGr, On Belgian keyboards. Those shown in bold are printed on the keys, and common to all systems, ° ª º ₢ ° Some notes, The AltGr+C combination results in the symbol ₢ for the former Brazilian currency, the Brazilian cruzeiro. The AltGr+Q, AltGr+W, AltGr+E combinations are useful as a replacement for the /. key, which is physically absent on non-Brazilian keyboards
6.
Unicode
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Unicode is a computing industry standard for the consistent encoding, representation, and handling of text expressed in most of the worlds writing systems. As of June 2016, the most recent version is Unicode 9.0, the standard is maintained by the Unicode Consortium. Unicodes success at unifying character sets has led to its widespread, the standard has been implemented in many recent technologies, including modern operating systems, XML, Java, and the. NET Framework. Unicode can be implemented by different character encodings, the most commonly used encodings are UTF-8, UTF-16 and the now-obsolete UCS-2. UTF-8 uses one byte for any ASCII character, all of which have the same values in both UTF-8 and ASCII encoding, and up to four bytes for other characters. UCS-2 uses a 16-bit code unit for each character but cannot encode every character in the current Unicode standard, UTF-16 extends UCS-2, using one 16-bit unit for the characters that were representable in UCS-2 and two 16-bit units to handle each of the additional characters. Many traditional character encodings share a common problem in that they allow bilingual computer processing, Unicode, in intent, encodes the underlying characters—graphemes and grapheme-like units—rather than the variant glyphs for such characters. In the case of Chinese characters, this leads to controversies over distinguishing the underlying character from its variant glyphs. In text processing, Unicode takes the role of providing a unique code point—a number, in other words, Unicode represents a character in an abstract way and leaves the visual rendering to other software, such as a web browser or word processor. This simple aim becomes complicated, however, because of concessions made by Unicodes designers in the hope of encouraging a more rapid adoption of Unicode, the first 256 code points were made identical to the content of ISO-8859-1 so as to make it trivial to convert existing western text. For other examples, see duplicate characters in Unicode and he explained that he name Unicode is intended to suggest a unique, unified, universal encoding. In this document, entitled Unicode 88, Becker outlined a 16-bit character model, Unicode could be roughly described as wide-body ASCII that has been stretched to 16 bits to encompass the characters of all the worlds living languages. In a properly engineered design,16 bits per character are more than sufficient for this purpose, Unicode aims in the first instance at the characters published in modern text, whose number is undoubtedly far below 214 =16,384. By the end of 1990, most of the work on mapping existing character encoding standards had been completed, the Unicode Consortium was incorporated in California on January 3,1991, and in October 1991, the first volume of the Unicode standard was published. The second volume, covering Han ideographs, was published in June 1992, in 1996, a surrogate character mechanism was implemented in Unicode 2.0, so that Unicode was no longer restricted to 16 bits. The Microsoft TrueType specification version 1.0 from 1992 used the name Apple Unicode instead of Unicode for the Platform ID in the naming table, Unicode defines a codespace of 1,114,112 code points in the range 0hex to 10FFFFhex. Normally a Unicode code point is referred to by writing U+ followed by its hexadecimal number, for code points in the Basic Multilingual Plane, four digits are used, for code points outside the BMP, five or six digits are used, as required. Code points in Planes 1 through 16 are accessed as surrogate pairs in UTF-16, within each plane, characters are allocated within named blocks of related characters
7.
Option key
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The Option key is a modifier key present on Apple keyboards. It is located between the Control key and Command key on a typical Mac keyboard, there are two option keys on modern Mac desktop and notebook keyboards, one on each side of the space bar. Apple commonly uses the symbol U+2325 ⌥ option key to represent the Option key, from 1980 to 1984, on the Apple II family, this key was known as the closed apple key, and had a black line drawing of a filled-in apple on it. Since the 1990s, alt typically appears on the key, as well, for use as an Alt key with non-Mac software, such as Unix, however, the Option key in a Mac operating system functions differently from the Alt key under other Unix-like systems or Microsoft Windows. Most notably, it is not used to access menus or hotkeys, but is used as a modifier for other command codes. In this regard, it is akin to the AltGr key, the options available differ depending on the keyboard input locale that the user has selected. English keyboard input, ⌥ Option+a produces the å character, and ⌥ Option+4 produces the cent sign ¢, the Option key can also provide access to dead key functionality. For example, holding down ⌥ Option while pressing will create a highlighted grave accent which will be added to the letter if possible – so if an e is then pressed. If an r is pressed instead, the two characters are not compatible so the result is r, the highlighted orange keys show the accents available from the combination of the ⌥ Option key and the keyboard characters e i n u. The accent then can be applied to associated letters both lower and uppercase, the additional characters a Mac will produce are a combination of both the ⌥ Option key and the ⇧ Shift key pressed down together. With this combination pressed the keyboard will now produce a different set or a version of the previous set in some cases. The Option key is used in conjunction with special keys like Tab ↹, delete. For example, ⌥ Option+Return typically produces a break that is not interpreted as a paragraph break. The key is used to provide for alternative menu items. Examples, Safari, Finder - the Option key causes the Close Window menu item to switch to Close All Windows when pressed down, consequently, clicking a windows close box with the option key depressed invokes close all as well. This functionality is a de facto Macintosh standard and available in other programs. IPhoto - the rotate image button toggles between a right and a rotate left. The iPhoto example is an example of a control whose behavior is governed by a preference which is inverted by holding down the Option key
