ASCII, abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of technical limitations of computer systems at the time it was invented, ASCII has just 128 code points, of which only 95 are printable characters, which severely limited its scope. Modern computer systems have evolved to use Unicode, which has millions of code points, but the first 128 of these are the same as the ASCII set.
The keyboard for IBM PC-compatible computers is standardized. However, during the more than 30 years of PC architecture being frequently updated, many keyboard layout variations have been developed.
The technology of computer keyboards includes many elements. Many different keyboard technologies have been developed for consumer demands and optimized for industrial applications. The standard full-size (100%) computer alphanumeric keyboard typically uses 101 to 105 keys; keyboards integrated in laptop computers are typically less comprehensive.
The Model F was a series of computer keyboards produced mainly from 1981–1985 and in reduced volume until 1994 by IBM and later Lexmark. Its mechanical-key design consisted of a buckling spring over a capacitive PCB, similar to the later Model M keyboard that used a membrane in place of the PCB.
The Alt keyAlt on a computer keyboard is used to change (alternate) the function of other pressed keys. Thus, the Alt key is a modifier key, used in a similar fashion to the Shift key. For example, simply pressing A will type the letter 'a', but holding down the Alt key while pressing A will cause the computer to perform an Alt+A function, which varies from program to program. The international standard ISO/IEC 9995-2 calls it Alternate key. The key is located on either side of the space bar, but in non-US PC keyboard layouts, rather than a second Alt key, there is an 'Alt Gr' key to the right of the space bar. Both placements are in accordance with ISO/IEC 9995-2. With some keyboard mappings, the right Alt key can be reconfigured to function as an AltGr key although not engraved as such.
Model Mkeyboards are a group of computer keyboards designed and manufactured by IBM starting in 1985, and later by Lexmark International, Maxi Switch, and Unicomp. The keyboard's different variations have their own distinct characteristics, with the vast majority having a buckling-spring key design and uniform profile, swappable keycaps. Model M keyboards are notable among computer enthusiasts and frequent typists due to their durability, typing-feel consistency, and their tactile and auditory feedback.
Backspace is the keyboard key that in typewriters originally pushed the carriage one position backwards, and in modern computer systems typically moves the display cursor one position backwards, deletes the character at that position, and shifts back any text after that position by one character.
Kinesis is a company based near Seattle that offers computer keyboards with ergonomic designs as alternatives to the traditional keyboard design. Most widely known among these are the contoured Advantage line, which features recessed keys in two bucket-like hollows to allow the user's fingers to reach keys with less effort. Moreover, the keys are laid out in perfect vertical rows to avoid the need for lateral movements during typing. In addition, the modifiers such as enter, alt, backspace, control, etc. are moved to a central location so they can be pressed with the stronger thumbs rather than the pinky fingers.
Apple Inc. has designed and developed many external keyboard models for use with families of Apple computers, such as the Apple II, Mac, and iPad. The Magic Keyboard and Magic Keyboard with Numeric Keypad designed to be used via either Bluetooth and USB connectivity, and have integrated rechargeable batteries; The Smart Keyboard and Magic Keyboard accessories for iPads are designed to be directly attached to and powered by a host iPad. All current Apple keyboards utilize low-profile key designs, and common modifier keys.
Das Keyboard is a series of computer keyboards sold by Metadot Corporation, a software company located in Austin, Texas. Some models feature blank keycaps, made with the purpose of improving touch typing skills. The current iterations employ mechanical keyswitches manufactured by either Cherry or Greetech. "The keyboard" in German is "die Tastatur", not "das Tastatur".
PCD Maltron Ltd, trading as Maltron, is a manufacturer of ergonomic special-needs keyboards. It was founded by South African-born inventor Lillian Malt and manufacturer Stephen Hobday. Maltron specialises in making keyboards for the prevention and etiological treatment of repetitive strain injury.
The Fn key, short form for function, is a modifier key on many keyboards, especially on laptops, used in a compact layout to combine keys which are normally kept separate. It is typically found on laptops due to their keyboard size restrictions. It is also found on many full-sized "multimedia" keyboards as the F-Lock key. It is mainly for the purpose of changing display or audio settings quickly, such as brightness, contrast, or volume, and is held down in conjunction with the appropriate key to change the settings.
A keycap is a small cover of plastic, metal, or other material placed over the keyswitch of a computer keyboard. Keycaps are often illustrated to indicate the key function or alphanumeric character they correspond to. Early keyboards were manufactured with the keyswitch and keycap integrated in one unit; keycaps separate from the switch were introduced to facilitate the production of different keyboard layouts.
ISO/IEC 9995Information technology — Keyboard layouts for text and office systems is an ISO/IEC standard series defining layout principles for computer keyboards. It does not define specific layouts but provides the base for national and industry standards which define such layouts.
The delete control character is the last character in the ASCII repertoire, with the code 127. It is supposed to do nothing and was designed to erase incorrect characters on paper tape. It is denoted as ^? in caret notation and is U+007F in Unicode.
A computer keyboard is a peripheral input device modeled after the typewriter keyboard which uses an arrangement of buttons or keys to act as mechanical levers or electronic switches. Replacing early punched cards and paper tape technology, interaction via teleprinter-style keyboards have been the main input method for computers since the 1970s, supplemented by the computer mouse since the 1980s.
A keyboard layout is any specific physical, visual, or functional arrangement of the keys, legends, or key-meaning associations (respectively) of a computer keyboard, mobile phone, or other computer-controlled typographic keyboard.
PFU Limited is a Japanese information technology company jointly owned by Ricoh and Fujitsu. The company was formed by the merger of Panafacom and USAC Electronic Industrial in 1987.
The delete key is a button on most computer keyboards which is typically used to delete either the character ahead of or beneath the cursor, or the currently-selected object. The key is sometimes referred to as the "forward delete" key. This is because the backspace key also deletes characters, but to the left of the cursor. On many keyboards, such as most Apple keyboards, the key with the backspace function is also labelled "delete".
ECMA-23 is a standard for a bit-paired keyboard layout adopted in 1969 and revised in 1975. As a bit-paired layout, shifted keys correspond to toggling bits in the ASCII keycode. This is most visible in the digits on the top row, where shifting 6789 give &'(), and ;+, :* and -= are paired.
