Alphanumeric keyboards include typewriters and computer keyboards. An alphanumeric keyboard is a device with many keys (usually marked with the letters of the alphabet, the numerical digits, and various extra keys.) Mechanical desktop typewriters, such as this Underwood Five, were long time standards of government agencies, newsrooms, and sales offices. ... A BlueGene supercomputer cabinet. ... A computer keyboard is a peripheral partially modeled after the typewriter keyboard. ... For other uses, see Alphabet (disambiguation). ... In mathematics and computer science, a numerical digit is a symbol, e. ...

The computer keyboard

After punch cards and paper tape, interaction via teletype-style keyboards became the main input device for computers. During the 1980s and 1990s almost all computers came equipped with them as the main form of interaction, and most users are familiar with using them. Typical QWERTY keyboard, photographed by User:eurleif. ... Typical QWERTY keyboard, photographed by User:eurleif. ... The punch card (or Hollerith card) is a recording medium for holding information for use by automated data processing machines. ... A teleprinter (teletypewriter, teletype or TTY) is a now largely obsolete electro-mechanical typewriter which can be used to communicate typed messages from point to point through a simple electrical communications channel, often just a pair of wires. ... The 1980s refers to the years from 1980 to 1989. ... For the band, see 1990s (band). ...

There are different types of keyboard technologies. There are several types of keyboard, usually differentiated by the switch technology employed in their operation. ...

The layout of keys on the modern-day English keyboard is called the QWERTY design, based on the most popular typewriter keyboard layout. This has been further extended to the standard 101-key PC keyboard layout, with the addition of cursor keys, a calculator-style numeric keypad, two groups of special function keys, a key for the Windows menu (on IBM and clones), and other modifier keys. In the late 1990s, computer manufacturers, such as Dell, add keys specifically related to the Internet and e-mail, but these have not become standard. Computers and other typing devices offer many different keyboard layouts for inputting data in different languages. ... The QWERTY keyboard layout used by Windows in the US QWERTY (pronounced ) is the most common modern-day keyboard layout on English-language computer and typewriter keyboards. ...

There is another kind of computer keyboard known as a chorded keyboard. These are rarely used. A Microwriter MW4 (circa 1980) A chorded keyboard (also called a chord keyboard or chording keyboard) is a computer input device that allows the user to enter characters or commands formed by pressing several keys together, like playing a chord on a piano. ...

Despite the development of alternative input devices such as the mouse, touch sensitive screens, pen devices, character recognition, voice recognition, and improvements in computer speed and memory size, the keyboard remains the most commonly used and most versatile device used for direct human input into computers.

See also

• Computer mouse
• Keyboard plaque
• GrOS keyboard
• extension cable