Earlier models were developed separately by individuals such as Royal Earl House and Frederick G.

The teleprinter, in its more contemporary form, was developed from 1907 to 1910 by American mechanical engineer Charles Krum and his son Howard, with early contributions by electrical engineer Frank Pearne. It was through such devices that modern computer keyboards inherited their layouts.Īs early as the 1870s, teleprinter-like devices were used to simultaneously type and transmit stock market text data from the keyboard across telegraph lines to stock ticker machines to be immediately copied and displayed onto ticker tape. While typewriters are the definitive ancestor of all key-based text entry devices, the computer keyboard as a device for electromechanical data entry and communication derives largely from the utility of two devices: teleprinters (or teletypes) and keypunches.

3 Non-standard layout and special-use types.

In normal usage, the keyboard is used as a text entry interface for typing text, numbers, and symbols into application software such as a word processor, web browser or social media app. In a modern computer, the interpretation of key presses is generally left to the software: the information sent to the computer, the scan code, tells it only which key (or keys) on which row and column, was pressed or released.

While most keyboard keys produce letters, numbers or symbols ( characters), other keys or simultaneous key presses can prompt the computer to execute system commands, such as such as the Control-Alt-Delete combination used with Microsoft Windows. However, producing some symbols may require pressing and holding several keys simultaneously or in sequence. Keyboard keys (buttons) typically have a set of characters engraved or printed on them, and each press of a key typically corresponds to a single written symbol. 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 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.

Image of keyboard keys