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Chord Keyset
A keyset or chorded keyboard (also called a chorded keyset, ''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. The large number of combinations available from a small number of keys allows text or commands to be entered with one hand, leaving the other hand free. A secondary advantage is that it can be built into a device (such as a pocket-sized computer or a bicycle handlebar) that is too small to contain a normal-sized keyboard. A chorded keyboard minus the board, typically designed to be used while held in the hand, is called a keyer. Douglas Engelbart introduced the chorded keyset as a computer interface in 1968 at what is often called "The Mother of All Demos". Principles of operation Each key is mapped to a number and then can be mapped to a corresponding letter or command. By pressing two or more keys together the user c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microwriter
The Microwriter is a hand-held portable word-processor with a chording keyboard. First demonstrated in 1978, it was invented by UK-based, US-born film director Cy Endfield and his partner Chris Rainey and was marketed in the early 1980s by Microwriter Ltd, of Mitcham, Surrey, UK. By using a mnemonic alphabet, it was claimed to allow note-taking of up to 8,000 characters at an input rate averaging 1.5 times that of handwriting. The Microwriter MW4 Although there was an earlier unit with an LED display, the MW4 with an LCD was the most common unit. The 23 cm × 12 cm × 5 cm (9" x 5" x 2") device comprises: * A six-button chording keyboard. * A single line LCD. * An 8 bit CDP1802 microprocessor. * Complete Word processing software in ROM. * 16 kilobytes of RAM. * Rechargeable Nickel-cadmium batteries - sufficient to run the device for 30 hours. * Various interfaces (see below). This device is capable of allowing the user to enter and edit several pages o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telegraph
Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas pigeon post is not. Ancient signalling systems, although sometimes quite extensive and sophisticated as in China, were generally not capable of transmitting arbitrary text messages. Possible messages were fixed and predetermined and such systems are thus not true telegraphs. The earliest true telegraph put into widespread use was the optical telegraph of Claude Chappe, invented in the late 18th century. The system was used extensively in France, and European nations occupied by France, during the Napoleonic era. The electric telegraph started to replace the optical telegraph in the mid-19th century. It was first taken up in Britain in the form of the Cooke and Wheatstone telegraph, initially used mostly as an aid to railway signalling. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
