Chorded keyboard
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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. 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 to do something else (such as running a machine or manipulating a mouse). A secondary advantage is that it can be built into a device (such as a pocket-sized computer) that's too small to contain a normal sized keyboard. In the latter case, the alternative is to include a QWERTY keyboard that's too small to be used easily.
Chord keyboards usually can't be used by a "hunt and peck" method, so their use is restricted to applications where additional training can be justified.
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Principles of operation
As a crude example, each finger might control one key which corresponds to one bit in a byte, so that eight keys and eight fingers, one could enter any character in the ASCII set - if the user could remember the binary codes. Practical devices are easier to operate than this - but the same principles apply.
There are many different designs based on the same concept, some requiring only one hand for operation.
Due to the small number of keys required (the minimal design only needs one key for each finger), a chorded keyboard is easily adapted from a board to a grip such as the one on a bicycle handle bar. In this case it is referred to as a keyer rather than a keyboard because the keys are no longer mounted to a board. A keyer is a good replacement for a chorded keyboard in portable applications such as the wearable computer. On the other hand, the failure of touch typing to penetrate the world after a century of availability leads buyers to question their ability to remember the chordings necessary.
Some claim that, because the fingers don't need to move as far, it saves time and can be typed on faster than a regular keyboard. Others claim it is slower because a regular keyboard allows the next key to be pressed while the last key is still held down, but a chording keyboard requires each chord to be completely released before the next is pressed. Definitive numbers (in words per minute) are hard to find. This is probably also due to the many different designs available.
History
The earliest known chord keyboard was the "five-needle" telegraph, designed by Wheatstone and Cooke in 1836, in which any two of the five needles could point left or right to indicate letters on a grid. It was designed to be used by untrained operators (who would determine which keys to press by looking at the grid), and was not used where trained telegraph operators were available.
The first widespread use of a chord keyboard was in the stenotype machine used by court reporters, which was invented in 1868 and is still in use. But the output of the stenotype is a phonetic code that has to be transcribed later (usually by the same operator who produced the original output), rather than arbitrary text.
The five-bit Baudot telegraph code was originally designed to be used with a 5-key chord keyboard, with the operator forming the codes manually. But telegraph operators were already using typewriters with QWERTY keyboards to "copy" received messages, and at the time it made more sense to build a typewriter that could generate the codes automatically, rather than making them learn to use a new input device.
The Perkins Brailler, first manufactured in 1951, uses a 6-key chord keyboard (plus a spacebar) to produce Braille output.
Researchers at IBM investigated chord keyboards for both typewriters and computer data entry as early as 1959, with the idea that it might be faster than touch-typing if some chords were used to enter whole words or parts of words. One of their designs had 14 keys that were dimpled on the edges as well as the top, so one finger could press two adjacent keys for additional combinations. Their results were inconclusive, but research continued until at least 1978.
Douglas Engelbart began investigating a variety of input devices (including chord keyboards) as early as 1960, with results published in 1968. His goal was to be able to edit text while leaving one hand free to operate a mouse or light pen. His 5-key "keyset" was very similar to the one used in the original Baudot system. Photographs of the terminals used at his lab show that some users had the mouse on the left and the keyset on the right, while other users arranged them the other way around. A few users became very proficient with the mouse and keyset, but when development of the mouse moved to PARC, the keyset was left behind.
Commercial Devices
| Image:Microwriter.png |
One of the earliest commercial models was the six-button Microwriter, designed by Cy Endfield and first sold in 1980. Microwriting is the system of chord keying and is based on a set of mnemonics. It was designed only for right-handed use. Chris Rainey, the co-inventor of Microwriting, re-introduced Microwriting for PC and Palm PDAs with a standalone miniature chording keyboard called CyKey which caters for both left and right handed users. CyKey (pronounced PSYCHE.) is named after the Microwriter chord system's co-inventor Cy Endfield, who died in 1995 but the name also reflects its intuitive nature.
A modern example of a chorded keyboard is the GKOS keyboard which is intended for tiny tablet PCs and wireless mobile terminals.
"Multiambic" keyers for use with wearable computers were invented in Canada in the 1970s. Multiambic keyers are like chording keyboards but without the board, i.e. the keys are grouped in a cluster for being handheld rather than for sitting on a flat surface.
Chording keyboards are also used as input devices for the visually impaired (sometimes combined with a refreshable braille display). Such keyboards use a minimum of seven keys, where each key corresponds to an individual braille point, except one key which is used as a spacebar. In some applications, the spacebar is used to produce additional chords which enable the user to issue editing commands, such as moving the cursor, deleting words, ETC. Note that the number of points used in braille computing is not 6, but 8, as this allows the user, among other things, to distinguish between small and capital letters, as well as identify the position of the cursor. As a result, most newer chorded keyboards for braille input include at least nine keys.
References
Baldini, Thierry, Bootstrapping: Douglas Engelbart, Coevolution, and the Origins of Personal Computing (2000), Chapters 2 & 3, ISBN 0804737231, ISBN 0804738718
Rochester, Bequaert, and Sharp, "The Chord Keyboard", IEEE Computer, December 1976, p57-63
Engelbart and English, "A Research Center for Augmenting Human Intellect", AFIPS Conf. Proc., Vol 33, 1968 Fall Joint Computer Conference, p395-410
Lockhead and Klemmer, An Evaluation of an 8-Key Word-Writing Typewriter, IBM Research Report RC-180, IBM Research Center, Yorktown Heights, NY, Nov 1959.
Seibel, "Data Entry Devices and Procedures", in Human Engineering Guide to Equipment Design, Van Cott and Kinkade (Eds), 1963
See also
External links
Desktop chording keyboards
- CyKey one-handed chording keyboard
- PIC-Key, an open source one-handed chording keyboard (has references, links, and other information about chording keyboards in general)
- BAT keyboard — One-handed desktop chording keyboard
Hand-held/wearable chording keyers
- GKOS back-panel chording keyboard, an open standard for handheld devices
- Twiddler 2 one-handed chording keyboard/mouse
- Data Egg one-handed chording keyboard for handheld devices (prototype only)
- "Body-coupled FingeRing" — Wireless wearable chorded keyer
- Yet another one-hand keyboard — Hobbyist's attempts at a hand-held chording keyerru :аккордовая клавиатура