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. 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 earliest known chord keyboard was part of the 'five-needle' telegraph operator station, 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. However, stenographers typically train for three years before reaching professional levels of speed and accuracy.

Many stenotype users can reach 300 words per minute. Currently stenotype machines hold the record for fastest word entry. Thad Starner from Georgia Institute of Technology and others published numerous studies showing that two-handed chorded text entry was faster and yielded fewer errors than on a QWERTY keyboard. These portable devices first became popular with the wearable computer movement in the 1980s. Practical devices generally use simpler chords for common characters ( e.g., Baudot), or may have ways to make it easier to remember the chords ( e.g., Microwriter ), but the same principles apply. Due to the small number of keys required, chording is easily adapted from a desktop to mobile environment. Since Engelbart introduced the keyset, several different designs have been developed based on similar concepts.Īs a crude example, each finger might control one key which corresponds to one bit in a byte, so that using seven keys and seven fingers, one could enter any character in the ASCII set-if the user could remember the binary codes. Unlike pressing a chord on a piano, the chord is recognized only after all the keys or mouse buttons are released.

If the user pressed keys 1 and 2 simultaneously, and then released the keys, 1 and 2 would be added to 3, and since C is the 3rd letter of the alphabet, and the letter 'c' appeared. The keys were mapped as follows: a = 1, b = 2, c = 3, d = 4, and so on. In Engelbart's original mapping, he used five keys: 1, 2, 4, 8, 16. By pressing two or more keys together the user can generate many combinations. An ergonomic chorded keyboard without the board is known as a keyer.Įach key is mapped to a number and then can be mapped to a corresponding letter or command.

G chord wireless numeric keypad