Chorded keyboard

Lore & Background

The earliest known chord keyboard was part of the five-needle telegraph operator station designed by Wheatstone and Cooke in 1836, where any two of five needles could point left or right to indicate letters on a grid. The first widespread use was the stenotype machine for court reporters, invented in 1868 and still in use. In 1874, the five-bit Baudot telegraph code and a matching 5-key chord keyboard were designed, optimized for speed and low wear. Braille writers, such as the Hall Braille Writer (1892) and the Perkins Brailler (1951), also use chord keyboards with 6 keys to produce braille output. After World War II, postal sorting offices researched chordic solutions. Researchers at IBM investigated chord keyboards from 1959 onward, and Doug Engelbart introduced a five-key keyset with a mouse in his famous 1968 demonstration. In the early 1980s, Philips Research labs studied a hexagonal key grid for telephone text entry, but it had force issues.

Reader's Guide

The chorded keyboard's significance lies in its ability to generate many characters from few keys, making it suitable for one-handed use and compact devices. Engelbart's 1968 demonstration introduced it as a computer interface alongside the mouse, and his team at SRI became proficient with it. Users at Xerox PARC continued experimenting with keysets in the early 1980s on the Xerox Star and Alto workstations. The article notes that Steve Jobs decided against incorporating the chorded keyset into the Apple Macintosh. Studies by Thad Starner and others showed two-handed chorded text entry could be faster and yield fewer errors than QWERTY, though stenotype machines hold the record for fastest word entry at 300 words per minute, requiring about three years of training. Practical devices often use simpler chords for common characters (e.g., Baudot) or memory aids (e.g., Microwriter). The chorded keyboard's legacy includes its use in wearable computers in the 1980s and ongoing research into efficient text entry.

Did You Know?

• Douglas Engelbart introduced the chorded keyset as a computer interface in 1968 at 'The Mother of All Demos'.
• The Perkins Brailler, first manufactured in 1951, uses a 6-key chord keyboard to produce braille output.
• Stenotype machines can reach 300 words per minute, but users typically train for three years to achieve professional speed.