Space-cadet keyboard
From Free net encyclopedia
The Space-cadet keyboard is a legendary device used on MIT Lisp machines, which inspired several still-current jargon terms in the field of computer science and influenced the design of Emacs.
This device was equipped with no fewer than seven shift keys: four keys for bucky bits ("control", "meta", "hyper", and "super") and three like regular shift keys, called "shift", "top", and "front". Many keys had three symbols on them: a letter and a symbol on the top, and a Greek letter on the front. For example, the "L" key had an "L" and a two-way arrow on the top, and the Greek letter lambda on the front. By pressing this key with the right hand while playing an appropriate "chord" with the left hand on the shift keys, you could get the following results:
| Key pressed | Result |
|---|---|
| L | l (lowercase l) |
| shift-L | L (uppercase L) |
| front-L | λ (lowercase lambda) |
| front-shift-L | Λ (uppercase lambda) |
| top-L | ⇔ (two-way arrow) |
Each of these might, in addition, be typed with any combination of the "control", "meta", "hyper", and "super" keys. On this keyboard, it is possible to type over 8,000 different characters! This allowed the user to type very complicated mathematical text, and also to have thousands of single-character commands at their disposal. Many hackers were actually willing to memorise the command meanings of that many characters if it reduced typing time (this attitude shaped the interface of Emacs). Other hackers, however, thought that so many bucky bits was overkill, and objected to this design on the grounds that such a keyboard can require three or four hands to operate.
External links
- Space Cadet - A discussion of the keyboard, with illustrative pictures.
- Jargon File - Jargon File entry on the Space-cadet keyboard.