Space-cadet keyboard
Encyclopedia
The space-cadet keyboard is a keyboard used on MIT Lisp machine
s and designed by Tom Knight, which inspired several still-current jargon terms in the field of computer science
and influenced the design of Emacs
. It was inspired by the Knight keyboard
(also developed by Tom Knight), which was developed for the Knight TV system, used with MIT's Incompatible Timesharing System
.
s: four keys for bucky bits ("control
", "meta
", "hyper", and "super
"; the latter two of which were introduced by this keyboard) and three 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 ("Λ") 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:
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 users were willing to memorise the command meanings of that many characters if it reduced typing time (this attitude shaped the interface of Emacs
). Other users, 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.
This keyboard included a Macro Key
which had limited application support. It also included four Roman Numeral keys (I, II, III, and IV) which allowed for easy interaction with lists of four or fewer choices.
Lisp machine
Lisp machines were general-purpose computers designed to efficiently run Lisp as their main software language. In a sense, they were the first commercial single-user workstations...
s and designed by Tom Knight, which inspired several still-current jargon terms in the field of computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
and influenced the design of Emacs
Emacs
Emacs is a class of text editors, usually characterized by their extensibility. GNU Emacs has over 1,000 commands. It also allows the user to combine these commands into macros to automate work.Development began in the mid-1970s and continues actively...
. It was inspired by the Knight keyboard
Knight keyboard
The Knight keyboard, designed by Tom Knight, was used with the MIT-AI lab's bitmapped display system. It was a precursor to the space-cadet keyboard....
(also developed by Tom Knight), which was developed for the Knight TV system, used with MIT's Incompatible Timesharing System
Incompatible Timesharing System
ITS, the Incompatible Timesharing System , was an early, revolutionary, and influential time-sharing operating system from MIT; it was developed principally by the Artificial Intelligence Laboratory at MIT, with some help from Project MAC.In addition to being technically influential ITS, the...
.
Description
This device was equipped with no fewer than seven modifier keyModifier key
In computing, a modifier key is a special key on a computer keyboard that modifies the normal action of another key when the two are pressed in combination....
s: four keys for bucky bits ("control
Control key
In computing, a Control key is a modifier key which, when pressed in conjunction with another key, will perform a special operation ; similar to the Shift key, the Control key rarely performs any function when pressed by itself...
", "meta
Meta key
The meta key is a special key on MIT keyboards, such as the space-cadet keyboard, and on Sun Microsystems keyboards, marked as a solid diamond.The key is similar in function to the Macintosh's command key, which has the same location...
", "hyper", and "super
Super key (keyboard button)
The Super key refers to several different keys throughout keyboard history. Originally the super key was a modifier key on the Space-cadet keyboard...
"; the latter two of which were introduced by this keyboard) and three shift keys, called "shift
Shift key
The shift key is a modifier key on a keyboard, used to type capital letters and other alternate "upper" characters. There are typically two shift keys, on the left and right sides of the row below the home row...
", "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 ("Λ") 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 (lowercase L) | |
| L (uppercase L) | |
| λ (lowercase lambda Lambda Lambda is the 11th letter of the Greek alphabet. In the system of Greek numerals lambda has a value of 30. Lambda is related to the Phoenician letter Lamed . Letters in other alphabets that stemmed from lambda include the Roman L and the Cyrillic letter El... ) |
|
| Λ (uppercase lambda) | |
| ⇔ (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
Computer keyboard
In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...
, 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 users were willing to memorise the command meanings of that many characters if it reduced typing time (this attitude shaped the interface of Emacs
Emacs
Emacs is a class of text editors, usually characterized by their extensibility. GNU Emacs has over 1,000 commands. It also allows the user to combine these commands into macros to automate work.Development began in the mid-1970s and continues actively...
). Other users, however, thought that so many bucky bits
Bucky bits
In computing, bucky bit in a binary representation of a character, is a bit that is set by pressing on a computer keyboard additional modifier key, other than ordinary shift key.-Overview:Setting a bucky bit changes the output character...
was overkill, and objected to this design on the grounds that such a keyboard can require three or four hands to operate.
This keyboard included a Macro Key
Macro key
The Macro key is a key that was featured on various early PC keyboards. It is typically found on the lower rows of the keyboard, either to the left of the "Z" key or to the right of the right Control key...
which had limited application support. It also included four Roman Numeral keys (I, II, III, and IV) which allowed for easy interaction with lists of four or fewer choices.
External links
- Space Cadet: a discussion of the keyboard, with illustrative pictures
- Jargon File entry on the space-cadet keyboard
- The Lisp keyboards: overview of the space-cadet and other famous Lisp keyboards