Bucky bit

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. A bucky bit allows to type a wider variety of characters and commands while maintaining a reasonable number of keys on a keyboard.

Examples of keys that could set bucky bits include: the alt key, control key, meta key, command key (<unicode|⌘>, a.k.a. the "open-apple key"), and option key (a.k.a. the "closed-apple key").

In ASCII, bucky bit is usually the 8th bit (also known as meta bit). However, in older character representations wider than 8 bits, more high bits could be used as bucky bits. In modern X Window, bucky bits are bits 18-23 of an event code.cite book
author=Raymond, Eric S.; Cameron, Debra; Rosenblatt, Bill
title=Learning GNU Emacs, 2nd Edition
publisher=O'Reilly
location=Sebastopol, CA
year=1996
pages=pp. 408-409
isbn=1-56592-152-6
url=http://books.google.com/books?id=a_lea3-w-1kC&pg=PA408&dq=bucky+keyboard&sig=9LABFYdvKHG8p7uJ20wNjDcjLO4#PPA408,M1]

History

The term was invented at Stanford and is based on Niklaus Wirth's nickname "Bucky". Niklaus Wirth was first to suggest an "EDIT" key to set the eighth bit of a 7-bit ASCII character sometime in 1964 or 1965. [cite book
title=The Jargon File
publisher=Xinware Corporation
pages=pp. 128
isbn=189745466X
url=http://books.google.com/books?id=tMiZKgIC4FgC&pg=PA216&dq=bucky+keyboard&sig=PLx7Kg9QaA2x85-PJXV_JQ_d9_k#PPA128,M1 ]

Bucky bits were used heavily on keyboards designed by Tom Knight in MIT, including space-cadet keyboards used on LISP machines. These could contain as many modifier keys as: "SHIFT", "CTRL", "META", "HYPER", "SUPER", "TOP", "FRONT", and "GREEK".cite book
author=Raymond, Eric S.; Cameron, Debra; Rosenblatt, Bill
title=Learning GNU Emacs, 2nd Edition
publisher=O'Reilly
location=Sebastopol, CA
year=1996
pages=pp. 408-409
isbn=1-56592-152-6
url=http://books.google.com/books?id=a_lea3-w-1kC&pg=PA408&dq=bucky+keyboard&sig=9LABFYdvKHG8p7uJ20wNjDcjLO4#PPA408,M1]

ee also

*ASCII
*Space-cadet keyboard
*Modifier key

References

External links

* [http://sicp.ai.mit.edu/Fall-2003/manuals/scheme-7.5.5/doc/scheme_6.html MIT Scheme reference]