Path: utzoo!utgpu!attcan!uunet!husc6!rutgers!apple!kchen
From: kchen@Apple.COM (Kok Chen)
Newsgroups: comp.graphics
Subject: Re: the word "bitmap"
Message-ID: <23448@apple.Apple.COM>
Date: 6 Jan 89 17:48:04 GMT
References: <8568@pasteur.Berkeley.EDU> <375@avsd.UUCP>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 26

In article <375@avsd.UUCP> childers@avsd.UUCP (Richard Childers) writes:
>
>	bit - the smallest *meaningful* quanta in the data set referred to

The word BIT was first suggested by J. Tukey (yes, same one the Cooley-Tukey
FFT refers to) as a contraction for BINARY-digit.  For a reference to that,
refer to C.E. Shannon, "A mathematical theory of Communication," BSTJ, July
and October, 1948.

The modern rigorous definition is based on the unit used to denote
Entropy.  When the logarithm used is base-2, the unit is in BITS, if it
is base-e, the unit is NATS (Natural digits) and when it is base-10, it
is in DITS (Decimal digits).

So, please don't use BITS to denote units of information that a single
two-state flip-flop cannot represent.  You will only confuse Information
Theorists (i.e., add to Entropy :-).

If you really want to bastardize the mathematical definitions, you might
want to use BYTS :-) :-)  Afterall, on a DEC-10 (20), a byte is anything
between 1 bit and 36 bits.  Then, you can go ahead and coin the next
bastardization - a BYTMAP.  :-) :-)


Kok Chen			{decwrl,sun}!apple!kchen
Apple Computer, Inc.