From keld@dkuug.dk Sun Apr 28 10:51:27 1991
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Date: Sun, 28 Apr 91 10:51:27 +0200
From: Keld J|rn Simonsen <keld@dkuug.dk>
Message-Id: <9104280851.AA19927@dkuug.dk>
To: wg15rin@dkuug.dk
Subject: new POSIX byte definition
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Here is a proposed new definition for byte in POSIX.2, based on
balloting objections and discussions with Greger.  Donn, see if my .1
references are valid and provide any other comments.  Keld, what does
RIN think of this?  The diffmark "1" is used for Draft 11.1.

Hal

 2.2.2.22  byte:

 An individually addressible unit of data storage that is equal to or       1
 larger than an octet, used to store a character or a portion of a          1
 character; see 2.2.2.24.                                                   1

 A byte is composed of a contiguous sequence of bits, the number of which   1
 is implementation defined.  The least significant bit is called the low-
 order bit; the most significant is called the high-order bit.
 [POSIX.1 {8}]

 NOTE:  This definition of byte is actually from the C Standard {7}
 because POSIX.1 {8} merely references it without copying the text.  It     1
 has been reworded slightly to clarify its intent without introducing the   1
 C Standard {7} terminology ``basic execution character set,'' which is     1
 inapplicable to this standard.  It deviates intentionally from the usage   1
 of byte in some other standards, where it is used as a synonym for octet   1
 (always eight bits).  On a POSIX.1 {8} system, a byte may be larger than   1
 eight bits so that it can be an integral portion of larger data objects    1
 that are not evenly divisible by eight bits (such as a 36-bit word that    1
 contains 4 9-bit bytes).                                                   1

 Rationale:

 This standard uses the term character to mean a sequence of one or more
 bytes representing a single graphic symbol, as defined in POSIX.1 {8}.     1
 The deviation in the exact text of the C Standard {7} definition for byte  1
 meets the intent of the C Standard {7} Rationale and the developers of     1
 POSIX.1 {8}, but clears up the ambiguity raised by the term basic          1
 execution character set, which is not defined in POSIX.1 {8}.  It is       1
 expected that a future version of POSIX.1 {8} will align with the text     1
 used here.  The octet-minimum requirement is merely a reflection of the    1
 {CHAR_BIT} value in POSIX.1 {8} and the C Standard {7}.                    1
                                                                            1