| 位元組的次方單位 | ||
|---|---|---|
| 十進制前綴 (SI) | ||
| 名字 | 縮寫 | 次方 |
| 千位元組 | KB | 103 |
| 百萬位元組 | MB | 106 |
| 吉位元組 | GB | 109 |
| 兆位元組 | TB | 1012 |
| 拍位元組 | PB | 1015 |
| 艾位元組 | EB | 1018 |
| 皆位元組 | ZB | 1021 |
| 佑位元組 | YB | 1024 |
| 二進制前綴 (IEC 60027-2) | ||
| 名字 | 縮寫 | 次方 |
| Kibibyte | KiB | 210 |
| Mebibyte | MiB | 220 |
| Gibibyte | GiB | 230 |
| Tebibyte | TiB | 240 |
| Pebibyte | PiB | 250 |
| Exbibyte | EiB | 260 |
| Zebibyte | ZiB | 270 |
| Yobibyte | YiB | 280 |
位元組（英語：Byte），通常用作計算機信息計量單位，不分數據類型。[1][2]是通信和數據存儲的概念。一個字節代表八個位元。從歷史的觀點上，「字節」表示用於編碼單個字符所需要的比特數量。歷史上字節長度曾基於硬件為1-48比特不等，最初通常使用6比特或9比特為一字節。今日標準以8比特作為一字節，因8為二進制整數。八個位元在一些規範（例如工業標準、計算機網絡、電信技術等）中常被稱為八位組。字節（Byte）可縮寫成B，例如MB表示Megabyte；位元（Bit）可縮寫成b，例如Mb表示Megabit。
歷史
字節一詞是Werner Buchholz於1956年6月在IBM Stretch計算機的早期設計階段發明的，該計算機的尋址為位和可變字段長度（VFL）指令，指令中編碼了字節大小。這是為了避免意外突變為比特而特意重寫的。
參考資料
- ↑ Blaauw, Gerrit Anne; Brooks, Jr., Frederick Phillips; Buchholz, Werner, 4: Natural Data Units, Buchholz, Werner (編), Planning a Computer System – Project Stretch (PDF), McGraw-Hill Book Company, Inc. / The Maple Press Company, York, PA.: 39–40, 1962 [2017-04-03], LCCN 61-10466,
[…] Terms used here to describe the structure imposed by the machine design, in addition to bit, are listed below.
Byte denotes a group of bits used to encode a character, or the number of bits transmitted in parallel to and from input-output units. A term other than character is used here because a given character may be represented in different applications by more than one code, and different codes may use different numbers of bits (i.e., different byte sizes). In input-output transmission the grouping of bits may be completely arbitrary and have no relation to actual characters. (The term is coined from bite, but respelled to avoid accidental mutation to bit.)
A word consists of the number of data bits transmitted in parallel from or to memory in one memory cycle. Word size is thus defined as a structural property of the memory. (The term catena was coined for this purpose by the designers of the Bull fr computer.)
Block refers to the number of words transmitted to or from an input-output unit in response to a single input-output instruction. Block size is a structural property of an input-output unit; it may have been fixed by the design or left to be varied by the program. […] - ↑ Bemer, Robert William, A proposal for a generalized card code of 256 characters, Communications of the ACM, 1959, 2 (9): 19–23, doi:10.1145/368424.368435
延伸閱讀
- Tafel, Hans Jörg. 寫於RWTH, Aachen, Germany. Einführung in die digitale Datenverarbeitung [Introduction to digital information processing]. Munich, Germany: Carl Hanser Verlag. 1971: 300. ISBN 3-446-10569-7 （德語）.
Byte = zusammengehörige Folge von i.a. neun Bits; davon sind acht Datenbits, das neunte ein Prüfbit
(NB. Defines a byte as a group of typically 9 bits; 8 data bits plus 1 parity bit.) - Programming with the PDP-10 Instruction Set (PDF). PDP-10 System Reference Manual 1. Digital Equipment Corporation (DEC). August 1969 [2017-04-05].
- Computer History Museum – Exhibits – Internet History – 1964: Internet History 1962 to 1992. Computer History Museum. 2017 [2015] [2017-04-03].
- Jaffer, Aubrey. Metric-Interchange-Format. 2011 [2008] [2017-04-03].
- Kozierok, Charles M. The TCP/IP Guide – Binary Information and Representation: Bits, Bytes, Nibbles, Octets and Characters – Byte versus Octet. 3.0. 2005-09-20 [2001] [2017-04-03].
參閲
- 八位元組（Octet）