ビット
ビット (bit) は、
1ビットの
ビットの
歴史 [編集 ]
データを
ラルフ・ハートレーは、1928
物理 的 表現 [編集 ]
ビットは、
ビットはいくつかの
伝送 と処理 [編集 ]
ビットは、シリアル
保存 [編集 ]
ジャカード
1950
DRAMなどの
単位 と記号 [編集 ]
ビットは、
複数 のビットを表 す単位 [編集 ]
ビットの | ||||||
---|---|---|---|---|---|---|
SI |
2 (IEC 60027-2による) | |||||
SI |
||||||
キロビット | kbit | 103 | 210 | キビビット | Kibit | 210 |
メガビット | Mbit | 106 | 220 | メビビット | Mibit | 220 |
ギガビット | Gbit | 109 | 230 | ギビビット | Gibit | 230 |
テラビット | Tbit | 1012 | 240 | テビビット | Tibit | 240 |
ペタビット | Pbit | 1015 | 250 | ペビビット | Pibit | 250 |
エクサビット | Ebit | 1018 | 260 | エクスビビット | Eibit | 260 |
ゼタビット | Zbit | 1021 | 270 | ゼビビット | Zibit | 270 |
ヨタビット | Ybit | 1024 | 280 | ヨビビット | Yibit | 280 |
情報 容量 と情報 圧縮 [編集 ]
ストレージの
ビット単位 の操作 [編集 ]
1980
バイトやワードといった
関連 項目 [編集 ]
整数 型 - プリミティブ
型 量子 ビット- ビットストリーム
- ボー
二進法 三 進 法 - バイト (byte)
- 8ビット
- オクテット (コンピュータ)
- キャラクタ (コンピュータ)
- ワード
- シャノン (
単位 ) - ナット (単位 ) - ハートレー (単位 ) 情報 量 - データ
量 の比較
脚注 [編集 ]
- ^ Coded Character Sets, History and Development (1 ed.). Addison-Wesley Publishing Company, Inc.. (1980). p. x. ISBN 978-0-201-14460-4. LCCN 77--90165. オリジナルの2016-11-18
時点 におけるアーカイブ。 2016年 5月 22日 閲覧 。 [1] - ^ Understanding Information Transmission, (2006)
- ^ Digital Communications, (2006)
- ^ IEEE Std 260.1-2004
- ^ “Units: B”. 2016
年 5月 4日 時点 のオリジナルよりアーカイブ。2019年 10月 1日 閲覧 。 - ^ Information theory and coding. McGraw-Hill. (1963)
- ^ a b “A Mathematical Theory of Communication”. Bell System Technical Journal 27 (3): 379–423. (July 1948). doi:10.1002/j.1538-7305.1948.tb01338.x. hdl:11858/00-001M-0000-002C-4314-2. オリジナルの1998-07-15
時点 におけるアーカイブ。 . "The choice of a logarithmic base corresponds to the choice of a unit for measuring information. If the base 2 is used the resulting units may be called binary digits, or more briefly bits, a word suggested by J. W. Tukey." - ^ “A Mathematical Theory of Communication”. Bell System Technical Journal 27 (4): 623–666. (October 1948). doi:10.1002/j.1538-7305.1948.tb00917.x. hdl:11858/00-001M-0000-002C-4314-2.
- ^ A Mathematical Theory of Communication. University of Illinois Press. (1949). ISBN 0-252-72548-4. オリジナルの1998-07-15
時点 におけるアーカイブ。 - ^ “Instrumental analysis”. Bulletin of the American Mathematical Society 42 (10): 649–669. (1936). doi:10.1090/S0002-9904-1936-06390-1. オリジナルの2014-10-06
時点 におけるアーカイブ。 . - ^ National Institute of Standards and Technology (2008), Guide for the Use of the International System of Units. Online version. Archived 3 June 2016 at the Wayback Machine.
- ^ “Why is a byte 8 bits? Or is it?”. Computer History Vignettes (2000
年 8月 8日 ). 2017年 4月 3日 時点 のオリジナルよりアーカイブ。2017年 4月 3日 閲覧 。 “[…] With IBM's STRETCH computer as background, handling 64-character words divisible into groups of 8 (I designed the character set for it, under the guidance of Dr. Werner Buchholz, the man who DID coin the term "byte" for an 8-bit grouping). […] The IBM 360 used 8-bit characters, although not ASCII directly. Thus Buchholz's "byte" caught on everywhere. I myself did not like the name for many reasons. […]” - ^ “7. The Shift Matrix”. The Link System. IBM. (1956-06-11). pp. 5–6. Stretch Memo No. 39G. オリジナルの2017-04-04
時点 におけるアーカイブ。 2016年 4月 4日 閲覧 . "[…] Most important, from the point of view of editing, will be the ability to handle any characters or digits, from 1 to 6 bits long […] the Shift Matrix to be used to convert a 60-bit word, coming from Memory in parallel, into characters, or "bytes" as we have called them, to be sent to the Adder serially. The 60 bits are dumped into magnetic cores on six different levels. Thus, if a 1 comes out of position 9, it appears in all six cores underneath. […] The Adder may accept all or only some of the bits. […] Assume that it is desired to operate on 4 bit decimal digits, starting at the right. The 0-diagonal is pulsed first, sending out the six bits 0 to 5, of which the Adder accepts only the first four (0-3). Bits 4 and 5 are ignored. Next, the 4 diagonal is pulsed. This sends out bits 4 to 9, of which the last two are again ignored, and so on. […] It is just as easy to use all six bits in alphanumeric work, or to handle bytes of only one bit for logical analysis, or to offset the bytes by any number of bits. […]" - ^ “The Word "Byte" Comes of Age...”. Byte Magazine 2 (2): 144. (February 1977) . "[…] The first reference found in the files was contained in an internal memo written in June 1956 during the early days of developing Stretch. A byte was described as consisting of any number of parallel bits from one to six. Thus a byte was assumed to have a length appropriate for the occasion. Its first use was in the context of the input-output equipment of the 1950s, which handled six bits at a time. The possibility of going to 8 bit bytes was considered in August 1956 and incorporated in the design of Stretch shortly thereafter. The first published reference to the term occurred in 1959 in a paper "Processing Data in Bits and Pieces" by G A Blaauw, F P Brooks Jr and W Buchholz in the IRE Transactions on Electronic Computers, June 1959, page 121. The notions of that paper were elaborated in Chapter 4 of Planning a Computer System (Project Stretch), edited by W Buchholz, McGraw-Hill Book Company (1962). The rationale for coining the term was explained there on page 40 as follows:
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 (ie, 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.)
System/360 took over many of the Stretch concepts, including the basic byte and word sizes, which are powers of 2. For economy, however, the byte size was fixed at the 8 bit maximum, and addressing at the bit level was replaced by byte addressing. […]" - ^ Buchholz-1962Buchholz, Werner, ed. (1962), “Chapter 4: Natural Data Units” (PDF), Planning a Computer System – Project Stretch, McGraw-Hill Book Company, Inc. / The Maple Press Company, York, PA., pp. 39–40, LCCN 61--10466, オリジナルの2017-04-03
時点 におけるアーカイブ。 2017年 4月 3日 閲覧 。 - ^ “A proposal for a generalized card code of 256 characters”. Communications of the ACM 2 (9): 19–23. (1959). doi:10.1145/368424.368435.
- ^ a b Information in small bits Information in Small Bits is a book produced as part of a non-profit outreach project of the IEEE Information Theory Society. The book introduces Claude Shannon and basic concepts of Information Theory to children 8+ using relatable cartoon stories and problem-solving activities.
外部 リンク[編集 ]
- Bit Calculator – a tool providing conversions between bit, byte, kilobit, kilobyte, megabit, megabyte, gigabit, gigabyte
- BitXByteConverter – a tool for computing file sizes, storage capacity, and digital information in various units
- ASCII24 - アスキー デジタル
用語 辞典 - ビット - e-Words ビット
- @IT:Insider's Computer Dictionary [bit]
- Microsoft Terminology