Editing Byte (section)

=== History of the conflicting definitions ===
[[File:Binaryvdecimal.svg|thumb|right|275px|Percentage difference between decimal and binary interpretations of the unit prefixes grows with increasing storage size]]

{{quote|When I see a disk advertised as having a capacity of one megabyte, what is this telling me? There are three plausible answers, and I wonder if anybody knows which one is correct ... Now this is not a really vital issue, as there is just under 5% difference between the smallest and largest alternatives. Nevertheless, it would [be] nice to know what the standard measure is, or if there is one.|Allan D. Pratt of ''Small Computers in Libraries'', 1982<ref name="pratt19820412">{{Cite magazine |last=Pratt |first=Allan D. |date=1982-04-12 |title=Kwandary |url=https://books.google.com/books?id=YjAEAAAAMBAJ&lpg=PA3&pg=PA21#v=onepage&q&f=true |access-date=2025-03-16 |department=Letters to the Editor |magazine=InfoWorld |page=21}}</ref>}}

Contemporary{{efn|Through the 1970s there were machines with [[Decimal computer|decimal]] architectures.}} computer memory has a [[Binary addressing|binary architecture]] making a definition of memory units based on powers of 2 most practical. The use of the metric prefix ''kilo'' for binary multiples arose as a convenience, because {{val|1,024}} is approximately {{val|1,000}}.<ref name="IEC_Binary" /> This definition was popular in early decades of [[personal computing]], with products like the [[Tandon Corporation|Tandon]] 5{{1/4}}-inch [[double density|DD]] floppy format (holding {{val|368,640}} bytes) being advertised as "360&nbsp;KB", following the {{val|1,024}}-byte convention. It was not universal, however. The [[Shugart Associates|Shugart]] SA-400 5{{1/4}}-inch [[floppy disk]] held 109,375 bytes unformatted,<ref>{{cite web |url=http://www.swtpc.com/mholley/SA400/SA400_Index.htm |title=SA400 minifloppy |publisher=Swtpc.com |date=2013-08-14 |access-date=2014-03-25 |url-status=dead |archive-date=2014-05-27 |archive-url=https://web.archive.org/web/20140527094602/http://www.swtpc.com/mholley/SA400/SA400_Index.htm}}</ref> and was advertised as "110&nbsp;Kbyte", using the 1000 convention.<ref>{{cite web |title=Shugart Associates SA 400 minifloppy™ Disk Drive |url=http://www.swtpc.com/mholley/SA400/SA400_Datasheet.pdf |access-date=2011-06-24 |url-status=dead |archive-date=2011-06-08 |archive-url=https://web.archive.org/web/20110608195322/http://www.swtpc.com/mholley/SA400/SA400_Datasheet.pdf}}</ref> Likewise, the 8-inch [[Digital Equipment Corporation|DEC]] RX01 floppy (1975) held {{val|256,256}} bytes formatted, and was advertised as "256k".<ref>{{cite web |title=RXS/RX11 floppy disk system maintenance manual |publisher=Digital Equipment Corporation |location=Maynard, Massachusetts |date=May 1975 |url=http://bitsavers.org/pdf/dec/disc/rx01/EK-RX01-MM-002_maint_Dec76.pdf |access-date=2011-06-24 |archive-url=https://web.archive.org/web/20110423194129/http://www.bitsavers.org/pdf/dec/disc/rx01/EK-RX01-MM-002_maint_Dec76.pdf |archive-date=2011-04-23 |url-status=dead}}</ref> Some devices were advertised using a ''mixture'' of the two definitions: most notably, floppy disks advertised as "1.44&nbsp;MB" have an actual capacity of {{val|1,440|u=KiB}}, the equivalent of 1.47&nbsp;MB or 1.41&nbsp;MiB.

In 1995, the [[International Union of Pure and Applied Chemistry]]'s (IUPAC) Interdivisional Committee on Nomenclature and Symbols attempted to resolve this ambiguity by proposing a set of [[binary prefixes]] for the powers of 1024, including kibi (kilobinary), mebi (megabinary), and gibi (gigabinary).<ref>IUCr 1995 Report - IUPAC Interdivisional Committee on Nomenclature and Symbols (IDCNS) http://ww1.iucr.org/iucr-top/cexec/rep95/idcns.htm {{Webarchive|url=https://web.archive.org/web/20201219055254/http://ww1.iucr.org/iucr-top/cexec/rep95/idcns.htm |date=2020-12-19 }}</ref><ref>"Binary Prefix" University of Auckland Department of Computer Science https://wiki.cs.auckland.ac.nz/stageonewiki/index.php/Binary_prefix {{Webarchive|url=https://web.archive.org/web/20201016032232/https://wiki.cs.auckland.ac.nz/stageonewiki/index.php/Binary_prefix |date=2020-10-16 }}</ref>

In December 1998, the [[International Electrotechnical Commission|IEC]] addressed such multiple usages and definitions by adopting the IUPAC's proposed prefixes (kibi, mebi, gibi, etc.) to unambiguously denote powers of 1024.<ref>{{cite web|url=http://physics.nist.gov/cuu/Units/binary.html|title=Prefixes for binary multiples|author=[[National Institute of Standards and Technology]]|url-status=live|archive-url=https://web.archive.org/web/20070808000831/http://physics.nist.gov/cuu/Units/binary.html|archive-date=2007-08-08}} "In December 1998 the [[International Electrotechnical Commission]] (IEC) [...] approved as an IEC International Standard names and symbols for prefixes for binary multiples for use in the fields of data processing and data transmission."</ref> Thus one kibibyte (1&nbsp;KiB) is 1024<sup>1</sup> bytes = 1024 bytes, one mebibyte (1&nbsp;MiB) is 1024<sup>2</sup> bytes = {{val|1048576}} bytes, and so on.

In 1999, [[Donald Knuth]] suggested calling the kibibyte a "large kilobyte" (''KKB'').<ref name=kilobyte>{{cite web | title = What is a kilobyte? | url = http://www-cs-faculty.stanford.edu/~uno/news99.html | access-date = 2010-05-20 | archive-date = 2011-06-06 | archive-url = https://web.archive.org/web/20110606103601/http://www-cs-faculty.stanford.edu/~uno/news99.html | url-status = live }}</ref>