Editing Binary prefix (section)

==== Floppy disks ====
[[Floppy disks]] used [[List of floppy disk formats|a variety of formats]], and their capacities was usually specified with SI-like prefixes "K" and "M" with either decimal or binary meaning. The capacity of the disks was often specified without accounting for the internal [[disk formatting|formatting]] overhead, leading to more irregularities.

The early 8-inch diskette formats could contain less than a megabyte with the capacities of those devices specified in kilobytes, kilobits or megabits.<ref>{{Cite web |date=2012-03-07 |title=IBM100 – The Floppy Disk |url=http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/floppy/breakthroughs/ |archive-url=https://web.archive.org/web/20120403025215/http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/floppy/breakthroughs/ |url-status=dead |archive-date=3 April 2012 |access-date=2023-10-17 |website=www-03.ibm.com |language=en-US}}</ref><ref>{{cite magazine|magazine=Datamation |title=Disc Storage |date= May 1972 |pages=154, 162, 164 |quote= CDS 100 ... stores over 600 kilobits, Model 650 ... store 1.5 megabits ... }}</ref>

The 5.25-inch diskette sold with the [[PC AT|IBM PC AT]] could hold {{nowrap|1200 × 1024}} = {{val|1228800}} bytes, and thus was marketed as "1200&nbsp;KB" with the binary sense of "KB".<ref>{{Cite web |last=Brutman |first=Michael B. |date=July 8, 2001 |title=Working with Disks: An intro to floppy disks and floppy drives |url=http://brutmanlabs.org/Diskettes/Diskette_handling.html |website=Brutmanlabs |access-date=2024-02-19  |archive-date=2024-02-19  |archive-url=https://web.archive.org/web/20240219085221/http://brutmanlabs.org/Diskettes/Diskette_handling.html |url-status=dead }}</ref> However, the capacity was also quoted "1.2&nbsp;MB",<ref>{{Cite web |title=Floppy disk storage {{!}} IBM |url=https://www.ibm.com/history/floppy-disk#1970s+high-density+storage |access-date=2024-12-14 |website=www.ibm.com |language=en}}</ref> which was a hybrid decimal and binary notation, since the "M" meant 1000 × 1024. The precise value was {{val|1.2288|u=MB}} (decimal) or {{val|1.171875|u=MiB}} (binary).

The 5.25-inch [[Disk II|Apple Disk II]] had 256 bytes per sector, 13 sectors per track, 35 tracks per side, or a total capacity of {{val|116480}} bytes. It was later upgraded to 16 sectors per track, giving a total of {{nowrap|140 × 2<sup>10</sup>}} = {{val|143360}} bytes, which was described as "140KB" using the binary sense of "K".

The most recent version of the physical hardware, the "3.5-inch diskette" cartridge, had 720 512-byte blocks (single-sided). Since two blocks comprised 1024 bytes, the capacity was quoted "360&nbsp;KB", with the binary sense of "K". On the other hand, the quoted capacity of "1.44&nbsp;MB" of the High Density ("HD") version was again a hybrid decimal and binary notation, since it meant 1440 pairs of 512-byte sectors, or {{nowrap|1440 × 2<sup>10</sup>}} = {{val|1474560|u=bytes}}. Some operating systems displayed the capacity of those disks using the binary sense of "MB", as "1.4&nbsp;MB" (which would be {{nowrap|1.4 × 2<sup>20</sup>}} ≈ {{val|1468000|u=bytes}}). User complaints forced both Apple{{citation needed|date=August 2023}} and Microsoft<ref name="msoftxxxx" /> to issue support bulletins explaining the discrepancy.