List of floppy disk formats - AbsoluteAstronomy.com

This is a list of different floppy disk

Floppy disk

A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...

formats.

IBM and DEC 8-inch formats

This is a list of 8-inch floppy disk

Floppy disk

A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...

ette formats as introduced by IBM

IBM

International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

and DEC

Digital Equipment Corporation

Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...

Revolutions per minute

Revolutions per minute is a measure of the frequency of a rotation. It annotates the number of full rotations completed in one minute around a fixed axis...

)
| align="center" | 90
| align="center" | 360
| align="center" | 360
| align="center" | 360
| align="center" | 360
| align="center" | 360
| align="center" | 360
| align="center" | 360
| align="center" | 360
|-
! bgcolor="#C0C0C0" rowspan="2" | Controller
! bgcolor="#C0C0C0" | Transfer rate (kbit/s)
| align="center" | 33.333
| align="center" | 250
| align="center" | 250
| align="center" | 250
| align="center" | 500
| align="center" | 500
| align="center" | 500
| align="center" | 500
| align="center" | 500
|-
! bgcolor="#C0C0C0" | Encoding
| align="center" | FM
| align="center" | FM
| align="center" | FM
| align="center" | FM
| align="center" | FM
| align="center" | FM
| align="center" | MFM

Modified Frequency Modulation

Modified Frequency Modulation, commonly MFM, is a line coding scheme used to encode the actual data-bits on most floppy disk formats, hardware examples include Amiga, most CP/M machines as well as IBM PC compatibles. Early hard disk drives also used this coding.MFM is a modification to the original...

Byte

The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...

s)
| align="center" | 128
| align="center" | 128
| align="center" | 128
| align="center" | 128
| align="center" | (side 0:128
1:256)
| align="center" | (side 0:128
1:256)
| align="center" | (side 0:128
1:256)
|-
! bgcolor="#C0C0C0" | Size (bytes)
| align="center" | N/A
| align="center" | N/A
| align="center" | 3,328
| align="center" | 3,328
| align="center" | 6,656
| align="center" | 6,656
| align="center" | 9,984
| align="center" | 9,984
| align="center" | 9,984
|-
! bgcolor="#C0C0C0" rowspan="4" | Geometry of
remaining cylinders
! bgcolor="#C0C0C0" | Usable cylinders
| align="center" | 32
| align="center" | 73
| align="center" | 74
| align="center" | 74
| align="center" | 74
| align="center" | 74
| align="center" | 74
| align="center" | 74
| align="center" | 74
|-
! bgcolor="#C0C0C0" | Sectors per track
| align="center" | 8
| align="center" | 26
| align="center" | 15
| align="center" | 8
| align="center" | 26
| align="center" | 15
| align="center" | 26
| align="center" | 15
| align="center" | 8
|-
! bgcolor="#C0C0C0" | Number of sectors
| align="center" | 256
| align="center" | 1,898
| align="center" | 1,110
| align="center" | 592
| align="center" | 3,848
| align="center" | 2,220
| align="center" | 3,848
| align="center" | 2,220
| align="center" | 1,184
|-
! bgcolor="#C0C0C0" | Sector size (bytes)
| align="center" | 319
| align="center" | 128
| align="center" | 256
| align="center" | 512
| align="center" | 128
| align="center" | 256
| align="center" | 256
| align="center" | 512
| align="center" | 1024
|-
! bgcolor="#C0C0C0" rowspan="2" | Capacity
! bgcolor="#C0C0C0" | Formatted (bytes)
| align="center" | 81,664
| align="center" | 242,944
| align="center" | 284,160
| align="center" | 303,104
| align="center" | 492,544
| align="center" | 568,320
| align="center" | 985,088
| align="center" | 1,136,640
| align="center" | 1,212,416
|-
! bgcolor="#C0C0C0" | Formatted (KiB)
| align="center" | 79.75
| align="center" | 237.25
| align="center" | 277.5
| align="center" | 296
| align="center" | 481
| align="center" | 555
| align="center" | 962
| align="center" | 1,110
| align="center" | 1,184
|-
| colspan=11|SS = Single Sided; DS = Double Sided; SD = Single Density; DD = Double Density; N/A = Not Applicable; TPI = Tracks per Inch; BPI = Bits per Inch>

In addition, Digital Equipment Corporation

Digital Equipment Corporation

Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...

Revolutions per minute

Revolutions per minute is a measure of the frequency of a rotation. It annotates the number of full rotations completed in one minute around a fixed axis...

Byte

Other manufacturers

Disk	Form factor	Year introduced	Formatted Storage capacity (in KiB Kibibyte The kibibyte is a multiple of the unit byte for quantities of digital information. The binary prefix kibi means 1024; therefore, 1 kibibyte is . The unit symbol for the kibibyte is KiB. The unit was established by the International Electrotechnical Commission in 1999 and has been accepted for use... = 1024 bytes if not stated)	Marketed capacity¹
IBM 23FD	8-inch	1971	79.7	?
Memorex 650	8-inch	1972	175 kB Kilobyte The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...	1.5 megabit Megabit The megabit is a multiple of the unit bit for digital information or computer storage. The prefix mega is defined in the International System of Units as a multiplier of 106 , and therefore... [unformatted]
IBM 33FD / Shugart 901	8-inch - SSSD	1973	237.25	3.1 Mbits unformatted
IBM 43FD / Shugart 850	8-inch - DSSD	1976	500.5	6.2 Mbits unformatted
Shugart SA 400	5¼-inch (35 track)	1976	89.6 kB	110 kB
IBM 53FD / Shugart 850	8-inch DSDD	1977	980 (CP/M CP/M CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc... ) - 1200 (MS-DOS FAT File Allocation Table File Allocation Table is a computer file system architecture now widely used on many computer systems and most memory cards, such as those used with digital cameras. FAT file systems are commonly found on floppy disks, flash memory cards, digital cameras, and many other portable devices because of... )	1.2 MB
	5¼-inch DD	1978	360 or 800	360 KB
HP single sided	3½-inch	1982	280	264 kB
	3-inch	1982	360	?
	3½-inch (DD at release)	1984	720	720 KB
	5¼-inch QD		720	720 KB
	5¼-inch HD	1982 YE Data YD380	1,182,720 bytes	1.2 MB
	3-inch DD	1984	720	?
Mitsumi Quick Disk	3-inch	1985	128 to 256	?
	2-inch	1985	720	?
	5¼-inch Perpendicular	1986	100 MB	?
	3½-inch HD	1987	1440	1.44 MB
	3½-inch ED	1987	2880	2.88 MB
Floptical Floptical Floptical refers to a type of disk drive that combines magnetic and optical technologies to store large amounts of data on media similar to 3½-inch floppy disks. The name is a portmanteau of the words 'floppy' and 'optical'... (LS)	3½-inch	1991	21000	21 MB
LS-120	3½-inch	1996	120.375 MB	120 MB
LS-240	3½-inch	1997	240.75 MB	240 MB
	3½-inch HiFD	1998/99	150/200 MB	150/200 MB
Abbreviations:
¹ The formatted capacities of floppy disks is less than the unformatted capacity, which does not include the sector and track headings required for use of the disk. The amount of capacity lost to this overhead depends on the application of the drive and is beyond the manufacturer's control. Mixtures of decimal SI-style prefixes and binary record lengths required care to properly calculate total capacity. Unlike semiconductor memory, which doubled in size each time an address pin was added to an integrated circuit package and so naturally favored counts that were powers of two, the capacity of a disk drive was the product of the sector size, number of sectors per track, number of tracks per side, (and in hard drives, the number of disk platters in the drive). Individual formatted sector lengths are arbitrarily set as powers of 2 (256 bytes, 512 bytes, etc.), and disk capacity is naturally calculated as multiples of the sector size. This led to an impure combination of decimal multiples of sectors and binary sector sizes. The "1.44 MB" value for the 3½-inch HD floppies is the most widely known example; where the "M" prefix is peculiar to the context of the disk drive and represents neither a decimal million nor a mebibyte Mebibyte The mebibyte is a multiple of the unit byte for digital information. The binary prefix mebi means 220, therefore 1 mebibyte is . The unit symbol for the mebibyte is MiB. The unit was established by the International Electrotechnical Commission in 2000 and has been accepted for use by all major... 2 ^20. See Ultimate capacity and speed.
Dates and capacities marked ? are of unclear origin and need source information; other listed capacities refer to: Formatted Storage Capacity is total size of all sectors on the disk: For 8-inch see Table of 8-inch floppy formats IBM 8-inch formats. Note that spare, hidden and otherwise reserved sectors are included in this number. For 5¼- and 3½-inch capacities quoted are from subsystem or system vendor statements. Marketed Capacity is the capacity, typically unformatted, by the original media OEM vendor or in the case of IBM media, the first OEM thereafter. Other formats may get more or less capacity from the same drives and disks.

Physical composition

Floppy disk physical characteristics
(capacity and tracks are nominal, per side)
Size	Density	Tracks	TPI	Coercivity	Capacity
3½ in	single	40	67.5	600 Oe	250 KB
	double	80	135	600 Oe	500 KB
	high	80	135	750 Oe	1000 KB
	extended	80	135	900 Oe	2000 KB
5¼ in	single/double	40	48	300 Oe	250 KB
	quad	80	96	300 Oe	500 KB
	high	80	96	600 Oe	750 KB
8 in	single/double	77	48	300 Oe	1000 KB

Known disk logical formats

Throughout the 1970s and 1980s, many different logical disk formats were used, depending on the hardware platform.

Common floppy disk formats, logical characteristics by platform
Platform	Size	Density	Bytes/ sector	Sectors/ track	Tracks/ side	Sides	Capacity	RPM	Encoding
IBM IBM International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas... (3740 format)	8 in	single	128	26	74	1	250.25 KiB	360	FM
Acorn Acorn The acorn, or oak nut, is the nut of the oaks and their close relatives . It usually contains a single seed , enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns vary from 1–6 cm long and 0.8–4 cm broad...	5¼ in	single	256	10	40	1	100 KiB	300	FM
		single	256	10	80	1	200 KiB		FM
		double	256	16	40	1	160 KiB		MFM
					80	1	320 KiB
					80	2	640 KiB
	3½ in (90 mm)	double	256	16	80	2	640 KiB	300	MFM
		double	1024	5			800 KiB
		high	1024	10			1600 KiB
Apple II Apple II The Apple II is an 8-bit home computer, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977...	5¼ in	double	256	13	35	1	113.75 KiB	300	GCR Group Code Recording In computer science, group code recording refers to several distinct but related encoding methods for magnetic media. The first, used in 6250 cpi magnetic tape, is an error-correcting code combined with a run length limited encoding scheme...
				13		2	227.50 KiB
				16		1	140 KiB
				16		2	280 KiB
	3½ in (90 mm)	double	512	Variable (8-12)	80	1	400 KiB	ZCAV Zone bit recording Zone Bit Recording is used by disk drives to store more sectors per track on outer tracks than on inner tracks. It is also called Zone Constant Angular Velocity ....	GCR
		double	512	Variable (8-12)	80	2	800 KiB		GCR
		high	512	18	80	2	1440 KiB	300	MFM
Apple Macintosh Macintosh The Macintosh , or Mac, is a series of several lines of personal computers designed, developed, and marketed by Apple Inc. The first Macintosh was introduced by Apple's then-chairman Steve Jobs on January 24, 1984; it was the first commercially successful personal computer to feature a mouse and a...	3½ in (90 mm)	double	512	Variable (8-12)	80	1	400 KiB	ZCAV	GCR
		double	512	Variable (8-12)	80	2	800 KiB	ZCAV	GCR
		high	512	18	80	2	1440 KiB	300	MFM
Atari 8-bit	5¼ in	single	128	18	40	1	90 KiB	288	FM
		enhanced	128	26			127 KiB		MFM
		double	256	18			180 KiB		MFM
Commodore Commodore International Commodore is the commonly used name for Commodore Business Machines , the U.S.-based home computer manufacturer and electronics manufacturer headquartered in West Chester, Pennsylvania, which also housed Commodore's corporate parent company, Commodore International Limited... (8-bit)	5¼ in	double	256	Variable (17-21)	35	1	170 KiB	300	GCR
	5¼ in	double	256	Variable (17-21)	35	2	340 KiB	300	GCR
Commodore Amiga Amiga The Amiga is a family of personal computers that was sold by Commodore in the 1980s and 1990s. The first model was launched in 1985 as a high-end home computer and became popular for its graphical, audio and multi-tasking abilities...	3½ in (90 mm)	double	512	11	80	2	880 KiB	300	MFM
	3½ in (90 mm)	high	512	22	80	2	1760 KiB	150	MFM
IBM PC IBM PC The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981... compatibles	8 in	single	128	26	77	1	250 KiB	360	MFM
		single	128	26	77	2	500 KiB
		double	1024	8	77	2	1232 KiB
	5¼ in	double	512	8/9	40	1	160/180 KiB	300	MFM
		double		8/9	40	2	320/360 KiB	300
		high		15	80	2	1200 KiB	360
	3½ in (90 mm)	double	512	9	80	2	720 KiB	300	MFM
		high		18	80		1440 KiB
				21	80		1680 KiB
				21	82		1720 KiB
		extended		36	80		2880 KiB
NEC NEC , a Japanese multinational IT company, has its headquarters in Minato, Tokyo, Japan. NEC, part of the Sumitomo Group, provides information technology and network solutions to business enterprises, communications services providers and government.... PC98	8 in	single	128	26	77	1	250.25 KiB	360	FM
	8 in	double	1024	8	77	2	1232 KiB	360	MFM
	5¼ in	double	512	8/9	80	2	640/720 KiB	360	MFM
		high	512	15	80		1200 KiB
		high	1024	8	77(80)		1232(1280) KiB
	3½ in (90 mm)	double	512	8/9	80	2	640/720 KiB	360	MFM
		high	512	15	80		1200 KiB
			1024	8	77(80)		1232(1280) KiB
			512	18	80		1440 KiB	300
SHARP Sharp Corporation is a Japanese multinational corporation that designs and manufactures electronic products. Headquartered in Abeno-ku, Osaka, Japan, Sharp employs more than 55,580 people worldwide as of June 2011. The company was founded in September 1912 and takes its name from one of its founder's first... X68000 Sharp X68000 The Sharp X68000, often referred to as the X68k, is a home computer released only in Japan by the Sharp Corporation. The first model was released in 1987, with a 10 MHz Motorola 68000 CPU, 1 MB of RAM and no hard drive; the last model was released in 1993 with a 25 MHz Motorola 68030...	5¼ in	high	1024	8	77	2	1232 KiB	360	MFM
	3½ in (90 mm)	high	1024	8	77	2	1232 KiB	360	MFM

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.