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Floppy disk

Updated: Wikipedia source

Floppy disk

A floppy disk, diskette, or floppy diskette (casually known as a floppy or a disk) is a type of disk storage made from a thin, flexible disk coated with a magnetic storage medium. It is enclosed in a square or nearly square plastic shell lined with fabric to help remove dust from the spinning disk. Floppy disks store digital data, which can be read or written when inserted into a floppy disk drive (FDD) connected to or built into a computer or other device. The three most popular formats of floppy disks (and their drives) are the 8-inch, 5¼-inch, and 3½-inch versions. The first floppy disks, invented and made by IBM in 1971, had a disk diameter of 8 inches (203.2 mm). Subsequently, the 5¼-inch (130 mm) and then the 3½-inch (90 mm) became a ubiquitous form of data storage and transfer into the first years of the 21st century. By the end of the 1980s, 5¼-inch disks had been superseded by 3½-inch disks. During this time, PCs frequently came equipped with drives of both sizes. By the mid-1990s, 5¼-inch drives had virtually disappeared, as the 3½-inch disk became the predominant format. The advantages of the 3½-inch disk were its higher capacity, its smaller physical size, and its rigid case which provided better protection from dirt and other environmental risks. Floppy disks were so common in late 20th-century culture that many electronic and software programs continue to use save icons that look like floppy disks well into the 21st century, as a form of skeuomorphic design. While floppy disk drives still have some limited uses, especially with legacy industrial computer equipment, they have been superseded by data storage methods with much greater data storage capacity and data transfer speed, such as USB flash drives, memory cards, optical discs, and storage available through local computer networks and cloud storage.

Tables

Historical sequence of floppy disk formats In quantities of bits (b) or bytes (B)Prefixes: k = 1,000; K = 1,024; M may mean 1,000,000 or 1,048, 576 or some other multiple. · Historical sequence of floppy disk formats
8-inch: IBM 23FD (read-only)
8-inch: IBM 23FD (read-only)
Disk format
8-inch: IBM 23FD (read-only)
Year introduced
1971
Formatted storage capacity
81.664 kB
Marketed capacity
Not marketed commercially
8-inch: Memorex 650
8-inch: Memorex 650
Disk format
8-inch: Memorex 650
Year introduced
1972
Formatted storage capacity
175 kB
Marketed capacity
1.5 megabit full track
8-inch: SS SDIBM 33FD / Shugart 901
8-inch: SS SDIBM 33FD / Shugart 901
Disk format
8-inch: SS SDIBM 33FD / Shugart 901
Year introduced
1973
Formatted storage capacity
242.844 kB
Marketed capacity
3.1 megabit unformatted
8-inch: DS SDIBM 43FD / Shugart 850
8-inch: DS SDIBM 43FD / Shugart 850
Disk format
8-inch: DS SDIBM 43FD / Shugart 850
Year introduced
1976
Formatted storage capacity
568.320 kB
Marketed capacity
6.2 megabit unformatted
5¼-inch (35 track) Shugart SA 400
5¼-inch (35 track) Shugart SA 400
Disk format
5¼-inch (35 track) Shugart SA 400
Year introduced
1976
Formatted storage capacity
87.5 KB
Marketed capacity
110 kB
8-inch DS DDIBM 53FD / Shugart 850
8-inch DS DDIBM 53FD / Shugart 850
Disk format
8-inch DS DDIBM 53FD / Shugart 850
Year introduced
1977
Formatted storage capacity
962–1,184 KB depending upon sector size
Marketed capacity
1.2 MB
5¼-inch DD
5¼-inch DD
Disk format
5¼-inch DD
Year introduced
1978
Formatted storage capacity
360 or 800 KB
Marketed capacity
360 KB
5¼-inch Apple Disk II (Pre-DOS 3.3)
5¼-inch Apple Disk II (Pre-DOS 3.3)
Disk format
5¼-inch Apple Disk II (Pre-DOS 3.3)
Year introduced
1978
Formatted storage capacity
113.75 KB (256 byte sectors, 13 sectors/track, 35 tracks)
Marketed capacity
113 KB
5¼-inch Atari DOS 2.0S
5¼-inch Atari DOS 2.0S
Disk format
5¼-inch Atari DOS 2.0S
Year introduced
1979
Formatted storage capacity
90 KB (128 byte sectors, 18 sectors/track, 40 tracks)
Marketed capacity
90 KB
5¼-inch Commodore DOS 1.0 (SSDD)
5¼-inch Commodore DOS 1.0 (SSDD)
Disk format
5¼-inch Commodore DOS 1.0 (SSDD)
Year introduced
1979
Formatted storage capacity
172.5 KB
Marketed capacity
170 KB
5¼-inch Commodore DOS 2.1 (SSDD)
5¼-inch Commodore DOS 2.1 (SSDD)
Disk format
5¼-inch Commodore DOS 2.1 (SSDD)
Year introduced
1980
Formatted storage capacity
170.75 KB
Marketed capacity
170 KB
5¼-inch Apple Disk II (DOS 3.3)
5¼-inch Apple Disk II (DOS 3.3)
Disk format
5¼-inch Apple Disk II (DOS 3.3)
Year introduced
1980
Formatted storage capacity
140 KB (256 byte sectors, 16 sectors/track, 35 tracks)
Marketed capacity
140 KB
5¼-inch Victor 9000 / ACT Sirius 1 (SSDD)
5¼-inch Victor 9000 / ACT Sirius 1 (SSDD)
Disk format
5¼-inch Victor 9000 / ACT Sirius 1 (SSDD)
Year introduced
1982
Formatted storage capacity
612 KB (512 byte sectors, 11–19 variable sectors / track, 80 tracks)
Marketed capacity
600 KB
5¼-inch Victor 9000 / ACT Sirius 1 (DSDD)
5¼-inch Victor 9000 / ACT Sirius 1 (DSDD)
Disk format
5¼-inch Victor 9000 / ACT Sirius 1 (DSDD)
Year introduced
1982
Formatted storage capacity
1,196 KB (512 byte sectors, 11–19 variable sectors / track, 80 tracks)
Marketed capacity
1,200 KB
3½-inch HP SS
3½-inch HP SS
Disk format
3½-inch HP SS
Year introduced
1982
Formatted storage capacity
280 KB (256 byte sectors, 16 sectors/track, 70 tracks)
Marketed capacity
264 KB
5¼-inch Atari DOS 3
5¼-inch Atari DOS 3
Disk format
5¼-inch Atari DOS 3
Year introduced
1983
Formatted storage capacity
127 KB (128 byte sectors, 26 sectors/track, 40 tracks)
Marketed capacity
130 KB
3-inch
3-inch
Disk format
3-inch
Year introduced
1982
Formatted storage capacity
?
Marketed capacity
125 KB (SS/SD),500 KB (DS/DD)
3½-inch SS DD (at release)
3½-inch SS DD (at release)
Disk format
3½-inch SS DD (at release)
Year introduced
1983
Formatted storage capacity
360 KB (400 KB on Macintosh)
Marketed capacity
500 KB
3½-inch DS DD
3½-inch DS DD
Disk format
3½-inch DS DD
Year introduced
1983
Formatted storage capacity
720 KB (800 KB on Macintosh and RISC OS, 880 KB on Amiga)
Marketed capacity
1 MB
5¼-inch QD
5¼-inch QD
Disk format
5¼-inch QD
Year introduced
1980
Formatted storage capacity
720 KB
Marketed capacity
720 KB
5¼-inch RX50 (SSQD)
5¼-inch RX50 (SSQD)
Disk format
5¼-inch RX50 (SSQD)
Year introduced
c. 1982
Formatted storage capacity
Marketed capacity
400 KB
5¼-inch HD
5¼-inch HD
Disk format
5¼-inch HD
Year introduced
1982
Formatted storage capacity
1,200 KB
Marketed capacity
1.2 MB
3-inch Mitsumi Quick Disk
3-inch Mitsumi Quick Disk
Disk format
3-inch Mitsumi Quick Disk
Year introduced
1985
Formatted storage capacity
128 to 256 KB
Marketed capacity
?
3-inch Famicom Disk System (derived from Quick Disk)
3-inch Famicom Disk System (derived from Quick Disk)
Disk format
3-inch Famicom Disk System (derived from Quick Disk)
Year introduced
1986
Formatted storage capacity
112 KB
Marketed capacity
128 KB
2-inch
2-inch
Disk format
2-inch
Year introduced
1989
Formatted storage capacity
720 KB
Marketed capacity
?
2½-inch Sharp CE-1600F, CE-140F(chassis: FDU-250, medium: CE-1650F)
2½-inch Sharp CE-1600F, CE-140F(chassis: FDU-250, medium: CE-1650F)
Disk format
2½-inch Sharp CE-1600F, CE-140F(chassis: FDU-250, medium: CE-1650F)
Year introduced
1986
Formatted storage capacity
Turnable diskette with 62,464 bytes per side(512 byte sectors, 8 sectors/track, 16 tracks, GCR (4/5) recording)
Marketed capacity
2× 64 KB (128 KB)
5¼-inch Perpendicular
5¼-inch Perpendicular
Disk format
5¼-inch Perpendicular
Year introduced
1986
Formatted storage capacity
100 KB per inch
Marketed capacity
?
3½-inch HD
3½-inch HD
Disk format
3½-inch HD
Year introduced
1986
Formatted storage capacity
1,440 KB (512 bytes sectors, 18 sectors/track, 160 tracks); 1,760 KB on Amiga
Marketed capacity
1.44 MB (2.0 MB unformatted)
3½-inch HD
3½-inch HD
Disk format
3½-inch HD
Year introduced
1987
Formatted storage capacity
1,600 KB on RISC OS
Marketed capacity
1.6 MB
3½-inch ED
3½-inch ED
Disk format
3½-inch ED
Year introduced
1987
Formatted storage capacity
2,880 KB (3,200 KB on Sinclair QL)
Marketed capacity
2.88 MB
3½-inch Floptical (LS)
3½-inch Floptical (LS)
Disk format
3½-inch Floptical (LS)
Year introduced
1991
Formatted storage capacity
20,385 KB
Marketed capacity
21 MB
3½-inch SuperDisk (LS-120)
3½-inch SuperDisk (LS-120)
Disk format
3½-inch SuperDisk (LS-120)
Year introduced
1996
Formatted storage capacity
120,375 KB
Marketed capacity
120 MB
3½-inch SuperDisk (LS-240)
3½-inch SuperDisk (LS-240)
Disk format
3½-inch SuperDisk (LS-240)
Year introduced
1997
Formatted storage capacity
240,750 KB
Marketed capacity
240 MB
3½-inch HiFD
3½-inch HiFD
Disk format
3½-inch HiFD
Year introduced
1998/99
Formatted storage capacity
?
Marketed capacity
150/200 MB
Abbreviations: SD = Single Density; DD = Double Density; QD = Quad Density; HD = High Density; ED = Extra-high Density; LS = Laser Servo; HiFD = High capacity Floppy Disk; SS = Single Sided; DS = Double Sided
Abbreviations: SD = Single Density; DD = Double Density; QD = Quad Density; HD = High Density; ED = Extra-high Density; LS = Laser Servo; HiFD = High capacity Floppy Disk; SS = Single Sided; DS = Double Sided
Disk format
Abbreviations: SD = Single Density; DD = Double Density; QD = Quad Density; HD = High Density; ED = Extra-high Density; LS = Laser Servo; HiFD = High capacity Floppy Disk; SS = Single Sided; DS = Double Sided
Formatted storage capacity is total size of all sectors on the disk: For 8-inch see List of floppy disk formats#IBM 8-inch formats. 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.
Formatted storage capacity is total size of all sectors on the disk: For 8-inch see List of floppy disk formats#IBM 8-inch formats. 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.
Disk format
Formatted storage capacity is total size of all sectors on the disk: For 8-inch see List of floppy disk formats#IBM 8-inch formats. 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.
Disk format
Year introduced
Formatted storage capacity
Marketed capacity
8-inch: IBM 23FD (read-only)
1971
81.664 kB
Not marketed commercially
8-inch: Memorex 650
1972
175 kB
megabit full track
8-inch: SS SDIBM 33FD / Shugart 901
1973
242.844 kB
megabit unformatted
8-inch: DS SDIBM 43FD / Shugart 850
1976
568.320 kB
megabit unformatted
5¼-inch (35 track) Shugart SA 400
1976
87.5 KB
110 kB
8-inch DS DDIBM 53FD / Shugart 850
1977
962–1,184 KB depending upon sector size
1.2 MB
5¼-inch DD
1978
360 or 800 KB
360 KB
5¼-inch Apple Disk II (Pre-DOS 3.3)
1978
byte sectors, 13 sectors/track, 35 tracks)
113 KB
5¼-inch Atari DOS 2.0S
1979
90 KB (128 byte sectors, 18 sectors/track, 40 tracks)
90 KB
5¼-inch Commodore DOS 1.0 (SSDD)
1979
172.5 KB
170 KB
5¼-inch Commodore DOS 2.1 (SSDD)
1980
170.75 KB
170 KB
5¼-inch Apple Disk II (DOS 3.3)
1980
140 KB (256 byte sectors, 16 sectors/track, 35 tracks)
140 KB
5¼-inch Victor 9000 / ACT Sirius 1 (SSDD)
1982
612 KB (512 byte sectors, 11–19 variable sectors / track, 80 tracks)
600 KB
5¼-inch Victor 9000 / ACT Sirius 1 (DSDD)
1982
1,196 KB (512 byte sectors, 11–19 variable sectors / track, 80 tracks)
1,200 KB
3½-inch HP SS
1982
280 KB (256 byte sectors, 16 sectors/track, 70 tracks)
264 KB
5¼-inch Atari DOS 3
1983
127 KB (128 byte sectors, 26 sectors/track, 40 tracks)
130 KB
3-inch
1982
?
125 KB (SS/SD),500 KB (DS/DD)
3½-inch SS DD (at release)
1983
360 KB (400 KB on Macintosh)
500 KB
3½-inch DS DD
1983
720 KB (800 KB on Macintosh and RISC OS, 880 KB on Amiga)
1 MB
5¼-inch QD
1980
720 KB
720 KB
5¼-inch RX50 (SSQD)
c. 1982
400 KB
5¼-inch HD
1982
1,200 KB
1.2 MB
3-inch Mitsumi Quick Disk
1985
128 to 256 KB
?
3-inch Famicom Disk System (derived from Quick Disk)
1986
112 KB
128 KB
2-inch
1989
720 KB
?
2½-inch Sharp CE-1600F, CE-140F(chassis: FDU-250, medium: CE-1650F)
1986
Turnable diskette with 62,464 bytes per side(512 byte sectors, 8 sectors/track, 16 tracks, GCR (4/5) recording)
2× 64 KB (128 KB)
5¼-inch Perpendicular
1986
100 KB per inch
?
3½-inch HD
1986
1,440 KB (512 bytes sectors, 18 sectors/track, 160 tracks); 1,760 KB on Amiga
MB unformatted)
3½-inch HD
1987
1,600 KB on RISC OS
1.6 MB
3½-inch ED
1987
2,880 KB (3,200 KB on Sinclair QL)
2.88 MB
3½-inch Floptical (LS)
1991
20,385 KB
21 MB
3½-inch SuperDisk (LS-120)
1996
120,375 KB
120 MB
3½-inch SuperDisk (LS-240)
1997
240,750 KB
240 MB
3½-inch HiFD
1998/99
?
150/200 MB
Abbreviations: SD = Single Density; DD = Double Density; QD = Quad Density; HD = High Density; ED = Extra-high Density; LS = Laser Servo; HiFD = High capacity Floppy Disk; SS = Single Sided; DS = Double Sided
Formatted storage capacity is total size of all sectors on the disk: For 8-inch see List of floppy disk formats#IBM 8-inch formats. 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.

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  81. retrogamer.info
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  82. Retrocomputing Stack Exchange
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  83. OSDev Wiki
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  84. Internet Archive
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  85. Internet Archive
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  86. "The floppy user guide"
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  87. The Apple II Plus/IIe Troubleshooting & Repair Guide
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  88. OS/2 Museum
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  89. Low End Mac
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  90. Siber-Sonic
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  91. ANSI X3.137, One- and Two-Sided, Unformatted, 90-mm (3.5-inch) 5,3-tpmm (135-tpi), Flexible Disk Cartridge for 7958 bpr
  92. IBM Journal of Research and Development
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  93. "Memorex 650 Flexible Disc File"
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  94. IEEE Transactions on Magnetics
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  95. "Shugart SA 400 Datasheet"
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  96. PET User Notes
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  97. Programming the PET/CBM: The Reference Encyclopedia For Commodore PET & CBM Users
    https://archive.org/details/COMPUTEs_Programming_the_PET-CBM_1982_Small_Systems_Services/page/n175
  98. GitHub
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  99. "Victor 9000 Hardware Reference Manual"
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  100. "Chronology of Events in the History of Microcomputers − 1981–1983 Business Takes Over"
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  102. RISC OS 3.7 User Guide
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  103. 1982 Disk/Trend Report – Flexible Disk Drives
  104. 1986 Disk/Trend Report, Flexible Disk Drives
  105. Eurogamer
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  106. InfoWorld
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  107. Sharp PC-1600 Service Manual
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  108. Sharp Service Manual Model CE-140F Pocket Disk Drive
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  109. Compute!
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  112. Upgrading and Repairing PCs, 15th Anniversary Edition
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  113. Hardware-Praxis – PCs warten reparieren, aufrüsten und konfigurieren
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  115. Intel 82077SL for Super-Dense Floppies
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  116. PC Mag
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  117. InfoWorld
    https://books.google.com/books?id=KjsEAAAAMBAJ&pg=PT22
  118. Retrocomputing Stack Exchange
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  119. Folklore
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  120. "Tech information on floppy disks drives and media"
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  121. Business Week
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  122. "floppy"
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