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Floppy disk

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An 8 inch floppy disk

The floppy disk (or a 3½ floppy for today's standard) is a removable magnetic storage medium. Floppy disks are used for moving information between computers, laptops or other devices. Some early digital cameras, electronic music instruments and older computer game consoles use floppy disks. Floppy disks are inserted in to a floppy disk drive or simply floppy drive to allow data to be read or stored.

Floppy disks store much less data than a CD-ROM disk or USB flash drive. A normal 3½ inch disk can store 1.44 megabytes of data. This is usually enough for simple text documents.

A special type of floppy disk was made in the late 1980s. It could store 2.88 MB of data. They did not become popular. Larger size floppy disks became available in the 1990s. The 2 most popular were the Zip drive and the Jaz drive, both made by Iomega.

Floppy disk technology has been around since the early 1970s (the 8-inch floppy was the first). Today, floppy disks have been replaced by other storage media, like USB flash drives.

The floppy drive

A USB floppy drive. This one can be plugged into any modern computer.
A 3 1/2 inch floppy disk

A floppy drive (often called drive “A” on a computer) can be connected to or installed in a personal computer (PC). It is the part of a computer that reads and writes the disk that can be removed. A disk, often called a floppy disk, is used to store files and carry them from one computer to another by using the floppy drive. The floppy drive reads the disk (or diskette) and the user is then able to open and change the files saved on the disk.


Historical sequence of floppy disk formats, including the last format to be generally adopted — the "1.44 MB" 3½-inch HD floppy, introduced 1987.
Floppy disk format Year introduced Storage capacity
(binary kilobytes if not stated)
8-inch (read-only) 1969 80
8-inch 1972 187.5 1.5 Mbit
8-inch 1973 256 256 KB
8-inch DD 1976 500 0.5 MB
5¼-inch 1976 223
8-inch double sided 1977 1200 1.2 MB
5¼-inch DD 1978 360 360 KB
HP single sided
1982 280 264 KB
3-inch 1982? 360?
3½-inch (DD at release) 1984 720 720 KB
5¼-inch QD 1984 1200 1.2 MB
3-inch DD 1984? 720?
Mitsumi Quick Disk
1985 128 to 256
2-inch 1985? 720?
5¼-inch Perpendicular 1986? 100 MiB
3½-inch HD 1987 1440 1.44 MB
3½-inch ED 1991 2880 2.88 MB
3½-inch LS-120 1996 120.375 MiB 120 MB
3½-inch LS-240 1997 240.75 MiB 240 MB
3½-inch HiFD 1998/99 150/200 MiB? 150/200 MB
Acronyms:  DD = Double Density; QD = Quad Density; HD = High Density ED = Extended Density; LS = Laser Servo; HiFD = High capacity Floppy Disk
Dates and capacities marked ? are of unclear origin and need source information; other listed capacities refer to:
  • For 8-inch: standard IBM formats as used by the System/370 mainframes and newer systems
  • For 5¼- and 3½-inch: standard PC formats, capacities quoted are the total size of all sectors on the disk and include space used for the bootsector and filesystem

Other formats may get more or less capacity from the same drives and disks.