floppy disk

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floppy disk

a flexible removable magnetic disk that stores information and can be used to store data for use in a microprocessor

floppy disk

[¦fläp·ē ′disk]
(computer science)
A flexible plastic disk coated with magnetic oxide and used for data entry to a computer; a slot in its protective envelope or housing, which remains stationary while the disk rotates, exposes the track positions for the magnetic read/write head of the drive unit. Also known as diskette.

floppy disk

(hardware, storage)
(Or "floppy", "diskette") A small, portable plastic disk coated in a magnetisable substance used for storing computer data, readable by a computer with a floppy disk drive. The physical size of disks has shrunk from the early 8 inch, to 5 1/4 inch ("minifloppy") to 3 1/2 inch ("microfloppy") while the data capacity has risen.

These disks are known as "floppy" disks (or diskettes) because the disk is flexible and the read/write head is in physical contact with the surface of the disk in contrast to "hard disks" (or winchesters) which are rigid and rely on a small fixed gap between the disk surface and the heads. Floppies may be either single-sided or double-sided.

3.5 inch floppies are less floppy than the larger disks because they come in a stiff plastic "envelope" or case, hence the alternative names "stiffy" or "crunchy" sometimes used to distinguish them from the floppier kind.

The following formats are used on IBM PCs and elsewhere:

Capacity Density Width 360K double 5.25" 720K double 3.5" 1.2M high 5.25" 1.44M high 3.5"

Double denisty and high density are usually abbreviated DD and HD. HD 3.5 inch disks have a second hole in the envelope and an overlapping "HD" logo.

floppy disk

An earlier, reusable magnetic storage medium and drive introduced by IBM in 1971. It was officially a "diskette," but nicknamed "floppy," because the first varieties were housed in bendable jackets. Starting in the late 1970s, the floppy was the first personal computer storage medium. Although computers with hard disks emerged in the 1980s, they had at least one floppy drive for distributing applications, backup and data transfer between machines. By the mid-1990s, the floppy gave way to the CD-ROM for software distribution, while local networks and the Internet became popular for backup and data exchange.

Like Magnetic Tape
The floppy's recording surface was a circular platter of magnetically coated plastic similar to magnetic tape, except that both sides were recordable. The drive grabbed and spun the platter inside its jacket, while the read/write head contacted the surface through an opening. At 300 RPM, floppies rotated considerably slower than a hard disk, and they came to a complete stop when there was no read/write activity.

Format Before Writing
Every new floppy had to be "formatted," which divides the disk into sectors (see format program). However, by looking at the external jacket, one could not always discern the recording format. See magnetic disk.
FLOPPY TYPES (most recent to oldest)                Storage CapacityJacket          Highest  Lowest  Creator

 3.5" rigid      1.44MB   400KB   Sony

 5.25" flexible  1.2MB    100KB   Shugart

 8" flexible     1.2MB    100KB   IBM


The Common Floppy Versions
Although ubiquitous in the late 1970s and early 1980s, the bendable 5.25" floppy was surpassed by the rigid 3.5" floppy in the late 1980s.


Anatomy of a 3.5" Floppy
The magnetic disk rotates between two liners inside the plastic jacket.


A Floppy-Based Computer
Floppy-based computers such as this Kaypro portable were the rage in the early 1980s. The computer was booted with the operating system floppy in the first drive, and the second drive was used for the application floppy.


Handwriting on the Wall
This 1999 headline foretold the floppy's future. Their value as a storage medium today is nil. (Article headline courtesy of the Philadelphia Inquirer.)


No Wonder
This 8GB microSD card (red arrow) sitting on top of one floppy disk holds the equivalent of 5,333 floppies. Any wonder the floppy is long extinct?