disket

Disket, also known as a diskette, is a small removable magnetic storage medium enclosed in a protective plastic shell. It stores digital data on a magnetic disk that spins inside the envelope and is read or written by a pair of read/write heads in a compatible drive. Diskets were a common medium for data storage, transfer, and software distribution from the 1970s through the 1990s.

Sizes and capacities: The main physical formats were 8-inch, 5.25-inch, and 3.5-inch. 8-inch disks could store up to about 1.2 MB in later variants. The 5.25-inch format offered a range from a few hundred kilobytes to about 1.2 MB (depending on density). The 3.5-inch format became dominant in the 1990s, with typical capacities of 720 KB (double-density) and 1.44 MB (high-density; some earlier or larger-capacity variants existed).

Formats and use: Disks were formatted with a logical data organization that allowed compatibility with various operating systems; the most widespread on personal computers was FAT12 used with DOS. Other platforms used their own formats. Diskets relied on magnetic flux transitions and were susceptible to data loss from magnetic fields, heat, or mechanical wear.

Decline and legacy: The advent of high-capacity optical media and then USB flash drives and cloud storage reduced the role of diskettes. They remained in use in some legacy systems and as a collector’s item among enthusiasts, museums, and educational kits. The disket’s footprint on computing history remains notable for shaping early media distribution and the way programs were packaged and loaded.