A CDE Definition
(1) (Frequency Division Duplexing) A transmission method that uses separate channels for the uplink and downlink (transmit and receive). If the channel frequencies are adjacent, a guard band may be used between them to reduce interference. Contrast with TDD.
(2) Abbreviation for floppy disk drive. See 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)
Jacket 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
Anatomy of a 3.5" Floppy
A Floppy-Based Computer
Handwriting on the Wall
Before/After Your Search Term
Terms By Topic
Click any of the following categories for a list of fundamental terms.