FLOPPY DISK

A floppy disk (also called diskette) is a circular plastic disk coated with a magnetically sensitive film, the same material that’s on a cassette tape. Designed to work with a floppy disk drive, floppies have long provided personal computer users with convenient, near-online storage. However, as computer programs have grown significantly in size, floppies are becoming less useful. Their capacity is so small that they cannot store some of the larger files people create. Floppy disk must be formatted before it can be used.

Introduced by IBM in the 1970s, the first floppy disks were packaged in eight-inch flexible packages. That’s where the term “floppy” came from. Most of today’s floppy disks are packaged in 3½-inch hard plastic cases (see Figure 1). Even though the package is no longer flexible, the term “floppy” still in used.

Compared to other storage media, floppy disks provide little room for storing data. The storage capacity of a floppy disk is determined by the density of the magnetic material on the disk’s surface. Double-density (DD) floppy disks offer up to 800 KB (Kilo-bytes) of storage, while high-density (HD) floppy disks offer up to 1.44 MB (Mega-bytes) of data.

Protecting Data

Floppy disks are designed to keep data safe. A sliding metal shutter protects the disk from fingerprints, dust, and dirt (see Figure 2). The write-protect tab (or write-protect notch), which can be closed and opened, protects data from being overwritten or deleted. The write-protect tab enables to turn any floppy disk into a read-only disk.

Floppy disks are designed to work with floppy disk drives. In desktop computer systems, this drive is installed in one of the system unit’s drive bays. In notebook (laptop) computers, the drive is often provided by means of an external unit that plugs into the system’s case. The letter label is also assigned to that drive, usually called Drive A. Floppy disks contain circular bands called tracks. Each track is divided into pie-shape wedges called sectors. Two or more sectors combine to form a cluster (see Figure 3). These are the layout locations where data are stored.

Before a magnetic disk can be used for storage, it must be prepared using a process called formatting. This process is necessary because different types of computers store data in different ways. For this reason, PCs cannot read Macintosh floppies unless the PC is running special software. Most Macintoshes are equipped with software that enables them to read PC floppies. In the formatting process, the disk drive’s read/write head lays down the magnetic patterns of tracks and sectors on the disk’s surface. This pattern enables the disk drive to store data in an organized manner. Be aware that formatting destroys all the data that has been recorded on a disk. Do not format disk that contains valuable data.

Floppy disks enable a computer user to exchange data with almost any other computer user. Even though its capacity is limited, almost every personal computer includes a floppy disk drive. This makes convenient for computer users to exchange small file between computers. Moreover, one of the important purposes of floppy disk is for booting up the computer system when necessary.