Secondary storage Devices
secondary storage device is a storage medium used for storing data, instruction
and output for archival purposes, so that whenever any data or instruction is
required in the future, it can be retrieved for reference, or for further
processing. Different kinds of secondary storage devices available are:
Disk: A floppy disk is a circular plastic disk coated with magnetic oxide and
enclosed within a square plastic cover. The data or instruction is stored in
the form of magnetic impulses. The floppy disks are available different sizes,
but the most commonly used floppy disks are 51/4” and 31/2”.
A hard disk is a storage device that contains one or more rigid disks
called platters coated with magnetic material sealed in an enclosure. It is
most often called a fixed disk as it is placed within the cabinet of the
computer system, and cannot be removed often like the floppy disks. The storage
capacity of the hard disk is more than a floppy disk. The data is stored in the
form of magnetic impulses.
Disk: An optical disk uses Optical Technology (LASER) to store and retrieve
data. The amount of data that can be stored on a single disk is enormous.
However, it faces only one drawback and that is, once recorded, it cannot be
modified or removed, but can be read as many times as you wish i.e. WORM (Write
Once Read Many times).
Tape: A cartridge tape is magnetic storage medium, but the only difference is
data is stored on a tape and not on a platter. It resembles the audio cassettes
and generally uses in microcomputers.
A spool tape is again a similar storage medium as compared to your cartridge tape.
But has a comparative higher capacity of data storage and size if compared to
the cartridge tape. They are generally used in minicomputers and mainframes.