Saturday, 1 August 2015

what is a secondary storage device?list different type of secondary storage devices used in computers.

Secondary Storage Device
the main memory or RAM of the computer is volatile. It cannot be used permanent storage because when computer is switched off, its contents are erased. storage capacity is also very small.

A secondary storage device is a computer hardware component. it is used to storage data and programs permanently for later use. secondary storage devices are also called auxiliary storage devices or backing storage devices. Examples of secondary storage devices are floppy disk, USB driver, hard disk, CD/DVD ROMs etc.

A secondary storage device performs two functions. these are writing and reading data to and from the storage media.
1-  Writing data means recording data form memory  to a storage medium.
2-   Reading or retrieving data means transferring data form storage medium in to computer's memory       for use by the operating system or application program.

Types Of Secondary Storage Devices
Following are important types of secondary storage devices:
1- Magnetic tape
2- Magnetic disk

Magnetic tape
Magnetic tape is the most popular and oldest storage medium.it is used to store large amount of data and instructions permanently. the magnetic tape is a plastic ribbon with width of 0.50 inch to 1 inch. one side of tape is coated with magnetic recording material. the storage capacity of tape is up to 100GB and offers an inexpensive way to store a lot of data on a single cassette.
Magnetic Disk
Magnetic disk is a device that write/reads data to and form a magnetic tape. it has two heads. these are write head and read head. the write head encodes the magnetic signals on the tape as it moves across the write head. similarly, the read head reads the stored data from tape and transfers it into the RAM.

what is a secondary storage device?list different type of secondary storage devices used in computers. Rating: 4.5 Diposkan Oleh: Ghulam Nabi

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