CHAPTER-7 COMPUTER NOTES(NON-PYTHON) FOR CLASS 11TH

 

FLOPPY DISK

Floppy disk is also known  as Diskettes are mostly used by personal computer users in 1980s.

Floppy disk is available in three sizes- 8 inch 5 1/4 inch and 3 1/2 inch .Floppy disk is transferable from one computer  to another. 

A 8 inch floppy disk can store  80KB(kilobytes) and  5 1/4 inch floppy disk can store 360 KB(kilobytes) of data . By 1986, IBM introduced the 3-1/2 inch floppy disk with 1.44 megabytes of storage space.

HARD DISK  

Hard Disk of personal computer are 5-inch or 3 1/2-inch Winchester disk is sealed module. Every PC contains at least one  hard disk that is able to store a large amount of data.

A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that uses magnetic storage to store and retrieve digital data using one or more rigid rapidly rotating platters coated with magnetic material. The platters are paired with magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces.

CD(COMPACT DISC)

Compact disc is a small disc containing data recorded in digital format. it is developed by Philips in early 1980s. A CD can store 650 MB(megabytes) to 700 MB.. 

        DVD(Digital Video/ Versatile disc) 

DVD is a digital optical disc storage format invented and developed in 1995 and released in late 1996. The medium can store any kind of digital data and is widely used for software and other computer files as well as video programs watched using DVD players.

DVD has a storage capacity of 4.7 GB for a single-layered, single-sided disc and 8.5 GB for a dual-layered.