cd-rom, cd-r dvd, (by shujaat abbas)
TRANSCRIPT
Storage Devices..?
Storage Devices
• The storage devices store data –even when the computer is turned off.
• It is used to keep important data and files which are of regular use on permanent basis.
Audio Casetes
Video Casetes
VCR
Floppy Disc
Floppy DiskFloppy Disk –is a removable disk that everyone is familiar with. Since it has a small capacity, it is typically used to store documents so that they can be used on more than one computer.
CD A audioCD A audio
Video CDVideo CD
CD Structure• A CD is flat, round, portable metal disc,
which is coated with a thin metal or plastic.
• It is usually 0.75 inches in diameter.
Compact Disc - read only memory (write once)
Data is encoded and read optically with a laser
Can store around 600 and 700 MB data
:-Compact Disc read-only memory is a Compact Disc that contains data accessible by a computer.
•Firstly the Compact Disc format was designed for music storage and playback,
•Later the format was adapted to hold any form of binary data.
CD-ROM
•CD-ROM are popularly used to distribute computer Software, including games and Multimedia applications, though any data can be stored (up to the capacity limit of a disc). Some CDs hold both computer data and audio with the latter capable of being played on a CD player, whilst data (such as software or digital video) is only usable on a computer (such as PC CD-ROMs. These are called Enhanced CDs.
Reading Speed
• Reading speed is measured in kB/s
• Reading speed determines the transfer of data in one second.
• 1× or 1-speed which gives a data transfer rate of 150 kB/s in the most common data format.
Advantages of CD-ROM
• Large storage space
• Compact and light
• Can be manufactured on a large scale
20
Disadvantage Of CD-ROM
• Slow Writing speed
• Not easily re-writable
• Cost Concerns
21
Summary
• Compact Disk is a type of optical storage.• It holds data through physical marks.• Its is played in a CD-Player, and is read at
different speeds.• Files system is required to write data on
CD by different methods.• CDs are compact storage devices that can
be moved from on place to another easily.
CD-Room
CD-R
CD-RW
DVDs (Digital Versatile Disc or Digital Video Disc)
DVD, is an optical disc storage media format, and was invented in 1995. Its main uses are video and data storage. DVDs are of the same dimensions as compact discs (CDs), but store more than six times as much data.
DVD-R
DVD-RW
DVD-ROOM
Development day by day
USB (Universal serial Bus)
USB 2.0 V/S 3.0
DownloadingDownloading
Need of Thinking
