SECONDARY STORAGE DEVICES Section I : Chapter No. 4
What are Basic Hardware of a Personal Computer?
Primary storage (RAM)
Optical disc drive
Secondary storage (Hard disk)
Hardwares of Personal Computers Figure 1. Basic hardware of a PC. (Wikipedia, 2007a)
Classification of Hardware Hardwares of Personal Computers Figure 2. Classification of Hardware. Input Devices 1 Processing Unit 2 Storage Devices 3 Output Devices 4 Key: Data flow
What are Types of Storage Devices? Hardwares of Personal Computers Figure 3. Classification of storage devices. Storage Devices Primary Storage Secondary Storage Read-Only Memory (ROM) Random-Access Memory (RAM)
Hardwares of Personal Computers Figure 5. A Hard disk.
Secondary Storage Hardwares of Personal Computers CD-Rom CD-R CD-RW Data can be Read only Read but write once Read & write Data capacity (MB) 650 650 650
Secondary Storage Hardwares of Personal Computers DVD ( Digital Versatile Disk or Digital Video Disk ) DVD-R / DVD+R DVD-RW / DVD+RW Data can be Read only Read but write once Read & write Data capacity (GB) Single layer: 4.7 Double layer: 8.5 Single layer: 4.7 Double layer: 8.5 Single layer: 4.7 Double layer: 8.5
A compact disc [sometimes spelled disk ] (CD) is a small, portable, round medium made of molded polymer for electronically recording, storing, and playing back audio, video, text, and other information in digital form
DVD is an optical disc technology with a 4.7 gigabyte storage capacity on a single-sided, one-layered disk, which is enough for a 133-minute movie. DVDs can be single- or double-sided, and can have two layers on each side; a double-sided, two-layered DVD will hold up to 17 gigabytes of video, audio, or other information. This compares to 650 megabyte s (.65 gigabyte) of storage for a CD-ROM disk.
DVD was originally said to stand for digital video disc , and later for digital versatile disc .
Hardwares of Personal Computers
Secondary Storage Hardwares of Personal Computers Figure 6. A C-R disk. Figure 7. A CD-RW disk.
Secondary Storage Hardwares of Personal Computers Figure 8. A DVD-R disk. Figure 9. A DVD+RW disk.