1. Chapter 4
Storing Information in
a Computer
Peter Norton’s®
Introduction to Computers

2. Learning Objectives:
• List four common types of storage devices.
• Name three common uses of floppy disks.
• Name the four data disk areas on floppy and hard disks.
• List three ways tape drives differ from disk drives.
• Identify four types of optical storage devices.
• Name and describe the four main disk drive interface standards.

3. Storage Media - the physical
components or materials on which
data is stored.

4. Storage Devices - the hardware
components that write data to, and
read it from, storage media.

5. Types of Storage:
• Magnetic
• Optical

6. Magnetic: the bits
are written and read
using magnetism.
Optical: the bits
are read
using light.

7. Magnetic Storage Devices:
• Diskettes
• Hard disks
• Removable hard disks
• Magnetic tape

8. Tape drive
Floppy drive
Hard drive

9. Optical Storage Devices:
• Compact Disk Read-Only Memory
(CD-ROM)
• Write Once, Read Many (WORM)
• Phase-Change Rewritable disks
• Magneto-optical disks

10. CD-ROM

11. Factors that Affect Drive
Performance:
• Average Access Time
• Data-transfer Rate

12. Average Access Time - the
average time it takes a read/write
head to move from one place on
the recording medium to any other
place on the medium.

13. Data-transfer Rate - a measure
of how long it takes the device to
read or write a given amount of
data.

14. Hard drive RAM
Head

15. Formatting - the process of
mapping a diskette by dividing it
into Tracks and Sectors.

16. Tracks - a set of magnetic
concentric circles.
Sector - a pie-like slice of disk.

18. Four Areas of a Disk:
• The boot record
• The file-allocation table (FAT)
• The root folder or directory
• The data area

20. Drive-Interface Standards:
• Integrated Drive Electronics (IDE)
• Enhanced Small Device Interface (ESDI)
• Small Computer System Interface (SCSI)

21. Learning Objectives:
Chapter 4 Review
• List four common types of storage devices.
• Name three common uses of floppy disks.
• Name the four data disk areas on floppy and hard disks.
• List three ways tape drives differ from disk drives.
• Identify four types of optical storage devices.
• Name and describe the four main disk drive interface standards.