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Competencies
!   Distinguish between primary & secondary
storage
SECONDARY
STORAGE
!   Discuss the different types of storage media
!   Describe the traditional floppy disk and the high
capacity floppy disks
!   Describe various types of hard disk devices
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
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Competencies cont.
Storage
!   Primary storage
!   Volatile
!   Temporary
!   Describe ways to improve hard-disk operations
!   Describe the different types of optical disks
!   Describe other kinds of secondary storage
!   Secondary storage
!   Nonvolatile
!   Permanent
!   Secondary storage
devices
characteristics
!   Media
!   Capacity
!   Storage devices
!   Access speed
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
8-5
Secondary Storage Devices
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Magnetic Tape
!   External storage
!   Provides sequential access
!   Information stored in sequence
!   Slower than disks which provide
direct access
!   Magnetic tape streamers or tape
cartridges used by both
mainframes and
microcomputers
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
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Traditional Floppy Disks
Types of Floppies
!   High capacity
!   Traditional
!   Floppies
!   Diskettes
!   Portable storage
media
!   Known as a floppy-disk cartridge
!   Require special disk drives
!   Three well known types
!   Zip disks
!   HiFD disks
!   SuperDisks
Traditional Floppy
Diskette
!   Floppy disk drives
(FDD)
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
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Hard Disks
Hard-Disk Cartridges
!   Use thicker, metallic platters for storage
!   Removable hard disks
!   Internal (fixed) or external
!   Used to complement
!   Faster access speed than a floppy diskette
internal hard disk
!   Direct or random access to data
!   Capacities of 10 to 20
!   Large capacity
GB
!   Sensitive instruments
PC Card Hard Disks
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
8-11
Hard-Disk Packs
!   Removable
!   Massive storage capacity
!   Common in mainframes
!   Resembles stack of vinyl records
8-12
Performance Enhancements
!   Disk caching
!   Redundant arrays of
inexpensive disks (RAID)
!   File compression
and decompression
!   Defragmentation
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
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Optical Disks
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Compact Disc
!   Compact
!   Optical format
!   Permanent storage
!   From 650 MB to 1 GB capacity
!   Laser beams reflect off pits
!   Rotation speeds vary
!   Two common types
!   CD
!   DVD
!   Types
!   Read only: CD-ROM
!   Write once: CD-R
!   Rewriteable: CD-RW
!   Picture CDs and Photo CDs
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
8-15
Digital Versatile Disc
8-16
Blu-Ray Technology
!   Digital Versatile Disk or Digital Video Disk
!   New standard in storage
(DVD)
!   Similar to CDs, but can store more data
!   Types
!   Blu-Ray
!   New disks use blue laser light instead of the red laser
light used in traditional CD players
!   Disks may ultimately hold
!   Read only: DVD-ROM
!  Over 30GB on one-sided disks
!  Over 50GB on two-sided disks
!   Write once: DVD-R
!   Rewritable: DVD-RW
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
8-17
DataPlay
!   Optical disk
!   Write once format
!   Quarter size
!   500 MB capacity
!   Holds 5 hours of CD-quality
sound
!   Use for storing and playing
music files
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
8-18
Solid-State Storage
!   Flash memory cards
!   Widely used in notebook computers
!   Used to record MP3 music files
!   Expanded digital camera use
!   Key chain hard drives
!   Key chain flash memory
devices
!   Connects to a USB port
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
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Internet Hard Drives
FAQs
!   What is the difference between primary storage
and secondary storage?
!   What kind of data access do floppy and hard
drives use ?
!   What is the C drive of a computer?
!   When would I use a hard-disk cartridge?
!   What is the difference between a CD and a
DVD?
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
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Discussion Questions
!   Discuss three ways to improve the performance
!
!
!
!
of hard disks.
  Describe the different types of compact discs.
  Describe the different types of DVDs.
  What are the advantages and disadvantages of
using an Internet hard drive?
  Describe solid state technology. Discuss the
many uses for key chain flash memory devices.
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
Participation Question
Optical disks that can be written on only once are
called identified as ____ .
A.  CD-ROM
B.  CD-R
C.  CD-RW
D.  CD-DVD
E.  CD-W
© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
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