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Competencies
Distinguish between primary & secondary
storage
Discuss the different types of storage media
D
Describe
ib the
h traditional
di i l floppy
fl
disk
di k andd the
h high
hi h
capacity floppy disks
Describe various types of hard disk devices
SECONDARY
STORAGE
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Competencies cont.
Storage
Primary storage
Describe ways to improve hard-disk operations
Describe the different types of optical disks
Describe other kinds of secondary storage
d i
devices
Volatile
Temporary
Secondary storage
Nonvolatile
Permanent
Secondary
y storage
g
characteristics
Media
Capacity
Storage devices
Access speed
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Secondary Storage Devices
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Traditional Floppy Disks
Traditional
Floppies
Diskettes
Portable storage
media
Floppy disk drives
(FDD)
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Traditional Floppy
Diskette
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Types of Floppies
Hard Disks
High capacity
Known as a floppy-disk cartridge
Require special disk drives
Three well known types
Use thicker, metallic platters for storage
Internal (fixed) or external
Faster access speed than a floppy diskette
Direct or random access to data
Large capacity
Sensitive instruments
Zip disks
HiFD disks
SuperDisks
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Hard-Disk Cartridges
Hard-Disk Packs
Removable
Massive storage capacity
Common in mainframes
Resembles stack of vinyl records
Removable hard disks
Used to complement
internal hard disk
Capacities of 10 to 20
GB
PC Card Hard Disks
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Performance Enhancements
Disk caching
Redundant arrays of
inexpensive
p
disks ((RAID))
Optical Disks
Compact
Permanent storage
Laser beams reflect off pits
Two common types
CD
DVD
File compression
and decompression
Defragmentation
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Compact Disc
8-14
Digital Versatile Disc
Optical format
From 650 MB to 1 GB capacity
Rotation speeds vary
Types
Digital Versatile Disk or Digital Video Disk
(DVD)
Similar to CDs, but can store more data
T
Types
Read only: DVD-ROM
Write once: DVD-R
Rewritable: DVD-RW
Read only: CD-ROM
Write once: CD-R
Rewriteable: CD-RW
Picture CDs and Photo CDs
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DataPlay
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Other Types of Secondary Storage
Optical disk
Write once format
Quarter size
Solid-state storage
Internet hard drives
500 MB capacity
Holds 5 hours of CD-quality
sound
Magnetic tape
Use for storing and playing
music files
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Magnetic Tape
External storage
Provides sequential access
Information stored in sequence
Sl
Slower
than
h disks
di k which
hi h provide
id
direct access
Magnetic tape streamers or tape
cartridges used by both
mainframes and
microcomputers
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8-18
Solid-State Storage
Flash memory cards
Widely used in notebook computers
Used to record MP3 music files
Key chain hard drives
Key chain flash memory
devices
Connects to a USB port
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A Look to the Future
Blu-Ray Technology
Internet Hard Drives
New standard in storage
Blu-Ray
New disks use blue laser light instead of the red laser
light used in traditional CD players
Disks may ultimately hold
Over 30GB on one-sided disks
Over 50GB on two-sided disks
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FAQs
Discussion Questions
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?
Discuss three ways to improve the performance
of hard disks.
Describe the different types of compact discs.
D
Describe
ib the
h different
diff
types off DVDs.
DVD
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.
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© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.
8-23
Participation Question
Optical disks that can be written on only once are
called:
A. CD-ROM
B. CD-R
CD R
C. CD-RW
D. CD-DVD
E. CD-W
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