Download Computers Are Your Future Twelfth Edition

Computers Are Your Future
Twelfth Edition
Chapter 4: System Software
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall
1
System Software
• System software
o Consists of all the programs that enable the
computer and its peripheral devices to function
smoothly
o Divided into two main categories:
• Operating System
• Utility Programs
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The Operating System
• Five basic functions
Starts the computer
Manages applications
Manages memory
Handles input and output
device messages
o Provides a user interface for
communication
o
o
o
o
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The Operating System
• Operation System (OS)
o Programs that coordinates:
• Interactions of hardware components to
each other
• Interaction between application software
and computer hardware
o Manages computers resources (i.e. RAM)
o Usually stored on hard disk
o Stored on memory chip on handheld
computers
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The Operating System
• Starting the computer
o Booting—loading the OS into RAM
• Cold boot - Starting computer when it has
not yet been turned on
• Warm boot - Restarting a computer that is
already on
o Restart Keys - Ctrl + Alt + Del
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The Operating System
• Managing applications
o Multitasking operating systems—permit more
than one application to run at the same time
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The Operating System
• Managing Memory
o RAM – located on motherboard to hold
programs and data
o Virtual memory—uses portion of hard disk to
extend RAM
o Adding more RAM —best way to improve computer
performance:
• Accessing data from hard disk is slower than
accessing from RAM
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The Operating System
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The Operating System
• Coordinating tasks
o Device Drivers —utility programs that enable
communications between a computer and peripheral
devices
o Interrupts—signals that notify OS that something
has happened and action is needed
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The Operating System
• Providing the user interface
o Allows the user to:
• Start application programs
• Manage storage devices
• Safely shut down the computer
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The Operating System
• Types of user interfaces
o Graphical user interface (GUI)
o Menu-driven user interface
o Command-line user interface
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The Operating System
• Types of user interfaces
o Graphical user interface (GUI)
• Uses icons—small images that represent
computer options
• Most popular
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Stand-Alone
Operating Systems
• Microsoft Windows 7
o Six versions
• Mac OS
o Used on Macintosh personal computers
o Stable, simple to use
• UNIX
o Hard to use—defaults to a command-line user interface
• Linux
o Open source software—source code is available to
users
o Powerful, free
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Stand-Alone
Operating Systems
• PC Versus Mac Versus Linux
o PCs
• Dominate marketplace
• Windows OS
• Intel or AMD chip
• More software available
o Macs
• Mac OS
• Motorola or IBM chip
• Most current OS can run Windows software
o Linux
• Can be installed on PC or Mac
• More secure—fewer viruses
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Stand-Alone
Operating Systems
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Stand-Alone
Operating Systems
• Microsoft Windows
Mobile
o Designed for smartphones and PDAs
o Includes simplified versions of
Windows programs
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System Utilities:
Housekeeping Tools
• Utility Programs
o Software Programs
• Backing up files
• Providing antivirus protection
• Searching for and managing files
• Disk Defragmentation
• Compressing files
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System Utilities:
Housekeeping Tools
• Backup software—copies
data found on the hard disk
to a backup device
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System Utilities:
Housekeeping Tools
• Antivirus software—protects the
computer from viruses
o Popular antivirus programs:
• BitDefender Antivirus
• Kaspersky Anti-virus
• Webroot AntiVirus with SpySweeper
• Norton AntiVirus
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System Utilities:
Housekeeping Tools
• Searching for and managing
files
o File manager—utility software that organizes and
manages data
• Copy files
• Delete files
o Search utility—enables you to locate files
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System Utilities:
Housekeeping Tools
• Scanning Disks
o Disk scanning programs—find and resolve
disk file storage problems
• Bad sector—irregularity on the disk’s
surface that can’t store data
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Disk Defragmentation
• Fragmented Disk
o Results from computer
creating and erasing files
on hard disk
o Reduces disk
performance – since
system looks in several
locations to find all file
segments
• Disk Defragmentation
Reorganizes stored data in a
more efficient manner
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System Utilities:
Housekeeping Tools
• File Compression utilities
o Decrease the size of files, resulting in faster
downloads
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