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 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 2

Five basic functions o Starts the computer o Manages applications o Manages memory o Handles input and output device messages o Provides a user interface for communication The Operating System Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 3

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 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 4

Starting the computer o Bootingloading 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 The Operating System Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 5

The Operating System Managing applications o Multitasking operating systemspermit more than one application to run at the same time Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 6

Managing Memory o RAM – located on motherboard to hold programs and data o Virtual memoryuses portion of hard disk to extend RAM o Adding more RAM best way to improve computer performance: Adding more RAM Accessing data from hard disk is slower than accessing from RAM The Operating System Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 7

The Operating System Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 8

Coordinating tasks o Device Drivers utility programs that enable communications between a computer and peripheral devices o Interruptssignals that notify OS that something has happened and action is needed The Operating System Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 9

The Operating System Providing the user interface o Allows the user to: Start application programs Manage storage devices Safely shut down the computer Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 10

Types of user interfaces o Graphical user interface (GUI) o Menu-driven user interface o Command-line user interface The Operating System Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 11

The Operating System Types of user interfaces o Graphical user interface (GUI) Uses iconssmall images that represent computer options Most popular Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 12

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 usedefaults to a command-line user interface Linux o Open source softwaresource code is available to users o Powerful, free Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 13

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 securefewer viruses Stand-Alone Operating Systems Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 14

Stand-Alone Operating Systems Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 15

Stand-Alone Operating Systems Microsoft Windows Mobile o Designed for smartphones and PDAs o Includes simplified versions of Windows programs Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 16

System Utilities: Housekeeping Tools Utility Programs o Software Programs Backing up files Providing antivirus protection Searching for and managing files Disk Defragmentation Compressing files Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 17

System Utilities: Housekeeping Tools Backup softwarecopies data found on the hard disk to a backup device Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 18

System Utilities: Housekeeping Tools Antivirus softwareprotects the computer from viruses o Popular antivirus programs: BitDefender Antivirus Kaspersky Anti-virus Webroot AntiVirus with SpySweeper Norton AntiVirus Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 19

System Utilities: Housekeeping Tools Searching for and managing files o File managerutility software that organizes and manages data Copy files Delete files o Search utilityenables you to locate files Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 20

System Utilities: Housekeeping Tools Scanning Disks o Disk scanning programsfind and resolve disk file storage problems Bad sectorirregularity on the disks surface that cant store data Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 21

Disk Defragmentation Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 22 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 Disk Defragmentation

System Utilities: Housekeeping Tools File Compression utilities o Decrease the size of files, resulting in faster downloads Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 23