Ch 3: System Software

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3
CHAPTER
System Software
2
Objectives

• By the end of this lecture, you should know how
  to
  
• Describe the differences between system software
  and application software.
• Discuss the three basic functions of any
  operating system.
• Describe the three categories of operating
  systems.
• Discuss the purpose of utilities and utility
  suites.
• Identify the five most essential utilities.
• Define device drivers.
• Discuss language translators.

3
Systems Software

• Background software that helps you interact with
  the computer
• Designed to handle
• Technical details
• Where programs stored
• How commands executed
• Where files saved
• How output handled

4
Four Kinds of Programs

• Operating system
• Utilities
• Device drivers
• Language translators

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Four Kinds of Programs

• Utilities
• perform specific tasks related to managing
  computer resources.
• Device drivers
• specialized programs designed to allow particular
  input or output devices to communicate with the
  rest of the computer system.
• Language translators
• convert the programming instructions written by
  programmers into a language that computers
  understand and process.

6
Operating Systems

• Every operating system performs three basic
  functions
• Resource management
• coordinate keyboard, mouse, printer, monitor,
  storage devices, and memory.
• Provide a user interface
• users interact with application programs and
  computer hardware through a windows-like
  graphical user interface (GUI) that use graphic
  objects called icons to represent commonly used
  features.
• Run applications
• the OS loads and runs application programs, such
  as word processors and spreadsheets, and support
  multitasking, which is the ability to run more
  than one application at a time.

7
Operating Systems

• Some widely used operating systems are
• Windows
• Mac OS
• Unix

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Windows

• Windows is the most popular microcomputer
  operating system.
• Windows gets its name from its use of rectangular
  boxes called windows.
• Over 80 percent of the market now uses Windows.
• It is designed to run with Intel and Intel
  compatible microprocessors such as Pentium IV.

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Windows

• Versions of Windows include
• Windows 95
• Windows 98
• Windows 2000
• Windows ME
• Windows XP

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Windows

• Multitasking - different programs running
  simultaneously with this operating system.
• The user interface of Windows is called the
  desktop.
• The desktop has two views
• Classic
• Web style look and feel of Internet Explorer
  browser.
• Windows and many other operating systems store
  information in a system of files and folders.
• Files are used to store data and programs and are
  stored on a secondary storage device such as the
  hard disk.
• Related files are stored within a folder, and for
  organization purposes, a folder can contain other
  folders.

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Windows

• The common way for users to interact with the
  Windows operating system is by selecting icons.
• The Start Menu of Windows displays a list of
  commands used to
• Gain access to information.
• Change hardware settings.
• Find information.
• Get online help.
• Run programs.
• Log off a network.
• Shut down the computer.

12
Mac OS

• Operating system designed to run only on
  Macintosh computers.
• It is a very powerful and easy to use operating
  system and comes in a variety of versions.
• Its market share is much less than Windows.
• Mac OS includes several unique features
• Sherlock - an innovative search feature for
  locating information on the Web or hard drive.
• Aqua an intuitive user interface.
• Dock provides a flexible tool for organizing
  files.

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Unix
Unix
Linux

• The Unix operating system was originally designed
  to run on minicomputers in network environments.
• A powerful operating system for microcomputers
  and servers on the Web.
• One important version of Unix is called Linux.
• Linux is not a proprietary operating system (it
  is not owned and licensed by a company).
• It was developed in 1991 by Linus Torvalds, a
  graduate student at the University of Helsinki.
• Torvalds provided the operating system free to
  others.

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Categories of OS

• Embedded hand-held
• 2. Network OS linked computers
• 3. Stand-alone OS desktop

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Categories of OS

• Embedded operating systems
• Used for handheld computers and smaller devices
  like PDAs.
• Completely stored within the device in its ROM
  memory.
• Popular embedded operating systems include
  Windows CE and Palm OS.

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Categories of OS

• Network operating systems (NOS)
• Used to control and coordinate computers that are
  linked together.
• Typically located on one of the connected
  computers hard disks.
• Called the network server, this computer
  coordinates all communication between linked
  computers.
• Popular network operating systems include
  NetWare, Windows NT Server, Windows XP Server,
  and UNIX.

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Categories of OS

• Stand-alone operating systems (desktop operating
  systems)
• Control a single desktop or notebook computers.
• Located on the computers hard disk.
• Often desktop computers and notebooks are part of
  a network.
• The desktop operating system works with the
  networks NOS to share and coordinate resources.
• Referred to as the client operating system
• Popular desktop operating systems include
  Windows, Mac OS, and some versions of UNIX.

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Utilities

• Utilities are specialized programs designed to
  assist users with tasks that will help run their
  computers without problems.
• Most operating system programs provide some
  utility programs.
• More powerful utility programs can be purchased.

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Essential Utilities

• Troubleshooting
• Antivirus
• Uninstall
• Backup
• File compression

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Utilities

• Troubleshooting
• programs that recognize and correct problems.
• Antivirus
• programs that guard your computer against
  viruses.
• Uninstall
• programs that allow you to remove unneeded
  programs from your hard disk.
• Backup programs
• programs that make copies of your files.
• File compression programs
• programs that reduce the size of files.

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Windows Utilities

• Backup
• utility program that makes a copy of selected or
  all files that have been saved onto a disk. It
  helps to protect you from the effects of a disk
  failure.
• Disk cleanup
• troubleshooting utility that identifies and
  eliminates nonessential files. This frees up
  valuable disk space and improves system
  performance.
• Disk defragmenter
• utility program that locates and eliminates
  unnecessary fragments and rearranges files and
  unused disk space to optimize operations.
• These utilities can be accessed from the Systems
  Tools menu.

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Utility Suites

• Several utility programs sold in a package is
  called a utility suite.
• The cost of the utility suite package is less
  than buying the programs separately.
• Two best-known utility suites are
• McAfee Office.
• Norton System Works.
• DataFellows

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Norton System Works

• Norton System Works includes a suite of five
  separate program groups.
• Each group can be purchased separately or as part
  of the suite.
• The five groups of Norton System Works are
• Norton Utilities a collection of 17 separate
  trouble-shooting utilities.
• finding and fixing problems
• improving system performance
• preventing problems from occurring
• troubleshooting other problems

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Norton System Works

• Norton AntiVirus a collection of antivirus
  programs.
• protection from over 21,000 different viruses
• quarantine or delete existing viruses
• automatically update its virus list to check for
  newest viruses

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Norton System Works

• Norton CleanSweep a collection of programs to
  safely remove programs and files.
• Archive, move, backup files
• Clean up your hard drive
• Protects existing files from damage
• Norton CrashGuard a collection of
  trouble-shooting utilities.
• automatically protects against programs that
  crash or freeze the display screen
• provides options to recover your current work
  before an event causes a crash or freeze

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Norton System Works

• Norton Web Services utilities to keep you
  alert.
• monitors system for out-of-date software
• notifies you of available software updates that
  can be installed from the Internet

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Device drivers

• Specialized programs
• Loaded into memory each time
• Add new device install device driver
• Whenever a new device is added to the computer
  system, a new device driver must be installed
  before the device can be used.

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Device drivers

• Drivers work with the operating system to allow
  communications between the device and the rest of
  the computer system.
• Many times, device drivers are available directly
  from the manufacturers Web site.
• Windows provides an Add/Remove Hardware Wizard
  that offers step-by-step guidance for the
  installation and removal of device drivers.

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Language translators

• Language translators convert human-oriented
  programming languages to machine language.
• Computers only understand a language consisting
  of 0s and 1s called machine language.
• To ease the burden of programming entirely in 0s
  and 1s, special programming languages were
  develop that more closely approximate human
  language.
• Language translators convert these programming
  statements into the zeros and ones that the
  computer is able to process.