Computer Concepts 7 by l79y007U

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									                            Chapter 3
                       Computer Software


              Section B: Personal Computer
                   Operating Systems


Computer Concepts 7th Edition
Parsons/Oja
Operating System Overview:
What does an operating
system do?
• An operating system (OS) is the
  master controller for all of the activities
  that take place within a computer.
     – Microsoft Windows XP, Mac OS, Linux,
       UNIX
• The operating system also interacts
  with application software, device
  drivers and hardware to manage a
  computer’s resources
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What does an operating
system do?




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Why does an operating
system need to manage
memory?
• When you want to run more than
  one program at a time, the OS
  has to divide up memory and set
  aside RAM for each program
• The OS must ensure that
  instructions and data from one
  area of memory don’t “leak” into
  an area allocated to another
  program
• If it fails, data can get corrupted,
  programs can “crash” and your
  computer will display error
  messages such as “General
  Protection Fault”

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How does the OS keep track
of storage resources?

• The OS acts as a filing clerk that stores
  and retrieves files from your disks and
  CDs
     – It remembers the names and locations of
       all your files
     – It keeps track of empty spaces where new
       files can be stored


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Why does the operating
system get involved with
peripheral devices?
• To ensure that they function correctly
• OS communicates with the device
  driver software so that the data can
  travel smoothly between the computer
  and the peripheral device
• OS controls peripherals to ensure input
  and output proceeds in an orderly
  fashion
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How does the operating
system affect the user
interface?
• A user interface can be defined as the
  combination of hardware and software
  that helps people and computers
  communicate with each other
• Two types of user interfaces
     – Graphical user interface (GUI) provides
       a way to point and click a mouse to select
       menu options and manipulate graphical
       objects that are displayed on the screen

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How does the operating
system affect the user
interface?
     – Command-line user interface requires
       users to type various memorized
       commands to run programs and
       accomplish tasks




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Where is the operating
system?

• Stored on the hard disk on most computers
• The OS’s small bootstrap program resides on the
  Master Boot Record (MBR) and provides the
  instructions to load the core parts into memory when
  system boots
     – These core components are called the kernel, and
       provides the most essential OS services, such as memory
       management and file access
• The kernel stays in memory all the time your
  computer is on
• Other parts of the OS, such as customization
  utilities, are loaded into memory as they are needed

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Do I ever interact directly
with the OS?
• Yes, typically through helpful tools
  called utilities, which are used to
     – Launch programs
     – Manage files
     – Get help
     – Customize the user interface
     – Configures equipment



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What are the most popular
operating systems?
• Microsoft Windows
     – Installed on over 80% of the world’s PCs
     – Since its introduction in 1985, it has evolved
       through several versions, such as Windows 3.1,
       NT, 95, 98, Me, 2000 and XP
• Mac OS
     – Used with Macintosh computers, manufactured
       by Apple Computer. Inc.
     – PC and Mac platforms are not compatible
          • Platform refers to the combination of a computer’s
            microprocessor and OS
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What are the most popular
operating systems?
• UNIX
     – Developed in 1969
     – Command-line interface
     – Many versions became available for mainframes
       and microcomputers
• Linux
     – Developed in 1991 by Linus Torvald as a school
       project, based on UNIX
     – Linux is free
     – Popular OS for e-mail and Web servers
     – Most Linux versions have a GUI interface
          • Red Hat Linux, Caldera OpenLinux, Debian, SuSE

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Is Mac OS similar to
windows?
• Developed several years before
  windows, it still has a GUI interface
• Both have windows, icons, menus and
  pointers




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The Mac OS




Chapter 3: Computer Software   14
Linux




Chapter 3: Computer Software   15
Why do I keep hearing about
DOS?

• First operating system that most people
  have used
• DOS (Disk Operating System) was
  developed by Microsoft
• Is part of the operating system kernel of
  Windows 3.1, 95, 98 and ME
     – DOS is well hidden behind the Windows GUI
     – Found in the MS-DOS Prompt in the Start menu


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Why do I keep hearing about
DOS?


  “DOS Command-Line Interface”
       Classic Course Labs

                    Found in your
             Computer Concepts BookOnCD


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What are the options for PDA
operating systems?
      Palm OS                  Windows Mobile OS




Chapter 3: Computer Software                       18
Self Quiz Questions

1.    To run more than one program at a time, the OS
      must allocate specific areas of _______ for each
      program.
2.    A _______ is the combination of hardware and
      software that helps people and computers
      communicate.
3.    The core part of an OS is called its _______.
4.    List 3 popular operating systems: _______,
      _______, _______
5.    Windows uses a _______ interface.
6.    DOS uses a _______ interface.


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Self Quiz Questions

1.    To run more than one program at a time, the OS
      must allocate specific areas of RAM for each
      program.
2.    A user interface is the combination of hardware
      and software that helps people and computers
      communicate.
3.    The core part of an OS is called its kernel .
4.    List 3 popular operating systems: Windows ,
      Mac OS , Linux
5.    Windows uses a graphical user interface.
6.    DOS uses a command-line interface.


Chapter 3: Computer Software                            20
Why do I keep hearing about
DOS?


    “Using the Windows Interface”
        New Perspectives Labs

                    Found in your
             Computer Concepts BookOnCD


Chapter 3: Computer Software              21

								
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