Transcript Chapter 5 - Nawar.us

Chapter 5
System Software: Operating
Systems and Utilities
Understanding Computers, 12th Edition, Enhanced
Chapter 5
1
Overview

This chapter covers:

Differences between system software and application
software

Functions of and differences among operating systems

Various types of operating systems

Functions of and various types of utility programs

A look at the possible future of operating systems
Understanding Computers, 12th Edition, Enhanced
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System Software vs. Application
Software
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System software acts as a mediator between
application programs and the hardware resources of
the computer system.
Application software provides the tools to perform
particular tasks on a PC, such as writing a letter,
processing orders, playing games, composing an
e-mail, and so forth.
 Mini-applications software also known as
gadgets are desktop features in Windows Vista
OS that the user can add to the sidebar or to the
desktop itself, including Clock, Slide Show,
Weather, Calendar, News Headlines Feeds, etc.
Understanding Computers, 12th Edition, Enhanced
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The Operating System

A computer’s operating system is the collection of
programs that manage and coordinate the activities
of the computer system.

Primary responsibilities are management and control.

The operating system is the go-between, meshing
the user’s application program with the resources of
the system.
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Functions of an Operating System

Booting the computer and configuring
devices.
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Interfacing with users.
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Managing and monitoring resources and jobs.
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File management.

Security.
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Processing Techniques for Increased
Efficiency
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Multitasking—the ability of an operating system to
work with more than one program (task) at a time.

Multithreading—the ability to process multiple
threads within a program at one time.

Time-sharing—technique for multiple programs to
share processing on a rotating basis.
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Processing Techniques for Increased
Efficiency, Cont’d.

Multiprocessing—the ability to use multiple CPUs
to process multiple jobs.

Parallel processing—the ability to use multiple
CPUs to process a single job faster.

Coprocessing—utilizing special processors for
specialized chores (e.g. math coprocessor).
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Processing Techniques for Increased
Efficiency, Cont’d.

Memory management, such as the use of virtual
memory.

Buffering and spooling
 A buffer is an area in RAM or on the hard drive to
hold input and output on their way in or out of
system.
 The process of placing items in buffer so they can
be retrieved by appropriate device is spooling.
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Differences Among Operating
Systems

Command line vs. graphical
user interface.

Personal vs. network operating
systems.

Types and numbers of
processors supported.

Support for virtualization and
other technologies
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Operating Systems for Desktop PCs
and Servers

PC operating systems are usually designed for use
on either:
 Desktop PCs (personal operating systems)
 Network servers (network operating systems)

Some operating systems have versions for both;
some personal operating systems have limited
networking capabilities.
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DOS

PC-DOS and MS-DOS were the dominant operating
systems until the early 1990s.

DOS traditionally used a command-line interface; it is
not widely used today.
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Understanding Computers, 12th Edition, Enhanced
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Windows

Many versions of the Windows operating system
have existed over the last several years.

Windows 3.x (an operating environment over DOS, not
an operating system).

Windows 95 and Windows 98 (personal operating
systems).

Windows Me (personal operating systems for home
PCs).
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Windows NT (network operating system).
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Windows, Cont’d.

Windows 2000 (network and professional operating
system).
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Windows XP (replaced both Windows 2000 and
Windows Me for home and office PCs; based on
Windows NT).
Windows Vista (replaced both Windows XP)
Windows 7 (currently not yet released)
Windows Server 2008 (latest network version).
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Understanding Computers, 12th Edition, Enhanced
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Mac OS
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Mac OS is the proprietary operating system used with
Apple computers.

Mac OS has a graphical user interface which is the
first ever to use a mouse.
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The newest version is Mac OS X Version 10.5.
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UNIX
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UNIX is a commonly-used, high-end PC and server
operating system.

Not built around any one particular family of
microprocessors—can be used on a variety of
computers.
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Though traditionally a command line operating
system, newer versions of UNIX use a GUI.
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Linux
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Linux is a version of Unix originally created in 1991.
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Linux is open-source software; has been collaboratively
modified by volunteer programmers all over the world.

Traditionally a command line operating system; many
versions now use a GUI.

Recent increased support from big name companies (Sun,
IBM, HP, and Novell, for instance) has increased the use
and support of Linux.
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NetWare


One of the most widely used operating system on
PC-based networks.
NetWare provides a shell around the users’ local
desktop operating systems so they can interact with
network resources.
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OS/2 and OS/2 Warp
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OS/2 is an operating system designed by IBM for
high-end PCs.

Available in both server and client versions (for
accessing an OS/2 server).

Discontinued since latest vesion OS/2 Warp 4 in
2006
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Solaris

Designed for Sun computers.

Can run on desktop PCs, servers, and some
supercomputers.
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The latest version is Solaris 10.
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Operating Systems for Handheld
PCs and Mobile Devices

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Windows Embedded—designed for nonpersonal computer-based devices (e.g.
ATMs, cash registers, CCTV systems, etc.).
Windows Mobile—designed for handheld
PCs, smart phones, and other mobile
devices.
Palm OS—designed by Palm Inc. for Palm
handheld PCs, currently called Garnet OS.
Symbian OS—designed by UK Symbian
Ltd. for use with smart phones.
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Understanding Computers, 12th Edition, Enhanced
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Operating Systems for Larger
Computers

Larger computers typically used operating systems
designed specifically for that type of system.

Many mainframes and supercomputers today are
running Linux.

A group of Linux PCs linked together to computer at
supercomputing levels is called a Linux supercluster.
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Utility Programs

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Utility program—a type of
systems program written to
perform a specific system
task, usually related to
managing or maintaining the
system.
Many utilities are built into
operating systems as well as
being available as standalone programs.
File management
programs—allow you to look
at and manage the files stored
on your PC (copy, move,
organize into folders, etc.).
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Utility Programs, Cont’d.
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Antivirus programs—find and eliminated
computer viruses on your PC.

Should be set up to run continuously and scan
incoming files and e-mail messages.
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Should be set up to do a complete scan of your
PC about once per week.

Need to be updated on a regular basis.
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Utility Programs, Cont’d.

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Diagnostic programs—evaluate the computer system
and make recommendations for fixing any errors
found.
Disk management programs—diagnose and repair
problems related to the hard drive.
 Disk defragmentation programs rearrange the files
on a hard drive to store them in contiguous
locations to speed up performance.
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Utility Programs, Cont’d.

Uninstall utilities remove programs from your hard
drive without leaving bits and pieces behind.
 Programs should never be deleted from the hard
drive without using an uninstall procedure, unless
there is no other alternative.

File compression programs make files smaller for
archiving or sending over the Internet.
 Compression programs can both compress (zip)
and decompress (unzip) files.
 Common programs are WinZip for Windows users
and Stuffit for Mac users.
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Utility Programs, Cont’d.

Backup utilities are programs designed to back up the
contents of a hard disk.
 You can usually specify certain files or folders to be
backed up or back up an entire drive.


Businesses should back up frequently and regularly;
individuals should back up their PC occasionally and
all important files each time they are modified.
Recovery utilities are designed to help you recover from
a major computer problem, such as rolling back your
hard drive to an earlier state if it quits working after you
install a new piece of hardware or software.
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Utility Programs, Cont’d.
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Encryption programs are used to secure e-mail
messages and files that are sent over the Internet or
other networks; can also be used with individual files
stored on a hard drive.
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Network and Internet utilities include:

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Performance monitors
Logging programs
Directory services or identity management programs
Firewall programs
Antispam and e-mail filtering programs
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The Future of Operating Systems

Will likely continue to become more user-friendly.

May eventually be driven primarily by a voice interface.

Will likely be used to access an increasing number of
Internet resources and applications, such as Web
based software and services.
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Will likely continue to support more synchronization
between an individual’s various computing devices,
such as a desktop PC, handheld PC, and smart phone.
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