Transcript Understanding Computers, 10/e, Chapter 6

Chapter 5
System Software: Operating
Systems and Utilities
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Overview

This chapter covers:

Differences between system software and application
software

Functions of and differences among operating systems

Various types of operating systems
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Functions of and various types of utility programs

A look at the possible future of operating systems
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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.
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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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The Operating System
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Functions of an Operating System

Booting the computer and configuring
devices.

Interfacing with users.
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Managing and monitoring resources and jobs.
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File management.
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Security.
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File Management
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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.
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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.
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Parallel processing—the ability to use multiple
CPUs to process a single job faster.
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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.
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Personal vs. network operating
systems.
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Types and numbers of
processors supported.
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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
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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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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).
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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).

Windows XP (latest version that replaces both
Windows 2000 and Windows Me for home and office
PCs; based on Windows NT).
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Windows Server 2003 (latest network version).
Windows Vista (?)
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Mac OS

Mac OS is the proprietary operating system used with
Apple computers.
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Mac OS has a graphical user interface.
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The newest version is Mac OS X Version 10.3.
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UNIX
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UNIX is a commonly-used, high-end PC and server
operating system.
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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.
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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

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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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Operating Systems for Handheld
PCs and Mobile Devices

Windows Embedded—designed for non-personal
computer-based devices (e.g. cash registers).

Windows Mobile—designed for handheld PCs,
smart phones, and other mobile devices.
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Palm OS—designed for Palm handheld PCs.
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Symbian OS—designed for use with smart
phones.
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Operating Systems for Larger
Computers

Larger computers typically used operating systems
designed specifically for that type of system.
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Many mainframes and supercomputers today are
running Linux.
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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 stand-alone programs.
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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.
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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.
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May eventually be driven primarily by a voice interface.
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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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Summary
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System software vs. application software

The operating system

Operating systems for desktop PCs and servers

Operating systems for handheld PCs and mobile devices

Operating systems for larger computers

Utility programs

The future of operating systems
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