2. Describe the two types of
software
Understand the startup process
for a personal computer
Describe the term user interface
Explain features common to
most operating systems
Know the difference between
stand-alone operating systems
and network operating systems
Identify various stand-alone
operating systems
Identify various network
operating systems
Recognize devices that use
embedded operating systems
Discuss the purpose of the
following utilities: file viewer,
file compression, diagnostic,
uninstaller, disk scanner, disk
defragmenter, backup, and
screen saver
Chapter 8 Objectives
Next
p.8.2
3. System Software
What is software?
The series of computer-language coded
instructions that tells the computer how to
perform tasks
Two types of
software
p.8.2
Next
application
software
system
software
4. System Software
What is system software?
Consists of the
programs that
control the
operations of the
computer and its
devices
Serves as the
interface between
the user, the
application
software, and the
computer's
hardware
Two types are
operating
systems and
utility programs
p.8.2
Next
5. Operating
System
Operating Systems
What is an operating system (OS)?
A set of programs
containing
instructions that
coordinate all the
activities among
computer hardware
resources
Required for a
computer to work
Sometimes called
the software
platform or platform
p.8.3
Next
Click to
view
animation
6. Operating
System
manage
programs
Operating Systems
What are the functions of an operating system?
p.8.3 Fig. 8-1
Next
start up the
computer
administer
security
control a
network
monitor
performance and
provide
housekeeping
servicesaccess the
Web
schedule jobs
and configure
devices
provide user
interface
manage
memory
7. Operating Systems
Where is the operating system located?
Resides on computer’s
hard disk in most cases
May reside on a ROM
chip on handheld
computers
p.8.3
Next
various operating systems
often are not compatible
with each other
same types of
computers may have
different operating
systems
different sizes of
computers typically
use different
operating systems
8. Operating Systems
What is a cross-platform application?
p.8.4 Fig. 8-2
Next
runs on
Windows 98
and
Windows NT
One that runs identically on multiple operating systems
Often has multiple versions, each corresponding to a
different operating system
9. Operating System
Functions
What is booting?
The process of starting or restarting a computer
p.8. 4
Next
cold boot
Process of turning on a
computer after it has been
powered off completely
warm boot
Process of restarting a
computer that is already
powered on
Also called a warm start
10. memory resident
• Instructions remain
in memory while the
computer is running
• The kernel is
memory resident
Operating System
Functions
What is the kernel?
The core of an operating
system
• Manages memory and devices
• Maintains the computer’s clocks
• Starts applications
• Assigns the computer’s resources,
such as devices, programs, data,
and information
Each time you boot a computer,
the kernel and other frequently
used operating system
instructions are loaded
• Loading a file means the file is
copied from the hard disk to the
computer's memoryp.8. 4
Next
nonresident
• Instructions remain on
the hard disk until
they are needed
• Other parts of the
operating system are
nonresident
11. Operating System
Functions
What messages display on the screen when you
boot the computer?
p.8.4 Fig. 8-3
Next
sound card and
CD-ROM drivers
loaded
message
devices detected
and tested
total amount of
memory
BIOS version and
copyright notice
12. Step 1: The power
supply sends a
signal to
components in the
system unit.
Step 1
Step 2: The
processor looks
for the BIOS.
processor
BIOS
Step 2
BIOS
basic input/output
system
Firmware that contains
the computer's startup
instructions
Operating System
Functions
How does a
personal
computer
boot up?
p.8. 5 Fig. 8-4
Next
13. processor
BIOS
CD-ROM drive
Step 3
Operating System
Functions
Step 3: The BIOS
performs the POST,
which checks
components such
as the mouse,
keyboard
connectors, and
expansion cards.
POST
power-on self test
expansion cards
p.8. 5 Fig. 8-4
Next
14. Operating System
Functions
p.8. 5 Fig. 8-4
Next
Step 4: The results
of the POST are
compared with data
in the CMOS chip.
processor
BIOS
CD-ROM drive
CMOS
Step 4
CMOS chip
Stores configuration
information about the
computer
Also detects new
devices connected to
the computer expansion cards
15. Operating System
Functions
p.8. 5 Fig. 8-4
Next
Step 5: The BIOS
looks for the system
files in drive A
(floppy disk drive)
and then drive C
(hard disk).
processor
BIOS
hard disk
CD-ROM drive
CMOS
floppy disk drive
Step 5
expansion cards
system files
Specific operating
system files loaded
during start up
16. Operating System
Functions
p.8. 5 Fig. 8-4
Next
Step 6: The boot
program loads the
kernel of the
operating system
into RAM from
storage (hard disk).
The operating
system in memory
takes control of the
computer.
processor
BIOS
hard disk
CD-ROM drive
(RAM) memory
modules
CMOS
floppy disk drive
Step 6
expansion cards
17. Step 7
Operating System
Functions
p.8. 5 Fig. 8-4
Next
Step 7: The operating system
loads configuration information
and displays the desktop on the
screen.
The operating system executes
programs in the StartUp folder.
registry
Several files that contain
the system configuration
information
Registry is constantly
accessed during the
computer's operation
StartUp folder
Contains a list of programs
that open automatically
when you boot the
computer
18. Operating System
Functions
What is a boot drive?
The drive from which your
personal computer boots
(starts)
In most cases, drive C
(the hard disk) is the boot
drive
p.8.6 Fig. 8-5
Next
19. Step 1: Click the Start
button on the taskbar,
point to Programs on the
Start menu, point to
Accessories on the
Programs submenu, point
to System Tools on the
Accessories submenu,
and then point to Backup.
Operating System
Functions
What is an emergency repair disk?
p.8.6 Fig. 8-5
Next
Step 2: Click Backup on
the System Tools
submenu to open the
Backup window. Point to
the Emergency Repair
Disk button.
Emergency
Repair Disk
button
Step 3: Click the
Emergency Repair Disk
button to create the
emergency repair disk.
Follow the on-screen
instructions.
A floppy disk, Zip® disk, or CD-ROM that contains system
files that will start the computer
Used when a hard disk becomes damaged and the
computer cannot boot
Also called a boot disk
or a rescue disk
To create a boot disk:
20. Allows you to type
keywords or press
special keys on the
keyboard to enter
data and
instructions
Set of commands
you use to interact
with the computer
is called the
command language
command-line interface
command
s entered
by user
graphical user interface (GUI)
Allows you to use
menus and visual
images to issue
commands
Controls how you enter data and instructions and how
information displays on the screen
Operating System
Functions
What is a user interface?
p.8.7 Fig. 8-6
Next
Click to
view animation
21. Operating System
Functions
What are features of a graphical user interface?
Menu: a set of
commands from
which you can
choose
Icon: a small
image that
represents a
program, an
instruction, a
file, or some
other object
Web pages can
be delivered or
pushed
automatically
to your screen
p.8.8 Fig. 8-7
Next
icons
function as
Web links
Web pages
pushed onto
the desktop
22. Operating System
Functions
How does an operating system manage programs?
Operating systems vary in
capabilities
• Number of users
• Number of programs
running at the same time
• Number of processors
Management of programs
directly affects user
productivity
p.8.8
Next
single user/single tasking
operating system
Allows only one user to
run one program at a time
Early systems were single
user
23. Operating System
Functions
What is multitasking?
Allows a single user to work on two or more applications that
reside in memory at the same time
p.8.9 Fig. 8-8
Next
The foreground
contains the
active
application: the
one you currently
are using
The other
programs that are
running, but are
not in use, are in
the background
background
applications
listed on the
toolbar
foreground
application
24. Operating System
Functions
p.8.9
Next
multiuser
Operating system enables two
or more users to run a
program simultaneously
multiprocessing
Operating system can support
two or more processors running
programs at the same time
fault-tolerant computer
Continues to operate even if one of its
components fails
Computer has duplicate components
such as processors, memory, and
disk drives
What are other program management
features of operating systems?
Click to
view
animation
25. clears items from
memory when the
processor no longer
requires them
monitors the
contents of memory
Operating System
Functions
What is memory management?
Optimizes the use of random access memory (RAM)
p.8.10
Next
allocates, or assigns, data
and instructions to an
area of memory while
they are being processed
26. RAM
(physical
memory)
disk
(virtual
memory)
page swapped out
RAM
(physical
memory)
disk
(virtual
memory)
Step 1: Operating
system transfers
least recently used
data and program
instructions to disk
because memory is
needed for other
functions.
page swapped in
page swapped out
RAM
(physical
memory)
disk
(virtual
memory)
Step 2: Operating
system transfers
data and program
instructions from
disk to memory
when they are
needed.
Operating System
Functions
What is virtual memory (VM) management?
The operating
system allocates a
portion of a
storage medium,
usually the hard
disk, to function
as additional RAM
p.8.10 Fig. 8-9
Next
27. Operating System
Functions
What are some virtual memory terms?
p.8.10
Next
swap file
The area of the
hard disk used
for virtual
memory
paging
The technique of
swapping items
between memory
and storage
thrashing
When an operating
system spends much
of its time paging,
instead of executing
application software
page
The amount of
data and program
instructions that
can swap at a
given time
28. job
An operation the
processor manages
Operating System
Functions
How does an operating system schedule jobs?
Adjusts the schedule of jobs based on their priority
A buffer is an area of memory or storage in which
items are placed while waiting to be transferred to or
from an input or output device
p.8.10
Next
processing
instructions
sending
information to
an output
device
transferring items
from storage to
memory and from
memory to storage
receiving
data from an
input device
29. server
print jobprint spoolerprint queue
server
jobs
to be
printed
disk
print jobprint spoolerprint queueprint queue print spooler print job
jobs
to be
printed
jobs
being
printed
server laser printerdisk
Print jobs are sent to a buffer instead of sending them
immediately to the printer
Multiple print jobs line up in a queue within the buffer
A program,
called a print
spooler,
intercepts
print jobs
from the
operating
system and
places them
in the queue
Operating System
Functions
What is spooling?
p.8.11 Fig. 8-10
Next
30. Operating System
Functions
What is a device driver?
p.8.11
Next
Click to view Web Link
then click Device Drivers
device driver
A small program that tells the operating system how
to communicate with a device
Also called a driver
Each device on a computer requires its
own specific driver
31. Step 1: Open the
Control Panel
window. Point to the
Add/Remove
Hardware icon. Add/Remove
Hardware icon
Step 2: Start the
Add/Remove Hardware
Wizard by double-
clicking the
Add/Remove Hardware
icon. Follow the on-
screen instructions.
Step 3: The
Add/Remove Hardware
Wizard searches for
Plug and Play devices
on your system. If it
finds any such
devices, it installs
them.
Step 4: If the
Add/Remove Hardware
Wizard cannot find any
Plug and Play devices,
you can select the type
of device you want to
install.
device
type
selected
Operating System
Functions
How do you install a device driver?
p.8.12 Fig. 8-11
Next
Step 5: Next you select
the manufacturer and
model you want to
install. You may be
requested to insert the
floppy disk, CD-ROM, or
DVD-ROM that contains
necessary driver files to
complete the installation
of the device.
manufacturer
selected
model
selected
32. Operating System
Functions
What is Plug and Play?
The computer can recognize a new device and assist
you in its installation by loading the necessary drivers
automatically and checking for conflicts with other
devices
Supported by most
devices and operating
systems today
p.8. 13
Next
Click to view Web Link
then click Plug and Play
33. Operating System
Functions
What is an interrupt request (IRQ)?
A communications line between a device and the
processor
Most computers have 16 IRQs, numbered 0 through 15
p.8. 13Fig. 8-12
Next
IRQs are
assigned
during
installation
34. Operating System
Functions
How does the operating system help access
the Web?
Typically
provides a
means to
establish Web
connections
Some include a
Web browser
and an e-mail
program
p.8.13 Fig. 8-13
Next
35. Operating System
Functions
How does an operating system monitor
performance?
Provides a program, called a performance monitor, that
assesses and reports information about various system
resources
and
devices
p.8.14 Fig. 8-14
Next
36. Operating System
Functions
How does an operating system manage
files?
Contains a program called a file manager
Performs
functions
related to
storage and
file
management
p.8.14 Fig. 8-15
Next
37. organizing,
copying, renaming,
deleting, moving,
and sorting files
Operating System
Functions
p.8.15
Next
displaying a
list of files on a
storage
medium
checking the
amount of used
or free space on
a storage
medium
formatting and
copying disks
creating shortcuts:
an icon on the
desktop that runs a
program when you
click it
What are some file manager functions?
38. Operating System
Functions
What is formatting?
The process of
preparing a disk for
reading and writing
Most floppy and hard
disk manufacturers
preformat their disks
Various operating
systems format disks
differently
p.8. 15
Next
39. Operating System
Functions
What is a file allocation table (FAT)?
A table of information
that the operating
system uses to locate
files on a disk
Defined during the
formatting process
Lists all files, file
types, and locations
Reformatting a disk
usually erases only
the file allocation table
and leaves the actual
files on the disk
p.8. 15
Next
40. Operating System
Functions
What is a network operating system?
An operating system that supports a network
Also called a network OS or NOS
p.8.15 Fig. 8-16
Next
A network is a
collection of
computers and
devices
connected
together via
communications
media and
devices
server controls access
laser
printer
client client client
41. Operating System
Functions
What are features of a network operating
system?
The server is the computer that controls access to the
network and provides a centralized storage area
The other computers on the network are called clients
p.8.15 Fig. 8-16
Next
Organizes and
coordinates how
multiple users
access and
share resources
on the network
Resources include
programs, files, and
devices such as
printers and drives
Network administrator
uses the network OS to
add and remove users,
computers, and other
devices to and from the
network
42. Operating System
Functions
How do operating systems administer
security?
Most multiuser operating systems allow each user to
log on
p.8.16 Fig. 8-17
log on
Process of
entering a user
name and a
password
user name
A unique combination
of characters that
identifies one specific
user
Also called a user ID
password
A combination of characters
associated with the user
name that allows access to
certain computer resources
Next
43. Operating System
Functions
How does a network administrator use the
network OS?
To establish
permissions to
resources
To define who can
access certain
resources
To define when they
can access those
resources
To assign passwords to
files and commands to
restrict access to only
authorized users
p.8. 16
Next
Active Directory (AD)
A feature of Windows 2000
Server that allows network
administrators to manage all
network information including
users, devices, settings, and
connections from a central
environment
44. device-independent
Run on many
manufacturers’
computers
device-dependent
One that runs only on
a specific type of
computer
proprietary software
Privately owned and
limited to a specific
vendor or computer
model
upward-compatible
Written for an earlier
version of the operating
system, but also runs with
the new version
Types of Operating
Systems
What are some characteristics of operating
systems?
p.8.17
Next
downward-compatible
Recognizes and works
with application software
written for an earlier
version of the operating
system
46. Stand-Alone Operating
Systems
What is a stand-alone operating system?
A complete
operating system
that works on a
desktop or
notebook
computer
Some, called client
operating
systems, also
work in
conjunction with a
network operating
system
p.8.17
Next
47. commands
entered by
user
Stand-Alone Operating
Systems
What is DOS (Disk Operating System)?
Refers to several single user operating systems
developed in the early 1980s for personal computers
Two more widely used versions were PC-DOS and MS-
DOS, both developed by Microsoft
p.8.17
Next
Used a
command line
interface and
added a menu-
driven interface
in later versions
48. Windows 95
A true multitasking
operating system
with downward
compatibility for
DOS and Windows
3.x
Stand-Alone Operating
Systems
What is Windows?
Developed by Microsoft to meet the need
for an operating system that had a GUI
p.8.18
Next
Click to
view
Web Link
then click
Windows
Windows 3.x
Refers to three early
versions of Microsoft
Windows that were
operating environments
with DOS
An operating environment
is a GUI that works in
combination with an
operating system to
simplify its use
Windows NT
Workstation
A client operating
system that could
connect to a
Windows NT server
Used a Windows 95
interface
49. Support for the
Universal Serial
Bus (USB)
Stand-Alone Operating
Systems
What are features of Windows 98?
Upgrade to Windows 95
More integrated with the
Internet than Windows 95
Included Internet Explorer, a
popular Web browser
The file manager, Windows
Explorer, had a Web browser
look and feel
An Active Desktop™ interface
allowing icons and file names to
work similar to Web links
p.8.18
Next
Support for
multimedia
technologies such
as DVD and Web
TV ™
50. Stand-Alone Operating
Systems
What is Windows 2000 Professional?
Upgrade to the
Windows NT
Workstation
operating
system
Complete
multitasking
client operating
system that has
a GUI
p.8.18 Fig. 8-19
Next
Click to
view video
51. FAT32
Registry Checker
Stand-Alone Operating
Systems
What are features of most Windows
operating systems?
p.8.18
Next
Active
Desktop™
Taskbar/toolbars
Windows
Explorer has a
Web browser
look and feel
Increased speed
Tune-Up Wizard
Universal
Serial Bus
Update Wizard
Multiple display
support
Hardware
support
Accessibility Settings
Wizard
52. Stand-Alone Operating
Systems
An operating
system that has
features
specifically for
the home user
Also called
Windows Me
Includes
multimedia
features
p.8.20 Fig. 8-21
Next
What is Windows Millennium
Edition (Me)?
53. Stand-Alone Operating
Systems
What is Mac OS?
A multitasking operating system available only for
computers manufactured by Apple
p.8.21 Fig. 8-22
Next
Click to view Web Link
then click Mac OS
Apple’s
Macintosh
operating system
was the first
commercially
successful GUI
Mac OS is the
current version
54. Stand-Alone Operating
Systems
What is OS/2 Warp?
IBM’s GUI multitasking client operating system
p.8.22 Fig. 8-23
Next
Supports
networking, the
Internet, Java,
and speech
recognition
Runs programs
written
specifically for
OS/2, as well as
most programs
written for DOS
and Windows
55. Company on the Cutting
Edge
Apple Computer, Inc.
Formed by Steven Jobs
and Stephen Wozniak in
1976
Began with the Apple I
circuit board developed in
Jobs’ garage
The Apple II product line
generated more than $1
billion in annual sales from
1977 until 1993
The current high-
performance Power
Macintosh line was
introduced in 1994,
followed by the iBook, the
PowerMac G4, and the Mac
OS X
p.8.21
Next
Click to view
Web Link
then click
Apple
56. Network Operating
Systems
What is a network operating system?
An operating
system that
supports a
network
Typically
resides on a
server
Client
computers on
the network rely
on the server(s)
for resources
p.8.22
Next
57. Network Operating
Systems
What is Novell’s Netware?
A widely used network
operating system designed
for client/server networks
Has a server portion that
resides on the network
server and a client portion
that resides on each client
computer connected to the
network
p.8.22
Next
Click to view Web Link
then click Novell
58. Network Operating
Systems
What is Windows 2000 Server?
Family of three products
• Windows 2000 Server: operating
system for the typical business
network
• Windows 2000 Advanced Server:
designed for e-commerce
applications
• Windows 2000 Datacenter Server:
best for demanding, large-scale
applications such as data
warehousing
p.8.22
Next
Windows NT server
Older version developed
as an operating system for
client/server networks
59. Network Operating
Systems
p.8.23
Next
What is OS/2 Warp Server for E-business?
IBM’s network
operating system
Designed for all sizes
of business
Includes Netscape as
its Web browser and
e-mail program
60. Network Operating
Systems
What is UNIX?
A multitasking operating system developed in the early
1970s by scientists at Bell Laboratories
Lacks interoperability across multiple platforms
p.8.23 Fig. 8-24
Next
Click to view Web Link
then click UNIX
Several versions
exist, each
slightly different
Command-line
interface
61. Network Operating
Systems
What is Linux?
A popular, free, multitasking UNIX-type operating system
p.8.24 Fig. 8-25
Next
Also includes many
programming
languages
Open-source
software
• Code is available
to the public
Some versions are
command-line and
others are GUI
62. Product on the Cutting
Edge
Operating system created by Linus
Torvalds
A free program offered as alternative to
Microsoft Windows and Apple Mac OS
Linux’ GNU General Public License
allows anyone to obtain and modify the
source code and then redistribute the
revised product
A large, friendly community of users
distribute the operating system and
provide an extensive number of user
groups, mailing lists, newsletters, and
forums
p.8.24
Next
Click to view Web Link
then click Linux
63. Technology Trailblazer
Linus Torvalds
Creator and lead technical
developer of the free
operating system Linux
A native of Finland
Credits the high level of
technology and superior
educational system of
Finland for giving him the
advantages of being able
to concentrate on his
brainstorm instead of
worrying about economic
issues
p.8.25
Next
Click to
view Web Link
then click
Linus Torvalds
64. Network Operating
Systems
What is Solaris™?
A version of UNIX
Developed by Sun Microsystems
A network operating system designed
specifically for e-commerce applications
Can manage high-traffic accounts
Incorporates security necessary for Web
transactions
Client computers use a version called CDE
(Common Desktop Environment)
p.8.25
Next
65. Embedded Operating
Systems
What is an embedded operating system?
The operating
system on most
handheld
computers and
small devices
Resides on a
ROM chip
p.8. 25
Next
Windows CE
Pocket
PC OS
Palm OS®
66. Incorporates many
elements of the
Windows GUI
Supports color,
sound, multitasking,
e-mail, and Internet
capabilities
Embedded Operating
Systems
What is Windows CE?
A scaled down Windows operating system designed
for use on wireless communications devices and
smaller computers
• Handheld computers
• In-vehicle devices
• Web-enabled devices
p.8. 25 Fig. 8-26
Next
Provides for scaled-down
versions of applications
67. Embedded Operating
Systems
What is an Auto PC?
A device mounted onto a vehicle’s dashboard that is powered
by Windows CE
Directed through voice commands
Provides information to the driver such as driving directions,
traffic conditions, weather, and stock quotes, and allows the
driver to access and listen to e-mail
Acts as a radio or an audio CD
Shares
information
with a
handheld or
notebook
computer
p.8. 25 Fig. 8-26
Next
68. Embedded Operating
Systems
What is Pocket PC OS®?
A scaled-down operating
system developed by
Microsoft
Works on a specific type of
handheld computer, called a
Pocket PC
Allows access to all the basic
PIM functions
Provides Web access
Supports handwriting
recognition
Allows document creation
p.8. 26 Fig. 8-27
Next
Click to
view video
69. Embedded Operating
Systems
What is Palm OS?
Used in handheld
computers
• Palm from Palm, Inc.
• Visor from Handspring®
Manages data and
synchronizes this
information with a
desktop computer
Some access the Internet
p.8. 26
Next
70. utility suites
Combine several utility
programs into a single
package
Utility Programs
What is a utility program?
A type of system
software that performs
a specific task
Usually related to
managing a computer,
its devices, or its
programs
Also called a utility
Most operating systems
include several utility
programs
You can also buy stand-
alone utilitiesp.8.27
Next
McAfee and Norton offer
utility suites and Web-
based utility services
Web-based utility service
You pay an annual fee that
allows you to access and
use a vendor’s utility
programs on the Web
71. Utility Programs
What is a file viewer?
Allows you to display and copy the contents of a file
Windows Explorer has a viewer called Imaging Preview
p.8.27 Fig. 8-28
Next Imaging Preview
72. Utility Programs
What is a file compression utility?
Shrinks the size of a file
Compressed files
• Take up less storage
space than the
original files
• Sometimes called
zipped files
• Usually have a .zip
extension
You must uncompress
a compressed file to
use it
Two popular utilities are
PKZIP™ and WinZip®
p.8.28 Fig. 8-29
Next
compressed
file
73. Utility Programs
What is a diagnostic
utility?
Compiles technical
information about your
computer's hardware
and certain system
software programs
Prepares a report
outlining any identified
problems
Windows includes the
utility Dr. Watson
p.8.28 Fig. 8-30
Next
74. Utility Programs
What is an uninstaller?
Removes an application, as well as any associated
entries in the system files
p.8.29 Fig. 8-31
Next
When an application
is installed, the
operating system
records information
it uses to run the
software in the
system files
The uninstaller
removes this
information
75. Utility Programs
What is a disk scanner?
Detects and corrects
both physical and logical
problems on a hard disk
or floppy disk
• A physical problem is
one with the media
• A logical problem is
one with the data
Searches for and
removes unnecessary
files
Windows includes two
disk scanners
p.8.29 Fig. 8-32
Next
76. fragmented file
The contents are scattered
across two or more
noncontiguous
sectors of a disk
fragmented
disk
file 1 before
defragmenting
disk after
defragmentation
process
file 1 after
defragmenting
Utility Programs
What is a disk defragmenter?
A utility that reorganizes the files
and unused space on a
computer's hard disk
Allows the operating system to
access data more
quickly and
programs to run
faster
p.8.30 Fig. 8-33
Next
Defragmenting the
disk reorganizes it
so the files are
stored in
contiguous sectors
77. Utility Programs
What is a backup utility?
Allows you to copy, or backup, selected files on your
entire hard disk onto another disk or tape
Backup utility monitors progress of the backup process
p.8.30 Fig. 8-34
Next
Many will compress
files during the
process
A restore program
reverses the
process and returns
backed up files to
their original forms
78. Utility Programs
What is a screen saver?
p.8.31 Fig. 8-35
Next
Click to
view video
Causes a monitor's screen
to display a moving image
or blank screen if no
keyboard or mouse activity
occurs for a specified time
period
Developed to prevent
ghosting, in which images
could be permanently
etched on a monitor’s
screen; no longer a
problem for modern
monitors
Popular for security, business,
or entertainment purposes
79. Technology Trailblazer
Phillip Katz
Developed PKZIP, a
data compression
utility
His innovative PKZIP
shareware cornered
the data
compression market
PKWARE has steady
annual sales of $5
million
p.8.29
Next
Click to view Web Link
then click Phillip Katz
80. Summary of Operating
Systems and Utility
Programs
System software
Operating systems
Operating system functions
Types of operating systems
Stand-alone operating systems
Network operating systems
Embedded operating systems
Utility programs