Discovering
Computers 2010
Living in a Digital World
System Software
• What is System software?
– consists of the programs that control or maintain the
operations of the computer and its devices.
– There are two types of system software:
Operating
systems
Utility
Programs
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Operating Systems
• An operating system (OS) is software that coordinate all
the activities among computer hardware resources.
•
Start and shut
down a
computer
Provide a user
interface
Manage
programs
Manage
memory
Coordinate
tasks
Configure
devices
Establish an
Internet
connection
Monitor
performance
Provide
utilities
Automatically
update
Control a
network
Administer
security
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Operating Systems
provide a user interface
start the computer
manage programs
administer
security
control a network
monitor
performance
provide file management
and other utilities
establish an
Internet connection
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schedule jobs and
configure devices
Operating System Functions
• The process of starting or restarting a computer is
called booting.
Cold boot
• Turning on
a computer
that has
been
powered off
completely
Warm boot
• Using the
operating
system to
restart a
computer
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Operating System Functions
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Operating System Functions
A boot drive is the drive from which
your computer starts.
• You can boot from a boot disk, which contains a
few system files that will start the computer.
– Also called a recovery disk
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Operating System Functions
• An operating system includes various shut down
options:
Sleep mode saves any open
documents and programs to
RAM, turns off all unneeded
functions, and then places
the computer in a lowpower state.
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Hibernate saves any open
documents and programs to
a hard disk before removing
power from the computer.
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Operating System Functions
• What is a user interface?
– controls how you enter data and instructions and how
information is displayed on the screen.
– There are two main types of user interfaces:
• GUI – graphical user interface
• Command Line
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Operating System Functions
• A graphical user interface (GUI) allows the user to
interact with menus and visual images.
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Operating System Functions
• With a command-line interface, a user uses the
keyboard to enter data and instructions.
• They are difficult to use because they require
exact spelling, grammar, and punctuation.
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Operating System Functions
• How an operating system handles programs
directly affects your productivity
Single user and
multiuser
Single tasking
and
multitasking
Foreground and
background
Multiprocessing
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Operating System Functions
• What is multi-tasking?
– Working on two or more
programs that reside in
memory at same time.
– Foreground
• Contains programs you are
currently using.
– Background
• Contains programs that are
running, but not currently
in use.
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Operating System Functions
• A multiprocessing operating system that is capable of
supporting and using more than one processor.
• A multiuser operating system is capable of supporting
more than one user at a time.
– Many operating systems only service one user at a time.
– Some operating systems must handle requests from many
users at the same time.
• Web servers, Database servers, DNS servers, File servers, etc…
• Windows Server & Unix operating systems can do
both functions.
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Operating System Functions
• Memory management optimizes the use of RAM.
• Virtual memory refers to an operating system borrowing
space from the hard drive when it runs out of space in
RAM memory.
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Operating System Functions
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Operating System Functions
• Operating systems typically provide a means to
establish connections to the Internet, wireless
network or other networks.
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Operating System Functions
• A performance monitor is a program that
assesses and reports information about various
computer resources and devices.
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Operating System Functions
• MAC OS X – Activity Monitor
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Operating System Functions
• Operating systems often provide tools for:
Managing files
Searching for
files
Viewing
images
Securing a
computer
Uninstalling
programs
Cleaning up
disks
Defragmenting
disks
Diagnosing
problems
Backing up
files and disks
Setting up
screen savers
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Types of Operating Systems
• Three categories of operating systems:
Embedded
Network
Stand-alone
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Types of Operating Systems
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Stand-Alone Operating Systems
• A stand-alone operating system is a complete
operating system that works on a desktop
computer, notebook computer, or mobile
computing device.
Windows
Vista
Mac OS X
UNIX
Linux
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Stand-Alone Operating Systems
• DOS
– Developed in the early 1980s for
personal computers.
– Microsoft developed the operating
system for IBM.
– No longer used today because it
doesn’t offer a GUI.
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Stand-Alone Operating Systems
• Windows Vista is Microsoft’s fastest, most
efficient operating system to date.
– Windows 7 is slated to replace it as Microsoft’s latest
operating system.
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Stand-Alone Operating Systems
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Stand-Alone Operating Systems
• The Macintosh operating system has set the
standard for operating system ease of use.
• Latest version is Mac OS X named “Snow Leopard”.
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Stand-Alone Operating Systems
• Unix
– Used mainly by power
users because if its
flexibility and power.
– Primarily used for
servers, but available
for computers of all
sizes.
– Most versions offer a
GUI.
– Developed in the early
1970s.
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Stand-Alone Operating Systems
• Linux
– Popular Unix-type
operating system.
– Many versions of Linux
are available and most
are free.
– Open-source software:
code is available to
public.
– Created by Linus Torvalds
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Server Operating Systems
Windows
Server 2008
UNIX
Linux
Solaris
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Server Operating Systems
• Windows Server 2008 is an upgrade to Windows
Server 2003.
– Operating system used to service the requests of many users.
– Web servers, File servers, Database servers, etc…
• Most editions include Hyper-V, a virtualization
technology.
– Virtualization is the practice of sharing or pooling computing
resources.
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Embedded Operating Systems
• An embedded operating system resides on a ROM chip
on a mobile device or consumer electronic device.
Windows
Embedded CE
Windows
Mobile
Blackberry
Palm OS
Embedded
Linux
iPhone OS
Symbian OS
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Embedded Operating Systems
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Utility Programs
• A utility program is a type of system software that
allows a user to perform maintenance-type tasks.
– Also called a utility.
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Utility Programs
• A file manager is a
utility that performs
functions related to file
management.
– Displaying a list of files
– Organizing files in folders.
– Copying, renaming,
deleting, moving, and
sorting files and folders.
– Creating shortcuts.
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Utility Programs
• A search utility is a program that attempts to
locate a file on your computer based on criteria
you specify.
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Utility Programs
• An image viewer allows
users to display, copy,
and print the contents
of a graphics file.
• An uninstaller removes
a program, as well as
any associated entries
in the system files.
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Utility Programs
• A disk cleanup utility searches for and removes
unnecessary files.
– Downloaded program
files.
– Temporary Internet
files.
– Deleted files.
– Unused program
files.
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Utility Programs
• A disk defragmenter reorganizes the files and
unused space on a computer’s hard disk so that the
operating system accesses data more quickly and
programs run faster.
– Defragmenting
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Utility Programs
• Disk defragmenter
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Utility Programs
• A backup utility allows
users to copy files or an
entire hard disk to
another storage
medium.
• A restore utility
reverses the process
and returns backed up
files to their original
form.
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Utility Programs
• A personal firewall detects and protects a
personal computer from unauthorized intrusions.
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Utility Programs
• An anti-virus program detects and protects a computer from
computer viruses.
• An anti-spyware program detects and protects a computer from
spyware.
– Spyware is a program that is placed on a computer without the owner’s
knowledge.
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Utility Programs
• Filters are programs that remove or block certain
items from being displayed.
Web
filters
Anti-spam
programs
Phishing
filters
Pop-up
blockers
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Utility Programs
• A file compression utility shrinks the size of a file(s).
– Compressing files frees up room on the storage media.
• Compressed files sometimes are called zipped files
– Can be uncompressed.
– Software is required to compress and uncompress files.
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Utility Programs
• A media player allows you to view images and
animation, listen to audio, and watch video files
on your computer.
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Utility Programs
• Disc burning software
writes text, graphics,
audio, and video files
on a recordable or
rewritable optical disc.
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Utility Programs
• A personal computer
maintenance utility
identifies and fixes
operating system
problems, detects and
repairs disk problems,
and includes the
capability of improving
a computer’s
performance.
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Quote of the day…
"Two things are infinite: the universe and human
stupidity; and I'm not sure about the universe."
--Albert Einstein
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