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Using Information
Technology
Chapter 4
System Software
System Software
The Power behind the Power
4.1 The Components of System Software
4.2 The Operating System: What It Does
4.3 Other System Software: Device Drivers & Utility
Programs
4.4 Common Operating Systems
4.5 The OS of the Future: “The Network is the
Computer”
4.6 Online Software & Application Software Providers:
Turning Point for the Software Industry?
4.1 The Components of System
Software
• Operating system the principal
component of
system software
• Device drivers help the computer
control peripheral
devices
• Utility programs support, enhance,
or expand existing
programs
4.2 The Operating System:
What It Does
• Booting - the process of loading an
operating system into a computer’s main
memory
The Operating System: What It
Does
• User interface - user-controllable display
screen that allows you to communicate, or
interact, with
your
computer
The Operating System: What It
Does
CPU Management
• Supervisor (kernel) - program which
remains in main memory while the
computer is running, and directs other
“nonresident” programs to perform tasks
that support application programs
The Operating System: What It
Does
File Management
•
•
•
•
•
Move
Rename
Delete
Copy
Back up
The Operating System: What It
Does
Task Management
Number of
Users
One
Number of
Processors
One
Order of
Processing
Concurrently
Multiprogramming
Time sharing
Multiple
One
Concurrently
Multiple
One
Round robin
Multiprocessing
One or
more
Two or more
Simultaneously
Multi-tasking
Processing of two or more programs
The Operating System: What It
Does
• Formatting
(initializing) a disk
- the process of
preparing that disk
so that it can store
data or programs
• Security
management
4.3 Other System Software:
Device Drivers & Utility
Programs
• Device drivers specialized
software
programs that
allow input and
output devices
to communicate
with the rest of
the computer
system
Utilities: Service Programs
• Backup utility - program which makes a
duplicate copy of the information on your
hard disk
• Data-recovery utility - program which
restores data that has been physically
damaged or corrupted
Utilities: Service Programs
• Antivirus software - program that scans
hard disks, floppy disks, and memory to
detect viruses
• Data compression utility - program which
removes redundant elements, gaps, and
unnecessary data from a computer’s
storage space so that less space (fewer
bits) is required to store or transmit data
Utilities: Service Programs
• Fragmentation - the
scattering of portions
of files about the disk
in nonadjacent areas,
thus greatly slowing
access to the files
• Defragmenter utility program that finds all
the scattered files on
your hard disk and
reorganizes them as
contiguous files
Utilities: Service Programs
• Disk scanner and
disk cleanup
utilities:
• Detect & remove
unnecessary files
• Detect & correct
disk problems
4.4 Common Operating Systems
Desktop & Laptop Operating
Systems
• Platform - the
particular
processor model
and operating
system on which a
computer system
is based
• Disk Operating
System (DOS) the original
operating system
produced by
Microsoft, which
had a hard-to-use
command-driven
user interface
Desktop & Laptop Operating
Systems
• Mac OS operating
system
which runs
only on
Apple
Macintosh
computers
Mac OS X
Desktop & Laptop Operating
Systems
• Microsoft Windows 3.X - released in 1992;
simply a layer over DOS
• Microsoft Windows 95/98 - successors to
3.X
• Plug and Play - the ability of a computer
to automatically configure a new
hardware component that is added to it
• Microsoft Windows Me (WinMe) Millennium Edition
Network Operating Systems
• Novell’s Netware - a long popular network
operating system for coordinating
microcomputer-based local area networks
(LANs) throughout a company or campus
Network Operating Systems
• Windows NT - Microsoft’s multitasking OS
designed to run on network servers; it
allows multiple users to share resources
such as data and programs
• Windows 2000 - successor to Windows
NT
Network Operating Systems
• Windows XP - Microsoft’s newest OS,
which combines elements of Windows
2000 and
Windows Me
New GUI featured in Windows XP
Network Operating Systems
• UNIX - a multitasking operating system for
multiple users with built-in networking
capability and versions that can run on all
kinds of computers
• Sun Microsystems’ Solaris
• Berkeley Software Distribution (BSD)
Network Operating Systems
• Linux - a free version of UNIX, with continual
improvements resulting from the efforts of
tens of
thousands of
volunteer
programmers
Network Operating Systems
• Open-source
software software which
any programmer
can download
from the Internet
for free and
modify with
suggested
improvements
Linus Torvalds, creator of
Linux
Operating Systems for Handhelds
• Palm OS - the dominant
OS for handhelds, which
runs the Palm and
Handspring Visor, and is
licensed to other
companies
• Windows CE (now
Pocket PC) - slimmeddown version of
Windows for handhelds
4.5 The OS of the Future:
“The Network is the Computer”
• .Net - Microsoft’s platform for an OS for
the entire Internet, designed to link
unrelated websites so that people can
organize all info in their lives using PCs
and smaller devices
The OS of the Future
• E-speak - H-P’s version of an Internet OS,
or “universal language,” that allows
different websites to communicate with
one another
The OS of the Future
• Jini - Sun Microsystems’ software
designed to let all types of electronic
gadgets on a wired or wireless network
communicate with one another
The Opposite Possibility: No One
Company Dominates
• Distributed system - a non-centralized
network consisting of several computers
and other devices that can communicate
with one another
4.6 Online Software &
Application Software Providers:
Turning Point for the Software
Industry?
• ASP (Application
Service
Provider) - a firm
that leases
software over
the Internet to
customers
Network Computers Revisited:
“Thin Clients” versus “Fat Clients”
Thin client - users download not only data but
also different kinds of application
software
from an
online
source
Network Computers Revisited:
“Thin Clients” versus “Fat Clients”
Fat client - users provide their own software and are usually
responsible for any upgrades of hardware and software
• Data can be input or downloaded from
online
sources.
From ERP to ASP: The Evolution
of “Rentalware”
• ERP (Enterprise resource planning)
software - large client/server software
applications that help companies
organize and operate their businesses