1. CHAPTER 2: COMPUTER
SYSTEMS
Software

2. At the end of the lesson, student should
be able to:
 State types of system software
i) Operating system
ii) Utility program
 Describe the differences between the operating
system and utility program

4. What is Operating System??
 Operating system is a set of programs containing
instructions that coordinate all the activities among
computer hardware resources.
 Most of operating system performs similar function
that includes starting a computer, provide a user
interface, managing program, managing memory
and configuring devices.
 Some operating system also allows users to
control a network and administer security.

5. Type of OS
 Three types of OS
 Stand-Alone Operating System – Windows XP,
Vista, Mac OS, Linux, DOS
 Network Operating System – Windows NT,
Windows server 2000, Linux, UNIX, Solaris
 Embedded Operating System – Windows CE, Palm
OS, Symbian OS, Embedded Linux

6. The Various Types of OS used on the
different Platforms
Proprietary Open Source
PC and IBM compatible  Microsoft DOS  Linux (Ubuntu, KDE,
 Microsoft Windows XP RedHat, open SUSE)
 Microsoft Windows Vista  FreeBSD
 TinyOS
Mac – Macintosh  Mac OS
(Apple)  Mac OS X

7. Functions of OS
Starting a computer. The process of starting or restarting a computer is called
booting.
p Provide a user interface. We interact with software through its user interface.
That is, user interface controls how you enter data and instructions and how
information is displayed on the screen. Three types of user interface are
i) Command Line Interface (CLI) Command Driven Interface
ii) Menu Driven Interface Menu Driven Interface
iii) Graphical User Interface (GUI) Icon Driven Interface
T Managing programs. Some operating systems support a single user only one
running program at a time. Others support thousands of users running multiple
programs.
a Managing memory. The computer’s operating system is responsible for
managing memory such as:
s allocating data and instruction to an area of memory while being processed
a Monitoring the contents of memory
o Configuring devices. A driver, short for device driver, is a small program that
tells the operating system how to communicate with specific device.

8. Interfaces of Operating System
1) Command Line
Interface (eg: DOS)
 requires a user to type
commands or press special
keys on the keyboard to enter
data and instructions that
instruct the operating system.
 it has to be typed one line at a
time.
 Example: rename a filename
from ABC.txt to DEF.txt
C:>rename abc.txt def.txt

9. 1) Menu Driven Interface
 enables the user to avoid
memorizing keywords such
as copy, paste and syntax.
 on screen, menu-drive
interface provide menus as
means of entering
commands.
 it shows all the options
available at a given point in
a form of text-based menu.

10. 1) Graphical User
Interface (eg:
Windows XP)
 makes use of the computer’s
graphics capabilities to
make the operating system
and programs easier to use,
which is also called ‘user
friendly’.
 interact with visual images
such as buttons, icons and
other graphical objects to
issue commands.

11. The different Interfaces of OS
Graphical User Interface
Command Line Interface (DOS) (Windows/Linux)
1) User have to 1) User have not to
memories all the memories all the
syntax to issue syntax to issue
command command
2) Difficult to use 2) Easy to use
3) Not user friendly 3) User friendly
4) Take a long time to 4) Take a short time to
learn learn

12. What is Utility Programs??
 Utility programs also known as service programs, is
a type of system software that allow user to
perform maintenance-type tasks, usually related
to manage a computer, its device or its programs.
 Two types of utility programs:
 Built in (windows explorer, disk cleanup, disk
defragmenter)
 Stand-alone utility (winzip, norton utility, kaspersky)

13. Differentiate between the Types and
Usage of Utility Programs
Utility Program Usage Examples
 is a utility program that
File Management performs functions related to Windows Explorer
files and disk management
 example; you can copy files
and programs from one disk
to another.
 is a utility programs that
Diagnostic Utility compiles technical information Norton Utilities
about a computer’s hardware
and certain system software
programs and then prepares
a report outlining any
identified problems

14. Utility Program Usage Examples
 is a system software that we
File Compression use to shrink the size of files so Winzip
they require less storage WinRar
space and reduce transmission PKzip
time if we send them over
internet
 is a program that protects a
Antivirus computer against viruses by Norton Antivirus
identifying and removing any Kaspersky
computer viruses found in a AntiVir
memory, storage media or AVG
incoming files Avast

15. Utility Program Usage Examples
 is a utility program
Defragmenter that reorganize file and Norton Speed Disk
unused space on a Disk Defragmenter
computer hard disk
 the defragment
eliminates fragmented
file
 is a utility programs
Disk Scanner that detect and corrects
both physical and
logical problems on a
hard disk and searches
for and remove
unnecessary software