WHAT IS
COMPUTER APPRECIATION
It entells a stage in computer study which
involves the learner to understand the terms or concepts and skills in
computer. Furthermore, it creates a platform through which students or
beginners receive thorough information relating to all the major and minor
components of the computer system. Note: for appreciation to take place in any
field of study, definitely the person must have pass through the techniques involved
in the concept and at the same time must have become acquainted with the
concept.
Therefore for any beginner to claim to have
appreciated computer, it the means that the person have become acquainted with
the concepts and skills as regards to
computer.
Therefore, students are highly advised to put
maximum concentration in this stage called “Computer
Appreciation”.
INTRODUCTION
TO COMPUTER:
In this paragraph, we look at where computer was
originally designed, what brought about its evolution and why we must use it.
Computer is the most powerful recent technology
ever developed, it was invented or earlier started from United States (U.S.A)
out of the need to combat the difficulties
people encounters in computing.
Just imagine in the olden days when people are passingthrough series of challenges in
areas of computation such as: Counting which was done by the use of
Fingers/Toes, Stones, Napiers Bone, Abacus Device etc. In addition to that,
even the time factor determination is done using human shadow, areas like
information sending and receiving was done with smoke. But presently, things
have totally changed in all areas of computing.
Even now, the list person as regards to
technology is using computer in one way or the other. Actually, the calls we
make, the messages we send online and through other means, our Banking are all
about computing.
Therefore, the importance of computer to mankind
cannot be quantified.
DEFINITION
OF COMPUTER:
The computer system is not a single unit rather
it is made up of disintegrated components. It then means that the definition
will not be complete without mentioning all the parts that aid data processing,
since computer is a data processing machine. Sometimes the generic term “Computer”
is used to describe the C.P.U and the peripheral devices used for data
processing.
Therefore, Computer can be defined as an
automatic electronic machine which accepts data as input, processes the data in
the processing unit in respect to a specified instruction, and inturn brings
out the information via the output unit.
TERMS
TO NOTE WHEN DEFINING COMPUTER:
AUTOMATIC:- This simply mean that it can be programmed to work in absence of
humans. E.g Robot, Security gadgets, Monitoring devices etc.
ELECTRONIC:- This is to explain that there must be an outer source of current through which the
computer can be connected for it to start working. Note that the word
“Electronic” comes from Electron, which also stands for current (+ve and –ve)
charges.
MACHINE
OR DEVICE:- for the fact that computer aid humans to
make work easier, it is therefore referred to as a machine or device.
DATA/INPUT:- These are raw facts or unprocessed data sent to the computer for
processing. Note that data is the opposite of information. The parts which data
enters the computer is known as input devices e.g keyboard, mouse, joystick
etc.
PROCESSING:- This is a means of modifying data automatically by the computer or
manually by the user. Basically, processing is done within the (C.P.U)
INFORMATION/OUTPUT:- This is a processed data. It can said to be the end product of data.
Information is produced via the output devices such as monitor or V.D.U (visual display unit), printer
etc. note: information produced through the monitor is known as softcopy while
via the printer is the hardcopy because, the softcopy can only be seen while
the hardcopy can be see, touched and also felt.
IMPORTANCE
OR USES OF COMPUTER:
Generally, computer is been used in every day
activities in one way or the other. Therefore its uses can be drawn from our
daily activities.
1.
It
can be used for the diagnoses of some malignant diseases e.g the X-Ray machine
used for the diagnoses of cancer.
2.
It
is used for the processing of different types of database
3.
It
is used in printing industries for large data processing.
4.
Computer
is highly used in research industries for their researches and new discoveries.
5.
Special
bodies like EFCC uses computer for
crime detection. Even political bodies uses computer for storing of political
database e.g voting records.
6.
Bankers
use computer to make transaction easier and other banking works.
AREAS OF APPLICATION OF
COMPUTER:
The
areas of application of computer cannot be over
emphasized in as much as it is been used by different persons in
different fields of life. The areas includes:
1.
Communication
industry:- for generating of telephone bills.
2.
PHCNalso uses it for the generation of\PHNC bills.
3.
Banks uses it for their accounting.
4.
It used in space technology
5.
INEC:- for
effective vote counting
6.
Institutionsof learning uses it for updating students record
examination processing. \etc.
ADVANTAGES
OF COMPUTER:
1.
It
is used for the processing of data
2.
It
creates employment opportunities
e.g Banking work, ICT’s etc.
3.
It
is used in the study of light by sciences.
4.
It
helps for the storing of information for future references.
5.
It
makes works easier for humans.
DISADVANTAGES
OF COMPUTER:
1.
Fraud:
people use computing in stealing money through the internet and other
fraudulent acts.
2.
It
exposes under age people to danger e.g pornography
3.
It
can cause unemployment:- Imagine were an one is working as a secretary without
the use of computer, but as soon as there is a change in technology which may
bring about the use of computer, he/she will be resigned.
4.
Loss
of information:- Any damage to a computer containing files may lead to loss of
information
5.
It
is very costly to purchase
6.
It
has a high cost of maintenance.
LIMITATIONS
OF COMPUTER:
Despite the immense powerful and potential
services gained from computer by humans, it still posses some leakages . Since
man has limitations, it also has too.
1.
It
cannot think on its own.
2.
It
depends on instructions given to it by humans to start working.
3. It cannot correct
mistakes.
4. Whatever you feed into
the computer is what you get back. i.e GIGO: Garbage in Garbage out. For
instance, you intend to type 20+ 20 to give 40, you then mistakenly type 2+2,
it will give you 4.
5.
Despite its immense powerful nature, it can be intentionally
destroyed by humans.
\GENERATIONS OF COMPUTER:
By generation, it is simply discussing about the
stages in which different computers was developed. NOTE: Each generation came
with a particular computer. Basically there are five generations of computer.
|
GENERATIONS
|
FEATURES
|
|
FIRST GENERATION
|
·
Uses vacuum tubes for circuitry.
·
They are very large in size.
·
Only operated by specialists.
·
Costly to maintain due to their large electrical power,
air conditioning and space requirement.
·
Used by military & research institutes e.g UNIVAC
(Universal Automatic Computers).
|
|
SECOND GENERATION
THIRD GENERATION
|
·
It was introduced in 1959.
·
The circuits were made of transistors.
·
Smaller than the 1st and are reliable.
·
The memories were magnetic tape.
·
It uses integrated circuit.
·
More reliable than the 1st& 2nd.
·
Mini-computer were introduced.
|
|
FORTH GENERATION
|
·
Uses large integrated Circuit
·
Memories are made of high silicon chips
·
More reliable than the former.
|
|
FIFTH GENERATION
|
·
Uses the latest form of circuit
·
High storage capacity and high in processing
·
It can handle so many tasks.
|
CHARACTERISTICS
OF COMPUTER:
The characteristics of computer includes:-
1.
Accuracy:- Computer has the ability to provide the right
answer provided the data is accurate.
2.
Storage:- It has large storage capacity.
3.
Versatile:- It can be programmed to handle so many tasks.
4.
Flexible: It can be modified to do many things.
5.
Speed:- It can process large amount of data within
few seconds compared to humans.
6.
Reliability:-computer is highly
reliable in executing its job.
CLASSIFICATIONS OF COMPUTER:
In classifying computer,
we will look at some prominent issues as regards to computer. They includes:-
1.
Size
2.
Purpose
3.
Types.
CLASSIFICATIONS OF COMPUTER BASED ON SIZE:
Computers based on size
includes:-
1.
Micro-Computers:- These can also be referred to as a personal Computer (PC),
because they can only a\be operated by one person at a given point in time but
when connected to a network, it can allow two or three persons to work with it.
They are computers found in Homes and Offices. E.g Desktop, Laptop, palmtop,
Notebook Computers etc.
2.
Mini-Computers:- As the name implies, they are the medium
computers in respect to size. They are larger than the micro-computers, and are
used for industrial purposes. Note, these computers can allow upto ten numbers
of persons to work on it at a given time.
3.
Mainframe-Computers:- These are the largest computers that exist. They can allow upto
fifty numbers of persons to work on it at a time, they are used in industries
for mass data processing. Note, these are also known as Super Computers.
CLASSIFICATIONS OF COMPUTER BASED ON PURPOSE:
They includes:-
1.
General Purpose
Computers:- These are computers used to handle different
job issues. They are programmable which gives it the ability to function as a
general purpose computers. E.g Micro-Computers.
2.
Special Purpose
Computers:- These are referred to as preprogrammable
computers (not programmable). They are used for a specific type of objective.
They are basically used \in Airports for monitoring. E.g Traffic control
computers, Security computers, Missile launching computers etc.
CLASSIFICATIONS OF COMPUTER BASED ON TYPES:
1.
Digital Computers:- They are computers that their signals are in
discrete form. i.e count form. They are used for calculations. E.g counting
machines, calculators etc. digital computers are programmable.
2.
Analog Computers:-Their signals are in
continuous form. they are use in measuring physical quantities e.g
Thermometers, Barometers, Speedometers’, Weighing machines etc.
3.
Hybrid Computers:- These are computers developed out of combining the function of Digital and Analog
computers together. They can be used to handle several tasks.
COMPONENTS
OF COMPLETE COMPUTER SYSTEM:
It is obvious that the human body is not made up
of a single part; we also need to understand that one cannot function or
execute any activity(s) effectively when all the parts are not complete. So
also the Computer behaves as such. Therefore, cannot function until are the parts
are complete. The parts of complete computer system are:-
1.
The
Hardware
2.
Software
HARDWARE:-These are the physical aspect of the
computer that can be seen, touched and also felt.
COMPONENTS OF THE HARDWARE:
1.
Keyboard:- This is an input
device used to send data into the computer system for processing.
2.
Mouse:- This is another input device basically use to
issue commands. Other input devices includes:- Joystick, \Touch screen etc.
3.
The System Unit:-It is the major part
of the computer used for data processing. Generally, the system unit is just
like a casing while the part that does the processing is called Central
Processing Unit (CPU).
4.
Monitor:- (V.D.U) The Monitor
is also known as visual Display Unit. It helps a user to see information. It is
an output device. We have Monochrome (Black and White), and Coloured Monitor.
Note, the monitor displays softcopy of an information
5.
Printer:- It is also an output
device which produces information in its Hardcopy. Printers come in different
forms: the Inkjet printers uses cartridge as the ink container while the Laser
printers uses toner as the ink container.
6.
Scanner:-It is used to transfer
images of different kind into the computer system. It is also an input device.
Note:- The above devices
are the major parts of the hardware components of the computer. With the
exception of these devices the definition of computer cannot stand.
Accessories which can also be referred to as hardware are:-
1.
Flash Drive:- For storing of information externally.
2.
Floppy Diskette:- it is also an
external storage device.
3.
CD-ROM:- (Compact Disk – Read
Only Memory) it is a circular shape external storage device.
4.
Speaker:-It is an output device
which produces sounds from the system.
5.
Earpiece:-It also an output
device that produces sounds.
THE
SYSTEM UNIT:
When we mention the system unit, we are simply
referring to the casing that houses the essential components of the system. But
in the long run, we mean the Central Processing Unit (C.P.U) which is the brain
of the computer where all works are done.
TYPES
OF SYSTEM UNIT:-
1.
Flat Bed System Unit:-This is a type of
system unit that the system is kept
flat on the desk and the monitor on it.
2.
Mini Tower System Unit:- It is a system unit which is been kept
vertical on the desk and the monitor by its side.
3.
Maxi Tower System Unit:- It is the same as the Mini Tower System Unit,
but is
larger than the Mini Tower System Tower Unit.
COMPONENTS
OF THE SYSTEM UNIT:
1.
Casing:-It is a rectangular
box that contains the C.P.U and other components.
2.
Power Supply Unit (Power
Pack):- This supply current to all the electrical
components of the computer.
3.
Mother Board:- It is the greenish rectangular box that
contains all the electrical components of the computer.
4.
CD-ROM:- (Compact
Disk-Read Only Memory) It is an optical Disk that holds information
recorded by the manufacturer, it cannot be written on or erased.
5.
CD-R:-(Compact Disk
Recordable):-
It only allows users to record data once. It cannot be erased or over written.
6.
CD-E (Erasable Disk or
CD-RW Compact Disk Rewritable) it can allow a user to write and over write. i.e
It can be used severally.
7.
Sound Cards:-It enables the computer
to produce sounds when playing music.
THE CENTRAL PROCESSING UNIT (C.P.U)
This is the most vital component of the computer system. It is a location where all arithmetic and logical operation takes place. It is basically the brain of the computer where all the processing is done.
The C.P.U is divided into the following:
1.
Arithmetic and logical
unit:
it is the part that handles arithmetic like addition, subtraction, division and
multiplication coupled with decision making.
2.
Control unit: it ensures that there
is a free flow of current in the circuit.
3.
Memory unit: it keeps tracks of
programmed instruction and processed data.
BOOTING
This
can be defined as a systematic way of preparing the computer for use, it is of
two types:
1.
Cold booting: it is a process of
starting the computer from its point of rest when not turned on.
2.
Warm booting: it is a means of
re-preparing the system for use by simply restarting it.
SHUTDOWN, TURNOFF, STAND BY, LOG OFF, RESTART.
1.
Shutdown/Turn off: it is a means of
sending the computer to its rest point
2.
Stand by/Log off: it is a process whereby
the computer is kept in an idle mode. Although it will still be on.Note: whenever a system is on Standby mode, to
welcome it back, just press the enter key.
3.
Restart: As the name implies,
it is used to reboot the computer.
MEMORY
It can be defined as
part of the computer system that keeps track of programmed instruction and
process data. It is divided into:
1.
Primary
memory
2.
Secondary
memory
1.
Primary Memory: it is made up of ROM
and RAM.
(a)
Rom: (Read Only Memory): As the name implies, it
simply means that, one can only read from it but cannot write on it. The
information are permanently stored and it is written by the manufacturers. The
ROM contains information that is only understood by the C.P.U whenever a
computer is switched on.
(b)
RAM: (Random Access Memory): it contains information
on temporary basis.While you are working with the system,the program you are
working with and the data are in RAM. That’s why it’s advisable that
usersshould save their jobs to the disk before turning off, or should in case
of power failure.
2. SecondaryMemory: As the name implies,
it is second of the primary memory. It helps user to save information from one
place to another which can be used for future reference e.g flash drive, floppy
disk, CD-ROM.The secondary memory is of two types:
(a) Internal storage unit: it stores
information internally into the computer system.It maybe a hard disk or local
disk (Drive C or D)
(b) External storage unit: It helps to store information from one place
to another which can be used for futurity .e.g. Flash drive, floppy disk,
CD-ROM etc.
SOFTWARES
Software can be defined
as a set of programmed instruction designed by program writers to enable the
computer execute its objective.Or it is said to be a set of programmed
instruction designed to exploit and facilitate the potential capacity of the
hardware’s.
Note: Without the
software, the hardware is just like a disk player without a CD-plate .i.e.
without the software the hardware remains dormant. More so, without your sim
card, one cannot make calls which is the primary aim of the phone.
TYPES
OF SOFTWARE
1.
System
software
2.
Application
software
3.
Personal
software
1. System software: This is the major
software as regards to the fact that it is the software that executes the most
important task like booting the computer and running it . In order words, it
can be a software that enhances the working of the computer generally e.g.
MS-WOS, MS-DOS etc
2.
Application software:These are
software designed by programmers to enable user carry out their tasks.
Application Software can be sub-divided into:
a.
Application packages
b.
User application programs
a.
Application packages: these are
packages use to handle different business issue
e.g. MS word , MS Excel, coral draw, MS Access ,peach tree
Accounting etc
(b) User application programs: These are instructions written by programmers or users required for the running of their individual business
3.Personal software:These are the users
of the Computer.eg computer operators, instructors,
Analyst,engineer’s,programmer’s etc.note; without
Software the hardware remains dormant.Therefore
without the computer user starting the computer, it will be at its
rest position for millions of years.
OPERATING
SYSTEM (O.S)
An operating system
(so) can be defined as a set of program
that acts as an interface between the computer and the user. It is system
software thatmanages the system resources, controls other software’ and at the
same time make sure that works given to the computer are properly executed and completed.
TYPES OF OPERATING SYSTEM
1
Single User Operating Systems: It is
an operating system that allows its user to carry out only one job at a given
point in time e.g. Microsoft Disk Operating System (Ms- Dos).
2 Multi –User
OperatingSystem:
It is an operating system that enables its user to carry outtwo or more task at
a particular point in time. e.g
Microsoft
Windows operating system (Ms-Wos)
FUNCTIONS
OF AN OPERATING SYSTEM
1.
The
operating system control all the activities of the computer such
as\coordinating the flow of data between different application programs.
2.
O.S
allows the computer user to get a result.
3.
It
serves as an interpreter between the computer and the user.
4.
It
loads it in the memory
5.
It
loads the user program in the memory.
WINDOWS (MS-WINDOWS-MS WOS)
Microsoft Windows are
operating system. It came out after MS DOS(Microsoft disk operating system) to
enable users run multiple tasks at a given point in time.
DEFINITION: Windows can be defined as an interactive and
multi-tasking operating system with graphical user interface (G.U.I).
It is a rectangular
environment full of graphics concerning the program been displayed on the
screen.
RELATIONSHIP BETWEEN WINDOWS AND O.S
The relationship between
windows and O.S is that the, window itself is a specific example of an operating
system and at the same time they posses the same features.
VERSIONS OF WINDOWS
1. Lower version windows: These are
windows that earlier existed.eg windows 3.0,3.1 ,4.0 ,4.1 etc
2. Higher
version windows: They are the recent windows in existence.eg windows 95, 98
,98 plus ,2000,2003 ,windows millennium(M.E) ,windows experience(X.P) ,windows
vista ,windows 7 etc.
FUNCTIONS
OF WINDOW ENVIRONMENT
1.
It
is used to run program(s)
2.
It
enables users to create files
3.
It
is used to check the property of external devices eg flash drive , CD-Rom etc
4.
It
can be used to create folder
5.
It
is used to move a file from one location to another
6
.It is used to decorate the desktop windows environment.
WINDOWS TECHNIQUES
Windows
techniques are operations that are done within any opened window with the use
of mouse.
The
techniques include:
1.
Pointing: it is the act of
moving the mouse pointer on top of an icon. It is used to indicate the name of
the icon pointed on.
2.
Clicking: This is the process of
selecting an item or icon by moving the mouse pointer on an icon and pressing
the left mouse button down.
3.
Double clicking: it is used to open an
item by simply pressing the left mouse button twice at the same time on top of
an icon.
4.
Right clicking: it display options
concerning the icon.This is done by pressing the right mouse button down.
5.
Dragging: This is used to move
an icon from one location to another by simply pressing the left mouse button
down on an icon with a move to the direction of your choice.
FOLDER /ICON (FULL
MANAGEMENT)
A folder can be define
as a store house for filesand programs. OR as a feature that houses files and
programs.It can also be called an ‘’ Icon‘’.THUS: anIcon can be defined as a
pictorial or diagrammatical representation of files and Program.
TYPES OF FOLDER
1.
System Folder:- These are folders already created by the
system. They are automatically created immediately after system’s
configuration. E.g
A My Computer:- It contains the configuration information and properties of the
system.
B My Document:- It contains all the jobs created and saved b y a user.
C My Network Place:-It contains the
network information and configuration of a computer.
D Recycle Bin:-It houses deleted files.
E Internet Explorer:-
It opens the global file.
2. Personal Folder:- As the name implies, they are folders created
by users e.g my picture, CJ’s folder, my fotos, my assignment.
STEPS TO CREAT A FOLDER
For the fact that folder Can be created in
different environment, especially in environments with the command “New”, it
simply means that the steps to create it varies.
1.
Using the Desktop:
(a)
Right
click on empty space on the desktop
(b)
Click
on new
(c)
Click
on folder
(d)
Type
the name you want for the folder
(e)
Press
enter key
2.
Using Windows Explorer:
(a)
Launch
window explorer
(b)
Click
on file menu
(c)
Click
on new
(d)
Click
on folder
(e)
Type
the name you want for the folder
(f)
Press
enter key
STEPS
TO RENAME A FOLDER
1.
Right
click on the folder you want to rename
2.
Click
on rename
3.
Type
the new name for the folder
4.
Press
enter key
STEPS
TO DELETE A FOLDER
1.
Right
click on the folder you want to delete
2.
Click
on delete
3.
Click
on yes
RECYCLE
BIN:- This can be defined as a location where deleted
items are found.
Note: After deleted jobs can
also be restored from the Recycle Bin.
STEPS
TO RESTORE DELETED FILE
1.
Launch
Recycle Bin
2.
Right
click on the file you want to restore
3.
Click
on restore, or click on restore all item in order to restore all the files
STEPS
TO DELETE FILE FROM THE RECYCLE BIN
1.
Launch
Recycle Bin
2.
Right
click on the file you want to delete
3.
Click
on delete. Or click on empty Recycle Bin in order to delete all the files at
the same time.
CUT COPY AND PASTE
These are commands or instruction used to move a
file or group of items from a given
location to another.
Note: Cut command moves an item from one location to another. While Copy
keeps the items in its original position after pasting. Paste on the other hand
can be defined as a command use to duplicate cut and c copied items.
Note: For a user to paste and item, he/she must first cut or copy an item.
i,e paste is dependent on cut and copy.
STEPS TO CUT OR COPY AN
ITEM(S)
1.
Right
click on the item you want to cut or copy
2.
Click
on cut or copy (optional)
STEPS
TO PASTE CUT AND COPIED ITEM
1.
Open
the environment you want to paste the item
2.
Click
on edit menu and click on paste or
3.
Right
click in the environment and click on paste.
DESKTOP
ENVIRONMENT
The Desktop environment is the first environment
that display immediately a system is booted.
FEATURES
OF THE DDESKTOP ENVIRONMENT
Features or properties of the desktop
environment simply refers to the elements or items found on the desktop.
1.
Icons or Folders: They are pictures or diagrams that represent files and programs on
the desktop.
2.
Wallpaper: It is graphical picture used to decorate the desktop.
3.
Screen saver: It is an animation that displays when the system is idle.
4.
Task bar: It contains the start button with date and time. In order words,
it can be refers to as the footer bar.
Note: Idleness mode of the system simply refers to a
situation whereby the system is turned on, but not in use.
STEPS
TO APPLY THE WALLPAPER
1.
Right
click on empty space on the desktop
2.
Click
on properties
3.
Click
on desktop
4.
Under
backgrounds, select any background of your choice
5.
Click
on apply and ok.
STEPS
TO APPLY SCREEN SAVER
1.
Right
click on empty space on the desktop
2.
Click
on properties
3.
Click
on screen saver
4.
Under
screen saver, select any screen saver of your choice
5.
Click
on apply and ok.
Note: To use a special text as screen saver e.g Jesus
is Lord, He is my Saviour, My Redeemer Liveth etc under screen saver, click on
3D text under screen saveer’s, click on setting, under custom text, type the
text for the screen saver, click on ok. Then apply and ok.
STEPS
TO SET THE SYSTEM DATE AND TIME
1.
Under
the task bar, right click on date and time
2.
Click
on adjust date and time
3.
Set
the date and time
4.
Click
on apply and ok.
STEPS
TO HIDE OR UNHIDE THE CONTENTS OF THE DESKTOP
1.
Right
click on empty space on the desktop
2.
Click
on Arrange icons by…
3.
Unmark
show desktop icons in order to hide it or mark show desktop icons in order to
display it.
STEPS
TO HIDE AND UNHIDE THE TASK BAR.
1.
Right click on the task bar
2.
Click on properties
3.
Mark “Auto-hide the task bar” in order to hide it or unmark “Auto-hide the task bar”
in order to display it.
VIRUS
AND ANTI-VIRUS
Computer Virus can be defined as programs
written by programmers to counter or interfere with the functionality of the
system. Virus programs are very harmful to the computer because they destroy
files and programs and even prevent the system from booting.
TYPES
OF COMPUTER VIRUS
1.
Boot-Sector Virus:-It is a type of virus
that hides itself in the boot sector of the system and therefore hinders it
from booting.
2.
Parasitic Virus:-These are virus that
hides in an executable files and disks. Whenever such file is runned, it
duplicate immediately to other programs and disks.
3.
Multi-Partite Virus:-These are virus that
posses the characteristics of both Boot-sector and Parasitic virus. These virus
affect the Boot sector of a system and even files.
MOST
POPULAR TYPES OF VIRUS
1.
Norton
Antivirus
2.
Stone
virus
3.
Diehard
2000
4.
Dark
Avenger
5.
Green
caterpillar
6.
Win
32 virus
7.
Doctor
Solomon virus
8.
Angello
virus.
CHARCTERISTICS
OF COMPUTER VIRUS
The characteristics or features of
computer virus are as follows:
1.
They
prevent the system from booting properly
2.
They
cause the system to slow down in operation
3.
They
cause programs to hang
4.
They
duplicate easily from one source to another computer
5.
They
are not Visible:- They normally hide in files or programs
6.
Sometimes,
they cause the system to display funny message
7.
They cause loss of data
8.
They
cause the appearance of symbols.
SOURCE
OF COMPUTER VIRUS
The source of computer virus includes:-
1.
Through
infected external devices e.g flash drive, memory card, Diskettes etc
2.
Through
computers in the same network Dorman
3.
Excess
browsing can also be another source of computer virus
4.
Excess
download of shareware
5.
Dust
particles on its own can cause virus spread
NON-VIRUS COMPUTER
PROBLEMS
This
chapter will help us to understand that not all computer problems are virus.
There are some minor problems the system will encounter which are not actually
virus. They includes:-
1.
Bugs:- These are minor errors found in a program. It
occurs when programming a software. Bugs can cause a program to run slow during
operation.
2.
Trojans:-They sometimes
performs unexpected action in a system. For instance, they can start formatting
a n disk or duplicating files without users instruction.
3.
Droppers:- They are virus
carriers. They are capable of installing virus program into a computer during
their operation.
4.
Hoaxes:-They always displays
false information to computer users.
5.
Human Errors/Mistakes:- Inexperienced computer users sometimes can press wrong keys
when using the computer, thereby causing the system to malfunction.
NAMES
OF SOME COMMON COMPUTER VIRUS
|
S/N
|
VIRUS
NAMES
|
TYPES
|
WHERE IT
AFFECTS
|
|
1
|
Ambulance
|
File Virus
|
It affects files
|
|
2
|
Amoeba
|
File Virus
|
It affects files
|
|
3
|
Angelina
|
Boot sector virus
|
It affects the boot
sector
|
|
4
|
Armageddon
|
File Virus
|
It affects the files
|
|
5
|
Bad Boy
|
File Virus
|
It affects files
|
|
6
|
Bad Guy
|
File Virus
|
It affects files
|
|
7
|
Big joke
|
File Virus
|
It affects
|
|
8
|
Brazil
|
Boot Sector
|
It affects boot sector
|
|
9
|
Bye Bye
|
Boot Sector
|
It affects the boot
sector
|
|
10
|
Casino
|
File Virus
|
It affects files
|
|
11
|
Cinderella
|
File Virus
|
It affects files
|
|
12
|
Demon
|
File Virus
|
It affects files
|
|
13
|
Die-hard
|
File Virus
|
It affects files
|
|
14
|
Desperado
|
File Virus
|
It affects files
|
|
15
|
Devil’s Dance
|
File Virus
|
It affects files
|
|
16
|
Empire Monkey
|
Boot Sector
|
It affects the boot
sector
|
|
17
|
ETC
|
File Virus
|
It affects files
|
|
18
|
Form
|
Boot Sector
|
It affects the boot
sector
|
|
19
|
Fish
|
File Virus
|
It affects files
|
|
20
|
Freddy
|
File Virus
|
It affects files
|
WAYS OF
PREVENTING COMPUTER VIRUS
1.
By inoculating the system:- Simply by installing Anti-Virus programs in a
system.
2.
User
Awareness:-Computer users should be aware of various means of virus spread so
as to prevent it.
3.
Users
stop coping from infected devices
4.
Avoidance
of excess downloading from the internet. Because, despite the amount of
Anti-virus program installed in a system, there are virus that surpasses it.
5.
Networks
should be properly controlled and monitored.
ANTI-VIRUS
These are programs specially designed by
programmers to counter the works of virus. They are programs use to keep a
system protected from virus.
TYPES
OF ANTI-VIRUS
1.
Norton
Anti-virus
2.
Doctor
Solomon Anti-virus
3.
Kaspersky
Anti-virus
4.
Avast
Anti-virus
5.
AVG
Anti-virus etc.
MEASUREMENT
OF DATA/INFORMATION
The smallest unit of information to be represented
in a computer is bit. It is either (O or I) which is a natural representation
of Binary. A bit is too small to represent a character. Hence (8) bits were
grouped together to form a byte. Collection of bytes (1000) gives kilobytes
etc.
Below are how data/information are
measured.
1 or O = Bit
8 Bits = A byte
1000 bytes = 1 Kilobyte
1000 Kilobytes = 1 Megabyte
1000 Megabytes = 1 Gigabyte
BASIC
COMPUTER ASSEMBLING
In this chapter, users are expected to
study all the parts of the computer system so as to make assembling easy.
In assembling the system, learners are
expected to note the following:
1.
Input
devices:- Which include Keyboard, Mouse,
Scanner, Joystick etc.
2.
System
unit:- which is the CPU
3.
Output
devices:- Monitor, printer etc
In addition, learners are advised to note
the ports or drives in which all the peripherals i.e input and output devices
will be connected. For instance, USB mouse and keyboard will be connected to
the USB port of the system. Then Ps2 mouse and keyboard also goes to the system
Ps2 port.
Note: All USB external devices goes to
the system USB port and Ps2 external devices to the system Ps2 port.
COMPUTER
TERMINOLOGIES AND ACRONYMS
1.
ICT:- Information and Communication Technology
2.
Info-Tech:- Information Technology
3.
Connectivity:-This is a means of
connecting computers together through modem or network and communication lines
to provide information access.
4.
Modem:- Modulate/Demodulate
5.
NUI:- Network User Interface
6.
GUI:- Graphic User Interface
7.
Registers:-These are high-speed
storage areas that temporarily store data during processing. E.g RAM
8.
RAM:- Random Access Memory
9.
ROM:- Read Only Memory
10. CD-ROM:- Compact Disk-Read
Only Memory
11. Chips:-These are tiny electronic component found in the system.
12. Peripherals:- These
are I/O devices
13. Surge protector:-A device that protect the computer from being
damaged by surges. (spikes of high voltage)
14. UPS:- Uninterruptible
Power Supply
15. Drive:-A location where external devices are loaded.
16. GIGO:- Garbage in Garbage
out
17. WYSIWYG:- What You See Is
What You Get
18. PC:- Personal Computer
19. MB:- Megabyte
20. GB:- Gigabyte
21. KB:- kilobyte
22. HDD:- Hard Disk Drive
23. FDD:- Floppy Disk Drive
24. USB:- Universal Serial
Bus
25. VDU:- Visual Display
Unit
26. O.S:- Operating System
27. MS DOS:- Microsoft Disk Operating
System
28. MS WOS:- Microsoft Windows
Operating System
29. LAN:- Local Area Network
30. MAN:- Metropolitan Area
Network
31. WAN:- Wide Area Network
32. CPU:- Central Processing
Unit
33. VGA:- Visual Graphic
Array
34.
Processor:-Major part of the CPU
for processing.
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