Academic
Year
2021/22
ICT
YEAR 9
OUR PURPOSE
Develop basic skills useful to access ICT
resources.
Inculcate basic good practices in the use
of ICT resources
To understand the implications of
technology in society, including social,
economic
and ethical uses
Inculcate basic computer literacy and
develop a base for further pursuit of
Information and Communication
Technology studies.
ARE YOU GOING TO ENJOY ICT?
Are you interested in Are you concern about Are you interested in
understanding how security issues that we
solving problems
technology has
face regarding your
with different
affected your life?
personal data?
software packages?
WHAT IS A
COMPUTER?
A COMPUTER IS AN ELECTRONIC DEVICE!
THAT MANIPULATES INFORMATION, OR DATA.
IT HAS THE ABILITY TO STORE, RETRIEVE,
AND PROCESS DATA.
WE CAN USE A COMPUTER TO TYPE DOCUMENTS,
SEND EMAIL, PLAY GAMES, AND BROWSE THE WEB.
YOU CAN ALSO USE IT TO EDIT OR CREATE
SPREADSHEETS, PRESENTATIONS, AND EVEN
VIDEOS.
Data : Raw facts, unorganized and do not have a
meaning on its own. (eg: 100, 212, 0, 32)
Information : Processed data & organized. It can
be a news or knowledge. (eg: 100,212,0 and 32 are
the freezing and boiling points of water in
fahrenheit and celsius)
1. PREPARATION OF COMPUTER
SPECIFICATIONS
TOPIC TO BE COVERED:
COMPUTERS AND PERIPHERAL DEVICES
SELECTION OF DEVICES FOR THE USER REQUIREMENT
CREATING COMPUTER SPECIFICATIONS
NON-TECHNICAL FACTORS TO BE CONSIDERED IN PURCHASING A
COMPUTER
USER?
THE ONE WHO USES A
COMPUTER IS GENERALLY
REFERRED TO AS A USER.
BRANDED COMPUTER?
A COMPUTER OFFERED BY A COMPANY LIKE
HP, COMPAQ, ACER ETC.
ASSEMBLED COMPUTER?
A COMPUTER CUSTOMIZED OR
CONFIGURED ACCORDING TO THE YOUR
NEEDS AND BUDGET TO THE BEST OF
PERFORMANCE WITH BRANDED PARTS.
PROGRAMMER
Different
Designations
OF Different
Users
Develops computer programs
NETWORK ADMINISTRATOR
Manages and maintains computer
Network
SYSTEM ANALYST
Designs information systems
SOFTWARE ENGINEER
Develops software
COMPUTER APPLICATION
ASSISTANT
WEB DEVELOPER
Develops and maintains websites
Uses office application packages for
office related tasks
END USERS
The end user is the individual who
uses the product after it has been fully
developed.
End user uses the software
maintained by the
Systems User.
SYSTEM USERS
System users represent servers or
software that are managed by a
Business Manager.
1.2 SELECTION OF A COMPUTER TO
SUIT USER REQUIREMENTS
User requirements relate to tasks that are carried out
by using a computer.
Server Computers:
Server means highly performing
computer machine that helps to
deliver many resources, data, or
services to another remotely
machine, called as the “Client”
over different types of network.
Can handle multiple requests
simultaneously.
Workstation, a highperformance
computer system
that is basically
designed for a single
user and has
advanced graphics
capabilities, large
storage capacity, and
a powerful central
processing unit.
TYPES OF COMPUTERS
1. NON PORTABLE
COMPUTERS
Server computers, workstations,
desktop computers and all-in-one
computers, are all operated using
the main electricity power supply.
1. These computers are large in
size and relatively heavy.
2. Therefore, they are installed
and used in places like houses,
schools or offices.
2. COMPUTERS FOR
MOBILE USE
Laptops, notebooks, tablet computers and a smart
phones can be considered
for mobile use.
They operated with re-chargeable batteries.
Therefore, they can be used when traveling in buses,
trains, aeroplanes or from any convenient place.
1.3 Computer peripheral devices
A peripheral device is an internal or external device that connects,
directly to a computer or other digital device but does not
contribute to the computer's primary function, such as computing.
It helps end users access and use the functionalities of a computer.
There are many different peripheral devices, but they fall into three general categories:
1. Input devices:
Are used to feed data and instructions into a computer such as a mouse and a keyboard
2. Output devices:
Are used to provide the information processed with the input data such as a monitor and a
printer
3. Storage devices:
Are used to store data such as a hard drive or flash drive .
Accordingly, input, storage and output devices are called peripheral devices.
Computer peripheral devices
OUTPUT UNIT
INPUT UNIT
This unit contains devices
with the help of which we
enter data into the computer.
This unit creates a link
between the user and the
computer. The input devices
translate the information into
a form understandable by the
computer.
CPU (Central
Processing Unit)
CPU is considered as the brain of
the computer. CPU performs all
types of data processing operations.
It stores data, intermediate results,
and instructions (program). It
controls the operation of all parts of
the computer.
CPU consists on following three
components:
Input Unit
Output Unit
Memory Unit
The output unit consists of
devices with the help of
which we get the
information from the
computer. This unit is a link
between the computer and
the users. Output devices
translate the computer's
output into a form
understandable by the users.
1.4 COMPUTER
SPECIFICATIONS
The specifications change
according to user requirements
in the above
example. Similarly depending
on the use of a computer its
specifications also
differs.
WHAT IS
SPECIFICATION?
Before purchasing an item consider:
Value
Quality
Specifications are generally about
the common features of an
item.
SPECIFICATIONS TO SUIT DIFFERENT USER
REQUIREMENTS
1.5 SPECIFICATIONS OF COMPUTERS &
PERIPHERAL DEVICES
The processor
Humans are considered the most intelligent
among all living beings. The brain helps
man to make decisions for actions taken.
The brain also has the ability to swiftly
respond to all sensations.
Much as the brain is most important for humans, the
processor is the most important part of a computer.
The processor processes data swiftly.
Every PC has a Central Processing Unit (CPU) this acts as the
brain of your system.
It connects to the Motherboard and works alongside the other
components processing many instructions at the same time
between the different hardware and memory systems.
.
1. Speed of the processor
A machine functions at a slower speed
takes a longer time to complete a task.
While a machine functions at a higher
speed takes lesser time to complete a task.
Therefore, the amounts of work that could be
carried out using these machines during a unit
time differs.
A machine working at a higher speed,
provides better results!
The clock speed measures how
The performance of a computer depends on the
fast a processor completes
speed of the processor.
operations,
A processor running at high speed is able to process
more data during a unit time.
That is, the performance of the computer is
increases. Then the software can be run faster.
Therefore, when selecting a processor, it is advisable
to select one with a greater speed.
PROCESSOR MANUFACTURERS,
SEVERAL PROCESSOR MANUFACTURING
COMPANIES, APPLE, INTEL AND AMD
(ADVANCED MICRO DEVICES) EXISTS.
A CPU can contain one or more
processing units. Each unit is
called a core.
A core contains an ALU, control
unit and registers.
TYPES OF PROCESSORS
Generally, the number of processors in a central
processing unit is used to classify the Central
Processing Unit.
The more cores a CPU has, the greater the number
of instructions it can process in a given space of
time.
When the number of processors in a central processing unit increases its
capacity also increases.
Table 1.4 shows examples for Intel processors.
Factors to Consider
When Buying a new
processor:
Number of cores
Clock Speed
ACTIVITIES
Refer to workbook for,
Activity 1.1 (PAGE 4)
Refer to workbook for,
Activity 1.2 (PAGE 4)
1.5.2
HARD
DISK
The hard disk provides permanent
storage space for storing data and to
installing all software.
The hard disk is the main secondary
storage device in a computer.
More data can be stored in a hard disk
with a greater storage capacity.
HDDs are a type of non-volatile storage,
retaining stored data even when
powered off.
SSD (Solid Disk Drive) is expensive
but there are no physical moving
parts, high heating resistance,
greater productivity, quality user
experience,Information stored in
microchips..
- Hard disk data storage device that uses magnetic storage
to store and retrieve digital information.(Cheaper, readwrite, which makes it possible to re-use the storage
capacity over and over again by deleting older data., the
storage capacity is also very large).
- Using one or more rigid rapidly rotating disks (platters)
coated with magnetic material. The platters are paired with
magnetic heads, usually arranged on a moving actuator
arm, which read and write data to the platter surfaces.
Can be damaged due to vibrations, shock or drop.
Data storage capacity is measured by units such as bits,
bytes, kilobytes, Megabytes, Gigabytes, Terabytes and
Petabytes.
Here's the list of things to be
considered when purchasing an
external hard-disk based storage
device.
o Storage
o Size
o Connectivity
o Budget
o Speed
o Software
o Warranty
o Platform
o Sturdiness
o Security
1.5.3 THE
MONITOR
DISPLAY
The main output
device
of
a
computer is its
monitor display.
Most often, a user
interacts with a
computer via its
monitor/ display.
The monitor size
is measured in terms
of its diagonal length
in inches.
For examples, a wall clock is larger
than a wrist watch. Time is easily
seen on a wall clock because of its
size.
Similarly, larger monitors have
better visibility.A larger monitor size
is useful in viewing a larger picture.
The monitor size
is measured in terms of its diagonal
length in inches.
MONITOR TECHNOLOGY
Monitors can be classified into the following types according to the
technology used by them:
CRT MONITORS
CATHODE RAY TUBE)
These monitors employ CRT technology,
With these monitors, a stream of intense
high energy electrons is used to form
images on a fluorescent screen.
CRT monitors consume more electricity
than the other two types. Further, they are
heavier and occupy more space due to its
size.While they are still in use, it would be
a good idea to phase these monitors out
for cheaper, lighter, and more reliable
monitors.
LED MONITOR
(LIGHT EMITTING DIODE)
LCD Monitors
(Liquid Crystal Display)
The advantages of LCD monitors include
their compact size which makes them
lightweight. They also don’t consume
much electricity as CRT monitors, and can
be run off of batteries which makes them
ideal for laptops.
LED monitors are said to use much lesser power than
CRT and LCD and are considered far more
environmentally friendly.
The advantages of LED monitors are that they
produce images with higher contrast are more
durable than CRT or LCD monitors, and features a
very thin design. They also don’t produce much heat
while running.
The only downside is that they can be more
expensive, especially for the high-end monitors like
the new curved displays that are being released.
Factors to Consider When Buying a
Computer Monitor
Size - The diagonal measurement of the screen
Resolution - The number of pixels a monitor has to
display an image.
Aspect Ratio - ratio between the display area’s
width and height.
Backlighting - LED backlighting has become more
commonplace with today’s computer monitors.
Video input - This really depends on the age of your
computer. If it’s older, you’ll need an analog, or VGA.
Newer computer models use a digital connection for
the monitor (e.g. DVI, HDMI or Display Port). Most
monitors come with one analog and one digital
video input.
Ergonomic flexibility - The stand the monitor sits
on is almost as important as the technical aspects
described above.
EVERY
ACCOMPLISHMENT ,
STARTS WITH THE
DECISION TO TRY!
1.5.4 MAIN MEMORY
RAM (RANDOM ACCESS MEMORY) IS
THE INTERNAL MEMORY OF THE CPU
FOR STORING DATA, PROGRAM, AND
PROGRAM RESULT.
IT IS A READ/WRITE MEMORY WHICH
The capacity of the main memory is
measured in units of bits.
(Mega Bite (MB) or Giga Bite (GB)
etc).
1024 MB = 1 GB
STORES DATA UNTIL THE MACHINE IS
WORKING. AS SOON AS THE MACHINE
IS SWITCHED OFF, DATA IS ERASED.
DATA AND INSTRUCTIONS ARE
STORED TEMPORARILY IN THE MAIN
MEMORY.RAM IS VOLATILE.
Higher capacity in the main
memory stores more data and instructions.
Therefore, a computer with a higher
main memory capacity is better.
1.5.5 Video Graphic Adapter
The Monitor is the main output device of a computer.
The output is fed to the monitor via the Video
(VGA)
Graphic Adapter (VGA).
There are two types of Video Graphic Adapter (VGAs).
On board VGA is fixed to the mother board and Separate
VGAs card can be fixed to mother board manually. The
separate VGA card has a separate video memory and a
processor. Separate VGA cards are useful for playing
computer games.
Modern computers use DV1 or HDMI ports instead of VGA
(Refer figure right)
port.
When HDMI cables are connected to a computer, a
television screen or multi media projector, both
sound and video signals are transmitted.
When a VGA is used for the same purpose, only
images are transmitted and a separate cable is
required for sound.
1.5.6 SOUND
CARDS
Sound ports
Audio out
The ports of a sound cards
use standard colour scheme
for identification purpose.
Light green - Audio out
Audio in
(to connect speaker or
Built in sound card on mother board
headphone)
External sound card
Light pink - Mic in (to
connect microphone)
Many computer are widely used for entertainment today.
Light blue - Line in (to
A sound card is required for listening to music and
feed sound with external
recording audio.
devices)
A microphone connected to the sound card can be used
to record (input) sounds.
while a speaker connected to the sound card can be used
to play (output) sounds.
1.5.7 Pre-Installed software
Systems software:
Programs that allow the hardware
to run properly and allow the user
to interact with the computer
Application software
Software applications,
that you may use in your daily work.
An operating system provides
the interface between the user
and the hardware.
The operating system is
essential to run application
software.
Once the operating system is
installed in a computer, the
necessary application software
can be installed.
Free and open source operating
systems such as Linux, Ubuntu can be
obtained free of charge.
Open source software?
Is any kind of program
where the developer behind
it chooses to release the
source code for free.
Whenever software has an
open source license, it
means anyone in the world
can download, modify and
distribute it without paying
fees to its original creator.
Licensed operating systems such as
Windows 8, Windows 10 to purchase.
A trial version of an operating systems
such as trail version of Windows 10 can
be used only for a limited period.
Required
application
software
depends on the requirement of the
user.
In buying a desktop computer
or a laptop computer
It is important to check whether
an operating system has been pre-installed.
Most often only DOS or LINUX computer
systems are pre-installed.
A computer with licensed software installed
is more expensive than a computer with a
free and open source operating system.
OPERATING SYSTEM
There are a few common
operating systems
available:
Mac OS X
Linux
Windows
Android
iOS
An operating system is the most important software
that runs on a computer.
It manages the computer's memory and processes, as
well as all of its software and hardware.
It also allows you to communicate with the computer
without knowing how to speak the computer's language.
Without an operating system, a computer is useless.
Types of operating
systems
Operating systems usually come
pre-loaded on any computer you
buy. Most people use the operating
system that comes with their
computer, but it's possible to
upgrade or even change operating
systems.
User interface
The OS provides a user
interface (UI), an
environment for the user
to interact with the
machine. The UI is either
graphical or text-based.
GRAPHICAL USER INTERFACE (GUI)
THE OS ON MOST COMPUTERS AND
SMARTPHONES PROVIDES AN ENVIRONMENT WITH
TILES, ICONS AND/OR MENUS. THIS TYPE OF
INTERFACE IS CALLED THE GRAPHICAL USER
INTERFACE (GUI) BECAUSE THE USER INTERACTS
WITH IMAGES THROUGH A MOUSE, KEYBOARD OR
TOUCHSCREEN.
COMMAND LINE INTERFACE (CLI)
AN OS ALSO PROVIDES A METHOD OF INTERACTION
THAT IS NON-GRAPHICAL, CALLED THE COMMAND LINE
INTERFACE (CLI). THIS IS A TEXT-ONLY SERVICE WITH
FEEDBACK FROM THE OS APPEARING IN TEXT. USING A
CLI REQUIRES KNOWLEDGE OF THE COMMANDS
AVAILABLE ON A PARTICULAR MACHINE.
FUNCTIONS OF THE
OPERATING SYSTEM
The operating system performs several key functions:
Interface - provides a user interface so it is easy to interact with the
computer.
Manages the CPU - runs applications and executes and cancels processes
Multi-tasks - allows multiple applications to run at the same time
Manages memory - transfers programs into and out of memory, allocates
free space between programs, and keeps track of memory usage
Manages peripherals - opens, closes and writes to peripheral devices such
as storage attached to the computer
Organises - creates a file system to organise files and directories
Security - provides security through user accounts and passwords
Utilities - provides tools for managing and organising hardware
1.6 Non-technical features to be
considered in purchasing a computer
1.6.1
WARRANTY
1.6.2
Price
1.6.3
Services
after-sale
1.6.4
Ports and
network
connections
WARRANTY
Warranty is an important factor to be
considered when purchasing a
computer.
Warranty given by the vendor and the
manufacturer assurers to cover the
defects for a certain period.
Customer can get this warranty in
many different ways
A. MANUFACTURER
WARRANTY
The warranty which is given by the
manufacturing company is known as the
manufacturer warranty. If the device
malfunctions during the warranty period,
it is either repaired or replaced with a
new one.
B. EXTENDED WARRANTY
Extended warranty is a prolonged
warranty given to customers in addition
to the standard warranty.
Customer needs bearing additional cost
for extended warranty
C. ON-SITE WARRANTY
If a customer obtains an on-site
warranty,technicians from the
respective company visit the place of
work to repair the product. They
generally maintain, replace faulty
parts and examine the operations of
the machine.
There is a standard warranty when purchasing a computer.
but, the warranty for the parts of the computer may differ from
the
standard.
For instance, a laptop computer with standard warranty for 3
years, may have only one year warranty for the battery
1.6.2 PRICE
THE
e.g.
PRICE
OF
A
COMPUTER
TO
THE
CAN
VARY
CUSTOMER
ACCORDING
REQUIREMENTS
1. The price of a computer is rather high with a high speed processor.
2. A computer with a large monitor is comparatively high in price.
3. Price is low of a computer with a lesser memory capacity.
4. A computer inclusive high capacity hard disk drive is high in price.
It is advisable to compare prices to suit one’s requirements from different
places and select the computer with the lowest price.
1.6.3 SERVICES AFTER-SALE
Computer sales centers provide the following after-sales services to customers;
1. Technical advice
2. Technical assistance
3. Telephone, e-mail and website information (i.e. contact information) of
the vendor.
It is advisable for a user to consider the given information in purchasing a
computer. Customer needs preparing specifications first. Then, a computer must
be bought from a vendor with a reputed name and must be from a recognized
manufacturer.
1.6.4 PORTS AND NETWORK
CONNECTIONS
Ports are used to connect the peripheral
devices to a computer. A user may
select peripheral devices to suit one’s
requirements.
However, the computer should
have the necessary ports to connect them.
Universal Serial Bus (USB)
Network ports/RJ45
connector
Bluetooth and Wi-Fi facilities
Universal Serial Bus (USB)
The USB is the most widely used port to connect peripheral devices to the
computer. Therefore, it is essential to have several USB ports.
Some peripheral devices that can be connected via USB Port;
Printer
Keyboard
Mouse
Scanner
External hard disk
External DVD drive
Digital camera
Web camera
Bar code reader
Memory card
Pen drive
NETWORK PORTS/RJ45
CONNECTOR
THE
COMPUTER
USES
RJ45
CONNECT
CONNECTOR
TO
A
TO
NETWORK.
Network port
USB Port
Bluetooth and Wi-Fi facilities
Bluetooth and Wi-Fi facilities provide cable free
(i.e. wireless) network
connections to computers.
Wi-fi
It is a medium range wireless technology
used to connect devices together. Wi-fi uses
radio waves to provide a connection to the
internet.
Wi-fi networks are often protected and
usually require a network key (essentially a
password) in order to log in. Devices that
use wi-fi need to have a wireless adapter to
enable them to communicate with the
wireless router.
Advantages of wi-fi:
Allows you to set up LANs without wires
Wi-fi enabled devices are now widely available
Users can log in from anywhere within the wi-fi network
using any wi-fi device.
Disadvantages of wi-fi:
Signal strength weakens the further away you are from the
router
The wireless connection may not be as secure as a wired
connection
Wi-fi signal can be affected by adverse weather conditions.
BLUETOOTH
Bluetooth communicates using radio frequencies and
requires no physical cable connections.
It was designed to enable a range of portable devices
to connect both to each other and to other.
Common uses of bluetooth are sharing data files
between mobile phones, or sending audio to
bluetooth speakers.
Advantages of bluetooth:
Low cost to set up
Uses relatively little power compared to other types
of wireless connection
You can easily set up bluetooth networks with other
bluetooth enabled devices
Disadvantages of bluetooth:
Short range
Low level of security
Low data transmission rate
Technical and non-technical specifications to be considered in
purchasing a computer
Important factors of technical specifications
THANK YOU!