INFORMATION COMMUNICATION TECHNOLOGY STUDY NOTES
a) Concepts of ICT – Terminologies
i) Computer
This is an electro-magnetic device that can be programmed to accept data (input), process it into
useful information (output) and store for later reuse (retrieve).
ii) Computer system
A system is a group of two or more interrelated components or subsystems that serve a common
purpose. A computer system comprises of input, processing, storage and output devices.
iii) Data
This refers to a collection of disorganized figures, facts, statistics, opinions or predictions that are not
useful for decision making.
-Also refers to the raw facts which have not been processed
iv) Information
This is processed data which is in a form that is meaningful for decision making
v) Information Communication Technology
Is an integration of computers, communication and other technologies applied to the collection and
storage of data that is subsequently processed and transmitted with the intention of providing
information to the recipient or decision makers
vi) Computer- Based Information Communication System (CBIS)
This comprises of computer hardware, computer software, data/information, people/users, procedures
and communication devices (network)
b) Functions of ICT
i) Functions of ICT in an organization
- It increases operational efficiency
- Enhances employee productivity
- Improves customer service
- Increases customer satisfaction
- Promote effective decision making
- Enables development of competitive products
- Enables Strategic Planning for future expansion
ii) Advantages of computer systems
- High speed processing
A super computer can process one trillion arithmetic operations in one second.
- Handle large volume of repetitive tasks
It can prepare a payroll by calculating hours worked, rate per hour, total wages, various
deductions and net wages for thousands of employees without getting bored.
- Has logical ability
Able to distinguish between numbers and decide which one is greater, negative or positive
- Remote processing
Through time sharing and telecommunication, many persons at different locations can use the
same computer at one location for information processing eg ATM banking or air-time top up.
- Enhance productivity
INFORMATION COMMUNICATION TECHNOLOGY NOTES PREPARED BY MR. ANTONY AMBIA Page 1
, Productivity increase once workers learn to use computers to perform their duties better and
faster
- Accelerate decision making
Managers can sort issues faster and make better decisions
- Reduce operation costs
Computers help to hold down the costs of labour, energy and paper work
- Reduce storage space
Information can be stored in computer components which occupy smaller space unlike paper
iii) Disadvantages of computers
- High initial costs-requires high initial cost to purchase and install the computers
- Require skilled operators-Training needs to be done for the computer operators
- Cause health problems-use of computers causes health related problems such as neck ache, eyes
- Reduce employment opportunities-one computer can perform several tasks that could have been
performed by several people hence causes unemployment
- Greater loss of data in case of breakage or system failure
c) Classification of computers
i) Classification by purpose
Analog Computers
These are computers that perform logical operations by measuring changes in physical magnitudes
and convert them to numeric values. These computers process data that is in a continuous form or
measurable quantities/units. Analog data includes physical variables like temperature, pressure,
length, weight, electrical voltages and resistance.
-Analog computers include thermometers, weighing scales, voltmeters and speedometers.
-These computers are used mainly for scientific and engineering purposes because they deal with
quantities that vary constantly.
-They give approximate results and are applied in industries, post office and weather stations
-Handles small volume of data.
Digital Computers
. These computers process data that is represented in the form of discrete or individually distinct
form usually in a binary or two state formats/digits 0 and 1. In the binary system, each 0 and 1 is
called a bit and a group of 8 bits is 1 byte.
Example of these devices include digital clock.
-handles high volume of data and gives accurate information
Hybrid Computers
These are computers that have the combined features of both the digital and analog computers.
Example is where patient’s vital signs like temperature, heart functions etc are measured and
converted to numbers and supplied to the digital components that monitor the patient’s vital signs. A
fluctuation can thus be noticed immediately.
ii) Classification by size
- Super computers
These are the most powerful, fastest, big in size and most expensive computers. Only a few of
these are manufactured each year because only a few organizations need and can afford their
processing capabilities. They have large memories and high processing speeds so fast that they
can process nearly a billion transactions per second and nearly a trillion arithmetic operations at
the same time. They apply parallel processing.
Application
INFORMATION COMMUNICATION TECHNOLOGY NOTES PREPARED BY MR. ANTONY AMBIA Page 2
, Worldwide weather forecasting and analysis of weather phenomena
Produce images that can be incorporated into movies
Aircraft design
Mathematical research
- Main frames
These are large, general purpose computers which can serve 100 or more end users.
They are fast with large storage capacities.
Application
Processing of high-volume batch applications eg in banks
Management of very large centralized databases
To control access, interpret queries and retrieve & update records
Ideal for transaction processing, financial applications, payroll calculations and airline
reservations.
- Mini computers
These are computers which are neither too big nor too small in size
They are designed to accommodate more than one user
The are a bit costly than micro computers
Their processing speed is a bit faster than micro computers
They have a large storage capacity than microcomputers and lesser than mainframe
computer
- Micro computers
These are computers that are small in size
They are designed for single user
They have low processing speed
They are less costly compared to others
They have small processors
They have small storage capacity
- Desktops
These are a type of microcomputers also called Personal Computers (PCs).
They are compact, powerful and versatile machines
They generally serve a single user
The desktop type may be one integral unit having monitor and CPU or may be separate (
Tower units)
- Laptops
These are powerful portable computers
They are designed for single user
They have low processing speed
They are less costly compared to others
They have small processors
They have small storage capacity
They use battery when not connected to main electricity
- Palm tops/microcontrollers/
Also called hidden, embedded, dedicated computers
They are restricted to perform a restricted number of tasks eg calculator
iii) Computer Generations
INFORMATION COMMUNICATION TECHNOLOGY NOTES PREPARED BY MR. ANTONY AMBIA Page 3
, The history of computer development is often referred to in reference to the different generations of computing
devices. A generation refers to the state of improvement in the product development process. This term is also used in
the different advancements of new computer technology. With each new generation, the circuitry has gotten smaller
and more advanced than the previous generation before it. As a result of the miniaturization, speed, power, and
computer memory has proportionally increased. New discoveries are constantly being developed that affect the way
we live, work and play.
Each generation of computers is characterized by major technological development that fundamentally changed the
way computers operate, resulting in increasingly smaller, cheaper, and more powerful and more efficient and reliable
devices.
First Generation - 1940-1956: Vacuum Tubes
The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often
enormous, taking up entire rooms.
A magnetic drum, also referred to as drum, is a metal cylinder coated with magnetic iron-oxide material on
which data and programs can be stored.
The tracks on a magnetic drum are assigned to channels located around the circumference of the drum,
forming adjacent circular bands that wind around the drum. A single drum can have up to 200 tracks. As the
drum rotates at a speed of up to 3,000 rpm, the device's read/write heads deposit magnetized spots on the
drum during the write operation and sense these spots during a read operation. This action is similar to that of
a magnetic tape or disk drive.
They were very expensive to operate
They used a great deal of electricity,
Generated a lot of heat, which was often the cause of malfunctions.
First generation computers relied on machine language to perform operations, and they could only solve one
problem at a time. Machine languages are the only languages understood by computers. While easily
understood by computers, machine languages are almost impossible for humans to use because they consist
entirely of numbers. Computer Programmers, therefore, use either high level programming languages or an
assembly language programming. An assembly language contains the same instructions as a machine language,
but the instructions and variables have names instead of being just numbers.
Acronym for Electronic Numerical Integrator and Computer, the world's first operational electronic digital
computer, developed by Army Ordnance to compute World War II ballistic firing tables. The ENIAC,
weighing 30 tons, using 200 kilowatts of electric power and consisting of 18,000 vacuum tubes, 1,500 relays,
and hundreds of thousands of resistors, capacitors, and inductors, was completed in 1945.
They had maintenance problems
They had limited primary memory
Second Generation - 1956-1963: Transistors
INFORMATION COMMUNICATION TECHNOLOGY NOTES PREPARED BY MR. ANTONY AMBIA Page 4
a) Concepts of ICT – Terminologies
i) Computer
This is an electro-magnetic device that can be programmed to accept data (input), process it into
useful information (output) and store for later reuse (retrieve).
ii) Computer system
A system is a group of two or more interrelated components or subsystems that serve a common
purpose. A computer system comprises of input, processing, storage and output devices.
iii) Data
This refers to a collection of disorganized figures, facts, statistics, opinions or predictions that are not
useful for decision making.
-Also refers to the raw facts which have not been processed
iv) Information
This is processed data which is in a form that is meaningful for decision making
v) Information Communication Technology
Is an integration of computers, communication and other technologies applied to the collection and
storage of data that is subsequently processed and transmitted with the intention of providing
information to the recipient or decision makers
vi) Computer- Based Information Communication System (CBIS)
This comprises of computer hardware, computer software, data/information, people/users, procedures
and communication devices (network)
b) Functions of ICT
i) Functions of ICT in an organization
- It increases operational efficiency
- Enhances employee productivity
- Improves customer service
- Increases customer satisfaction
- Promote effective decision making
- Enables development of competitive products
- Enables Strategic Planning for future expansion
ii) Advantages of computer systems
- High speed processing
A super computer can process one trillion arithmetic operations in one second.
- Handle large volume of repetitive tasks
It can prepare a payroll by calculating hours worked, rate per hour, total wages, various
deductions and net wages for thousands of employees without getting bored.
- Has logical ability
Able to distinguish between numbers and decide which one is greater, negative or positive
- Remote processing
Through time sharing and telecommunication, many persons at different locations can use the
same computer at one location for information processing eg ATM banking or air-time top up.
- Enhance productivity
INFORMATION COMMUNICATION TECHNOLOGY NOTES PREPARED BY MR. ANTONY AMBIA Page 1
, Productivity increase once workers learn to use computers to perform their duties better and
faster
- Accelerate decision making
Managers can sort issues faster and make better decisions
- Reduce operation costs
Computers help to hold down the costs of labour, energy and paper work
- Reduce storage space
Information can be stored in computer components which occupy smaller space unlike paper
iii) Disadvantages of computers
- High initial costs-requires high initial cost to purchase and install the computers
- Require skilled operators-Training needs to be done for the computer operators
- Cause health problems-use of computers causes health related problems such as neck ache, eyes
- Reduce employment opportunities-one computer can perform several tasks that could have been
performed by several people hence causes unemployment
- Greater loss of data in case of breakage or system failure
c) Classification of computers
i) Classification by purpose
Analog Computers
These are computers that perform logical operations by measuring changes in physical magnitudes
and convert them to numeric values. These computers process data that is in a continuous form or
measurable quantities/units. Analog data includes physical variables like temperature, pressure,
length, weight, electrical voltages and resistance.
-Analog computers include thermometers, weighing scales, voltmeters and speedometers.
-These computers are used mainly for scientific and engineering purposes because they deal with
quantities that vary constantly.
-They give approximate results and are applied in industries, post office and weather stations
-Handles small volume of data.
Digital Computers
. These computers process data that is represented in the form of discrete or individually distinct
form usually in a binary or two state formats/digits 0 and 1. In the binary system, each 0 and 1 is
called a bit and a group of 8 bits is 1 byte.
Example of these devices include digital clock.
-handles high volume of data and gives accurate information
Hybrid Computers
These are computers that have the combined features of both the digital and analog computers.
Example is where patient’s vital signs like temperature, heart functions etc are measured and
converted to numbers and supplied to the digital components that monitor the patient’s vital signs. A
fluctuation can thus be noticed immediately.
ii) Classification by size
- Super computers
These are the most powerful, fastest, big in size and most expensive computers. Only a few of
these are manufactured each year because only a few organizations need and can afford their
processing capabilities. They have large memories and high processing speeds so fast that they
can process nearly a billion transactions per second and nearly a trillion arithmetic operations at
the same time. They apply parallel processing.
Application
INFORMATION COMMUNICATION TECHNOLOGY NOTES PREPARED BY MR. ANTONY AMBIA Page 2
, Worldwide weather forecasting and analysis of weather phenomena
Produce images that can be incorporated into movies
Aircraft design
Mathematical research
- Main frames
These are large, general purpose computers which can serve 100 or more end users.
They are fast with large storage capacities.
Application
Processing of high-volume batch applications eg in banks
Management of very large centralized databases
To control access, interpret queries and retrieve & update records
Ideal for transaction processing, financial applications, payroll calculations and airline
reservations.
- Mini computers
These are computers which are neither too big nor too small in size
They are designed to accommodate more than one user
The are a bit costly than micro computers
Their processing speed is a bit faster than micro computers
They have a large storage capacity than microcomputers and lesser than mainframe
computer
- Micro computers
These are computers that are small in size
They are designed for single user
They have low processing speed
They are less costly compared to others
They have small processors
They have small storage capacity
- Desktops
These are a type of microcomputers also called Personal Computers (PCs).
They are compact, powerful and versatile machines
They generally serve a single user
The desktop type may be one integral unit having monitor and CPU or may be separate (
Tower units)
- Laptops
These are powerful portable computers
They are designed for single user
They have low processing speed
They are less costly compared to others
They have small processors
They have small storage capacity
They use battery when not connected to main electricity
- Palm tops/microcontrollers/
Also called hidden, embedded, dedicated computers
They are restricted to perform a restricted number of tasks eg calculator
iii) Computer Generations
INFORMATION COMMUNICATION TECHNOLOGY NOTES PREPARED BY MR. ANTONY AMBIA Page 3
, The history of computer development is often referred to in reference to the different generations of computing
devices. A generation refers to the state of improvement in the product development process. This term is also used in
the different advancements of new computer technology. With each new generation, the circuitry has gotten smaller
and more advanced than the previous generation before it. As a result of the miniaturization, speed, power, and
computer memory has proportionally increased. New discoveries are constantly being developed that affect the way
we live, work and play.
Each generation of computers is characterized by major technological development that fundamentally changed the
way computers operate, resulting in increasingly smaller, cheaper, and more powerful and more efficient and reliable
devices.
First Generation - 1940-1956: Vacuum Tubes
The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often
enormous, taking up entire rooms.
A magnetic drum, also referred to as drum, is a metal cylinder coated with magnetic iron-oxide material on
which data and programs can be stored.
The tracks on a magnetic drum are assigned to channels located around the circumference of the drum,
forming adjacent circular bands that wind around the drum. A single drum can have up to 200 tracks. As the
drum rotates at a speed of up to 3,000 rpm, the device's read/write heads deposit magnetized spots on the
drum during the write operation and sense these spots during a read operation. This action is similar to that of
a magnetic tape or disk drive.
They were very expensive to operate
They used a great deal of electricity,
Generated a lot of heat, which was often the cause of malfunctions.
First generation computers relied on machine language to perform operations, and they could only solve one
problem at a time. Machine languages are the only languages understood by computers. While easily
understood by computers, machine languages are almost impossible for humans to use because they consist
entirely of numbers. Computer Programmers, therefore, use either high level programming languages or an
assembly language programming. An assembly language contains the same instructions as a machine language,
but the instructions and variables have names instead of being just numbers.
Acronym for Electronic Numerical Integrator and Computer, the world's first operational electronic digital
computer, developed by Army Ordnance to compute World War II ballistic firing tables. The ENIAC,
weighing 30 tons, using 200 kilowatts of electric power and consisting of 18,000 vacuum tubes, 1,500 relays,
and hundreds of thousands of resistors, capacitors, and inductors, was completed in 1945.
They had maintenance problems
They had limited primary memory
Second Generation - 1956-1963: Transistors
INFORMATION COMMUNICATION TECHNOLOGY NOTES PREPARED BY MR. ANTONY AMBIA Page 4
