MOMBASA AVIATION TRAINING INSTITUTE
INFORMATION COMMUNICATION TECHNOLOGY
TOPIC 1: COMPUTER FUNDAMENTAL
Computer is a programmable electronic device designed to accept data, perform prescribed
mathematical and logical operations at high speed, and display the results of these operations.
i. Evolution of computers
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. They were very expensive to operate and in addition to
using a great deal of electricity, generated a lot of heat, which was often the cause of
malfunctions. Input was based on punched cards and paper tape, and output was displayed on
printouts. The UNIVAC and ENIAC computers are examples of first-generation computing
devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S.
Census Bureau in 1951.
Characteristic
Used vacuum tubes for circuitry Solved one problem at a time
Electron emitting metal in vacuum
tubes burned out easily Used input based on punched cards
Used magnetic drums for memory Had their outputs displayed in print
outs
Were huge, slow, expensive, and
many times undependable Used magnetic tapes
Were expensive to operate Used machine language
Were power hungry Had limited primary memory
Generated a lot of heat which would Were programming only in machine
make them malfunction language
Second Generation (1956-1963) Transistors
Transistors replaced vacuum tubes and ushered in the second generation of computers. The
transistor was invented in 1947 but did not see widespread use in computers until the late 1950s.
The transistor was far superior to the vacuum tube, allowing computers to become smaller,
faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors.
Though the transistor still generated a great deal of heat that subjected the computer to damage,
it was a vast improvement over the vacuum tube. Second-generation computers still relied on
punched cards for input and printouts for output. High-level programming languages were also
being developed at this time, such as early versions of COBOL and FORTRAN. These were also
the first computers that stored their instructions in their memory, which moved from a magnetic
drum to magnetic core technology.
Characteristics
Used transistors Were slightly smaller, cheaper, faster
Faster and more reliable than first
generation systems Generated heat though a little less
Lecturer: Stephen Wandera Magero Page 1
, Still relied on punch cards and Were still costly
printouts for input/output
Needed air conditioning
Allowed assembly and high-level
languages Introduced assembly language and
operating system software
Stored data in magnetic media
Third Generation (1964-1971) Integrated Circuits
The development of the integrated circuit was the hallmark of the third generation of computers.
Transistors were miniaturized and placed on silicon chips, called semiconductors, which
drastically increased the speed and efficiency of computers. Instead of punched cards and
printouts, users interacted with third generation computers through keyboards and monitors and
interfaced with an operating system, which allowed the device to run many different applications
at one time with a central program that monitored the memory. Computers for the first time
became accessible to a mass audience because they were smaller and cheaper than their
predecessors.
Characteristics
Used ICs Output was visualized on the
Used parallel processing monitors
Were slightly smaller, cheaper, faster Used operating systems, thus
permitting multitasking
Used motherboards
Simplified programming languages
Data was input using keyboards i.e. BASIC
Fourth Generation (1971-Present) Microprocessors
The microprocessor brought the fourth generation of computers, as thousands of integrated
circuits were built onto a single silicon chip. What in the first generation filled an entire room
could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the
components of the computer from the central processing unit and memory to input/output
controls on a single chip. In 1981 IBM introduced its first computer for the home user, and in
1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop
computers and into many areas of life as more and more everyday products began to use
microprocessors. As these small computers became more powerful, they could be linked together
to form networks, which eventually led to the development of the Internet. Fourth generation
computers also saw the development of GUIs, the mouse and handheld devices.
Characteristics
Used CPUs which contained Were used in networks
thousands of transistors Were cheap
Were much smaller and fitted on a Were very fast
desktops, laps and palms Register over 19 billion transistors in
Used a mouse high-end microprocessors
Fifth Generation (Present and Beyond) Artificial Intelligence
Lecturer: Stephen Wandera Magero Page 2
,Fifth generation computing devices, based on artificial intelligence, are still in development,
though there are some applications, such as voice recognition, that are being used today. The use
of parallel processing and superconductors is helping to make artificial intelligence a reality.
Quantum computation and molecular and nanotechnology will radically change the face of
computers in years to come. The goal of fifth-generation computing is to develop devices that
respond to natural language input and are capable of learning and self-organization.
ii. Classification of computers/classification of computers
Basically computers can be categorized under the following classifications
Classification by capacity
Classification by function
Classification by purpose
Classification by power
Classification by Capacity
Under this we look at the physical size of a computer and the number of people a computer can
accommodate at a time, under this category we have the following
Main frame computers
Super computers
Mini computers
Micro computers
Mainframe
Mainframe is very large in size and is an expensive computer capable of supporting hundreds or
even thousands of users simultaneously. Mainframe executes many programs concurrently and
supports many simultaneous execution of programs
Characteristics of mainframe computers
They were the earliest which were around up to 1960
They were very large almost to fill a room
They were water or air cooled computers
They were very expensive
It’s could accommodate up to 1000 users at ago
Supercomputer
Supercomputers are one of the fastest computers currently available. Supercomputers are very
expensive and are employed for specialized applications that require immense amount of
mathematical calculations (number crunching). For example, weather forecasting, scientific
simulations, (animated) graphics, fluid dynamic calculations, nuclear energy research, electronic
design, and analysis of geological data (e.g. in petrochemical prospecting).
Characteristics of super computer
They are computers with very high mathematical capabilities
These computers are used primarily for research purposes, oil exploration, and weather
forecasting.
These are very powerful micro computer, which can support up to four users
They are large computers with faster processing using multiple processors and superior
technology
Lecturer: Stephen Wandera Magero Page 3
, Mini computers
It is a midsize multi-processing system capable of supporting up to 250 users simultaneously.
Characteristics of mini computer
They are small versions of main frame
They are less powerful in operation than main frame computers
They have fewer processors they can support up to 100 users at age
They can be used in banking, education and industrial areas
They have the same basic structures as the larger main frame computers
Mini computers are heavily used as network servers in the business industry
Micro computers
Characteristics of micro computers
These are small computers which support only one user at a go
They are mainly used in homes and can commonly refer to as personal computers.
Classifications by functions
This refers to how computers are designed to operate; this method of classification gives three
major categories of computers i.e. Digital, Analog, and Hybrid.
Digital Computers
These are computers which carry out their operation in distinct steps using digits. These
computers deal with data represented as a series of zeros and ones. They perform their operations
by noting the presence or absence of physical signal in a particular position. This ON and OFF
condition represents binary data that can be manipulated arithmetically or logically to produce a
solution
Analog Computers
These are computers which operate by measurement and they use continuous values as opposed
to discrete values. E.g. Thermometer, Car speed, Barometer etc Analog computers they are
mainly used for scientific and engineering purpose.
Hybrid computers
These are computers which combine the feature of digital and analog, a hybrid computer is a
combination of analog and digital computers linked together by an interface system for
converting analog data to data and vice versa, they are used in scientific research and other
specialized application
Classification by purpose
Here computer are classified according to what they were designed to do, some computers are
designed to perform a specific task (Special purpose computers), while others are designed to
perform a number of tasks (general purpose computers)
Special purpose computers
These are computers which were designed to carry out a specific purpose or for a particular
specific purpose. Such computers might be found in a specific laboratory where they perform
complicated mathematical operations
General purpose computers
These are computers which were designed to perform wide variety of operations using a wide
variety of programming languages, such computers could be found in of purposes, such as
research by professors, class assignment by students and registration by staff.
Lecturer: Stephen Wandera Magero Page 4
INFORMATION COMMUNICATION TECHNOLOGY
TOPIC 1: COMPUTER FUNDAMENTAL
Computer is a programmable electronic device designed to accept data, perform prescribed
mathematical and logical operations at high speed, and display the results of these operations.
i. Evolution of computers
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. They were very expensive to operate and in addition to
using a great deal of electricity, generated a lot of heat, which was often the cause of
malfunctions. Input was based on punched cards and paper tape, and output was displayed on
printouts. The UNIVAC and ENIAC computers are examples of first-generation computing
devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S.
Census Bureau in 1951.
Characteristic
Used vacuum tubes for circuitry Solved one problem at a time
Electron emitting metal in vacuum
tubes burned out easily Used input based on punched cards
Used magnetic drums for memory Had their outputs displayed in print
outs
Were huge, slow, expensive, and
many times undependable Used magnetic tapes
Were expensive to operate Used machine language
Were power hungry Had limited primary memory
Generated a lot of heat which would Were programming only in machine
make them malfunction language
Second Generation (1956-1963) Transistors
Transistors replaced vacuum tubes and ushered in the second generation of computers. The
transistor was invented in 1947 but did not see widespread use in computers until the late 1950s.
The transistor was far superior to the vacuum tube, allowing computers to become smaller,
faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors.
Though the transistor still generated a great deal of heat that subjected the computer to damage,
it was a vast improvement over the vacuum tube. Second-generation computers still relied on
punched cards for input and printouts for output. High-level programming languages were also
being developed at this time, such as early versions of COBOL and FORTRAN. These were also
the first computers that stored their instructions in their memory, which moved from a magnetic
drum to magnetic core technology.
Characteristics
Used transistors Were slightly smaller, cheaper, faster
Faster and more reliable than first
generation systems Generated heat though a little less
Lecturer: Stephen Wandera Magero Page 1
, Still relied on punch cards and Were still costly
printouts for input/output
Needed air conditioning
Allowed assembly and high-level
languages Introduced assembly language and
operating system software
Stored data in magnetic media
Third Generation (1964-1971) Integrated Circuits
The development of the integrated circuit was the hallmark of the third generation of computers.
Transistors were miniaturized and placed on silicon chips, called semiconductors, which
drastically increased the speed and efficiency of computers. Instead of punched cards and
printouts, users interacted with third generation computers through keyboards and monitors and
interfaced with an operating system, which allowed the device to run many different applications
at one time with a central program that monitored the memory. Computers for the first time
became accessible to a mass audience because they were smaller and cheaper than their
predecessors.
Characteristics
Used ICs Output was visualized on the
Used parallel processing monitors
Were slightly smaller, cheaper, faster Used operating systems, thus
permitting multitasking
Used motherboards
Simplified programming languages
Data was input using keyboards i.e. BASIC
Fourth Generation (1971-Present) Microprocessors
The microprocessor brought the fourth generation of computers, as thousands of integrated
circuits were built onto a single silicon chip. What in the first generation filled an entire room
could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the
components of the computer from the central processing unit and memory to input/output
controls on a single chip. In 1981 IBM introduced its first computer for the home user, and in
1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop
computers and into many areas of life as more and more everyday products began to use
microprocessors. As these small computers became more powerful, they could be linked together
to form networks, which eventually led to the development of the Internet. Fourth generation
computers also saw the development of GUIs, the mouse and handheld devices.
Characteristics
Used CPUs which contained Were used in networks
thousands of transistors Were cheap
Were much smaller and fitted on a Were very fast
desktops, laps and palms Register over 19 billion transistors in
Used a mouse high-end microprocessors
Fifth Generation (Present and Beyond) Artificial Intelligence
Lecturer: Stephen Wandera Magero Page 2
,Fifth generation computing devices, based on artificial intelligence, are still in development,
though there are some applications, such as voice recognition, that are being used today. The use
of parallel processing and superconductors is helping to make artificial intelligence a reality.
Quantum computation and molecular and nanotechnology will radically change the face of
computers in years to come. The goal of fifth-generation computing is to develop devices that
respond to natural language input and are capable of learning and self-organization.
ii. Classification of computers/classification of computers
Basically computers can be categorized under the following classifications
Classification by capacity
Classification by function
Classification by purpose
Classification by power
Classification by Capacity
Under this we look at the physical size of a computer and the number of people a computer can
accommodate at a time, under this category we have the following
Main frame computers
Super computers
Mini computers
Micro computers
Mainframe
Mainframe is very large in size and is an expensive computer capable of supporting hundreds or
even thousands of users simultaneously. Mainframe executes many programs concurrently and
supports many simultaneous execution of programs
Characteristics of mainframe computers
They were the earliest which were around up to 1960
They were very large almost to fill a room
They were water or air cooled computers
They were very expensive
It’s could accommodate up to 1000 users at ago
Supercomputer
Supercomputers are one of the fastest computers currently available. Supercomputers are very
expensive and are employed for specialized applications that require immense amount of
mathematical calculations (number crunching). For example, weather forecasting, scientific
simulations, (animated) graphics, fluid dynamic calculations, nuclear energy research, electronic
design, and analysis of geological data (e.g. in petrochemical prospecting).
Characteristics of super computer
They are computers with very high mathematical capabilities
These computers are used primarily for research purposes, oil exploration, and weather
forecasting.
These are very powerful micro computer, which can support up to four users
They are large computers with faster processing using multiple processors and superior
technology
Lecturer: Stephen Wandera Magero Page 3
, Mini computers
It is a midsize multi-processing system capable of supporting up to 250 users simultaneously.
Characteristics of mini computer
They are small versions of main frame
They are less powerful in operation than main frame computers
They have fewer processors they can support up to 100 users at age
They can be used in banking, education and industrial areas
They have the same basic structures as the larger main frame computers
Mini computers are heavily used as network servers in the business industry
Micro computers
Characteristics of micro computers
These are small computers which support only one user at a go
They are mainly used in homes and can commonly refer to as personal computers.
Classifications by functions
This refers to how computers are designed to operate; this method of classification gives three
major categories of computers i.e. Digital, Analog, and Hybrid.
Digital Computers
These are computers which carry out their operation in distinct steps using digits. These
computers deal with data represented as a series of zeros and ones. They perform their operations
by noting the presence or absence of physical signal in a particular position. This ON and OFF
condition represents binary data that can be manipulated arithmetically or logically to produce a
solution
Analog Computers
These are computers which operate by measurement and they use continuous values as opposed
to discrete values. E.g. Thermometer, Car speed, Barometer etc Analog computers they are
mainly used for scientific and engineering purpose.
Hybrid computers
These are computers which combine the feature of digital and analog, a hybrid computer is a
combination of analog and digital computers linked together by an interface system for
converting analog data to data and vice versa, they are used in scientific research and other
specialized application
Classification by purpose
Here computer are classified according to what they were designed to do, some computers are
designed to perform a specific task (Special purpose computers), while others are designed to
perform a number of tasks (general purpose computers)
Special purpose computers
These are computers which were designed to carry out a specific purpose or for a particular
specific purpose. Such computers might be found in a specific laboratory where they perform
complicated mathematical operations
General purpose computers
These are computers which were designed to perform wide variety of operations using a wide
variety of programming languages, such computers could be found in of purposes, such as
research by professors, class assignment by students and registration by staff.
Lecturer: Stephen Wandera Magero Page 4
