Computer Training Guide
For Beginners
Microsoft Window XP
Re-Edition
Seunsmith Networks Innovation
A computer is device that can receive,
collect, process and store data. They are used as tools in every part of
society together with the Internet. Computers nowadays are complex; there are a
lot of different components inside them, and they all serve different purposes.
They all need to work together for the computer to work; knowing how a computer
works makes it easier to use a computer by being able to understand how a
computer will respond.
Computers are machines that perform tasks or calculations
according to a set of instructions, or programs. The
first fully electronic computers, introduced in the 1940s, were huge machines
that required teams of people to operate. Compared to those early machines,
today's computers are amazing. Not only are they thousands of times faster,
they can fit on your desk, in your lap, or even in your pocket.
Computers work through an interaction of hardware and
software. Hardware refers to the parts of a computer
that you can see and touch, including the case and everything inside it. The
most important piece of hardware is a tiny rectangular chip inside your
computer called the central processing unit (CPU),
or microprocessor. It's the "brain" of
your computer—the part that translates instructions and performs calculations.
Hardware items such as your monitor, keyboard, mouse, printer, and other items
are often called hardware devices, or devices.
GENERATIONS OF COMPUTERS
The First Generation Computers 1940 – 1954 (Vacuum Tubes)
The first generation of computer makes used Vacuum Tubes. They were very large in
size and programming on them was very difficult. Some of the computers of this
generation are as follows:-
MARK – I:
This was the first electronic computer
developed by Howard Aiken. It was about 15metres long and the wires connecting
the various parts of the machine were about 800 Km long. The main advantage of
this computer was that it was fully automatic and much more reliable than other
electronic computers.
ENIAC:
This was
the first fully electronic digital computer developed by J.PRESPER ECKERT and JOHN
MAUCHLY.
The full Name of ENIAC is called (Electronic
Numerical Integrator and Computer) was the
first general-purpose electronic computer. It was built for the United States
military to calculate the paths of artillery shells. Physically, ENIAC was
enormous, weighing more than 27,000 kilograms (60,000 pounds) and filling a
large room. To process data, ENIAC used about 18,000 vacuum tubes, each the
size of a small light bulb. The tubes burned out easily and had to be
constantly replaced.
EDVAC: Picture 1.2
EDVAC was also developed by the makers of
ENIAC. It was a stored program machine unlike its predecessor. The full name of
EDVAC is called (Electronic Discrete Variable Automatic Computer)
The EDVAC
was a binary serial computer with automatic addition, subtraction, multiplication,
programmed division and automatic checking with an ultrasonic serial memory[1] capacity
of 1,000 44-bit words (later
set to 1,024 words, thus giving a memory, in modern terms, of 5.5 kilobytes).
UNIVAC I: Picture 1.3
UNIVAC was
the first commercially available electronic computer developed by J.PRESPER ECKERT and JOHN MAUCHLY. It was also the first
computer to handle both numeric and text data. The full name of UNIVAC is
called Universal Automatic Computer
Limitation of the First Generation Computer
·
The major limitations of first generation
computers were :
·
The operating speed was very low.
·
Power consumption was very high.
·
They required large space for installation.
·
The Programming capability was quite low.
·
Quit larger, they generate lot of heat
require special housing.
·
The Medium internal store.
Second Generation Computers 1956-1963
(Transistor):
The
invention of Transistors marked the
start of the second generation. These transistors took place of the vacuum
tubes used in the first generation computers.
A transistor is a device composed of semi-conductor
materials (germanium and silicon) that can both conduct and insulate
Transistors switch and modulate electronic current. The transistor was the
first device designed to act as both a transmitter, converting sound waves into
electronic waves, and resistor, controlling electronic current.
The name transistor comes from the 'trans' of transmitter
and 'sistor' of resistor.
First large scale machines were made using these
technologies to meet the requirements of atomic energy laboratories. One of the
other benefits to the programming group was that the second generation replaced
Machine language with the assembly language. Even though complex in itself
Assembly language was much easier than the binary code.
These
generations are categorized by their technology as follows:
·
ICT(ICL) 1300,
·
BM 1401
Limitations of second-generation computers were:
·
They used transistors as their main
component.
·
They were smaller, faster and more efficient
than first-generation computers.
·
They also contained all the components we
associate with modern-day computers like printer, memory, disk storage,
operating system.
·
They are cheaper than the first generation
computers.
·
Maintenance requirement is still high.
·
Very costly.
Third Generation Computers 1964-1971
(Integrate Circuit)
An integrated circuit or monolithic
integrated circuit (also referred to as an IC, a chip, or a microchip)
is a set of electronic circuits on one small plate ("chip") of
semiconductor material, normally silicon. This can be made much smaller than a
discrete circuit made from independent components.
Although transistors
were great deal of improvement over the vacuum tubes, they generated heat and
damaged the sensitive areas of the computer. The Integrate
Circuit(IC) was invented in 1958 by Jack Kirby. It combined
electronic components onto a small silicon disc, made from quartz. More
advancement made possible the fittings of even more components on a small chip
or a semi conductor. Also in third generation computers, the operating systems
allowed the machines to run many different applications. These applications
were monitored and coordinated by the computer's memory.
·
IBM-360
series,
·
ICL – 1900,
·
ICL – 2903,
·
PDP – 11/45
Limitations
of third-generation computers were:
·
They used Integrated Circuits, popularly
known as chips.
·
These computers were smaller than the
second-generation computers.
·
Capacities of main memory were greatly
enlarged.
·
They used an operating system that allowed
machines to run many different programs simultaneously.
·
Power requirement became less.
·
Maintenance of IC required sophisticated
technology
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.
Fifth Generation (Present and Beyond)
Artificial Intelligence:
Fifth
generations computers are only in the minds of advance research scientists and
being tested out in the laboratories. These computers will be under Artificial
Intelligence (AI), they will be able to take commands in an audio visual way
and carry out instructions. Many of the operations which require low human
intelligence will be performed by these computers.
Parallel
Processing is coming and showing the possibility that the power of many CPU's
can be used side by side, and computers will be more powerful than those under
central processing. Advances in Super Conductor technology will greatly improve
the speed of information traffic. Future looks bright for the computers.
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