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Introduction To Computers
What is a Computer?
The word Computer comes from the wordcompute .
A computer is considered to be a calculating devicethat can perform arithmetic operation at enormous
speed.
More accurately a computer is an electronic device
used to process data.A computer can convert data into information that is
useful to people.
It is also called Data Processor.
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Components of a Computer
System
A complete computer system includes
four different parts:
Hardware
Software
DataUser
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Computer Hardware
A computer's hardware consists of
electronic devices; the parts you can see
and touch.The term "device" refers to any piece of
hardware used by the computer, such as
a keyboard, monitor, modem, mouse, etc.
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Computer Hardware
The four primary components of a computer systemare:
Input :Input devices send data and instructions tothe central processing unit.
Output: Central processing unit executes computerinstructions. Memory holds data and programstemporarily.
Processing: Output devices make processed dataavailable to the user.
Secondary Storage :Secondary storage devices store
data and programs permanently.
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Input Devices
Input devicesaccept data and instructions from theuser or from another computer system.
Also, the input devices send the data or instructions to
the processing unit to be processed into usefulinformation.
The most commonly used input devices are :
1. Keyboard ,
2. Mouse. There are other input devices, such as touch screen,
joystick, modem, scanner, and voice recognitionsystems.
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Keyboard
The keyboard looks like the typewriter. A numeric
keypad is located to the right of the keyboard. Numeric
keys have the same placement as a 10-key calculator,
which allow the operator to enter data rapidly.
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The mouse is a device that allows you to
control the movement of the insertion
point on the screen. The operator placesthe palm of the hand over the mouse and
moves it across a mouse pad, which
provides traction for the rolling ballinside the device.
Mouse
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Characteristics of Computer
Speed :
While talking about the speed of a computer,
we do not talk in terms of seconds or even
milliseconds (10-3). Our units of speed are
microseconds (10-6), the nanoseconds (10-9), and
even the picoseconds (10-12). A powerful
computer is capable of performing about 3 to 4
million simple arithmetic operations persecond.
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Characteristics of Computer
1. Accuracy :
The accuracy of a computer is consistently high
and the degree of a particular computer
depends upon its design. But for a particular
computer, each and every calculation is
performed with the same accuracy.
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Characteristics of Computer
3. Diligence :
Unlike human beings, a computer is free from
monotony, tiredness, lack of concentration,and
hence can work for hours together without
creating any error
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Characteristics of Computer
4. Versatility :
Versatility is one of the most wonderfulthings about a computer.
All that is required to change its talent is to slipin a new program into it.
Briefly, a computer is capable of performing
any task provided that the task can be reduced
to a series of logical steps.
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Characteristics of Computer
5. Power of Remembering:
A computer can store and recall any amount of
information because of its secondary storage
capability.
Every piece of information can be retained as
long as desired by the user and can be recalled
as and when necessary.
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Characteristics of Computer
6. No I.Q :
A computer is not a magical device. It can only
perform tasks that a human being can. It
possesses no intelligence of its own. Its I.Q. is
zero.
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Characteristics of Computer
7. No Feelings :
Computers are devoid of emotions. They have
no feelings and no instincts because they are
machines.
Computers cannot make judgments of their
own, their judgment is based on the
instructions given to them in the form of
programs that are written by us.
They are only as good as man makes and uses
them.