Computer Studies

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Computer Studies
Chp 4 Input and Output Devices
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4.1 Input devices
Input devices lets us enter enter and commands
into a computer. Early computers required the
data to be prepared in a form that the method.
The trend of data inputting is towards reducing
the number of keying-in steps. The computer reads
data directly from the source. This is called the
direct input method.
This is a input and output devices
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This is a input devices method.
Keyboard The most common method of entering data
into a computer is by typing on a keyboard. A
computer keyboard resembles a typewriter
keyboard with additional keys.
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Pointing devices 1 Mouse A mouse is the most
popular devices . It has a ball-bearing on its
underside. If you put it on, the screens mouse
will on!
2 Game paddle A game paddle is a device that
lets the user interact with a computer game1
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3 Light pen A light pen is a light-sensitive
pen-shaped device. When placed against the
screen, its positive is detected.
4 Touch screen Touch screen allow us to select
options by touching the screen without
fingers.
5 Digitizer and graphic tablet It is use for
drawing the graphic!
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Scanning devices 1 Image scanner It allows
direct entry of digital images of pictures and
text.
2 Bar Code reader A bar code reader is usually
read the bar code of the something which is
identification the number is or is not true!
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And the other things items is scanning devices...
Magnetic ink character recognition
Optical mark recognition
Optical character recognition
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Voice-input devices It use the speech recognition
devices make inputting by voice possible.
Digital camera It functions like an ordinary
camera except that the image is stored in digital
format on the cameras internal memory.
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4.2 Output devices
Output devices present information in a form that
can be understood by us.
Visual display units are monitors, which are
output on the screen!
Printers Printers can be divided into two types
Impact printers and non- impact printers. Impact
printers have physical touch, but another have
not physical touch! Dot matrix printer is impact
printers, laser and ink jet printer are
non-impact printer!
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This is different between dot matrix, ink jet and
laser printer!
Plotter is the expensive of printers because it
is can print out of size is very big!
Speech synthesizer It is similar to a speech
recognition device, but only in reverse!