2. SCOPE AND HISTORY OF COMPUTER:
British mathematician Charles Babbage invented
computer between 1833 to 1871.
A computer is an electronic device that processes
data,converting it in to information that is useful to people.
At the very beginning, the Main frame Computer was the model. However, as
it was costly and required more staff, The Micro computers appeared
afterwards, with the particularity of using microprocessors.
The highly used computer nowadays is the Super Computer which is
very powerful and adapted for many tasks.
First generations Electronic computer(1937-1953)
Second generation computers(1954-1962)
Third-Generation computer(1972-1984)
Fifth generations computers(1983-1990)
Sixth generation computers(1990-Till Date)
3. SCOPE OF COMPUTER:
Certain characteristics of computer interaction can make computers well
suited for distance learning. The features listed below the prospect of
the computer use look more promising:
Routine daily tasks such as banking or buying groceries.
Active learner participations.
Linking of new learning to concrete on the job problems.
Follow up, feedback and implementation support from pears or
experts.
Self direction control over stop or start, time and place of learning or
communication activity.
4. Entering data or instructions into a computer is
called input.
Therefore, an input device is a device which
enters data or instructions into a computer.
Input devices are necessary to convert data into
a form which can be understood by computers.
.
5. Many input devices can be classified according to:
Classification of input devices.
Pointing devices, which are input devices used to specify a
position in space, can further be classified according to:
Whether the input is direct or indirect. With direct input, the
input space coincides with the display. Touch screens and
light pens involve direct input. Examples involving indirect
input include the mouse and trackball.
6. Some Input Devices are :-
Scanner Mouse
Bar Code Reader Keyboard
Joystick
7. A joystick looks like a stick fixed onto a box.
It controls the cursor on the screen, so we can say
it is alternate to the mouse.
Most joysticks include two buttons called triggers.
Joysticks are used mostly for computer games.
8. This input device controls the cursor on the
computer screen.
It is Invented by Douglas Engelbart of
Stanford Research Center in 1963, and
pioneered by Xerox in the 1970s.
It is quite easy to operate a mouse, the user simply
moves the cursor along the table.
Once the cursor is at the desired location, the user
can give instructions to the computer by clicking
the button.
9. Keyboards come in different shapes and sizes
depending on the type of brand. They are similar
to typewriters.
10. The black and white lines printed on certain
products which represent information like the
country of origin, the price of it etc are bar codes.
They can be read by a bar code reader which are
commonly used in Supermarkets and shops.
11. This looks like a photocopying machine, its function is
to scan any document placed on its flat glass and
send the contents to the computer.
Some major manufacturers of scanners include:
Epson, Hewlett-Packard, Microtek, and Relisys.
Scanners usually come with software, such as
Adobe's Photoshop product, that lets you resize and
otherwise modify a captured image.
12. An output device is any piece of computer hardware equipment used to
communicate the results of data processing carried out by an information
processing system (such as a computer) which converts the
electronically generated information into human-readable form.
When computer processed your data, you often need to
produce output of the results. This output could be a display on the
computer screen, hardcopy on printed pages, or even the
audio playback of music you composed on the computer
13. Audio is music, speech, or any other sound. Video
consists of images played back at speeds to provide the
appearance of full motion.
Translate the data processed by the the computer in the
format that people can understand,apperciate and work
with such as Video,text & Image.
Some types of output are:
Video
Audio
Text
Graphics
15. The monitor is one of the most important output
devices, it is used to display text and pictures.
The monitor is also known as the Visual Display Unit
(VDU)
16. The Speakers
Speakers are one of the most common output
devices used with computer systems.
The speakers receive audio input from a device
such as a computer or an audio receiver.
The purpose of speakers is to produce audio
output that can be heard by the listener.
Speakers are transducers that convert
electromagnetic waves into sound waves.
17. There are several types of printers, some are:
Dot matrix- Consists of a print head with a number of
pins which move in and out to print in the form of dots.
Ink- jet- Consists of a print head with a number of tiny
nozzles and coloured ink to form tiny dots.
Laser- Prints images by transferring ‘ ink powder’ onto
a piece of paper using a laser beam.
18. The Projector
A Projector is an output device that can take images generated
by a computer and reproduce them on a large, flat (usually lightly
colored) surface. For example, Projectors are used in meetings to
help ensure that all participants can view the information being
presented.
A Plotter is a type of printer that interprets commands from a
computer to make line drawings on paper with one or more
automated pens.
19. A plotter produces its output using special pens across the paper to
create a drawing.
Engineers, architects and designers use plotters to produce their
drawings or designs.
There are a number of different types of plotters such as Drum
Plotter and Flatbed Plotter.
