|COMPUTER : the Technology|
Next, the Future.....
|April 2, 2009|
This is also called VDU (Visual Display Unit). It is used to get the data in the form of soft copy. Their functioning is exactly similar to the television. It contains a CRT which emits the electrons to trace a regular pattern of horizontal lines on the screen.
This is a pointing device which contains a roller in its base. When the mouse is moved on any surface, the pointer on the screen is also moved. It contains a potentiometer coupled with the roller. This potentiometer senses the motion of mouse & convert it into digital value. A mouse may contain two or three buttons.
This is most commonly used device which acts as input device. Its structure is like typewriter.It contains no. of keys which have some specific ASCII values. Like ‘A’ has ASCII value 65. When this is pressed , it is converted into 65 & this 65 is sent to CPU in the form of Binary language (i.e. 1000001). Then operations are done on this data.
These devices gives the hard copy of the output. These are in different types.
Impact - Have mechanical contact in between paper & printing head
Non Impact - No mechanical contact between paper & printing head
Line Printers - print line wise (E.g. Drum Printer)
Character Printer - print character wise (E.g. Daisy Printer)
NON IMPACT -
Speakers receive the sound in the form of electric current from the sound card & convert it to sound format. These are used for listening to music, chatting, seminars for presentations, etc.
The scanner is an input device like the photocopier machine which makes the electronic copy of the picture or document which can be further edited.