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- 1Features of a Keyboard- how is works/ how data is capturedUnderneath the keys there is a key matrix,
Each key has a unique binary code.
...which is stored in a buffer
When the return key is pressed
...the contents of the buffer are sent to the computer - 2How a mouse worksThe mouse has a roller ball
...which moves as the mouse is moved
The movement of the roller ball is detected by roller (one of X and Y)
...and converted into binary signals
When the button on the mouse is clicked
...a signal is sent to the computer - 3The operation of a typical touch- screenThe edges of the screen emit light beams
When a finger touches the screen the beams are broken
... identifying the co-ordinate
... of the user's selection - 4Advantages and disadvantages of using a touch screen and not a monitor or keyboard+ve: Easier to use than a keyboard by someone with limited experience
+ve: More suited to a public environment as it easier to keep clean
-ve: More expensive, as a touch screen is more complex than a monitor - 5Main features of a Optical Mark ReaderSpecially designed forms are used
Marks made in pre-set positions on the form
...are detected by light
... and the positions determined from a stored template
The marks are made by hand or printed on - 6Main features of an Optical Character ReaderA printed document is scanned on a flatbed scanner
The image is captured using light
Special software can interpret and convert the letters
...as ASCII text
... which then can be processed as a standard word processed text - 7The operation of a smart cardThe card us embedded with a microchip
The chip contains data relevant to the application
The card is read by the host computer
...using a magnetic card reader
Access is via a serial interface - 8How data is captured by a bar code reader
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- AS - Level Ict Fichas sobre Sin título, creado por hannahbanana2014 el 22/04/2016.
- Creado por
- hannahbanana2014
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