07-04-2012, 12:43 PM
Input and Output
ch4.ppt (Size: 412.5 KB / Downloads: 30)
The computer user is very aware of inputting data and the output (processed information) that is the result.
Keyboard
A keyboard is similar to a typewriter keyboard. Not all keyboards are traditional. Customized keyboards can be found in business, schools, and homes.
Trackball
The trackball stays in one place while the user rolls the ball directly with one hand.
Trackballs are ideal when a flat surface does not exist.
Scanner
A scanner is an optical recognition system that uses light to scan an image and convert it into electrical signals.
The signals are then processed so that the image appears on the computer monitor
Optical Character Recognition (OCR)
OCR devices use a light source to read special characters or printed text.
OCR devices can “read” pages in a book or sale tags on store merchandise.
Bar Codes
Bar codes appear on the product as a series of zebra-like stripes.
Bar codes are used to identify a product when read by a device called a bar code reader.