Input and Output Devices
By Tencho Sherpa
Bar Code Reader
It is a device which is used to read the code from the products which are usually in the form of Bars. It has a light sensitive detector which tells the cashier the values of the bars on the product & changes them into numeric code. These Bar Code Readers are mainly used in shopping malls
It is a pointing device which contains a photocell mounted at it's tip. It senses the light from the screen when it becomes closer to the screen, & generates a pulse. So for identifying a particular location on the screen these light pens are very useful. But these days, not much is in use.