12. Barcode Reader

Barcode readers ( and the input devices on the following pages) are classed as automatic input devices.

Most items that are for sale in shops have a barcode printed somewhere on the packaging.

The barcode is a series of vertical bars of varying widths that give information about:

• the country of manufacture
• the name of the manufacturer
• a product code

The barcode does NOT contain the price of the item - this is held on the company database.

A barcode reader is an automatic input device which is used to scan or 'read' the barcode by using a visible red light. The reflected light is translated into digital data that is interpreted by the computer to identify the product and price from the database.

The main advantage of using a barcode system is that any price change only needs to be made to the database and not every single product package.

Barcodes are also used on books to show the book's ISBN number - have a look at any textbook that you have in your bag. They are also used on library tickets so that when your ticket is scanned, the database brings up your account and any books which you still have out on loan are displayed.