Chapter 3 Hardware: Unit 3.2: Input and Output Devices (Unfinished)

Question 1

Define barcode

Answer 1

Series of dark and light parallel lines of varying thickness. The numbers 0 to 9 are each represented by a unique series of lines.

Question 2

What happens when a barcode is scanned?

Answer 2

The barcode is first of all read by a red laser or red LED
Light is reflected back off the barcode; the dark areas reflect little or no light, which allows the bars to be read
The reflected light is read by sensors (photoelectric cells)
As the laser or LED light is scanned across the barcode, a pattern is generated, which is converted into digital data – this allows the computer to understand the barcode

Question 3

What happens after a barcode is read?

Answer 3

The barcode number is looked up in the stock database (the barcode is known as the key field in the stock item record); this key field uniquely identifies each stock item
When the barcode number is found, the stock item record is looked up
The price and other stock item details are sent back to the checkout (or point of sale terminal (POS))
The number of stock items in the record is reduced by 1 each time the barcode is read
This new value for number of stock is written back to the stock item record
The number of stock items is compared to the re-order level; if it is less than or equal to this value, more stock items are automatically ordered
Once an order for more stock items is generated, a flag is added to the record to stop re-ordering every time the stock item barcode is read
When new stock items arrive, the stock levels are updated in the database.

Question 4

What are the advantages to the management using barcodes?

Answer 4

Much easier and faster to change prices on stock items
Much better, more up-to-date sales information/sales trends
No need to price every stock item on the shelves (this reduces time and cost to the management)
Allows for automatic stock control
Possible to check customer buying habits more easily by linking barcodes

Question 5

What are the advantages for the customer using barcodes?

Answer 5

Faster checkout queues
Errors in charging customers is reduced
The customer is given an itemised bill
Cost savings can be passed on to the customer
Better track of ‘sell by dates’ so food should be fresher