WHAT IS THE BIOS? (Informaticinfo)

WHAT IS THE BIOS?

BIOS is for Basic Input Output System. At the starting up of the computer (called the boot) there is an egg and chicken problem. The operating system is located on the hard disk but there is need of an operating system to handle the access to the hard disk. So how can one launch the system?

The answer is the BIOS. That one is located on the motherboard. It is a set of pre-recorded instructions (programs). These are permanently stored on read only memory (ROM). These programs are conceived to handle in a limited way keyboard, monitor, disks and other basic functions to run the computer without the operating system with the purpose of starting that one. Once that OS is started it takes control of the operations.

A small part of the BIOS is not recorded on ROM and is editable. This allows to change parameters. One usually gets access to these parameters at boot time by pressing the key "Delete" or F1. The system normally prints a message like "HIT 'DEL' TO ENTER SETUP". And you come to a screen which shows you the various parameters of the BIOS and which allows you to change them. Carefulness is advised. Change them only if you know what you are doing.

It can be useful to know that with most modern computers the BIOS is not really recorded in ROM but with another type of memory which can be edited through a certain treatment called "BIOS flashing". This is occasionnally done to update the BIOS but extreme caution has to be taken here and you should refrain from doing it if your system works properly as you could cause irreversible and undesirable changes.