Do you know BIOS....?


wiseGEEK Writing Contest

If you are a person that usually involved with computers for a long period of time, you must have heard this word “BIOS” before. Even we didn’t care much about these four letters, it really cares about the startup process of the computer. Have you ever wondered what will be happening inside the computer, when we turn on our computer? When we finding an answer to this question we definitely need to know about BIOS.

It’s a reality that, lot of people doesn’t know about the components of our body and their functionality’s. It’s the same situation when we consider about computers. So we can begin to get a basic idea about the computer from its very first step, while we understand about BIOS. Actually BIOS acts a main part when we need to start our computer. It’s just like a core of something. BIOS stand for Basic Input Output System. It is considered as a little chip where we can store little piece of data (software) within it.

We know that there is something calls microprocessor which acts like the brain of the computer. Just like our human body computer also has some parts to control over the brain. We name these other parts as “Peripheral Devices”. Ex: Hard disk, CD ROM etc. these peripheral devices does different type of things in different ways. Because of this reason microprocessor needs to know, what each of these peripherals do at a given time. These details about the peripherals are provided by operating system (OS).

Especially processor needs to know what each of this device do, when the computer begins to start (When computer switched on). In order to do that microprocessor needs to access the operating system. But unfortunately this operating system also stored inside a peripheral device. It can be a hard disk, floppy disk or a CD ROM. So how can processor access the operating system? This is where BIOS acts its part. Actually computer architectures develop this BIOS chip to answer the above question fast and accurate.

BIOS chip introduces the main peripheral devices like CD ROM, Hard Disk and Floppy Disk to processor, at the very first moment when the computer starts. If the BIOS chip wasn’t there inside the computer, Processor cannot understand what is hard disk? , what are the data stored inside the hard disk? Then as a result of that computer doesn’t begin to operate. So now we can understand the main thing done by BIOS. In addition to this main task BIOS perform some other tasks also. At the first moment when we turn on our computer, BIOS perform a Power On Self Test (POST) on each peripheral device in computer. In here what the BIOS chip do is, it write some data to the device and read the data back from the device. The purpose of this POST is to identify any errors within a peripheral device. We know that when we turn on our computer, we can see some details about the main devices of our computer through the monitor. Now we can understand how and why this thing happens? It is done by BIOS chip.

Actually even graphic card, TV card and other devices also has its own BIOS chips. The main BIOS chip gives commands to these sub BIOS chips at the Power On Self Test (POST). But Remember! In order to perform every task inside BIOS chip, it also needs some piece of software within it. This little piece of software stored in a flash memory chip which is attached to the main Mother Board. In early computers we could see this flash memory chip as a distinct part. But in modern computers this flash memory chip is included inside the Mother Board. So we can’t see it anymore.

However BIOS chip doesn’t keep data about the peripheral devices. The main thing it does is, helping the processor to load the operating system to the main memory. In other words we can say BIOS chip act as a mother to the computer until her computer son reach the age of fully loaded operating system.

This submission was not accepted into the wiseGEEK Writing Contest because it answers a question already answered on wiseGEEK.

submitted by Isuru Madushanka Jayarathna