Here you go my first Hub page. I will start of with my Fav Sub Hacks , Technology. In this world, nearly 80% of the people uses either computer \ Notebook \ Netbook etc. But how many will know, what happens when you power on the system. I am here to tell a bit stuff about that guy who does all. He is BIOS(Basic Input Output System). BIOS does a lot of stuff on power on. It does a basic POST(Power On Self test) to check whether all our soldiers(Components RAM, Processor, PCI etc) are fine.

Just wanna to tell you guys on the background tasks executed when you powered on a PC/Laptop.

Before start I just want to clarify about BIOS - Basic Input Output System. This is the one responsible for doing all the tasks when you powered on.

The BIOS Program is always located in a special reserved memory area. The 64K of the first MB of System memory(Address from F000h to FFFFh).

The set of functions BIOS performs are as follows.

• Initialising all the Hardwares connected.
• Providing the Setup Menu(When boots, press F2 to see this screen). This is an User configurable page, where you can set passwords, HDD Locking support, configurable boot options etc.
• Booting up the System.

What does all this have to do with the BIOS?

The BIOS is actually the pillar that supports Hardware, Operating System and Application, because it provides the standard interface that DOS uses (or whatever the operating system is). The system hardware itself is the "mess at the bottom of the pile" that we are trying to have to avoid dealing with. In some ways, the most amazing part of all of this is that DOS itself will run on so many different machines.

The BIOS is what makes this possible. Instead of DOS having to talk directly to the hardware, of which there are many, many possibilities. It talks to the BIOS, which is what is customized to the hardware. The BIOS hides the hardware from the operating system so it doesn't have to worry about it, by providing standardized services to the operating system.

I said earlier during Boot if User Press F2, the following Screen will appear.  

When you turn on your computer, the BIOS does several things. This is its usual sequence:

- Check the CMOS Setup for custom settings.

- Load the interrupt handlers and device drivers.

- Initialize registers and power management.

- Perform the power-on self-test (POST).

- Display system settings.

- Determine which devices are bootable.

- Initiate the bootstrap sequence.

Others Include..

Activating other BIOS chips on different cards installed in the computer - For example, SCSI and Video & graphics cards often have their own BIOS Chip embedded into the Card.

Providing a set of low-level routines that the operating system uses to interface to different hardware devices - It is these routines that give the BIOS its name. They manage things like the keyboard, the screen, and the serial and parallel ports, especially when the computer is booting.

Managing a collection of settings for the hard disks, clock, etc.