BIOS is short for
Basic Input Output System. It is much more than the name suggests. One might think that BIOS controls input and output system. But the BIOS does much more and it is not possible for any operating system to continue without a proper BIOS in place.
BIOS has been there in our computers since the days of DOS – Disk Operating System… even prior to the structured DOS created by Microsoft. It is one of the most important components of the computer though it does not take the credit by appearing on your screen regularly. This post also looks at the most basic component of computers and explains why is it required in computers for computers to work.
What is BIOS?
BIOS is a firmware, in short. It is stored on a chip on a part of the computer motherboard and is basically, a set of instructions that run to help load the operating system. You OS would fail to load, if not for the BIOS!
When you turn on the computer, BIOS instructions are initiated. These instructions make it check the RAM and the Processor (for faults) on your computer.
1. It enumerates the RAM by checking each compartment to see if all of them are working.
2. After checking out RAM and Processor, it checks for other devices attached to the computer
3. It detects all the peripherals, including the keyboard and mouse and then checks for the boot options
4. Boot options are checked in the sequence configured on your BIOS: Boot from CD-ROM, Boot From Hard Drive, Boot from LAN etc.
5. It checks for bootstraps on the devices in the order you or the machine vendor configured the BIOS.
6. It passes reigns of the computer to operating system by loading the essential parts of the OS into the random access memory (RAM) reserved for the OS, after bootstrap is located.
This is not a comprehensive list of functions of the BIOS. It also checks up CMOS (see ▼ Spoiler), and other chips to set up the date and time on the computer, and to load the device drivers into the memory. It checks and uploads input and output interrupts (signals) to the RAM so that the operating system knows what is happening. For example, if a user presses a key, an interrupt request is created and passed on to the BIOS which sends it to the operating system. The operating system then decides what action to take, according to the way it is programmed.
twc
