What is BIOS?

BIOS stand for Basic Input Output System and also known as System BIOS. It is a ROM flash memory that carries the basic instructions on what computer is supposed to do. It is mounted on the computer motherboard. The software stored in it checks if all the computer hardware and other component are working well before it give way for the operating system to take over. If there is any hardware part that is not functioning well the Error message will be displayed i.e. keyboard not connected.

BIOS chip

BIOS from American Megatrends Inc

Functions of a System BIOS

BIO is an important component of computer and if not present the computer may even not boot at all. Its main functions includes:

Carries out the POST (Power On Shelf Test): this involve checking if all the computer hardware are connected and working as expected to and if not it give an Error message.

Loads operating system: They loads Bootstrap loader which then takes over and boot computer using the available operating system

BIOS setup: It offer basic setup when one can change date, set hardware password and set other hardware configuration i.e. the boot order of storage media. It is also known as CMOS setup.


BIOS manufacturers

The chip is manufacturer by some of the renowned companies in the world which include:

AMI – American Megatrends Inc. It is the world largest BIOS manufacture. According to their website it was founded in 1985. It headquarter is in Atlanta but many offices around the world. Apart from BIOS firmware they also manufacture motherboards.

A Phoenix technology is another company that manufactures BIOS Firmware. It is a Silicon Valley company. Phoenix headquarters are located in Campbell, California with offices worldwide.

Another company involved is Winbond Electronics Corporation. It was established in 1987. There headquarters are in Central Taiwan Science Park, Taiwan. They also involved in manufacturing of main memories RAM.

How BIOS work.

When the computer is powered the first software that run is the firmware installed in the BIOS. First it checks the CMOS (Complementary Metal Oxide Semiconductor) chip content which includes:

  1. System date/time:- set date and time
  2. Boot sequence: set where system to check operating system first to start booting
  3. Drive configuration:- configure CD/DVD drive, floppy
  4. Security: to set password to accessing BIOS setup
  5. Mouse and keyboard: lock or unlock the use of any
  6. Plug and play:- set how plug and play devices are connected.
  7. Power management:- setting different ways of managing power e.g. standby.


After checking the information, it then starts the POST process. When that is done it then checks where the bootstrap is located and load, then it to give the operating system room to take over the operation of the computer.


How to upgrade BIOS

Today BIOS firmware is stored in a flash ROM which means it can be upgraded if need be. Upgrading is sometimes called flashing the ROM. Upgrade is not recommended unless it is important to do so. An upgrade may be done if:

  1. To fix a damaged BIOS
  2. Allow use of newer hardware which the current BIOS cannot handle
  3. To get a new version of BIOS which bugs has been fixed.

First check the BIOS version of your computer. Also do a backup of your BIOS information incase anything goes wrong when updating. Then go to the computer manufacturer website, this may vary from one manufacturer to another, and download the latest version. Make sure you get the exact BIOS for your computer. Install the updates and restart the computer. It should restart without a problem unless the upgrade was not done well.

If you get the upgrade from a CD or a flash disk, you insert it and then run the upgrade. After installation the system ask if you want to restart of it ma restart automatically.

Restoring BIOS setup

If something went wrong well upgrading the computer may not restart again and you may need to restore back to the previous BIOS setup before upgrade. One you can use the backup that you created early before you start the upgrade. Another way is to restart the computer and go to BIOS setup then select on restoring previous setting or set all to default setting.

How to check BIOS information

Restart the computer and before anything start appearing on the screen click on DELETE key on the keyboard or any other key that will allow viewing of BIOS setup. If it is locked with a password it will open a command line so that you can key in the password. After that you will be presented with information has discussed early.

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