BIOS Chip

The BIOS chip is host to the Basic Input/Output System, without this chip a computer would not be able to boot-up.  It contains a low-level program which carries out a POST (power-on self-test) as soon as the computer is turned on.  If that test is sucessful the BIOS will be transfered to system memory and continue running from there.  All the motherbaord components and add-on components will then be initialised.  The BIOS effectively breaths life in to a computer.

Not all BIOS chips are the same, some function differently to others.  However, most motherboards built today do use similar BIOS chips, commonly made by Award Software or Pheonix Technologies.  Some boards even have multiple BIOS chips providing back-up in the event of a failure.

Photo shows a removable BIOS chip marked

Modern BIOS chips are EEPROMs, this means the contents can be erased and updated with a new BIOS program.  Updating the BIOS can be useful to fix any bugs in the previous BIOS.  Care needs to be taken when flashing the BIOS chip with an update, a failed flash can render a PC useless until the BIOS is replaced with a working chip.  The removable chip design makes recovering from a bad flash a little easier.

Many important system settings can be changed via the BIOS set-up screens.  When building a computer from scratch, you will almost certainly need to access the BIOS settings sooner after assembly is complete.

Further reading on BIOS

Guide: AMD Athlon 64 Motherboard BIOS Settings

Guide: Installing XP using nVRAID (covers RAID set-up in the BIOS)

Useful external link

www.award-bios.com