Next to your CPU, your BIOS (Basic Input-Output System) chip is probably the most important microprocessor on your motherboard - because this is what stores your system configuration information and is the `heart' of your system hardware information database.  If your BIOS information is incorrect, your PC will not start!  Other names for BIOS are "CMOS" and, on a user level, your DOS "SETUP" program (hardware target  program for system configuration updates).  Information in your BIOS is controlled by CMOS technology and is what is called PROM (programmable read only memory - also called `firmware') and the guts of it can only be changed by `flash' programs from the BIOS chip manufacturer.   You, however, can change the basic BIOS PC configuration settings from "Setup" during the boot process.

On a `generic' PC you can access `setup' by tapping your `del' key on boot-up.  On other PC's, `F1', `F2', F10', `esc', or `ctrl-esc' will get you there.  When installing a new hard drive, enabling USB support, configuring comm ports, etc., getting into `Setup' and understanding what it does for your computer is a very important!!

For you hardware enthusiasts, I took the above picture of my BIOS chip with my Olympus digital camera.  Also notice the wafer shaped motherboard battery (which keeps the BIOS information intact when your PC is turned off) below the AMIBIOS chip.