Short for Basic Input/Output System, the BIOS (pronounced bye-oss) is a ROM chip located on all motherboards that allows you to access and set up your computer system at the most basic level. In the picture below, is an example of what a BIOS chip may look like on your computer motherboard. In this example, this is a picture of an early AMIBIOS, a type of BIOS manufactured by the AMI. Another good example of a BIOS manufacturer is Phoenix.