The BIOS in your computer is that black screen (sometimes with colors) that you see when you boot up your computer. Have you ever wondered what your computer is doing while you’re waiting for it to boot into your operating system? If so, prepare to be amazed. 

The BIOS establishes an interface between the operating system and the hardware. The BIOS enables the peripheral devices and internal devices. The BIOS is basically built in software that runs from a chip on the motherboard. This eliminates the requirement for a hard drive to run the BIOS. 

The BIOS is placed on a permanent place on the motherboard. The use of a ROM chip to store the BIOS code allows the computer to computer to be in absence of a hard drive. Therefore, the computer is always bootable. 

The placement of the BIOS on a ROM chip speeds up the annoying bootup process. Most computer manufacturers copy the BIOS to RAM each time the computer is booted up. This is even faster because RAM is faster in access time than ROM. This process is known as shadowing. 

At first, the BIOS used to be in a non-upgradeable chip. But as time progressed, computer engineers realized a need for a flash or (an upgradeable) BIOS. The term for an "upgradeable BIOS" is referred to as flash BIOS. This means that the BIOS is stored on flash memory therefore, the user can upgrade the BIOS if he/she needs too. 

PC BIOSs are fairly standardized. Although, minor differences will be present depending on the manufacturer of the BIOS. Furthermore, the BIOS will differ in between the versions that are released. 

All material and images on these pages are copyright Joseph,Ed. This page was developed for the Thinkquest1999 competition.