BIOS
Short for Basic Input/Output System,
the BIOS, ROM BIOS, or System BIOS is a chip located on all computer motherboards that contains instructions and setup for how your system should boot and how it operates.
In the picture to the right, is an example of what a BIOS chip may look like in your computer.
The BIOS includes instructions on how to load basic computer hardware and includes a test referred to as a POST (Power On Self Test) that helps verify the computer meets requirements to boot up properly. If the computer does not pass the POST, you will receive a combination of beeps indicating what is malfunctioning within the computer.
In most PCs, the BIOS has 4 main functions as mentioned below.
- POST - Test computer hardware, ensuring hardware is properly functioning before starting process of loading operating system. Additional information on the POST can be found on our POST and Beep Codes page.
- Bootstrap Loader - Process of locating the operating system. If capable operating system located, BIOS will pass the control to it.
- BIOS - Software and drivers that interface between the operating system and your hardware. When running DOS or Windows you are using complete BIOS support.
- BIOS / CMOS Setup - Configuration program that allows you to configure hardware settings including system settings such as computer passwords, time, and date.
- How to enter the BIOS or CMOS setup.
- Additional information and help with BIOS updates.
- How to clear an unknown BIOS or CMOS password.
- Complete computer BIOS help and support.
Also see: ACPI, BBS, BIOS shadow, BPB, CMOS, EFI, Firmware, Flash BIOS, FWH, Motherboard definitions, PROM, UEFI