What is a BIOS?

BIOS is an acronym for Basic Input/Output Systems. The BIOS is a key component of the boot process. It is responsible for addressing and mapping the various hardware components of the computer system into memory so that the operating system can communicate with it. The BIOS also performs the Power-On Self Test of the hardware known as POST. Without the BIOS, a computer would not be able to boot into its operating system.

Each BIOS and main board model combination is custom-designed to work with specific hardware components and hardware versions, which is largely dictated by the processor and chipsets that are incorporated onto the main board. This would imply that a BIOS would work across main boards that use the same processor and chipset. However, slight design differences from one main board to another make this not true.

Note: The main board is commonly referred to as a motherboard in the PC industry. In Apple® computers, it is referred to as the logic board.

Note: Boot speed, boot efficiency and size in Bytes are also taken into consideration when a BIOS is ported.

Historically, the BIOS and its settings were stored into CMOS (complementary metal-oxide semiconductor) and was commonly referred to as the CMOS Setup. The CMOS and Real-Time Clock (RTC) required an electric charge to maintain their settings. This was typically performed by an on-board battery. As the battery aged, the electrical charge that maintained the CMOS settings diminished. The BIOS and RTC would then revert to its default settings, resulting in, "Press F1 to enter the CMOS setup."

Note: The terms CMOS setup and BIOS setup were frequently used interchangeably in the 1990s and far into the 2000s.

Beginning in the late 1990s, main board manufacturers started to store the BIOS into flash memory. There are two benefits for doing this.

  • Flash memory does not require a charge to maintain its settings.
  • The size of the BIOS can be increased.

Note: Although the BIOS settings are stored in Flash memory, a battery is required to maintain the main board's RTC settings.

What is UEFI firmware?

UEFI is the new version of the BIOS. UEFI is an acronym for Unified Extensible Firmware Interface. UEFI firmware performs all the tasks of the BIOS, but also allows users to access the boot settings once the operating system has fully loaded.

Note: For more information on UEFI, please visit the UEFI FAQ.

Is there a backdoor password for the AMIBIOS CMOS Setup?

No, there is no back door BIOS password. If you forgot your BIOS password, you'll need to contact your board manufacturer or computer manufacturer for the proper instructions on how to reset the BIOS password.

Why does the AMI Logo show up all of a sudden? Is this some kind of Malware?

All computers ship with a BIOS or UEFI firmware. AMI is a BIOS and UEFI firmware developer. The AMI Logo is hidden from view if the BIOS/UEFI firmware is set to QUIET BOOT or SILENT BOOT. If that setting is changed, the AMI Logo will appear during the boot sequence. For more information click here.

Why is the BIOS/UEFI Flash procedure different between my motherboard manual and your website?

Follow the BIOS/UEFI Flash instruction provided in the main board manual.

I have a computer (notebook, laptop and/or desktop) with your BIOS. It shows an error code. What does this error code mean?

Error codes can differ between main board models. Contact the main board manufacturer to obtain the proper error code definitions.

You can also visit the BIOS and UEFI Firmware Support. Scroll down to For End Users: Multiple Support Options and download the status codes or beep codes document.

Where can I find a list of all computer hardware manufacturers?

There are many hardware manufacturers located all around the world. For more information, click here.