What does a computer's BIOS do?
Created | Updated Feb 13, 2002
BIOS ... yet another computer term
In today's fast-paced tech society, computer acronyms are used in daily conversation like tissue paper in an allergy clinic. But what to all of these TLAs (Three Letter Acronyms) and FLAs (Four Letter Acronyms) mean? This entry describes the BIOS, one of the most mystical of computer terms.
BIOS - Basic Input Output System
BIOS stands for 'Basic Input Output System' ... in English, the lowest form on communication your computer's software has with the computer's hardware. BIOS does nasty icky things to your hardware that are best unknown to the user and their software.
The BIOS has three major functions:
- POST - Power On Self Test
- Setup - allow users to configure the BIOS
- Bootstrap - boot to an operating system so the user can play computer games while pretending to run useful computer applications
All of the system hardware on the motherboard is tested and configured by the BIOS during POST (Power On Self Test). Memory, video, keyboard, that green thing the disk drives attach to ... all of the things that make sure software like Microsoft Windows can load and crash like it should.
Setup is the most dangerous part of the BIOS. While most computer users have no reason to change the myriad of BIOS configuration options, many choose to do so without knowledge of the ramifications. Changing BIOS setup options like drive type, memory speed, Plug'n'Play (PnP), and cache mode can improve system performance. But, many users have no clue what these settings really do (you obviously don't know what the BIOS does ... why else would you look up the term?) so this often leads to disaster. For this reason, entering the BIOS usually requires the use of a secret keystroke ... DEL, F2, CTRL-ALT-ESC, or the dreaded "Niberian Death Stroke" (an eleven-key sequence requiring the user to press the final key with their nose).
Bootstrap is the final stage of the BIOS. This is when the small BIOS (128KB to 256KB on most computers) completes its configuration tasks and hands the system over to an operating system like LINUX or Microsoft Windows.
While very few BIOS related problems occurr after bootstrap, most people will blame their computer's misbehaivor on BIOS because it's a cool term that nobody understands.
