연구하는 인생/♣COMPUTER

What BIOS Does

hanngill 2009. 7. 23. 05:32
What BIOS Does



The BIOS software has a number of different roles, but its most important role is to load the operating system. When you turn on your computer and the microprocessor tries to execute its first instruction, it has to get that instruction from somewhere. It cannot get it from the operating system because the operating system is located on a hard disk, and the microprocessor cannot get to it without some instructions that tell it how. The BIOS provides those instructions. Some of the other common tasks that the BIOS performs include:

* A power-on self-test (POST) for all of the different hardware components in the system to make sure everything is working properly

* Activating other BIOS chips on different cards installed in the computer - For example, SCSI and graphics cards often have their own BIOS chips.

* Providing a set of low-level routines that the operating system uses to interface to different hardware devices - It is these routines that give the BIOS its name. They manage things like the keyboard, the screen, and the serial and parallel ports, especially when the computer is booting.

* Managing a collection of settings for the hard disks, clock, etc.

The BIOS is special software that interfaces the major hardware components of your computer with the operating system. It is usually stored on a Flash memory chip on the motherboard, but sometimes the chip is another type of ROM.


BIOS uses Flash memory, a type of ROM.

When you turn on your computer, the BIOS does several things. This is its usual sequence:
  1. Check the CMOS Setup for custom settings
  2. Load the interrupt handlers and device drivers
  3. Initialize registers and power management
  4. Perform the power-on self-test (POST)
  5. Display system settings
  6. Determine which devices are bootable
  7. Initiate the bootstrap sequence
The first thing the BIOS does is check the information stored in a tiny (64 bytes) amount of RAM located on a complementary metal oxide semiconductor (CMOS) chip. The CMOS Setup provides detailed information particular to your system and can be altered as your system changes. The BIOS uses this information to modify or supplement its default programming as needed. We will talk more about these settings later. Interrupt handlers are small pieces of software that act as translators between the hardware components and the operating system. For example, when you press a key on your keyboard, the signal is sent to the keyboard interrupt handler, which tells the CPU what it is and passes it on to the operating system. The device drivers are other pieces of software that identify the base hardware components such as keyboard, mouse, hard drive and floppy drive. Since the BIOS is constantly intercepting signals to and from the hardware, it is usually copied, or shadowed, into RAM to run faster.
 
 
 
 
What is BIOS and its functions?


The BIOS stands for Basic Input/Output. It is a set of instructions contained in special type of volatile memory chip built onto your motherboard. It enables you to use the keyboard, see a display on the monitor, access the hard drive or CD drive, etc., all without the need for an operating system. The BIOS is the software that carries you from the moment you power on your computer to the point where the operating system begins to load, providing the instructions necessary to access the hard disk, memory and other hardware.

One other function of the BIOS is to give instructions for the power-on self test (POST). This self test ensures that the computer has all of the necessary parts and functionality needed to successfully start itself, such as use of memory, a keyboard and other parts. If errors are detected during the test, the BIOS instructs the computer to give a code that reveals the problem. Error codes are typically a series of beeps heard shortly after startup.

This is a very simplistic definition though, as the BIOS has many more functions. All the hardware attached to the motherboard, such as the memory, processor, video card and disk drives, can be configured to a greater or lesser degree through the BIOS. Memory timings, processor speed and overclocking, hard disk detection and booting are all properties controlled by the motherboard's BIOS.
Many PC manufacturers today use flash-memory cards to hold BIOS information. This allows users to update the BIOS version on computers after a vendor releases an update. This system was designed to solve problems with the original BIOS or to add new functionality
 
 
BIOS Definition - What does BIOS mean ?


BIOS - Basic Input Output System

The CPU in a PC needs a way of communicating with the many different hardware devices that are installed, each hardware device has its own special BIOS software which allows for this communication.

The BIOS contains special software instructions that enable the CPU to communicate with and control devices, it is usually stored in ROM and can be either built-in to the motherboard or on the device itself.

The main BIOS in a system is stored inside a microchip on your motherboard and is the first piece of software your computer runs when you (boot up) turn it on.

It uses the information stored in the CMOS memory for configuration purposes.

A Flash BIOS can be updated with new information and many motherboard manufacturers publish updates for their respective BIOS on their websites.
 
 
BIOS UPDATE INSTRUCTION


Overview

Pronounced "bye-ose," BIOS is an acronym for basic input/output system. The BIOS is built-in software that determines what a computer can do without accessing programs from a disk. on PCs, the BIOS contains all the code required to control the keyboard, display screen, disk drives, serial communications, and a number of miscellaneous functions.

The BIOS is typically placed on a ROM chip that comes with the computer (it is often called a ROM BIOS). This ensures that the BIOS will always be available and will not be damaged by disk failures. It also makes it possible for a computer to boot itself.

FLASH BIOS
Most modern PCs have a flash BIOS, which means that the BIOS has been recorded on a rewriteable memory chip, which can be updated if necessary.

The PC BIOS is standardized, so all PCs are alike at this level (although there are different BIOS versions). Additional DOS functions are usually added through software modules. This means you can upgrade to a newer version of DOS without changing the BIOS.

PC BIOSes that can handle Plug-and-Play (PnP) devices are known as PnP BIOSes, or PnP-aware BIOSes. These BIOSes are always implemented with flash memory rather than ROM.


Be CARE FULL ABOUT THE FOLLOWING POINTS BEFORE PERFORMING THE UPDATE ACTION
* Update the BIOS on your computer only if the newer BIOS version specifically solves a problem you have. We do not recommend BIOS updates for computers that do not need it. You can view all new BIOS fixes in the Release Notes included on the BIOS download page in Download Center.

* Before initiating a BIOS update, be sure to read and precisely follow the update instructions. You may wish to print the instructions for easy reference.

* If a BIOS update process is interrupted, your computer may not function properly. We recommend the process be done in an environment with a steady power supply (preferably with UPS).

* All images in the examples used in the instructions are specific to the Intel® Desktop Board D945PLNM or DQ965CO and are for illustration purposes only. You need to select the correct BIOS files for your desktop board.


METHODS

There are up to five methods of updating an Intel® Desktop Board BIOS to the latest version. The number of options made available for any particular board may vary, depending on drive support and BIOS update file size. You only need to use one.

* Express BIOS Update [printable PDF]
* Iflash BIOS Update [printable PDF]
* ISO Image BIOS Update [printable PDF]
* Recovery BIOS Update [printable PDF]
* Integrator Toolkit BIOS Files [printable PDF]
 
 

'연구하는 인생 > ♣COMPUTER' 카테고리의 다른 글

[스크랩] FLV 변환 프로그램. SHOW  (0) 2009.12.04
ADOBE FLASH  (0) 2009.10.12
BIOS Setup  (0) 2009.07.23
Internet Explorer 키보드 바로 가기  (0) 2009.07.13
** Keyboard shortcuts   (0) 2009.07.12