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What Is the BIOS?

This chapter is from the book

BIOS Updates

First of all, you should know that the BIOS that ships with your motherboard is not necessarily the latest version or the most stable version. Reputable motherboard manufacturers constantly improve on their motherboard BIOS and regularly release BIOS updates.

These BIOS updates are important because they correct bugs and sometimes provide additional capabilities. You can think of them as driver updates or software patches. You should always keep the motherboard BIOS up to date.

In the following figure, you can see the list of changes in two BIOS updates for the ABIT NF7-S motherboard.

Figure 1.3Figure 1.3 Details of BIOS updates for the ABIT NF7-S motherboard. (Courtesy of ABIT Computer Corporation. Used with permission.)

As you can see, the bug fixes and feature enhancements are both numerous and important. It really pays to keep your BIOS updated!

How Do I Update the BIOS?

The process of updating the BIOS can be summarized in the following steps:

  1. Determine your BIOS version.

  2. Obtain the appropriate BIOS update.

  3. Prepare a BIOS flash disk.

  4. Flash the motherboard BIOS.

Now let's go through the process step by step.


The term flash or flashing is used to describe the act of updating the BIOS.

Determining the BIOS Version

Before you update your BIOS, it's best to find out what version of BIOS you are currently using. If you already have the latest version, then there's no point in going through the process.

The display of the BIOS version number or ID varies from manufacturer to manufacturer. However, it is most commonly the last two or four digits or letters at the end of the string that appears when you boot up the computer.

Figure 1.4Figure 1.4 Determining the BIOS ID. (Courtesy of ABIT Computer Corporation. Used with permission.)

Your motherboard manufacturer may use numbers or letters to represent the BIOS version or ID. The following is an example of the BIOS version or ID.

Because this string only appears for a few seconds when you start up the computer, you might want to turn on your monitor a few seconds before you start up your computer because some monitors take some time to initialize.

You can also use the Pause key to freeze the screen so that you can search for and identify the BIOS ID. Pressing any key after that will unfreeze the screen and allow the booting process to continue.

In the preceding example, the BIOS ID is a two-digit number (00). Other motherboards may use four digits or even letters instead of digits. Some even use a mix of letters and digits.

If the BIOS ID does not appear as it does in the example, please check the manual that came with your motherboard. Your motherboard manufacturer may have chosen to show the BIOS ID somewhere else.

Obtaining the BIOS Update

Now that you know your BIOS ID, it's time to check whether your motherboard manufacturer has a BIOS update for you.

BIOS updates are best obtained directly from the manufacturer's website instead of other distribution points like hardware sites and unofficial mirrors. This ensures that you have the very latest BIOS update available and reduces the risk of downloading a virus-infected copy.

So, head over to your motherboard manufacturer's website. The BIOS updates are usually listed in the Downloads or Support section of the website.

Please note that while different motherboard models may appear to have the same BIOS ID, you must download only the BIOS that was specifically meant for your motherboard. Flashing a BIOS update that was meant for another motherboard will likely cause your motherboard to fail.

After you have found the page listing the BIOS updates for your motherboard, there may be a long list of BIOS updates. For example, the adjacent figure shows a few of the BIOS updates for the ABIT KT7A-RAID-motherboard.

Although the number of BIOS updates may be confusing, don't worry! You don't have to download and flash all of them. All you need to do is download and flash the latest version.

However, you must first determine whether there is an update for your BIOS. Remember the BIOS ID? Compare it against the list of BIOS IDs.

Irrespective of how the BIOS ID appears, motherboard manufacturers always progressively label BIOS updates.

If your BIOS ID is a number, larger numbers always denote a newer BIOS. For example, a BIOS with an ID of 01 is newer than a BIOS with an ID of 00 but older than a BIOS with an ID of 02.

If the BIOS ID is made up of letters, letters lower in alphabetical order always denote a newer BIOS. For example, a BIOS with an ID of AB is newer than a BIOS with an ID of AA but older than a BIOS with an ID of AC.

Figure 1.5Figure 1.5 List of BIOS updates for the ABIT KT7A-RAID motherboard. (Courtesy of ABIT Computer Corporation. Used with permission.)

The same goes even if your BIOS ID is a mix of letters and numbers, just like in the preceding KT7A-RAID example.

If your BIOS ID is the latest BIOS ID, then there's no need to proceed further with the BIOS flash. You already have the latest version. Just make sure you check back once in a while.

If there's a newer BIOS ID than your current BIOS ID, download the new BIOS image. It usually comes prepackaged with the flash utility in the form of a compressed ZIP file or a self-extracting compressed file.

Preparing a BIOS Flash Disk

Now that you have the compressed file containing the BIOS update, it's time to prepare a clean DOS boot disk. This is because most flash utilities require the use of real mode DOS. Also, to prevent conflicts, nothing other than the necessary boot files should be loaded into this boot disk.

You can easily create a clean boot disk in Windows. Even Windows XP, which does not support DOS, comes with a utility that allows you to create your own DOS boot disk. Just remember to use a reliable floppy disk. A defective disk may cause the BIOS update to be corrupted.

In Windows XP, all you need to do is bring up the floppy format utility. Just right-click on your floppy drive in Windows Explorer and click on Format. The Format 31/2 screen appears.

Among the format options, there is an option called Create an MS-DOS startup disk. Check this option and click Start to format the floppy disk. Windows XP will then format your floppy disk, make it bootable and copy all the necessary files for it to boot up into real mode DOS.

After you have a clean DOS boot disk, all you need to do is extract the BIOS update file and the flash utility and copy them into the boot disk.

The BIOS update file or image usually has a .bin extension. Some come with a .rom extension. However, they are all the same; they are just BIOS image files. Write down the name of the BIOS image file. It will come in handy later.

Figure 1.6Figure 1.6 Creating a boot disk in Windows XP.

Flashing the Motherboard BIOS

There are actually a few ways you can flash your BIOS. The traditional way is by a DOS boot disk. However these days, manufacturers are implementing newer methods.

For example, many BIOS now come with their own flash utility. Some manufacturers even provide you with a utility that allows you to flash the BIOS online!

For simplicity's sake, we will only touch on the common DOS flashing method using the AwardFlash software.

The AwardFlash software is probably the most common flash utility around. It is used to flash the BIOS of motherboards using the AwardBIOS. Please note that the AwardFlash utility is DOS-based. It cannot be used in a Windows-based environment. You must boot up using a DOS boot disk before using this utility.

The following is a screen capture of the available commands of the 8.23K version of the AwardFlash utility:

Figure 1.7Figure 1.7 AwardFlash utility commands..

As you can see, the utility is quite versatile. It provides numerous options. Of course, most of them are not necessary for our use. The manufacturer of our reference motherboard, ABIT, recommends the following parameters:

A:\>awdflash bios.bin /cc /cd /cp /py /sn /cks /r

This essentially tells the AwardFlash utility to do the following:

  1. Skip back up of original BIOS image.

  2. Show the bios.bin BIOS image file's checksum.

  3. Program the Flash BIOS with the bios.bin BIOS image file.

  4. Clear CMOS data after programming the Flash BIOS.

  5. Clear DMI data after programming the Flash BIOS.

  6. Clear PnP (ESCD) data after programming the Flash BIOS.

  7. Automatically reset the computer after programming is complete.

Please consult your motherboard manufacturer for its recommended parameters. Different manufacturers may recommend different parameters even if they are all using the same AwardFlash utility.

If you run this command after booting up in DOS, the AwardFlash utility automatically updates the motherboard's Flash BIOS with the new BIOS image and clears the CMOS, DMI, and ESCD data before resetting the computer for the changes to take effect.

After the computer is rebooted, the new BIOS takes effect. Remember, because the CMOS data has been cleared during the flash process, the BIOS reverts to default settings. You should access the BIOS setup utility to set up the various parameters as well as optimize it.

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