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Fine-tuning the Compaq BIOS

Compaq likes to keep its BIOS off limits to most users. However, if you are a technician you often need to update or fix the BIOS. Check out Mike Jackman?s Daily Drill Down on getting around the Compaq BIOS barrier using TweakBIOS.

A Compaq BIOS is like a file cabinet with many locked drawers and few open ones. The computer maker limits the settings users can change, unlike more liberal manufacturers that let users tinker with advanced settings.

This means that Compaq prevents the owners of their computers from exploring the mysteries of their Basic Input/Output System (BIOS) settings, and from trying to make their computers run better and faster. To penetrate a Compaq BIOS, users need a map and a key. In this Daily Drill Down, I will provide both by explaining where Compaq owners can read BIOS information in DOS and in Windows, and by presenting a tool called TweakBIOS. With TweakBIOS, many settings that Compaq tried to hide are illuminated. I will also list some BIOS resources.

BIOS in 7 words
A BIOS is a computer's self-knowledge.

What that means
Though a simplification, the above definition is accurate. The BIOS is the first software that the computer loads. It tells all the other software loaded on top of it what hardware the computer has and how to use it. The best analogy I can think of is a baby learning it has fingers, and toes, and a nose. Using the BIOS, the computer figures out instructions about the peripherals it has available. After a while, the instructions are burned into memory, just like the BIOS is burned into a ROM chip.

As soon as the computer wakes up, the BIOS provides its first instructions, and tests the hardware using the Power On Self Test (POST). At this point, a BIOS that is made by a company, such as Phoenix or IBM, displays helpful information like the type of BIOS, revision date, serial number, and a hardware list. But since we’re discussing a Compaq BIOS, that information is not present. After all hardware tests okay, the BIOS turns over control to the operating system and informs the OS all about the hardware.

The BIOS is the first-level software, also called the lowest-level software. The levels that make up a computer are as follows:

0. Hardware
2. Operating System
3. Applications

The BIOS also contains simple software routines that higher-level software once used for hardware tasks such as reading and writing to hard drives or managing power. Newer operating systems take over many of the traditional BIOS functions. For more information, read a useful overview of the BIOS on the PC Guide Web site.

Customizing the BIOS
The user can’t change the BIOS, since it is permanently engraved in ROM. The exception to this is when users flash-upgrade the entire BIOS chip to a new version. TechProGuild has a nice article on how to do this, called “Flashing your BIOS.”

To make BIOS settings changeable, they need to be stored in a place that can be modified and that is more persistent than a hard drive, which can crash or be erased. Thus, settings are stored in Complimentary Metal Oxide Semiconductor (CMOS) memory. A small long-life battery, usually attached to the motherboard, refreshes this low-power CMOS chip. For this reason, the setup application is sometimes called CMOS Setup, although sometimes its called BIOS Setup, while Compaq prefers Computer Setup. Whatever the name, by running a setup application, users can change the settings stored there.

Getting into your BIOS
As far as I know, all Compaq Computer Setup applications start the same way: Power on the computer, wait for the cursor to blink in the upper right-hand corner of the screen, and then press [F10]. In a few moments, the Computer Setup application will start.

A series of cascading menus lets users view system information and change options for passwords, boot, and device configurations. For instance, under Boot Options, users can change the order of the devices that the computer checks for a boot loader. Under Device Options, users can configure support for display controllers, USB ports, and other hardware settings. The BIOS on my two Compaq Armada notebooks doesn’t offer many options, but desktops offer more since they have more devices for a user to change.

Author’s note
A good series that explains many basic BIOS settings can be found on TechProGuild. The first article in the series is “Basic BIOS settings, part 1.” Read the second part here.

Viewing version information
Sometimes a problem upgrading a computer processor or device is the fault of the BIOS. In that case, check the computer model at Compaq’s Support area to see if there’s an upgrade. To learn whether or not you need an upgrade, you’ll need certain BIOS information. Unfortunately, Compaq withholds this information during startup. You can boot into the Computer Setup program and read the system information, but that’s inconvenient, as you have to shut down and restart your system. Here are a few other ways to view that information. These methods are not exactly the same in all Windows operating systems, but they’re close. The examples here are from Windows 98.

System Information utility
Start the System Information utility by navigating to Start | Programs | Accessories | System Tools | System Information. In the left pane, expand Components and click System. On the top pane, click the Advanced Information radio button. On the right pane, scroll down to System board information. There, you can view the BIOS date, name, and version, as shown in Figure A. You can also view the registry key where the information is stored.

Figure A
The Microsoft System Information utility lets you view the BIOS information that Compaq hides.

Registry Editor
Open the Registry Editor by navigating to Start | Run, typing Regedit in the text box, and pressing [Enter]. Drill down to the entry titled HKEY_LOCAL_MACHINE\Enum\Root\*PNP0C01\0000. Click on 0000. In the right pane, you’ll see the same BIOS information as above (see Figure B).

Be careful when you’re in the Registry Editor. Any changes you make to registry settings could be harmful, if not fatal, to your operating system.

Figure B
BIOS information is found in HKEY_LOCAL_MACHINE\Enum\Root\*PNP0C01\0000.

Using DEBUG can be more harmful than using the Registry Editor. This program can actually change settings and write to your hard drive and to memory.

This old DOS application is still proving its worth. Open a DOS prompt or command prompt. At the prompt, type DEBUG. A minus (-) sign will appear. That’s the program’s prompt. Next, type the following command:

This command displays 32 bytes of memory after you boot up from the RAM address where the BIOS is copied, or shadowed. This range contains the make and date of the BIOS in Compaq systems, as shown in Figure C. In case you’re unfamiliar with DEBUG, note that hex values are displayed in the first column, while ASCII values are displayed in the second column. Once you’ve seen your BIOS date, press q to quit DEBUG before you do some damage.

Figure C
DEBUG is another useful utility for uncovering your Compaq BIOS information.

Getting past the gatekeeper
Compaq’s Computer Setup application is a gatekeeper preventing users from fine-tuning the BIOS. If you can’t open the gate, certain programs allow you to go around it. There’s no reason to expect that Compaq’s settings are the most optimal ones for your machine.

One program I recommend for overcoming the limitations of Compaq’s BIOS is TweakBIOS. You can download an evaluation from the Miro Web site. If you like it, a registered version costs $20. Though the last update to the application was made in 1999, it still lets you change most of the settings supported by many chipsets, including the Intel 820 and 840 models. Chipsets refer to the group of controller chips on your motherboard. They control the settings for all the data busses on the computer. (For more information about chipsets, read the TechProGuild feature “Motherboard chipsets—the good, the bad, and the ugly.”)

Before you go changing advanced BIOS settings, you might want to read up on them. A superb source of information is The BIOS Companion, by Electrocution Technical Publishers. A PDF version of this giant 550-page manual costs only $15. Some helpful Web sites to try are’s BIOS Setup Information Guide and PC Guide’s Advanced Chipset Features.

Not really the BIOS
For the sake of accuracy, I should mention that when you change many of the advanced BIOS settings, you’re not really changing the system BIOS. Motherboard makers have added screens to the BIOS programs they’ve licensed that let you change settings for other chipsets. These chips are BIOS too, but for other functions of the motherboard. Its a small point, but it's significant. Using TweakBIOS, you’ll be adjusting the properties of other devices, not just system BIOS settings saved in your CMOS.

Using TweakBIOS
You don’t necessarily need to know what you’re doing to play with TweakBIOS, as the application has helpful hints. One safety net is that the application won’t save your changes permanently; they’re only used until the system is restarted. The registered version lets you save settings to a file which you can open after you reboot. As far as I know, that’s the only difference between the free and registered versions.

TweakBIOS works as a DOS program or within a Windows MS-DOS prompt. Before you change a setting when working within Windows, save any work you’re doing, as your new settings could freeze the operating system.

Workaround for NT systems
If you have Windows NT or 2000, you can’t use TweakBIOS within the OS because these OSs won’t let software directly access the hardware. Instead, there’s a workaround. Boot into your system using a DOS system disk. Start TWEAKS.EXE and adjust your settings. When you’re finished, close the program and run the utility INT19.EXE. This program will start your operating system without rebooting the computer. Pretty clever, huh?

Once you download and unzip the program, start it by double-clicking TWEAKS.EXE. The program will open in an MS-DOS prompt, listing the chipsets it found and can configure (see Figure D).

Figure D
TweakBIOS lists chips that it can configure.

As an example of how the program works, let’s look at settings for the Intel 440BX CPU-to-PCI Bridge. To open the configuration screen, select that choice and press [Enter]. The first setting is for the Latency Timer. Note that the value has an asterisk to its left. This symbol uses a color code. A green asterisk next to the value means that the setting is unchanged, while a red one indicates a change from the original setting that hasn’t been applied yet. A white asterisk means the change has been applied, while a yellow asterisk means you have returned to the original setting but haven’t applied it yet.

Information about the chipset (such as vendor and revision number), cache, and memory configuration fills the first three rows on the right-hand column. A row below that is a help message. This one informs you that the higher value is generally better. Using the Page Up and Page Down keys, I can change these values. I set a value of 96 (see Figure E).

Figure E
A configuration screen offers helpful tips for adjusting settings.

After saving my work, I accepted the new value by pressing [F10], and then Y (Yes). Not only didn’t my computer freeze up, but I also experienced an immediate increase in speed on the desktop. I could tell this by the speed at which windows refreshed.

Standard procedure is to change one value and then test for stability. The way you change values is the same for all other settings. If the program doesn’t have any information for a setting, it displays the message No Help Available.

Three common settings are for timing, memory, and enabling or disabling features. Timing settings are values. Values include latency, a term that means the time taken between a data request and the beginning of the data transfer. In a chipset, this is the time it takes for a channel to become empty. Setting the number lower (less waiting) should be faster, but oddly enough, sometimes setting the wait time higher means better performance because it tunes the system to the actual speed of the computer channel.

Memory settings consist of shadowing and caching, among others.
  • Shadowing means that BIOS is copied into RAM, which is faster than ROM. BIOS routines are read from the faster memory. However, for a video BIOS, shadowing may not have any benefit in Windows 9x or NT. Read up on advanced configurations before changing.
  • Caching DRAM can improve performance of the video BIOS by further caching the shadowed information.

Other features should be used with caution. Check the advanced BIOS resources mentioned in this article. Some features may be disabled that would run faster if enabled. In general, enabling is faster than disabling.

Tweaking a BIOS is a matter of trial and error. Even if Compaq trusted you enough to let you use Computer Setup to make changes, you would have to reboot after each single change to test its effects. By using a program such as TweakBIOS, you not only avoid Compaq’s gate keeping, but you can explore the mysteries of your Compaq computer’s BIOS more conveniently while staying within your operating system.

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