Build Your Own Computer, Part III, Setting Up the BIOS

Apr 29, 2001

The Bottom Line Setting up the BIOS is the means to personalize/customize your computer system. Have no fear, follow the cited cautions, and it will be safe and easy.

You have been warned many times by the so-called gurus, computer shop owners, consultants, not to mess with the BIOS, Basic Input/Output System. As with most of their utterances, such stuff is self-serving to say the least. With a small bit of prudence and a tiny bit of effort, you can and should utilize the flexibility of the BIOS to suit your own individual purposes. When assembling or modifying your own computer it is always a good idea to set the BIOS yourself, rather than just blindly accept the defaults. In this part we will examine the BIOS settings and see how to utilize them.

Before we look inside, let’s make sure that we all have some idea of just what the BIOS is. Keeping with our tradition of using English instead of Geek-speak, the information will be practically rather than technically oriented, however a bit of Geek will occasionally appear. The BIOS, in its most fundamental self, is the link between the hardware and the software, all drivers are BIOS elements, but not all drivers are contained within THE BIOS. THE BIOS is just the motherboard BIOS. Other BIOS elements exist outside the motherboard BIOS also known as the ROM BIOS or CMOS. For the curious, CMOS is the acronym for Complementary Metal Oxide Semiconductor. It is not of any real concern to most people to know just what that means, but without delving into particle physics, it refers to the existence of both n-channel and p-channel devices on the same substrate. CMOS devices require much less voltage than the earlier bipolar devices which were either n-channel or p-channel devices. The engineers already know this, the non-engineers do not understand it, but it is of little practical concern to users. For the moment we will just consider the motherboard BIOS. This is the BIOS that is referred to upon boot up when you see a message like, “To enter the BIOS, press Delete”. It seems sort of odd to press, “Delete” to enter any place, but then to shut down you first press “START”. Some of Bills cohorts had a real sense of humor. Or maybe it’s just meant to confuse the unwary. Most modern motherboards, including the Antec board that I selected, have a “flash BIOS”, which means that it can be updated by software usually attainable from the BIOS manufacturers web site. More on just how to do this at a later time. It will also be assumed that you have a motherboard manual that covers the BIOS. If you are building your own system, you undoubtedly got one with the motherboard. If you are upgrading a branded system, you may or may not have one, so we will consider the more generalized and critical settings here.

As soon as you see the Enter Bios message appear, press the appropriate key, typically DELETE, and you will see the BIOS menu screen appear. Now is the time for the aforementioned prudence and effort. You always want a baseline of the BIOS if you are upgrading. If you are installing a totally new system, you will want to establish the baseline BIOS also. There is always a menu choice to restore the default settings, so you really can’t do much permanent harm. To establish the baseline you open each choice in the BIOS menu and note the settings. I do this by using my motherboard manuals, BIOS chapter. Here you will see the choices for each setting. I merely check the setting that I am using to give me my documented baseline. Whenever I change a setting, I note it in the manual, making sure that I do not obliterate the prior setting, just in case I need to go back. There are utilities that record the BIOS settings, but you may need to get things running properly again to restore them, so using the manual is safer. It is a good idea to note your BIOS manufacturer and version, found in the manual as well as displayed on your screen during boot up. This is to make sure that you have the latest version, assuming that it is flash-upgradeable.

My Antec motherboard uses the Award BIOS so the specifics cited here relate to that. Others are quite similar, so there should be no problem. The BIOS menu usually has two columns of items. You navigate with the arrow keys. The entry in the upper left is usually, Standard CMOS Setup. Open this by clicking on it. Here is where you set the clock parameters, the IDE device parameters, identify your monitor type and give “halt” instructions. To set the IDE device parameters, use “auto” under the TYPE column. If you do not have the full set of 4 Primary and Slave IDE devices, select NONE under the TYPE column for that device slot which is not used. Now you do not have to worry about the other columns, since your devices will be automatically detected along with their parameters. If your “A” drive is a 1.44M floppy set that next to the “Drive A” position. Use the up,down arrow keys to select the row you wish and the Page Up,Down keys to change the selection. I use “All Errors” for the HALT ON selection. When you are done, press ESCAPE and you will be back to the menu page.

The next menu item is BIOS Features Set Up. Open it and you will see two columns of choices. At first these might seem somewhat cryptic, but the manual should tell you what they do and you can scroll through the settings to make your selection. If in doubt, stick with the default. These, like all BIOS settings allow you to tailor your system resources to match the installed hardware. For example, disabling an unused com port can free up an IRQ for other uses. For this section, the defaults are generally good choices. Some of the more important settings are; CPU Internal-External cache, Enabled; Quick Power on self test, Enabled; Boot up floppy seek, Enabled; Boot up Numlock Status, ON; Gate A20 option, FAST; Security option, SETUP; IDE second channel control, Enabled; PCI-VGA Palette Snoop, Disabled; OS Select for DRAM greater than 64MB, Non-OS2; Video Bios Shadow, Enabled. You may also set the Boot sequence to suite your set up, for example, if you have a floppy, a bootable hard drive and a bootable SCSI, you may set the sequence to be C, SCSI, A. This means that C drive will be looked at first for a boot sector, than the SCSI drive and finally the floppy. If you set the floppy first, your boot up will take slightly longer, because the BIOS is searching for a boot disk. Remember, you really cannot make a serious error, as it is quite easy to go back and change things. There are three linked settings; Typematic Rate Setting/Typematic Rate/Typematic Delay. When the Typematic Rate Setting is Enabled, the Typematic Rate allows you to set the rate at which the keyboard keys are accelerated and the Typmatic Delay selects the delay between the instant that a key was pressed and the beginning of the acceleration. These Typmatic settings allow you to adjust for your typing speed/skill. Either accept the default "Typematic Rate Setting Disabled" or experiment with the settings to suit your typing ability. Again, press ESCAPE when you are done.

The next menu item is the Chipset Features Setup. Here is where a great deal of customization gets done. Again refer to you manual for information about each setting. If you are using any USB devices make sure that the On Chip USB is enabled. The Antec motherboard has full USB capability. If you are not using USB devices, select disabled. If you have an AGP card installed, set the AGP 2X mode to ENABLED, assuming that your video card supports 2X and the AGP aperture size to a setting compatible with your card. Don’t worry too much; if you do not know your AGP card’s X capability, they are downward compatible, so you can set the BIOS to the highest level. These items are highly dependent upon your particular system configuration, so you select that which you need. If a particular device does not work, you may have made the wrong choice here, so just come back and reset it. Now you see why the BIOS baseline is important. Again, don’t be overly concerned; the settings are easy to change. Most of the time your choices are limited to enabled/disabled, so it is hard to go too far wrong. Just a word of advice, most of the times only change one setting at a time, so that you can see the effects. If it takes more than one setting for a function, such as the AGP card, modify that rule to be make only one functional change at a time.

The next menu item is Power Management Setup. I tend to disable most of these features, again refer to the manual for just what they do. Initially, use the defaults for the IRQ setting on this page. You can always tweak it later.

The next menu item is the PNP/PCI Configuration Setup. Here again, stick with the defaults for the initial setup and tweak it later, if needed. Refer to your manual for description of the entries.

The Integrated Peripherals menu is the last one that I use, I don’t bother with the Password setting since I am the only person to use my machine. If you do indeed have a password required and you forget it, there is a way around it. Just remove the battery on the motherboard and let it sit for a few seconds. Then replace it, start to boot and reenter the BIOS setup to put things back right. You do have a copy of your BIOS settings, don’t’ you? For the other settings in this section, most have the “auto’ choice. Use it. The UR2 settings are for infrared devices. If you do not have any, don’t worry about these; they only have meaning when IR is enabled. Here you may select you parallel port mode, be it EPP, SPP, ECP or EPP+ECP. I use the latter setting. Of course this depends upon the type of device connected to the port.

When you have completed all your BIOS inputs, go to the main menu page, by clicking ESCAPE. On the right side, you will see the SAVE & EXIT choice. Take it and click YES when prompted to save the changes. That’s it, the boot process will now continue with the new BIOS settings.

Since the BIOS is used to link the software and hardware, it is apparent that many of the settings are applicable to the particular installed hardware base. The hardware device instructions should tell you if there are any special BIOS settings required for them, and just a modicum of introspection should let you know which are needed for your specific system. As an example of what I mean, if you do not have any USB devices attached, make sure that you have all USB functions in the BIOS disabled. The reverse is true if you have such devices attached.

That’s enough for now, in the next part we will examine the considerations and procedures for adding hardware.

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