Auldfart's How To Guides   Bios Explained        Your BIOS is the key to a smooth running system, but what exactly is it, how do you control it and how do you optimise it? The BIOS (basic input/output system) is one of the most fundamental components in your machine.              It performs several functions including testing the hardware at startup, initiating the operating system, and also supporting the transfer of data among hardware devices once your OS is running. Without it, your machine would be a disparate collection of hardware that simply couldn't work together.         As the BIOS is needed before your machine is capable of interfacing with complex systems such as hard drives, the BIOS is physically held in an EEPROM chip on your PC's motherboard.            Originally this BIOS chip wasn't writable, which made updating the BIOS for new technologies a real nightmare, but these days it can be updated from the machine it is installed in, using the very operating system it supports.            The BIOS needs to store information about your system, and to do this it interfaces with the CMOS chip, which uses a small amount of low power storage space.            Another task of the BIOS is to keep track of time, so that your files can be date- and time-stamped, which is why the BIOS also has access to the Real Time Clock.            So you don't have to type all of this information in each time you start your machine, the BIOS also has access to a battery to keep the clock ticking over and also provide enough juice to keep the CMOS alive.             One of the more important aspects of the modern BIOS is that it has been streamlined to work in the majority of systems without any user   intervention.                The obvious down side to this is that many of the settings are not optimised for your particular system, meaning your machine is not performing to its potential.          The good news is that over the next pages we're going to introduce you to everything you need to make an informed choice about your machine's BIOS so that you can configure Windows to load quicker, your machine to run faster and the world to generally be a far better place.             So now that you know what the BIOS is capable of you'll want to know how to configure the BIOS to your own requirements. Thankfully, part of the BIOS code contains a configuration utility, which provides an interface for altering the most important settings.             To enter this utility, you have to hit a certain key before the BIOS runs through the POST. The key you press varies from machine to machine, but it is typically [Del] or [F1] in desktops, and [F2] in laptops.             If you have an Intel motherboard, you'll need to set a jumper on the motherboard to enter this configuration utility. Have a look at your motherboard manual if you are having no luck.            Once you enter the BIOS Setup Utility, there are a number of screens you need to work on, and as there are several manufacturers and versions of BIOS these screens can look markedly different.              The key information should be available in each system, but it may be under another name - take a look at the boxout to the right for more information. For this article we are going to concentrate on the Award BIOS as this is the most widespread version currently available. A different BIOS         Your machine may not have all the options or setting listed in this feature. Here's how the major BIOSes differ and how you can translate this guide for your own use.      There are only two major BIOS manufacturers in existence these days, and of those Award is by far the most prevalent, with AMI covering the niche markets.          This wasn't always the case though, and there is a chance that the BIOS beating away in your machine isn't made by Award, and thus offers different settings to those outlined over these pages.            Even if you have an Award BIOS, there is still a chance that the setting and screens you are presented with will differ to those shown on these pages, simply because each BIOS is tailored to your individual motherboard.         If this is the case, don't despair: the main options should still be present, and you should be able to work out what the majority of settings refer to.           The main section that is going to cause problems is the Advanced Chipset Features screen, which is known simply as Advanced in the Phoenix BIOS and Advanced Features in the AMI BIOS.             Despite the various names, the section deals with the all-important timing details, and as there is no industry standard for the naming of these parts and options you may be baffled by some of the references.           As a general rule of thumb, if you have an option to define wait states or have an option with Latency in the title, then the lower the value the better - although your memory does need to be fast enough to support this without problems. If you are having real problems decoding your own BIOS Setup program, then try and read your motherboard manual, as this is one area that manufacturers do try and provide detail on (even it is in broken English).           If you have a Phoenix BIOS then it's worth checking out the User manual on the Phoenix Web site for more information about the generic BIOS settings. Standard CMOS Features           This is the first option under the BIOS Setup Utility, and the main screen for setting the current date and time as well as configuring the various drives in your machine.          It's worth checking the time entry every couple of months, as the clocks used in PCs are notoriously bad at keeping track of the passing seconds. If you have an older machine, you may also need to change the time value to take into account daylight saving.           The table below this is where you configure your hard drives. Many PCs ship with each entry set to 'Auto' these days, which means the BIOS determines the settings for your hard drives.              The problem with this is that it takes a little longer to configure this each time you boot than setting up your drives explicitly. To speed up your boot time, set any entries with no drive attached to None (don't forget to change this setting if you add another drive). Also note that you can't define your CD-ROM drives here, so leave those entries to Auto.             Below this section you can define the floppy drive(s) you have installed in your machine. The most common setting is for Drive A to be set to 1.44M, 3.5in - the standard floppy drive. If you have anything different, you need to define it here.  The Video option underneath this is rather antiquated too, and should be set to VGA for all but the most ancient PCs. The final option, Halt On, enables you to define which circumstances cause the BIOS to halt the boot process. If you want your machine to boot regardless, set this to No Errors - particularly useful for servers. Most systems should be set to All Errors. Advanced BIOS Features          This section covers a lot of options covering everything from virus protection to the order in which your drives are accessed. You should only need to configure the options on this screen once, if at all.             The anti-virus protection offered by your BIOS is of the most basic variety, merely monitoring your hard drives, producing a warning message if anything tries accessing the boot sector.  Installing a new operating system or using disk diagnostic utilities will trigger this message; in these cases you should turn this off.        The Internal and External Cache settings should be left enabled, except for overclockers trying to pinpoint the reason they cannot achieve a higher speed.           The Quick Power On Self Test should be enabled unless you have changed the system in some way. The next group of settings define the order in which the BIOS searches for a bootable partition. Configure this to your own requirements, but make sure your CD-ROM is listed before your hard drive if you need to boot from a CD.             The next interesting option is the Gate A20 setting, which has options of Normal or Fast. Set this to Fast for better memory performance - this will use the BIOS timing controls instead of the keyboard controller.            The Security Option setting defines what should be protect by the BIOS password, and works in conjunction with the Set Password options on the main screen. Setting this option to System will force the BIOS to ask for the password each time the machine boots, while setting it to Setup will only ask for the password if you access the BIOS set-up utility.          The last group of settings define whether the Video BIOS should be shadowed in your main system memory. For best performance disable this option, and also disable the memory address ranges below this setting. This option is present for legacy reasons and has been made redundant by modern graphics cards. Flashing your BIOS               In many ways the BIOS is akin to a low-level device driver, and as such it is liable to bugs, incompatibilities, oversights and general errors that can stop it performing quite as well as it should do.          Thankfully you can update - or flash - the BIOS yourself to eliminate some of these problems, and in many cases improve performance and gain new options in the set-up program too.            As your BIOS is specifically modified for your motherboard, there is no central Web site that you can go to for a generic update. Instead you have to track down your motherboard manufacturer's Web site, and see if there is an update on there.          If you don't know who made your motherboard see page 31 for some tips to identify it. If the manufacturer has gone out of business, then there's little chance that an update exists, in which case you are going to have to make do with the current version of the BIOS.        Once you find the Web site, you need to find the BIOS update for the exact version of your motherboard - something close or similar will not suffice.                Simply download the updated BIOS (which should end with a .bin extension) and the utility you need to flash your particular BIOS (you should find this with your BIOS update). A three-step walkthrough is all you need to flash your BIOS - see the bottom of page 38 for the very thing you need. Warning!           If you try updating the BIOS with the wrong file, or if something goes wrong during the flash process you could end up with a machine that refuses to boot.             Having said that, even if this happens, you should be able to get your PC working if you take the correct precautions. Modern motherboards have a boot-block BIOS, a small area of the BIOS that isn't overwritten when you flash it. This boot-block BIOS only supports a floppy drive, and is capable of running an AUTOEXEC.BAT file.          So as long you made a back-up copy of the current BIOS file, you can recover your system by creating a diskette with the old BIOS file, the flashing program and a simple Autoexec.bat file that references the two - in other words, Awdflash *.bin.             Boot from this disk and your PC should work again. If you have an AMI Bios it's even easier: rename the old BIOS file to AMIBOOT.ROM and copy it onto a blank floppy disk, then reboot from that disk. Flashing your BIOS              •Download the latest BIOS for your board from the manufacturer's Web site. The site should also contain the flashing utility (awdflash.exe for the Award BIOS). • Download drdflash from www.abitfaq.it and run it to create a bootable floppy. Copy the files from step one to this disk, then reboot from it.           • At the DOS prompt type awdflash.exe *.bin and press [Return] to update the BIOS. Create a backup of your current BIOS when prompted, and restart when done.   Advanced Chipset Features            The Advanced Chipset Screen boasts important timing settings that can mean the difference between a stumbling behemoth and a speedy performer.         As the effectiveness of these settings are determined by the other hardware in your machine, it's worth benchmarking your machine before and after changing most of these, to see if they have a positive effect or not.          Rather than sketch over this section now, we'll refer you to issue 108, and the hardware tips section, where we'll cover the various performance tweaks on offer in more depth. Integrated Peripherals The Integrated Peripherals screen is unique to your particular motherboard, and you will undoubtedly have options here that we do not.         You should have entries for the majority of components that need to be covered, and any extra features that you can turn on or off here are usually straightforward. If you have no devices attached to an IDE channel, you can disable that channel on this screen, freeing an IRQ into the bargain.              The next eight settings are connected to the above channels, and enable you to take manual control over the PIO and Ultra DMA characteristics of any drives you have connected.            You should leave these on Auto unless you are overclocking - and even so, fiddling with these can result in loss of data, so they are best left alone. Another setting concerned with your hard drive's data transfer is IDE HDD Block Mode - set this to Enabled for best performance.             The Init Display First option is only valid if you have more than one graphics card in your machine. As your machine is capable of using either device as its main graphics card, this is where you can specify whether to use the AGP or PCI card. If you only have the one graphics card, it doesn't matter what you set this to.           If your system is devoid of a floppy drive, you don't use the serial ports, the onboard sound or you don't use the printer port, you can free up a lot of resources by explicitly turning these off in the BIOS.             If you do use a printer, then check your printer manual to see which parallel port mode you should be using - if in doubt, set it as ECP. If you connect an external drive to your machine through the parallel port, then EPP is a better choice. Power Management Setup           While the idea of your machine being able to turn itself on and off conjures up nightmarish visions of computer awareness, in reality Power Management is actually rather mundane.            The main use for power management is to turn off your monitor and power down your drives if you haven't used your machine for an extended period.            While this isn't generally an issue for most of us, there are occasions when you need to leave your machine running for an extended period of time, and here the ability to react to events can be essential.         There are actually several different types of Power Management doing the rounds, but the main one for compatibility reasons is APM (Advanced Power Management), which was devised by Intel and Microsoft. This is supported by Windows, and provides a far more attractive and dynamic interface for controlling your machine's power use.            When it comes to actually configuring your machine for power management, you need to work out what you need the machine to react to and when and how it should power down.             Most of these can be set in Windows itself, but for reacting to events - such as the LAN being started, or the activation of the phone line, you will need to access the Wake Up Events option on this screen.            In here you can configure whether your machine should switch itself on when such an event takes place - perfect for remote access. You can also set the machine to come on at a set time on a set day of the month, using the RTC Alarm Resume function. So if you find your machine always boots up when the phone rings, you now know where to come to turn it off. PnP/PCI Configurations        While this screen looks rather innocuous, it is actually responsible for more frustration than any other, for it is on this screen that the system IRQs are shared out.         While the PC's reliance on IRQs isn't quite as critical as it once was, there are still a worrying number of expansion devices that refuse to share IRQs.        In theory, most of us should enable the top option, which asks whether the machine is running with a plug-and-play OS installed, but in practice you actually have more control over the system's IRQs by disabling this.          If you install a new device in your machine, and you are faced with a new IRQ conflict, then enabling Reset Configuration Data will force the BIOS to rebuild the IRQ, DMA and I/O tables, which can solve your problem. The BIOS will automatically configure this back to disabled on rebooting. If the hardware in your machine is working without any problems, and you're not experiencing any major IRQ conflicts, then you should leave the Resource Controlled By option to Auto (ESCD).             Only if you have a conflict should you change this to Manual and set the troublesome IRQ to Legacy ISA. You'll need to locate the troublesome IRQ by using the Windows System Information utility. If you are using a reasonably up-to-date graphics card, then make sure that the Assign IRQ for VGA option is Enabled, as newer cards require one.            Conversely, if you don't connect any USB devices to your machine (and don't intend to) you can disable the option to Assign IRQ for USB and thus free up the IRQ.            PC Health StatusThis screen doesn't actually have any values that you can change, but it does show you the fundamental temperatures and voltages at the heart of your machine.            For most users nothing more than a cursory glance is needed to make sure that everything is well within the parameters defined by your processor's manufacturer (check AMD's or Intel's Web site). If you are overclocking, however, it is well worth checking this screen to make sure that no values are rising uncontrollably. Frequency/Voltage Control          Unless you are overclocking, setting up your processor should be a simple case of selecting the Auto or Default setting for the CPU Host/PCI Clock. Most of you should also elect to Auto Detect DIMM/PCI Clk to configure the machine as the processor manufacturer intended.              The Spread Spectrum Modulated option helps reduce the electromagnetic interference created by the clock generator, but with a nasty down side in that it reduces system performance and stability - set this to Disabled. If you are interested in overclocking your machine, then this is the screen to visit to perform the dastardly deed.          What you can achieve on this screen is entirely controlled by your actual motherboard, the version of BIOS you are running and the capabilities of the processor itself. Don't forget to check the voltages and temperatures, though. More on this in next month's magazine. Troubleshooting           While the BIOS set-up utility is pretty straightforward, and it's easy to undo any changes you have made, there are occasions when you'll be unable to put your finger on the exact setting that has caused Windows to stop booting.               At times like these the solution is to load a set of defaults that will set the BIOS back to the factory standard settings. While this will undo any changes you may have made, it should render your machine useable again.       Most BIOSes support two different defaults to select from - either Fail-Safe or Optimised. Try the Optimised one first, and if that doesn't work, try the slower Fail-Safe option. Once your machine is working, you can start tweaking again.            Another common problem with the BIOS concerns forgotten, or unknown, passwords. While losing the ability to enter the set-up utility can be annoying, it's generally not a critical problem, but what if you're asked for a password as your machine boots? If this happens your choices are a little more limited. If you have an Award BIOS, try a password of Award_SW, or AMI if you have an AMI BIOS.        Failing that you need to erase the settings in the BIOS. To do this, you need to remove the CMOS battery from the motherboard (it looks like a large watch battery in most PCs). Turn on your machine, and you should get a BIOS error message. Turn the machine off again and reinstall the battery. When you power up you should now be able to enter the BIOS unchecked. The other area that comes under the remit of the BIOS is problems that occur during the Power On Self Test (POST).         This is a series of tests that the BIOS runs to check that the hardware in your machine is functioning properly and that there are no low-level conflicts stopping the hardware from working.      As you turn your machine on, the BIOS runs these tests and compares the results with the information stored inside the CMOS. If the BIOS detects a problem with a piece of hardware at this point, it can inform you of the error using a series of beeps, lights or even speech. With this information you should be able to correct the problem and get your PC working again.