The third color photo shows the main features of the heart and soul of your computer its motherboard. The motherboard holds most of the electronics and circuits that your computer needs to follow your orders. Depending on the type of processor that you’ve chosen, the top of your motherboard has a big square or slot socket to hold your computer’s CPU chip and several rows of small slots to hold your RAM (memory) modules.

Ten years ago, buying a motherboard by itself was much harder. However, with the constant acceleration of CPU speeds and the requirements of today’s software, folks in the mall are selling motherboards rather than ice cream. Some companies that advertise in Computer Shopper magazine or operate Web-based parts stores sell nothing but motherboards. And you can generally buy a bare motherboard at your local computer store if it has a repair shop. Motherboard sizes Today’s motherboards follow the ATX standard size guidelines older computers used Baby AT or AT motherboards, but those are antiques now.

To ensure that you get a case that accepts your board, buying your motherboard first is a good idea. If you’ve found a used case or motherboard, make sure that whatever you buy fits your existing part. For example, an ATX motherboard requires an ATX case and an ATX power supply (ahem) an AT-size motherboard doesn’t fit in an ATX case. All of today’s processors require an ATX case.

Motherboard features

While you’re shopping for a motherboard, keep these guidelines in mind:

- Stick with a minimum of a Pentium 4 or an Athlon XP. You might have a strong temptation to jump on a great price for a Pentium III motherboard. No matter what the processor speed, however, you’ll be buying yesterday’s technology, and you won’t have the Pentium 4 class power that you need for running many current (or future) programs and operating systems. Even if the advertisement reads “A Good Pick for Windows XP,” say good-bye to the Pentium III (as readers of the first edition of this article said good-bye to the 486 and the original Pentium).

Okay, okay so I guess if you were given a Pentium III motherboard by your next-door neighbor, you can use it but don’t expect it to keep up with the latest software, and (as they used to say in the TV show Mission: Impossible) “the Secretary will disavow all knowledge of your actions.”

- Consider an onboard drive controller. As you might infer from the name, the drive controller sends and receives data to your hard drives and CD-ROM/DVD drive. (Think of a referee at a soccer match, and you get the idea.) Power users favor an onboard UltraDMA/133 controller, a serial ATA (SATA) controller, or a small computer system interface (SCSI) controller on a standard Pentium-series motherboard. Why UltraDMA/133, SATA, or SCSI? Because these standard controllers provide you with faster performance than the enhanced integrated drive electronics (EIDE) drive controller.A motherboard with an onboard controller doesn’t need a separate hard drive/floppy drive controller. Therefore, you can save that adapter slot for another toy.

- Spend extra for onboard ports. Like an onboard drive controller, onboard USB and FireWire ports save an adapter slot. Many motherboards now carry onboard sound cards. In fact, some motherboards even have built-in video cards, although I prefer to add my own video adapter. An ATX motherboard should (by definition) already have serial and parallel ports onboard.

Before you install the motherboard in your case, it’s time for a warning about the dangers of static electricity. Static can damage electrical components in the blink of an eye, and not even Thomas Edison himself could fix them.

I won’t launch into a terribly interesting discussion of how static was discovered in 400 B.C. by somebody we don’t know with a piece of silk and a glass rod. For all I care, the discovery of static electricity could have been made by prehistoric man shuffling across a bearskin rug.

Instead, just remember this simple rule while handling motherboards, adapter cards, circuit boards, and other computer parts: Before installing any circuit board, adapter card, or part on your computer (or before removing it from the case), discharge any static electricity that you might be harboring by touching something else made of metal. (You can discharge static also by touching your spouse on the earlobe, although I don’t recommend this method.)

Typically, the metal chassis of your computer is a good choice, although you can also touch a metal table or chair. If your computer is plugged in with the cover off (which happens quite often when you’re installing a hard drive or an adapter card), you can touch the metal housing of your power supply for a perfect ground.

Antistatic strips are available for keyboards and wrist rests that discharge static. However, the only time that I ever worry about static is when I’m handling parts and circuit boards, so I don’t use this item.

Make sure that your new motherboard has at least two PCI slots and one AGP or PCI-Express slot. Avoid any motherboard that includes more than a single industry standard architecture (ISA) slot; peripheral component interconnect (PCI) technology provides better performance for your adapter cards (for example, a PCI video capture card or a hard drive controller card). Your accelerated graphics port (AGP) or PCIExpress slot, on the other hand, is dedicated to your video card.

Every motherboard carries a set of chips called the BIOS. (This silly acronym stands for basic input-output system.) Your BIOS determines much of what your computer can do and also controls what happens for different types of input. For example, your BIOS keeps track of what hard drives and floppy drives you can use, what happens when you press a key on the keyboard, and how data is read and written to RAM. You can usually forget about your computer’s BIOS and just let it do its work, but if your computer suffers a hardware failure or a serious error, it’s your BIOS that displays the error message. Most computers today use one of five brand-name BIOS chipsets: Intel, Award, Phoenix, NVIDIA, or AMI.

- Make sure that you update your flash BIOS. Today’s motherboards include flash BIOS, which sounds like the name of a hero from a science fiction film. This is actually a good feature; it enables you to update the capabilities of your computer with new features and bug fixes from the motherboard manufacturer. I check regularly for motherboard BIOS updates on the manufacturer’s Web site.

- Choose more random access memory. All motherboards have a maximum amount of random access memory (RAM) that they can handle.

Unless NASA has chosen you to control the next shuttle launch, a board that supports 2 to 3GB RAM should be sufficient. Real techno-nerds or ultra-power-users might demand support for up to 6GB RAM, although it’s not likely that they’ll ever use it all on a personal computer until the arrival of Windows Vista.