Motherboard

Motherboard Basics

The motherboard is the main part of your computer that everything else plugs into. Sometimes it is called the system board. A typical motherboard is a sheet of olive green or brown fiberglass with a myriad of thin gold lines on it and chips sticking off of it.

By itself, the motherboard is just an empty plate. Its the hardware that sits on it that does the work. On it sits the CPU, memory sockets, BIOS, etc. The little gold lines act like electronic roadways of information between each of these features.

These roads enable the different parts of the computer to communicate and perform the functions of your computer, all with the motherboard being the hub of the activity. Because of this "central-ness" in your PC's operation, the motherboard is a key ingredient to performance in your PC. All of your hardware is tied together though the circuitry of your motherboard, so the speed in which your motherboard handles and slings around information is key to any speed you will get out of your PC.

Minimally, a motherboard will include the CPU, a math coprocessor (usually included in the CPU nowdays), clock/timing circuitry, cache, RAM, BIOS, parellel and serial ports, and expansion slots. I will briefly touch on each component on the motherboard.


The CPU

The CPU is usually the most prominent chip on your motherboard. It will be imprinted with the type of CPU that it is, such as "AMD K6-2" or "Intel Pentium II" and it will have the chip manufacturer's logo on it. If you cannot see this, you'll probably see a CPU fan. On Socket 7 motherboards, the processor itself is barely visible. Instead you'll see a large fan which sits upon it. This fan is quite large and is screwed right on top of the CPU. Its job is to keep the CPU cool while the system is on.

Newer motherboards with Pentium II, III, or Athlon processors cannot hide the CPU under the fan. The processor, on these boards, is tall and sticks straight up off the board. You will see a CPU fan attached to one side of the processor. Today's CPU's get extremely hot while they are in operation.

The CPU is the computer's brain. It's job is to process information and sling information around to all of the various hardwares that need it. CPU's vary in sizes and speeds.

The above are the absolute basics. For more detailed info on the processor, go to the Processor section.


The BIOS

The BIOS is another very important part of your computer that makes its home on your motherboard. "BIOS" stands for Basic Input/Output System. It usually resides on a series of chips. These chips are typically the biggest chips on your motherboard other than the CPU and the chipset. Also, there is usually a big sticker on it that says BIOS. The sticker also says what kind of BIOS it is, such as Award or AMIBIOS, and what year it is.

If the CPU is the brain, the BIOS is the nervous system. It takes care of the behind-the-scenes stuff, much like our nervous system makes sure we breathe while we aren't thinking about it. BIOS handles the dirty work: how the floppy disks grab data or what happens when you press a key on your keyboard. You know...thegrunt work. It also kicks in when you turn on your computer, letting the computer know how many drives it has and where they are.

When you turn on your computer, the BIOS determines what hardware is installed. It finds out if the hardware is working and if any of the parts have their own BIOS. If it finds any BIOS type programming on any of the parts, it lets those parts take inventory before returning to its task. For example, most video cards have their own BIOS chip. So, the main BIOS turns control over to the video card until it is done, then resumes to check the rest of the computer.

All this happens behind the scenes every time you boot. You may notice the POST, or Power On Self Test, plus you'll also see your various lights flash. When your BIOS tests the hard drive, floppy drive, and keyboard, you'll see lights flash on them. Once all this is done, your BIOS loads up the operating system. It does this by looking for and reading your various boot up files such as Config.sys and Autoexec.bat. From there, your operating system takes over.

As you can see, BIOS is important. Every computer needs it. And like CPU's, it comes in versions. The versions are based on years though. The newer the BIOS, the newer and fancier parts it can handle. You can usually see what date yours is by looking at the sticker on the chip itself, but if you don't have a little sticker, you can go to the BIOS screen on your monitor. This is done sometimes by hitting F1 shortly after you power up your computer. Here it should tell you who made the BIOS and when.
Most of the time, you buy new BIOS by buying a new motherboard. It comes with it. It is usually hard to find BIOs chips otherwise and install them yourself. Most newer computers have upgradable BIOS where you pop in new BIOS software and it copies this data over to the chips. This is called "flashing" your bios.


Math Coprocessors

There is not too much to say about math coprocessors. It is basically a number cruncher or a real fast calculator. It cranks out fast answers to math problems, helping the CPU do its job faster because it doesn't have to think as hard. It can take care of the floating point calculations.

Coprocessors are optional in older computers. They just speed up math. Do you need one? Well, if you are running math intensive software such as CAD drawing or other software that plays with arrays, irrational numbers, or trigonometric functions, yeah, a coprocessor might be something worth having. Some might think spreadsheets could use a coprocessor, but really, these do not require much math since it is mostly addition and subtracting. For almost all typical business applications, like the word processor, there really isn't a point.

If you have a 486DX or a Pentium, you already have a coprocessor. They're built right in. All modern processors, or any processor you would most likely see in a decent computer, has the coprocessor built in. If you have an SX machine, you dont have one. With these CPU's you will have to get an external one that fits into a separate slot on the motherboard. If you have such a setup, you'll find that the coprocessor is almost as large as the CPU. It is probably the most noticeable chip on the board other than the CPU.

In short, the math coprocessor is now a non-issue, since it is built-in to ALL computers made in the last few years.


DIP Switches and Jumpers

Dip switches and jumpers are your way of telling the computer what is installed on it. DIP switches are very small and are usually flipped with a pointed object such as a bent paper clip or a ballpoint pen.

Jumpers are small pins on the board with plastic or metal devices that go over the pins. This device is called a bridge. When the bridge is connected to any two pins, it completes the circuit between those pins, telling the computer what it need to know. Jumpers are much more common than switches, but they are harder to use. If asked to remove a bridge, always save it for later. A little trick is to leave the bridge hanging on one pin. The computer will think the bridge is gone, but its still there so that you don't lose it. Also, knowing the jumper settings for your device can be a chore. You must have the device's manual to do it.


Integrated Circuitry


Many times you'll have your I/O and video circuitry built right on to your motherboard.

Usually, I/O adapters on the motherboard are of the IDE/EIDE interface and they are marked HDD for hard drive and FDD for the floppy. You simply plug your data ribbons into these and you can bypass the need for a separate I/O card. The downside is that if you want to use a system other than that on the motherboard, you have to disable the circuitry on the board. For example, if you feel like using SCSI, then you'll have to disable the IDE on the board. For most users, using the IDE interface on the board works just fine. Some more expensive boards have SCSI adapters hard-wired onto the board.

Other motherboards have built in video circuitry. This is less common than the drive interface, but it happens. This allows you to bypass buying a separate video card and saves a slot. But, again, if you want to upgrade your video later on, you'll have to disable the video on the board and buy that fancy new card anyway.


The Rest

Other than the above , you have the battery, the keyboard connector, the expansion slots, and the Memory(SDRAM) slots.

The battery is pretty noticeable. It is a little cylinder just like your run of the mill Energizer, but shorter. Most batteries are small, round, and flat. These types fit into a small socket and are held in my a small metal tab. Its job is mainly to keep the system time and a few other settings when the computer's power is off. If you are asked what time it is or what kind of hard drive you have when you turn on your computer, you probably need a new battery.

The keyboard connector is self-explanatory, so let me explain.=) You plug your keyboard into it. The prongs on your keyboard wire's end will match up (hopefully) with the little holes on the connector on the motherboard. They come in large 5-pin setups or smaller PS/2's. This complicated setup is usually located next to the battery.

Expansion slots are explained in the Cards section of the site. They come in different types: ISA, PCI, and AGP.