How Computers Work – Part 4 – The Motherboard III [Mega Series]

The RAM Controller
If you don’t understand the concept of a bus on the computer, I suggest you read part 3 of the mega series (part 2 of the motherboard chapter). To the right of the CPU socket, you’ll notice a series of long slots that support a certain type of random access memory (RAM) card. We’ll go through this a bit later, but it’s important for you to know that the RAM controller bus holds all the physical memory cards of your computer. See the picture below to get an idea:

It might be important for you to know that the typical motherboard can have anywhere from 2-6 RAM slots.

The Chipset
The motherboard’s chipset manages the communication and message queue from different parts of the motherboard. Near the CPU socket, you have the northbridge chip, which manages the most important interactions, such as those with the CPU, the RAM, and any dedicated graphics.

Towards the bottom of the motherboard, you have the southbridge chip, which manages all other interactions, such as the PCI bus, the drives, and USB ports. Of course, the chipset can be more complex than this, but I prefer to give you a simpler description. It’s not like you’re going to make your own motherboard, right?

The IDE Controller
IDE stands for Integrated Drive Electronics, which represents the standard which all new drives use. Instead of having a circuit board separated from the drive, manufacturers now integrate them just below the body. It took them a decade or so to realize they can do this, when it takes a 3-year-old only a few minutes to realize that sticking a fork in a wall outlet isn’t a good idea. Both realizations require the same level of intelligence.

Besides gathering power from the PSU, a drive also needs a link that helps it communicate with the rest of your computer. The IDE controller helps make this happen with a couple of connectors. Depending on how old your computer is, the IDE controller could have some long and fat connectors with many teeth (ATA), or it could have a set of small and thin connectors that look much less scary (Serial ATA, or SATA).

The Back Panel Connectors
You can go your whole life without opening your computer and still see the back panel connectors, for as the name implies, they’re located on the rear end of the computer. The motherboard always manages the back panel connectors using a series of on-board chips.

On-board graphics are managed by the motherboard’s graphics chip. The USB ports on the back where you connect your USB humping dog are also controlled by the motherboard’s USB interface, and so on.


How Computers Work – Part 3 – The Motherboard – II [Mega Series]

The CPU Socket

There’s not much to say here, except maybe the fact that this part of the motherboard houses the central processing unit (CPU). Almost every circuit in the motherboard leads here, and some of them even have the privilege of sitting right next to it. The CPU socket allows the processor to connect to the motherboard, and there might be different ways of doing this:

The Pin-Grid Array
The Land-Grid Array
And The Ball-Grid Array

Each of these arrays house all the contacts on the processor that are essential to its function. You probably now understand why you pay an IT guy to stare at your computer’s innards. If you didn’t, have a look at…

The Peripheral Bus

Just like the name implies, the peripheral bus is a system that transports signals between peripheral components and the processor, much like a public transportation system, especially when it turns into an old dysfunctional heap of metal. Your peripheral bus houses all the expansion cards on your computer. They could include network cards (NICs), display adapters (graphics cards), and anything else the motherboard didn’t come with. Normally, a motherboard has all these things, but sometimes you want to expand its capabilities.

Simpler Explanation

The peripheral bus is basically where you connect your sound card, your network card, or any other kind of card that has to connect to the inside of your computer. You know that place where you connect things near the bottom of your computer? That’s basically where the cards sit. Each of them has a metal faceplate in the front that contains the external connectors to the devices you use.

In-Depth Explanation (Geek Talk)

The bus consists of slots, and before you call me a pervert, there are different flavors of bus slots, depending on how old your motherboard is: ISA (Industry Standard Architecture) – really old, PCI (Peripheral Component Interconnect) – practically every motherboard has this, PCIe (Perihperal Component Interconnect Express) – found in newer motherboards, and AGP (Accelerated Graphics Port) – replaced by PCIe x16.

There’s a lot of material on each of these, and I’m going to try to sum them up:

ISA – The oldest type of expansion slot, known to house basically any expansion card back in the day of the dinosaur computers. This was used for networking, sound, gaming, graphics, and many more other practical uses.

PCI – This kind of expansion slot quickly replaced ISA as the new standard for computer systems, and had basically the same uses. Communication was much faster and the cards were smaller.

How Computers Work – Part 2 – The Motherboard – I [Mega Series]

Parts of The Motherboard

At least with only the PSU and motherboard, your computer can send a beep code through the internal case speaker when it notices nothing else is connected to it.

Your motherboard consists of a south bridge, a north bridge, the CPU socket, the RAM bus, the peripheral component bus, and the drive connector buses. If all of these things look confusing, that’s because they are, and there’s no easier way to list the names. We’ll go a little deeper into the function of each of these pieces a little later.

Form Factors

Your motherboard has to fit inside the computer’s body, which means it has to have certain dimensions and a compatible shape. Due to these constraints, a motherboard has to have a certain form factor. This tells you whether the motherboard fits in the case or not. An ATX computer case, for example, can fit a motherboard with an ATX form factor or anything smaller, such as MicroATX. The only thing you need to remember here is that the form factor is equivalent to the dimensions of the motherboard. Any questions?! No? Let’s move on, then.

How the Motherboard Works

The motherboard’s workings can be related to a nervous system for your computer. It carries messages from one point to another and serves as a railway for every signal. That’s why you see all those little lines leading from one part of the board to another. All the juice that flows to the motherboard comes from a thick “trunk” cable leading in from the power supply. Along with other components connected to it, the motherboard transforms the DC electrical signal into information.

How Computers Work – Part 1 – The Power Supply [Mega Series]

How the Power Supply Works

The computer needs a type of adapter that will convert this current from AC to direct current (DC) – a feasible type of electrical supply for the motherboard and components attached to it. Here comes the power supply to the rescue. This simple box converts the evil AC to good, holy and pure DC, which is then distributed to each individual component on the computer that requires it. Although the motherboard gets a nice fat slice of the juice, smaller cables from the power supply also lead to the hard drives, certain expansion cards, and your tongue, if you have the ambition for that.

Each component receives a certain voltage from its dedicated cable. You see, the motherboard can’t provide power to all the components connected to it through the big fat cable it gets from the PSU. Certain components, such as the hard drives and CD DVD burners, need a certain amount of dedicated amperage and voltage that cannot be shared with anything else. In fact, most of the cables on your computer that look like colorful intestines are dedicated power cables for storage components, peripheral drives, and expansion cards.