The motherboard (mobo), simply speaking, is the main printed circuit board (pcb) inside a personal computer (pc). It is composed of several layers of compressed thin fiberglass, which some are coated with copper and others bare, and measured in the millionths of an inch. Once formed, it allows for the transfer of electronic pulses composed of energy and data to flow from point to point on electrical pathways. Now you know just about as much as I did when I started to write this article. (Note: For some interesting reading on the subject of manufacturing a mobo, read this!)

In plain-speak, a mobo is the backbone of your pc. It is the circuit board upon which all the other components of the computer depend upon to operate. For example, to watch a DVD on your computer, the DVD drive must somehow get that signal processed and sent to the monitor and speakers. The video signal goes from the drive through the mobo to the video car while the sound signal goes through the mobo to the onboard sound or audio card. There are other processes involved but that is just the basic concept.

Now there are different types, or form factors, of mobos out there. For a home pc, the most prevalent form factor now being sold today is the ATX (ATX, FlexATX, and MicroATX). The ATX form factor came about around 1995 as an improvement over the AT form factor. One of the biggest improvements was the integration of the I/O panel (the panel on the back of your computer where you plug your mouse and keyboard into), or Input/Output panel, into the mobo itself rather than having them attached by connector cables. Additionally, some “feng shui” of the layout now allowed you to put in a full size PCI card without worrying about hitting the cpu.

Below is an image of an ATX mobo and IÂ’ve labeled the various basic components of the cpu.

1. PCI Slots - Peripheral Component Interconnect. When you hear someone mention “Add-On” cards when talking about a PC, this is where they are installed. PCI cards typically are sound cards, USB hub cards, modems, and NICs among others.

2. AGP (Video Card) Slot – Accelerated Graphics Port. A specially designed port to improve data transfer rates over the PCI standard which gives you better graphics.

3. ATX 20-pin power connector – This is how the motherboard receives it power. It also typically supplies power to the I/O panel, RAM, cpu, “add-on” cards, and video card.

4. ATX 4-pin power connector – This supplies the mobo with a steady 3.3V power supply rather than having to incorporate a voltage regulator on the mobo to reduce a 5V to a 3.3 (AMD boards only). On an Intel board, a 6-pin is used.

5. I/O (Input/Output) – This is where the main input/output connectors on your computer are located. They typically include the keyboard, mouse, printer, USB, and Ethernet connectors, among others.

6. Northbridge – This chipset is where the main communication between the RAM, cpu, and southbridge take place. On this mobo, it has a heatsink/fan combo attached to it. Some mobos will have just a heatsink while others won't have anything on the chipset.

7. ZIF socket – Zero Insertion Force socket. This is where your cpu resides. If your cpu chip doesn’t just slip into place all on its own, chances are that you might have to use that five pound rubber mallet that BigAkita likes to use when building computers (see post #11).

8. Memory sockets – This is where you install your RAM sticks. There are different types of memory sockets which we will cover in a later issue.

9. Floppy drive controller – This is the port where your floppy drive (3.5”) connects to the mobo.

10. Primary/Secondary IDE controllers – The primary controller is for your bootable drive, typically your hard drive. The secondary is usually for your disc drives. If you look really closely on your own mobo, you'll see that they are marked "Primary" and "Secondary".

11. USB headers – When installing additional hardware, such as internal card readers or LED front panels, this is where they are connected.

12. S-ATA (or SATA) connectors – A newer format for connecting hard drives to the motherboard. Not all mobos will have these yet.

13. CMOS Battery – This battery supplies power to a small part of your memory that remembers the start-up settings. Without it, you would have to re-enter the settings every time you started your computer.

14. FPIO – Front Panel Input/Output – These are the headers for your power and reset button, in addition to your power LEDs and onboard speaker.

15. S-ATA (or SATA) link – Chipset controller for your SATA headers.

16. Southbridge – This chipset usually handles all the other buses that the Northbridge doesn’t handle, such as your mouse.

Now that you know the general layout of an ATX mobo, weÂ’ll start to get more in-depth next week with the various parts on the motherboard. If you have any questions or see a mistake, please feel free to post your question or send me a private message. IÂ’m learning this stuff as I go along, just like all you lurkers out there.

Take care out there this week,

Rob

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So that's where the CPU thingie goes!

Never cheap out on the Motherboard, the rest of the system can be top notch, and be held back by picking a bad one!

Good job Rob!

Good job Rob!!!

Deja Vu...... or is it just me?

Good Job, Rob. Great for those just starting out in the PC world