Motherboard

The Motherboard is the main circuit board of the computer. Its circuit chips house the BIOS and other necessary information. The Processor connects onto the motherboard. It has several ports and slots to connect other "cards" of chips.

In the above tower, the Motherboard is the large green circuit board in the back of the tower, behind the other parts.

Here are some of the main parts of a typical motherboard. Though there are several different types of boards, they all house the same basic components.

Power Supply

The power supply fits into the tower and its many wires plug into other components of the computer. The motherboard, Disk Drives, fans must all be plugged into the power supply. On the outside of the computer, a cord, plugged into the power supply, plugs into an electrical outlet.

PCI Expansion Slots

PCI Expansion Slots are slots found on the motherboard with corresponding openings in the tower case. These slots allow for additional cards to be connected to the motherboard. Such cards include: Network Interface Cards, Modems, Video Cards, and Sound Cards.

Network Card
(allows computer to connect to a network)

Modem
(allows computer to connect to other
computers via a phone line)

Video Card
(allows computer to video devices)

Sound Card
(allows computer to use sound devices)

Processor

The Central Processing Unit, or CPU is the heart of the computer. It is the component that actually executes instructions.

The Processor is very sensitive. The Heat Sink is a device placed on top of the processor to keep it as cool as possible.

A Small Fan rests on top of the Heat Sink to blow the warm air away from the Processor and Heat Sink.

DIMM Slots

RAM, or Random Access Memory, fits into DIMM Slots on the motherboard. RAM is used by the computer as recyclable memory to run the programs.

RAM

"Sticks" of RAM are identified by the amount of memory they hold. The RAM is measured in mutliples of 8 MegaBytes. Some examples are: 64 MB, 128 MB, 256 MB, and 512 MB.

Cables

The Drives of the computer are attached to the Motherboard IDE Cables. These IDE Cables are flat groups of wires. The #1 wire is usually identified by a different color, such as red.

IDE Cables
(for hard drives, CD & Zip Drives)

Notice the twist in this Floppy Connection Cable. The end with this twist is connected to the Floppy Drive.

Floppy Cable

Tower Vents

Computers, do to the large amount of "work" it does, generates a lot of heat. This heat can be very damaging to the delicate circuits of the system. Case Fans are connected to the tower at Ventilation points. These fans allow for constant air flow to keep the system as cool as possible.

5.25 Inch Drive Bays

An open section on the computer used for expansion for 5.25 inch add-on's to your computer. Adapters can be used to install for smaller components in these bays.

These bays are usually filled with CD/DVD Drives.

CD-ROM Drive
(Reads CDs)

CD-RW Drive
(Reads & Writes CDs)

DVD-ROM Drive
(Reads CDs & DVDs)

DVD-RW
(Reads & Writes CDs & DVDs)

3.5 Inch Drive Bays

A open section on the computer used for expansion for 3.5 inch add-on's to your computer. These bays are usually filled with Hard Drives and Floppy or Zip Drives.

Hard Drive
(Holds all of the data stored on the computer)

Floppy Drive
(Removable Floppies hold about 1.5 KB of data)

Zip Drive
(Removable Zip Disks can hold 100 - 750 MB of data)

LED Cables

In addition to the IDE, Floppy, and Power Supply Cables, there are several other cables that must be connected inside the computer tower.

Theses cables are sometimes lumped together and called LED cables because they hook the LED lights and other front panel accessories up to the motherboard.

These cables usually consist of small, colored-coded wires that are twisted together.

Four main types are: