ashraf yassen
28-06-2004, 07:11 AM
Motherboard
The motherboard is like a car chassis. In a car, everything is connected to the chassis either directly or indirectly. In a PC, everything is connected to the motherboard - either directly or indirectly. A motherboard is a thin, flat piece of circuit board, usually of green or gold color, usually slightly larger than a piece of paper.
A motherboard has a number of special sockets that accept the various PC components. The are sockets for the microprocessor...
Sockets for RAM...
Sockets to provide power...
Connectors for floppy drives and hard drives...
As well connectors for external devices such as mice, printers, joysticks and keyboards.
A few components are soldered directly to the motherboard.
Between the various devices, the motherboard is filled with tiny wires, called "traces", which electrically link the various components of the PC together.
All motherboards also have multi-purpose "expansion slots" that allow the addition of optional components. There are thousands of different types of optional devices that can be added to a PC. These would include scanners, modems, network cards, sound cards, tape backups, etc. The expansion slots are the connections that allow optional devices to communicate with the PC. The device used to connect to the expansion slots is generically called an "expansion card" or just a "card". There are different types of expansion slots for different types of cards.
The position of the expansion slots and external components is very standardized. They have to be. The motherboard is mounted to the box or case, the part of the PC that you actually see.
The box needs to have holes that allow devices to be able to access the external connectors. For example, if the motherboard has a connector for a keyboard, there needs to be a hole in the box though which the keyboard plug is inserted!
Equally important, if the expansion slots allow us to add cards to the PC, then there also must be holes that allow different devices to connect to their cards.
Clearly, there must be a certain type of box to go with a certain type, or layout, of motherboard. Fortunately, there are very few different layouts of motherboard, requiring only a few different types of boxes. We’ll visit this in more detail later.
Power Supply
The Power Supply, as its name implies, provides the necessary electrical power to make the PC operate. The power supply takes standard 110 volt AC power and converts it into 12, 5 and sometimes 3.3 volt DC power. The vast majority of power supplies are about the size of a shoebox cut in half and are usually gray of metal colored.
Leading out of the power supply are a number of connectors. There is one set of connectors for the motherboard...
And a number of other "general use" connectors that are used to provide power to any device which needs electricity.
On most PCs the back of the power supply is visible, with a connection for the power plug. There is always a fan that is used to keep the interior of the PC cool.
Floppy Drive
The floppy drive allows you to access floppy diskettes. The are two types of floppy drives, a 3 ½" and a 5 ¼". The 5 ¼" drive is completely obsolete but is still encountered on older PCs.
The floppy drive is connected to the computer via a 34-pin ribbon cable, which in turn is connected to the floppy controller. In early PCs, the floppy controller was a special card that was inserted into an expansion slot. Today’s PCs all have the floppy controller built into the motherboard.
Floppy ribbon cables are unique from any other type of cable in two ways. First, they are the narrowest ribbon cable, only slightly more than 1" wide. Second, there is a twist in the cable, usually close to where the floppy cable is connected to the floppy drive.
A PC can support up to two floppy drives. If a PC has two floppy drives, they will be connected to the same ribbon cable.
Last, floppy drives need power. They will have one of the power connectors attached to supply power to the floppy.
The motherboard is like a car chassis. In a car, everything is connected to the chassis either directly or indirectly. In a PC, everything is connected to the motherboard - either directly or indirectly. A motherboard is a thin, flat piece of circuit board, usually of green or gold color, usually slightly larger than a piece of paper.
A motherboard has a number of special sockets that accept the various PC components. The are sockets for the microprocessor...
Sockets for RAM...
Sockets to provide power...
Connectors for floppy drives and hard drives...
As well connectors for external devices such as mice, printers, joysticks and keyboards.
A few components are soldered directly to the motherboard.
Between the various devices, the motherboard is filled with tiny wires, called "traces", which electrically link the various components of the PC together.
All motherboards also have multi-purpose "expansion slots" that allow the addition of optional components. There are thousands of different types of optional devices that can be added to a PC. These would include scanners, modems, network cards, sound cards, tape backups, etc. The expansion slots are the connections that allow optional devices to communicate with the PC. The device used to connect to the expansion slots is generically called an "expansion card" or just a "card". There are different types of expansion slots for different types of cards.
The position of the expansion slots and external components is very standardized. They have to be. The motherboard is mounted to the box or case, the part of the PC that you actually see.
The box needs to have holes that allow devices to be able to access the external connectors. For example, if the motherboard has a connector for a keyboard, there needs to be a hole in the box though which the keyboard plug is inserted!
Equally important, if the expansion slots allow us to add cards to the PC, then there also must be holes that allow different devices to connect to their cards.
Clearly, there must be a certain type of box to go with a certain type, or layout, of motherboard. Fortunately, there are very few different layouts of motherboard, requiring only a few different types of boxes. We’ll visit this in more detail later.
Power Supply
The Power Supply, as its name implies, provides the necessary electrical power to make the PC operate. The power supply takes standard 110 volt AC power and converts it into 12, 5 and sometimes 3.3 volt DC power. The vast majority of power supplies are about the size of a shoebox cut in half and are usually gray of metal colored.
Leading out of the power supply are a number of connectors. There is one set of connectors for the motherboard...
And a number of other "general use" connectors that are used to provide power to any device which needs electricity.
On most PCs the back of the power supply is visible, with a connection for the power plug. There is always a fan that is used to keep the interior of the PC cool.
Floppy Drive
The floppy drive allows you to access floppy diskettes. The are two types of floppy drives, a 3 ½" and a 5 ¼". The 5 ¼" drive is completely obsolete but is still encountered on older PCs.
The floppy drive is connected to the computer via a 34-pin ribbon cable, which in turn is connected to the floppy controller. In early PCs, the floppy controller was a special card that was inserted into an expansion slot. Today’s PCs all have the floppy controller built into the motherboard.
Floppy ribbon cables are unique from any other type of cable in two ways. First, they are the narrowest ribbon cable, only slightly more than 1" wide. Second, there is a twist in the cable, usually close to where the floppy cable is connected to the floppy drive.
A PC can support up to two floppy drives. If a PC has two floppy drives, they will be connected to the same ribbon cable.
Last, floppy drives need power. They will have one of the power connectors attached to supply power to the floppy.