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Motherboard of a Computer( Definition and Components)

The Motherboard of a computer also known as the System Board ,the main board or Circuit board is the platform on which the various components that make up the hardware of the computer are connected. The entire computer circuitry finds their base on the System board. It could be said to be the most important part of the computer.

From the picture of System board displayed we can find expansion slots, CPU heat sink, PCI, Power connector, on-board disk drive connectors, memory slots, keyboard connectors, Peripheral ports and connectors and the underlying circuitry.

Over the years there has been a phenomenal growth in the design and configuration of the motherboard. The computer industry is an outfit highly regulated and driven by standards. This is to ensure compliance especially with respect to compatibility of components design and sizes irrespective of the manufacturer, though configuration may differs in line with the purpose the system is met to serve. Although with this standard, motherboards are of different sizes and make. Hence we would be discussing the types of Motherboard, Form factors and their components.

Types of Computer Motherboard

The types of system board should not be confused with Form factors. There are basically two types of motherboards. The integrated and the nonintegrated system board. Each as follows:

1. Integrated Motherboard: The integrated system board has most of its components soldered on the board unlike expansion cards that are detachable. This type of motherboard as an advantage and also a drawback. Its main advantage is its simplicity as much space is conserved, portable and perhaps cheaper to manufacture.

The major drawback is when an on board component is faulty; the entire System board has to be replaced. However, such faulty components in some motherboards can be disabled and replaced by an expansion card but this has to be done by a highly experienced technician. Sometimes the cost of doing so may outweigh its benefits.

2. Non-integrated Motherboard: The non-integrated system board has expansion slots with some of its components detachable like the video adapter, disk controllers etc. The major advantage of this type of System board is its flexibility with respect to replacement of faulty components. When an expansion card is faulty it can easily be replaced.

Motherboard of a Computer Form Factors

The form factors of a computer motherboard should not be confused with its types as discussed above. Form factors of a motherboard have to do with the mode of design, position of components and their sizes. Computers are classified according to their form factors. As indicated earlier, the World of computing is driven by standards and by implication the design of components and sizes are regulated in such a way that they are interchangeable or they can fit into system boards irrespective of the manufacturer especially in compliance with the IBM standard.

This as to be made clear as there are propriety motherboards designed to suit specific needs of individual manufacturer. Such system boards may not abide with such standard and their housing are modified to suit such designs. Over the years we see motherboard form factors changing in line with emerging technologies and evolving demands.

One of the earliest form factors was the advance technology (AT) industrial standard; it has 12 X 113 in 305 X 27933mm dimension. It came into existence in 1984 and by 1985 Baby AT was launched by IBM which serves as the industrial standard for all IBM System compatibles. It has the same functionality with AT but with lesser expansion slots.

It received wide acceptability as a result of its small size but was short lived due to overheating of the processor. Most of its expansion slots are on the same line as a result there are a minimum number of expansion cards it can accommodate in terms of number and sizes. More so the position of the processor is not in alignment with the power supply fan except a heat sink is created.

This drawback lead to ATX (Advanced Technology Extended) coming on board created by Intel 1995. The ATX form factor has 12 x 9.6 in 305 x 244mm in dimension. By implication Full ATX system board as was popularly called cannot fit into Baby ATX case design and vice versa.

The ATX slots are well positioned given room for maximum number of expansion cards and the processor is closed to the power supply fan so the downside of its predecessors is ameliorated. The ATX gained the most popularity within the era of its creation and have seen a number of variants and derivatives since then up to time of this discourse. MicroATX, MiniATX, FlexATX etc. form factors are the offshoot of ATX and up to the present a number of its derivatives are still in the making.

Apart from the various derivatives of ATX form factor, another motherboard configuration that also gain popularity was the new low profile extended (NLX) form factor. The NLX system board is uniquely designed, an example of a nonintegrated motherboard with its expansion slots placed sideways via a riser card. Low profile case design was used for it housing and space is maximally utilized.

Balanced technology extended (BTX) was released by Intel, 2004, intended to replace ATX form factor. But most manufacturers did not buy into its technology and consequently it did not gain popularity.

Each of these form factors are in their own class and are used or manufactured in line with users demand. By implication, the demand for a particular system board should be purpose driven and ability to afford the cost. It should be born in mind, that in most cases each form factor goes with a befitting case design.

 ATX Motherboard Labeled as follows: 1. Processor Socket 2. Chipset 3. RAM Slots 4. AGP graphic Card Slot 5. PCI Slots 6. CNR Modern Slot 7.Audio Chip 8. I/O Chip 9.BIOS 10. ATX Power connector 11. Floppy Drive Connector 12. ATA Connectors

ATX Motherboard Labeled as follows: 1. Processor Socket 2. Chipset 3. RAM Slots 4. AGP graphic Card Slot 5. PCI Slots 6. CNR Modern Slot 7.Audio Chip 8. I/O Chip 9.BIOS 10. ATX Power connector 11. Floppy Drive Connector 12. ATA Connectors

Components of a Computer Motherboard

The following are the main components found on a computer motherboard:

  1. Memory and their Slots: The computer memory (RAM) is one of the most important parts of the system board. The number of memory chips of a motherboard depends on the type of computer and its capacity. There slots are usually white and black and very close to each other.
  2. Expansion cards: Expansion cards are a typical component of nonintegrated system board as indicated earlier in this discourse. An example is a graphic card. However this can be integrated into the motherboard it depends on the type of circuitry.
  3. CPU and slots: The central processing unit and the sockets is highly prolific part of the computer. It is located right on the motherboard. And it is easily identifiable as a result of the heat sink or cooling fan directly on it.
  4. BIOS Chip: Just like the CPU, the BIOS chip occupies a top position in terms of the order of importance on the system board. It directs the CPU with respect to how it relates with other parts of the computer. The Basic Input and Out System chip or integrated circuit is fixed on board and it is easily identified. BIOS and the name of the manufacturer are usually written on the chip.
  5. CMOS Battery: The complementary Metal Oxide Semiconductor (CMOS) is a small battery on the system board that powers the CMOS memory. The CMOS memory keep very important settings in the computer such as date, time, configuration of the hard drive etc. in such a way that when the computer is switched off such settings are maintained. In order for this to be, the memory most always has power on. This is achieved via the CMOS battery. If a computer looses correct time and date for example, it is an indication that the CMOS battery is weak.
  6. Power Supply and Connectors: This is the electrical unit of the system. It is the unit that supplies power as required for the smooth running of the computer. If it is bad the system will not power on. The power supply pack can be replaced when faulty.
  7. Keyboard Connector: This is one of the most important input device for a desktop computer. It's connector is located on the motherboard. Keyboard connectors have two main types, the AT and the PS/2 Connector. The AT has round connecting interface into the motherboard, while the PS/2 connector is rectangular in shape and is smaller. Modern motherboards come with both connecting points.
  8. Mouse Connector: The mouse is also a very important input device on the computer. Its connecting port is located on the motherboard. The connecting interface is usually round or a USB like interface.
  9. Floppy and Hard Disk Connectors: The Hard drive is the mass storage device of the computer system, same with the floppy disk. They are onboard connecting interfaces that enable the computer communicate with both drives.
  10. Expansion slots: Expansion slots on the motherboard or a riser board make it possible for an additional card or board to be connected to the main board. There are different types serving different purposes. Mostly you come across PCI, PCI Express and AGP expansion slots. And for those computers manufactured before 1997, their slots are slightly different from what is obtainable today, though most of them are being faced out.
  11. Peripheral ports and Slots: The functions performed by the computer require in most cases an external device connection either for uploading or to download data or as the case may be. There are various peripheral ports and slots met for this purpose. The most important peripheral ports are the universal serial bus (USB), Serial, Ethernet, Parallel, Video, sound, Game ports.
  12. Jumpers and DIP switches: Jumpers and DIP switches used to configure the system board serving as a regulator for the amount of voltage supply as required by the various components on the motherboard especially the processor. This is automatic in some recent motherboards form factors.
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These are the main components of a computer motherboard. There are other peripherals which represents basic electronics components such as capacitors, resistors, regulators etc. All these work together to make up a complete and working circuitry.

The motherboard of a computer is in a state of flux especially with respect to it form factors. Although it is a gradual process, in recent times we have seen a remarkable advancement in its configuration and design whether as a propriety design or in line with existing industrial standard. This is applicable for Desktop and Laptop computers system boards.

It suffices to say that we shall continue to see these changes as technology and computers users demand grow over time.


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