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The motherboard of a Computer: Definition and Components

I love computers and I enjoy giving tips on how to troubleshoot them.

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

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

Over the years there has been 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 the compatibility of components design and sizes irrespective of the manufacturer, though the configuration may differ in line with the purpose the system is met to serve. Although with this standard, motherboards are of different sizes and make. Each type of computer motherboard has narrowed the type of components that can fit in. Hence we would be discussing the types of motherboards, Form factors, and their components.

Types of Computer Motherboard

The types of system boards should not be confused with Form factors. There are basically two types of motherboards. The integrated and the nonintegrated system board. Discussed 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 has 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 onboard 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 the 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, the 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 has to be made clear as there are propriety motherboards designed to suit the specific needs of the individual manufacturers. Such system boards may not abide by 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 advanced 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 as 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 in 1995. The ATX form factor has 12 x 9.6 in 305 x 244mm in dimension. By implication, the Full ATX system board as was popularly called cannot fit into the Baby ATX case design and vice versa.

The ATX slots are well positioned given room for a maximum number of expansion cards and the processor is close to the power supply fan so the downside of its predecessors is ameliorated. The ATX gained popularity within the era of its creation and has seen a number of variants and derivatives since then up to the 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 the 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. A low profile case design was used for its housing and space is maximally utilized.

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

Each of these form factors is in its own class and is used or manufactured in line with the user's demands. By implication, the demand for a particular system board should be purpose-driven and able to afford the cost. It should be borne 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:

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  1. Memory and their Slots: 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. Their slots are usually white and black and very close to each other.
  2. Expansion cards: Expansion cards are a typical component of a 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 system circuitry.
  3. CPU and slots: The central processing unit and the sockets are highly prolific parts 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 to 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 keeps very important settings in the computer such as date, time, the 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 must always have power over it. This is achieved via the CMOS battery. If a computer loses the 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 devices for a desktop computer. Its connector is located on the motherboard. Keyboard connectors have two main types, the AT and the PS/2 Connector. The AT has a round connecting interface to the motherboard, while the PS/2 connector is rectangular in shape and 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, the same as the floppy disk. They are onboard connecting interfaces that enable the computer to 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 downloading 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, and Game ports.
  12. Jumpers and DIP switches: Jumpers and DIP switches are 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 motherboard form factors.

These are the main components of a computer motherboard. There are other peripherals that represent basic electronic 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 its 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 standards. This is applicable for Desktop and Laptop computer system boards.

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

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.


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