[[Strand 3: IT Systems]]

3.1 Hardware



What is a Motherboard?

The motherboard is the most essential component in a personal computer. It is the piece of hardware which contains the computer's micro-processing chip and everything attached to it is vital to making the computer run. A motherboard, also known as a main board, logic board or system board, and sometimes abbreviated as mobo. The motherboard also contains the connectors for attaching additional boards.

Types of Motherboards

The CPU is the first thing that comes to mind when many people think about a computer's speed and performance. The faster the processor, the faster the computer can think. In the early days of PC computers, all processors had the same set of pins that would connect the CPU to the motherboard, called the Pin Grid Array (PGA). These pins fit into a socket layout called Socket 7. This meant that any processor would fit into any motherboard. Today, however, CPU manufacturers Intel and AMD use a variety of PGA’s none of which fit into Socket 7. As microprocessors advance, they need more and more pins, both to handle new features and to provide more and more power to the chip.
Current socket arrangements are often named for the number of pins in the PGA. Commonly used sockets are:

Socket 478 - for older processors
Socket 754
Socket 939 - for newer and faster processors
Socket AM2 - for the newest processors
Socket A - for older processors

But now the newest Intel CPU does not have a PGA. It has an LGA, also known as Socket T. LGA stands for Land Grid Array. An LGA is different from a PGA in that the pins are actually part of the socket, not the CPU.
Components of a Motherboard.

If you open your computer’s case, the motherboard is the flat rectangular piece of circuit board to which everything seems to connect to for one reason or another. The Motherboard contains the following key components:

  • A microprocessor "socket" which defines what kind of central processing unit the motherboard uses.
  • A chipset which forms the computer's logic system. It is usually composed of two parts called bridges (a "north" bridge and its opposite, "south" bridge), which connects the CPU to the rest of the system.
  • A Basic Input/Output System (BIOS) chip which controls the most basic function of a computer, and how to repair it.
  • A real-time clock which is a battery-operated chip which maintains the system's time, and other basic functions.
The motherboard also has slots or ports for the attachment of various peripherals or support system/hardware. There is an Accelerated Graphics Port, which is used exclusively for video cards; Integrated Drive Electronics, which provides the interfaces for the hard disk drives; Memory or RAM cards; and Peripheral Component Interconnect also known as PCI, which provides electronic connections for video capture cards and network cards, among others.

How a Motherboard works.
The CPU is an assembly of transistors and other devices which perform and or processes countless programmed tasks. The CPU rests in a "socket" on the motherboard which is connected to the other components through the board's printed circuits. The most important connections are to the chipsets - especially the Northbridge chipset which is connected to the main computer memory (hard disk and RAM), while the Southbridge set is connected to the peripherals - video and audio cards, etc.
Aside from these, the most important element of the motherboard is the BIOS chip - which performs key functions like checking power supply, the hard disk drive, operating system, etc. before the computer actually starts "booting up". Turning on the computer automatically starts the BIOS chip up to perform its diagnostic functions, after which it powers up the CPU which - in its turn - starts powering up the other peripherals (hard disk, operating system, video and audio, etc.