MOTHERBOADS
By the name, it is the mother figure of the foundation of the entire system. Each and every component of a PC somehow connects to the motherboard. In basic terms it provides a data path for all other components and controls some of the components.
The heart of the motherboard is the “Chipset” and the most important component connect to the motherboard is the CPU (Central Processing Unit) or simply the Processor. Other than the CPU connecting socket/slot, there is room for RAM, ROM, CMOS, Cache, I/O Ports, Expansion slot, Clock, I/O Buses and possible integrated controllers and components.
Over the years from IBM PC/XT, motherboard have passed a series of transformations and modifications, with the advancing technology, more powerful and smaller chips have been developed and remain less to be placed on the motherboard, resulting smaller dimensions.
In modern PC market, different types of motherboards can be found, because of the continuous modification of the product to improve the functionality and to provide a competitive edge, either in price or performance for the designer. Due to this some motherboards available with everything integrated (or onboard) such as Video, Audio, LAN (Local Area Network), Modem, etc. And some boards with minimum integrated components, but these are larger in size, because the board should have enough room for all add on cards. The days, where the processors of different manufacturers can be plugged in to same motherboard are gone and now manufacturers use different types of CPU sockets, so the users have to buy compatible pair of a processor and a motherboard, upgrading processor without motherboard is limited to the same manufacturer and sometimes the same processor type, in some cases, some manufacturers change the socket for the processor in the newer versions and automatically users have to go for a new motherboard with the new processor.
In modern market, there are four notable chipset manufactures for the processor brads Intel and AMD, namely Intel, VIA, SIS, AMD and Nvidia. The main producers are Intel and VIA.
Motherboards are manufacturing according to the Form Factors. Form factor is a minimum specification that defines the physical characteristics of a motherboard. Basically the form factor defines the length and the width. There are number of form factors defined for computers from time to time with the advancing technology,
· XT (Extended Technology) -
o Used in original IBM PC and PC/XT (8088)
o Very few integrated devices
o The only I/O port is the keyboard connector.
· AT (Advanced Technology)
o Used with 286/386 processors
o Very few integrated ports.
o Keyboard connector is on board and is a DIN5 connector.
· Baby AT (BAT)
o A smaller version of AT form factor (8.5”x13”to10”).
o Socket 5 or 7 CPU socket.
o Very few I/O ports onboard.
o Some BAT board have both AT and ATX power connector.
· ATX
o Designed by Intel (1995).
o Mouse and the keyboard have PS/2 connector onboard.
o 20 pin power supply connector instead of 2 AT connectors.
o Bios may be flashable.
· LPX
o Designed by Western Digital.
o Used in low profile desktops (mini).
o Normally, the video chip comes integrated to the motherboard.
o It has cooling problems as airflow is blocked by the riser.
o In some cases the expansion cards cover the memory modules and dealing with memory modules is quite difficult.
· NLX
o This is the successor of LPX.
o A joint venture by major PC manufacturers in 1997.
o Some boards got an AGP slot.
· MICRO ATX
o Introduced in late 90’s
o Smaller version of ATX.
o Maximum size – 9.6” in length and width.
o It has double size I/O panel.
o In most cases got integrated graphics, audio, LAN/modem hardware.
· FLEX ATX
o Introduce in 1999.
o Only for processors with socket type design.
o Size – 9” x 7.5”
o Smaller and low cost.
o Uses CNR (Communications and Network Riser)
· ITX
o Introduced in 2000 by VIA technologies.
o Size – 8.5” x 7.5”
o Uses ACR (Audio Communication Riser).
