CertiGuide to A+ (Core Hardware)  9  Chapter 0001:  Power Supplies - System Board

NLX Form Factor 1 Northbridge

Recall in Chapter 0000 how IBM quickly got the IBM PC ready for market. The company used almost entirely, 'off-the-shelf' electronic components. Major parts of the system board were consumed by purchasing a standard component known as Transistor-to-Transistor Logic (TTL). IBM arranged these TTLs on the system board to create a computer in very little time.

One inventive company looked at all the real estate on the system board being used by the TTL’s. They engineered the exact same circuit design, and put the TTL’s, resistors, capacitors and transistors into five different IC's. With this stroke of brilliance, hundreds of components were reduced to five. This may be the most popular form of IC in use today. This type of IC is known as an Application Specific Integrated Circuit (ASIC).

Prior the to ASIC, ICs were designed to perform a specific function, in a very generic manner. For example, the 555 IC was a clock chip. But it was not specifically built to power a jumbo digital clock, with alarm, complete with the electronics to drive a display. An ASIC would have the 555 design along with the necessary electronics to drive display and a alarm buzzer.

As computer requirements became more sophisticated, the ASIC grew more complex, and the number of chips needs became less. The chipset of 5 chips became one chip. Today two chips not only control the computer, they can have features that used to require expansion cards be added into the computer. For example, on-board sound is now a common feature in a chipset.

As time has marched forward, the chipset has been reduced in count, dropping to either 2 chips or even the minimum count of 1 chip.

NLX Form Factor 1 Northbridge