Motherboards Visit for more Learning Resources Form factor

Motherboards Visit for more Learning Resources

• Form factor defines – Size of the motherboard – General location of components and parts • Chipset defines – Type of processor and RAM supported • Built-in components – With a built-in NIC, extra NIC not needed

• Motherboards are officially printed circuit boards (PCBs) – PCBs come in multiple layers with highways of wires (bus systems) in the layers – These highways of wires are called traces • Boards are standardized so that they can fit in cases

The AT Form Factor • IBM invented the AT form factor in the early ’ 80 s – – Lasted through mid ’ 90 s Currently obsolete Large keyboard socket, split power socket (P 8/P 9) Baby AT was smaller version • Alternatives were – LPX – NLX

ATX Form Factor • Created in 1995 – About same size as Baby AT – Had many ports accessible from rear of PC including mini-DIN – RAM was closer to Northbridge and CPU for better performance – Uses the soft power feature to turn PC on and off through software

ATX Motherboard Parts

M/B Components • • CPU BIOS RAM Cache Memory Bus Expansion Slot Onboard I/O Connectors Onboard IDE Connectors

CPU • Brain of Computer • Majority of computing tasks are performed • Heat sink is installed for heat dissipation

‘BIOS basic input and output system • It is a ROM chip • Contains programs neccesary for PC boot • Also for POST(Power on Self test)

RAM Random Access Memory • Used for storing programs temporarily • Located on SIMM(Single Inline Memory Module) • Or • Located on DIMM(Dual Inline Memory Module)

Cache Memory • Fastest memory • Lies between CPU and RAM • CPU access cache more frequently than RAM

Bus Expansion Slot • System expansion is done thr’these slots • Adapters are installed with it. Types of slots include ISA industry Standard Architecture VESA PCI AGP

ON board i/o connectors • In recent systems one or 2 serial ports com 1 and com 2 and parallel ports(LPT 1, LPT 2) are present on mtherboard.

ON board IDE connectors • Similar to parallel and serial ports IDE connectors for connecting Floppy Disks, Hard Disk and CD Drives.

ATX Spin Offs • Micro. ATX and Flex. ATX two smaller versions of ATX – Many techs and Web sites use the term mini-ATX to describe these boards – Cases need to be matched to motherboards – Can’t put a larger motherboard into a smaller case – Case manufacturers have made accommodations for smaller motherboards in larger cases

ATX Spin-offs • BTX (Balanced Technology Extended) – Due to heat, cooler form factors needed • Three subtypes of BTX – micro. BTX – pico. BTX designed to replace ATX designed to replace micro. ATX designed to replace Flex. ATX • Proprietary form factors – Unique to a specific company – Don’t follow standards and drive purchase to that company – Difficult to support

Chipsets

Chipsets • A chipset defines – The processor type – Type and capacity of RAM – What internal and external devices the motherboard will support – Serves as an electronic interface among the CPU, RAM, and I/O devices • Most modern chipsets have two primary chips – Northbridge – Southbridge

Chipset Chips • Northbridge – Helps the CPU work with RAM (on Intel-based systems) – Communicates with video on newer AMD systems • Southbridge – Handles expansion devices and mass storage drives – Sits between expansion slots and EIDE and FDD controllers – Also called the I/O Controller Hub (ICH 5) or peripheral bus controller • Super I/O chip – Provides legacy support

Northbridge • Older Northbridge functions – Worked similar on Intel • Newer Northbridge functions – Only AMD

Chipset Schematic • Schematic of an older chipset

Chipset Schematic • Schematic of an modern chipset For more detail contact us