Motherboard

An Introduction

PCI SLOTS

PCI stands for "Peripheral Component Interconnect." A 64-bit PCI slot has 64 connections to the motherboard. Each connection is capable of handling 1 bit of data at a time

ISA SLOTS

ISA slots can only handle 32 bits of data at a time . A 32-bit ISA slot has 32 connections to the motherboard . Older technology ISA slots were 8-bit and 16-bit

AMR Slot The audio/modem riser,

also known as an AMR slot, is an expansion slot found on the motherboards of some Pentium III, Pentium 4, and Athlon personal computers. It was designed by Intel to interface with chipsets and provide analog functionality, such as sound cards and modems, on an expansion card. it has been superseded by the Advanced Communications Riser (ACR) and Intel's own Communications and Networking Riser (CNR)

North and South Bridge The chipset is the "glue"

that connects the microprocessor to the rest of the motherboard and therefore to the rest of the computer. On a PC, it consists of two basic parts -- the north bridge and the south bridge . The north bridge typically handles communications among the CPU, RAM, and PCI Express (or AGP) video cards, and the Southbridge

South Bridge The southbridge can usually be distinguished from the

north bridge by not being directly connected to the CPU. Rather, the northbridge ties the southbridge to the CPU. Through the use of controller integrated channel circuitry, the northbridge can directly link signal from

the I/O units to the CPU for data control and access.

SIMM Single in-line memory module, which

is a type of RAM memory module. A SIMM is a small circuit board

designed to hold a set of RAM chips. Two types of SIMM's have been in

general use. 30-pin SIMM's and 72-pin SIMM's.

30-bit SIMM's have 8-bit data buses; 72-pin SIMM's have 32-bit data buses.

The pinouts for all SIMMs is not completely standard. Some manufacturers, such as HP, Compaq, and IBM used non-standard pinouts in their proprietary SIMMs

DIMM DIMM, or dual in-line

memory module, has a 64-bit path to memory chips . DIMMs are commonly used in personal computers, servers and high-end workstations. The DIMM makes physical contact with the data bus of the computer through teeth like connectors that fit into a socket on the mother board.

SODIMM SODIMM, or small outline dual in-

line memory module, is made with integrated circuits and is about half the size of DIMM modules . is designed for use in notebook computers and other

space-restricted environments

BIOS A BIOS (Basic Input/Output System) is

an electronic set of instructions that a computer uses to successfully start operating. The BIOS is located on a chip inside of the computer and is designed in a way that protects it from disk failure.

main function of the BIOS is to give instructions for the power-on self test (POST). This self test ensures that the computer has all of the necessary parts and functionality needed to successfully start itself, such as use of memory, a keyboard and other parts. If errors are detected during the test, the BIOS instructs the computer to give a code that reveals the problem.

CPU Heat Sinks and Cooling Fans

Since CPUs generate so much heat, computer systems use a cooling fan to keep temperatures between 90 and 110 degrees Fahrenheit

Older CPUs used a heat sink, which is a clip-on device that mounts on top of the CPU and pulls heat away from it

The combination of heat sink and cooling fan is sometimes called a cooler

CPU Heat Sinks and Cooling Fans

The System Unit

What is a chip?

p. 4.04 Fig. 4-4 Next

dual inline packages (DIP) holds memory chips

pin grid array (PGA) package holds processor chips

Small piece of semi-conducting material on which integrated circuits are etched

Integrated circuits contain many microscopic pathways capable of carrying electrical current

                             

                                                                                                 

                                                                                               

                               

Parallel Port

Serial PortsUSB Ports

SERIAL PORTConsidered to be one of the most basic external connections to a computer, the serial port has been an integral part of most computers for more than 20 years. Although many of the newer systems have done away with the serial port completely in favor of USB connections, most modems still use the serial port, as do some printers, PDAs and digital cameras. Few computers have more than two serial ports.

If you have a printer connected to your computer, there is a good chance that it uses the parallel port. While USB is becoming increasingly popular, the parallel port is still a commonly used interface for printers. Parallel ports can be used to connect a host of popular computer peripherals:

• Printers

• Scanners

• CD burners

• External hard drives

• Iomega Zip removable drives

• Network adapters

• Tape backup drives

Parallel Ports

The goal of USB is to end all of these headaches. The Universal Serial Bus gives you a single, standardized, easy-to-use way to connect up to 127 devices to a computer.

Just about every peripheral made now comes in a USB version. A sample list of USB devices that you can buy today includes:

Printers Scanners Mice Joysticks Flight yokes

Digital cameras Webcams Scientific data acquisition devices

Modems Speakers Telephones Video phones

Storage devices such as Zip drives Network connections

Connecting a USB device to a computer is simple -- you find the USB connector on the back of your machine and plug the USB connector into it.

Universal Serial Bus (USB) Ports

The rectangular socket is a typical USB socket on the back of a PC

A typical USB connector, called an "A" connection

CPU SOCKETS A CPU socket or CPU slot is an electrical component that attaches to a

printed circuit board (PCB) and is designed to house a CPU .CPU socket structure is largely dependent on the packaging of the CPU it is designed to house

An ATX power connector is a power connector which can be used with the ATX (Advanced Technology Extended) motherboard form factor in personal computers .

IDE IDE (Integrated Drive Electronics) is a standard electronic

interface used between a computer motherboard's data

paths or bus and the computer's disk storage devices. The ANSI name for IDE is Advanced Technology Attachment (ATA) . IDE cable is attached to a CD/DVD drive (unseen) installed in a drive bay at the top of the case, but it could also have been attached to the same cable, because a single IDE cable can accommodate two IDE drives, which can include a CD/DVD drive. The second cable is attached to the motherboard using the connector beside the connector to which the hard disk drive is connected.

SATA The serial ATA, or SATA

computer bus, is a storage-interface for connecting host bus adapters to mass storage devices such as hard disk drives and optical drives. The SATA host adapter is integrated into almost all modern consumer laptop computers and desktop motherboards.

Serial ATA was designed to replace the older ATA (AT Attachment) standard (also known as EIDE). It is able to use the same low level commands, but serial ATA host-adapters and devices communicate via a high-speed serial cable over two pairs of conductors. In contrast, the parallel ATA (the redesignation for the legacy ATA specifications) used 16 data conductors each operating at a much lower speed.

SATA POWER CONNECTOR

SMPS Switch Mode Power Supply The primary function of SMPS is to convert the

alternating current (AC) power available in homes into direct current (DC) required for a computer system

The SMPS or power supply of a computer comes in

different form factor styles LPX ATX SFX