Created by: Benton Kaeb The Motherboard Created by: Benton Kaeb

Parts of the Motherboard Processor RAM slots (may be SIMM or DIMM) Cache memory BIOS chip CMOS battery Expansion slots Ports and Connections Serial Parallel Video and Audio USB Firewire Network Interface Card (NIC)

Motherboard Breakdown

Processor One of the easiest items to find on the motherboard Located below the main cooling fan on most motherboards Remove cooling fan and processor is glued to the heat sync with special tech glue that is almost impossible to remove. Most common port for a processor is the ZIF port or zero insertion force port Older processors used the SEC port or single edge contact port which somewhat resembled the RAM ports

ZIF Port

RAM Ports (SIMM,DIMM) Two types of RAM ports SIMM- Single inline memory module DIMM- dual inline memory module 72 pin SIMM and 168 pin DIMM are the most common SIMM and DIMM RAM must be installed in pairs in order to fill “a memory bank” Ex: If you install a 72 pin SIMM(32 bits) in a 64 bit machine then you must add another 72 pin SIMM in order to match the processor’s bit path.

SIMM and DIMM

Cache Memory Cache memory- increases performance by storing frequently used programs codes or data that can be later accessed by the processor at a faster speed. Cache memory comes in layers. The first being L1 cache and is integrated with the processor. L2 cache, as well as L3 cache, is located outside of the CPU and is installed on the motherboard Most computers today have at least two levels of cache memory the first level being smaller than the others

BIOS Chip (ROM) BIOS- Basic Input-Output System- is the low level program code that allows all the system devices to communicate with one another Stored on the motherboard in a BIOS chip In today’s machines the ROM BIOS is no longer only read only memory. Todays BIOS chips run as EEPROM (electronically erasable programmable ROM) which means you can get special programs from the BIOS manufacturer that allows you to write to the ROM chip Only IT professionals should write to the ROM chip Usually the biggest chip found on the motherboard.

BIOS Chip

CMOS and its Battery CMOS- Complementary Metal-Oxide Semiconductor- holds the computer inventory. CMOS’s purpose is to hold the computer’s inventory of all system components and all of the components properties. The system inventory is stored in what is called CMOS RAM. Any type of RAM loses its contents upon shutdown, therefore we need a battery to keep CMOS with a charge so that it does not lose its inventory contents. The battery that powers the CMOS is located on the motherboard and needs changed every couple years.

CMOS Battery

Expansion Slots Expansion slots are ports located on the motherboard for the purpose of expanding the functionality of your computer There are three types of common expansion slots PCI- peripheral component interconnect- one of the newer expansion slots, most commonly used expansion slot today, popular for their Plug and Play architecture AGP- Advanced Graphics Port- appeared in 1997, has twice the speed of PCI ports, most commonly used for graphics/video cards ISA- industry standard architecture- first major expansion slot, not commonly used today

Expansion Slots

External Ports and Connectors Serial Ports- also known as communication (COM) ports. Serial ports send “series” of data, or one bit at a time in single file until the transfer of data is complete Serial ports are labeled COM1, COM2, COM3, etc… Two types of serial ports: DB9 male- 9 pin serial DB25 male- 25 pin serial Parallel Ports- also known as the printer port, not used any more (most printers use USB) Video Adapter- also known as the video card port Responsible for converting digital data transmitted from the CPU to analog data that can be displayed on the monitor. Contains 15 pins and is usually shown with a blue sticker and/or monitor icon

Ports

External Ports or Connectors Cont. PS/2- the old style mouse and keyboard ports, rarely used today Contains six pins and mouse is usually green and keyboard is usually purple Sound- there are three sound ports Line-in: usually blue, allows many different types of audio connections Line-out: usually green, allows the connection of speakers MIC-in: Microphone port, usually red, allows connections of a microphone for recording NIC ports- Network Interphase card- most are built in today, used for connection of a RJ45 jack connection on Ethernet cable

PS/2, Sound, and NIC

External Ports or Connections Cont. USB- Universal Serial Bus- high speed serial technology with two common types USB1- 12Mbps USB2- 480Mbps USB ports support daisy chaining which means you can plug multiple devices into a USB splitter Fire wire- faster connection than USB, two standards IEEE1394- 400Mbps IEEE1394b- 800Mbps

Power Connections Everything on the computer needs power from somewhere to run. Everything is supplied power by the power supply. (except itself) Power from the power supply is supplied through many ports that are all numbered P1-P9 Power from the power supply is given in 3.3, 5, or 12 volts Power connection labeled P1 is the main power for the motherboard called the ATX power connector (connects to a ATX motherboard)

Power Supply Connectors P1 = ATX Power Connector

Drive Connections There are two types of drive connectors for hard drive and CD (floppy uses only IDE) IDE- Integrated Drive Electronics- appeared in 1980’s In 40 pin or 80 pin IDE ribbon cables (floppy uses 34 pin connection) SATA- Serial Advanced Technology Attachment- average transfer rate of 150Mbps, up to 600Mbps Replaced IDE cables and connections SCSI- Small Computer System Interface- used in servers, 50 pin cable/connection, faster than IDE

IDE, SATA, and SCSI

Jumpers and DIP switches A Jumper is a set of pins that have a plastic cap over them to create an electrical connection. The cap contains a piece of metal that creates an electrical “jump”. A DIP switch or Dual Inline Package Switch is a set of switches that can be turned on or off to enable/disable functionality on the motherboard. Do not mess with the configuration of the switch without consulting your motherboard’s documentation.

Jumper and DIP Switch

Types of Motherboards Two common types of motherboards are ATX and MicroATX boards shown below.

Remember: Homework and Quiz