the Physical Computer
a Training Module of the
Assistive Technology Division
Mississippi Department of Rehabilitation Services

 

the Motherboard

The motherboard holds the internal workings of the computer. There are slots for PCI cards, AGP cards, the processor (ZIF socket), RAM, IDE connectors, floppy disk connectors, AT power connector.

The motherboard also contains the buses, the North Bridge chip, the South Bridge chip.
a typical motherboard
PC connections
 The motherboard has input/output connections that fit through the case and provide access to the motherboard via the rear of the computer. These are diagrammatic representations of typical connectors found on motherboards or on cards.
Integrated Motherboard Connections
View as it appears when looking at the back of the computer case.
1. PS/2 Keyboard
6-pin Female mini DIN connector for attaching a PS/2 keyboard.
2. PS/2 Mouse
6-pin Female mini DIN connector for attaching a PS/2 mouse.
3. USB ports
UHCI Universal Serial Bus root hub for connecting devices such as a keyboard, mouse, scanner, digital camera, or other USB-compatible devices.
4. LAN or Modem (Optional)
A LAN (RJ-45) or Modem (RJ-11) jack for connection to a Local Area Network or phone line.
5. COM A
9-pin Male mini DIN serial connector for attaching a mouse or other serial device.
6. VGA
15-pin Female DB connector for attaching to a (S)VGA monitor.
7. Parallel Port LPT-1
25-pin Female Centronics connector supporting both EPP and ECP modes for connection to a printer or other parallel device.
8. Line-Out
1/8" stereo audio connection for attaching speakers or headphones.
9. Line-In
1/8" stereo audio connection for attaching an external CD player, tape deck, or other audio device.
10. Microphone
1/8" stereo audio connection for attaching a microphone.
11. MIDI or Joystick
15-pin Female DB connector for attaching a joystick or game pad. It can also be used to connect MIDI devices.
motherboard rear

a motherboard with the processor and fan installed

Locate:

PCI slots
RAM slots
Processor
Chipset
IDE connectors
Floppy connector
AGP slot
CMOS battery
Rear Input/Ouput Module

same motherboard with markings

Chipsets

the Northbridge chip contols data flow from processor, AGP, memory. this chip will generally have a heat sink or fan on top of it.

the Southbridge chip controls the flow amongst PCI slots, USB, serial, parallel, drives, and audio.


this is the same motherboard with RAID controllers

RAID
Random Array of Independent Disks

RAID 0 is stripping. Data flows simultaneously onto multiple hard drives that are configured to function as a single drive. When stripped to two drives the data flow is twice as fast.

RAID 1 is mirroring. Data flow simultaneously onto a mirrored drive. The second drive is an exact copy of the first. This provides redundancy.
The CMOS battery provides the motherboard with a power supply to hold BIOS settings.
This photo shows the primary and secondary IDE controllers in the left foreground, the floppy controller in the right foreground. Just behind the floppy is the ATX power connector. The long horizontal slots in the middle are DIMM RAM slots.

 

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