Motherboard is the primary circuit board in a computer that connects all other components including the CPU, RAM, graphic card, and peripherals. It provides sockets and slots for components to be added or upgraded. Motherboards are classified by components (integrated vs non-integrated), form factor (ATX, micro-ATX, etc.), and type (desktop, laptop, server). Key components include the CPU socket, RAM slots, expansion slots, chipset, connectors, ports, BIOS chip and voltage regulator. Manufacturers include ASUS, Intel, Gigabyte and others. Factors for selecting a motherboard include size, CPU/RAM support, expansion options and features.

1. Motherboards

2. Introduction
 Motherboard is the most important
component of the system, it is
infrastructure device of the computer.
 It is the primary board of the computer.
 It is also called as back bone of the
computer.
 All the components of the computer
should connect to the motherboard.
 All communication devices (ports) are
connected to the motherboard.

3. Classification
 Motherboards are classified based on
components, technology and features.
 Integrated and Non integrated.
 AT motherboards and ATX motherboards.
 Desktop, Server and Laptop
motherboards.

4. Based on components
Integrated Non Integrated
 These boards comes
with all components
integrated by
manufacturers.
 Occupies less space
in cabinet.
 Cost is less.
 If any one component
is not working, has to
replace entire board.
 These boards comes
with all slots. Not
components.
 Occupies more space
in cabinet.
 Cost is more.
 If any component is
not working, we can
replace that
component only.

5. Components of motherboard
 Microprocessor socket/slot
 RAM slots
 Expansion slots
 Chipset
 Connectors
 Ports
 ROM (CMOS)
 Lithium ion battery

6. Expansion slots
ISA AGP
PCI Processor slot
PCIX RAM slots
PCMCIA Processor socket
The places where Add-on-cards can be added to the computer.

7. ISA
 Industry Standard Architecture.
 Black in color.
 8 – bit ISA
 16 – bit ISA
 16 – bit is backward compatible.
 Data transfer rate is very less.
 VGA cards and LAN cards.
 Speed is 8 MHZ.

8. PCI
 Peripheral Component Interconnect.
 White in color.
 It is a 32 – bit slot.
 Speed is 33MHZ.
 VGA, LAN, sound cards, internal modem
and USB cards.

9. PCIX
 PCI Extended.
 Creamy in color.
 It is 64 – bit slot.
 Speed is high compared to ISA and PCI.
 Speed is 68 MHZ.
 We can connect all latest cards and TV
tuner.
 Backward compatible.

10. PCMCIA
 Personal Computer Memory Card
International Association.
 Laptop slots, available in 64 – bit and
 128 – bit.
 Type 1, Type 2, Type 3.
 Also known as PC cards.
 Type 3 is meant for external memory
devices.

11. Connectors
 System panel connectors
 USB headers
 ATX 12V connector
 ATX power connectors
 CPU fan connector
 SATA connectors
 IDE connectors
 Floppy disk connectors
 Digital audio connectors

12. ports
 DIN
 PS2
 USB
 Serial
 Parallel
 VGA
 RJ – 45, RJ – 11
 Sound ports

13. DIN
 Dutch Industry Nob
 5 – pin , big in size
 DTR is less

14. PS2
 Personal system 2
 6 pins along with notch
 DTR is high compared to DIN.

15. USB
 Universal Serial Bus
 Usb 1.1  12mbps
 2.0 450 Mbps
 2.1  480 Mbps
 127 devices

16. Serial
 9 pin male port (5 +4)
 Serial keyboards
 External modem, to configure switches.
 COM port

17. Parallel port
 25 pin female port (13 +12)
 LPT port
 Printers and scanners

18. VGA
 Visual Graphics Adapter
 Monitor port
 15 pin female port (5+5+5)

19. RJ 45
 LAN

20. Voltage Regulator
 Voltage regulator is an integrated circuit,
that regulates the voltage supplied to the
motherboard.
 Voltage regulator protects the digital
devices from power surges and spikes.
 It supplies constant voltage to the digital
components of the motherboard.
 Voltage Regulator Module (VRM).

21. Manufacturers of the motherboards
 ASUS AsusTek Incorporation
 Intel
 AMI  American Megatrends
Incorporation
 Gigabyte
 Mercury

22. Factors to select motherboards
 Size of motherboards
 Speed of CPU
 RAM slots
 Expansion slots
 SATA support
 Different types of ports
 Chipset
 Bus speed

23. Jumpers
 Motherboard must be configured before
installed in the system.
 Motherboard configuration can be done
with the help of jumpers.
 These are plastic caps available in
different colors.

24. Motherboards