Copyright © 2007 Heathkit Company, Inc. All Rights Reserved PC Fundamentals Presentation 3 – The Motherboard

2 Objectives At the end of this presentation, you will be able to:

3 Explain how power is distributed throughout the motherboard. Identify and explain the purpose of several circuits on the motherboard. Identify and explain the purpose of the ISA expansion bus, the PCI expansion bus, and the accelerated graphics port (AGP). Identify and explain the purpose of the DIMMs. Identify and explain the purpose of each of the field replaceable units (FRUs) on the motherboard.

4 Motherboard Form Factors AT-Type Baby or Mini AT ATX-Type LPX Mini LPX Proprietary Designs

5 Evolution of the Motherboard Processors have gone through several generations. Busses have evolved Memory has evolved

6 Evolution of the Pentium Processor II III D I

7 The AT and ATX Motherboards AT ATX

8 AT Motherboard with Pentium CPU

Power Distribution

10 AT-Motherboard Power Connectors Black Wires Black Wires

11 Power Connector

Edge View of Motherboard

13 Voltages supplied to the motherboard + 5 Volts - 5 Volts + 12 Volts - 12 Volts

14 Voltage Regulator

15 CPU Socket

16 The MPU

17 The Pin Grid Array (PGA) Socket.

18 MPU Socket Lever 18

19 Fan Heat Sink 19 CPU

20 Industry Standard Architecture (ISA) Bus. 8-MHz Speed Supports 8-bit and 16-bit data transfer Used for slow speed operations such as modems and sound cards.

21 ISA BUS

22 8-bit Cards 16-bit Cards 22

23 Motherboard ISA boards installed. 16-Bit 8-Bit

24 Peripheral Component Interconnect (PCI) Bus 33 MHz Handles 32-bit and 64-bit data transfers Processor independent Supports Plug and Play

25 PCI BUS

26 SIMMs

27 Single In-line Memory Module (SIMM)

28 Cache Memory Cache Memory

29 The Chipset The support chips that make the microprocessor a microcomputer. Applications Specific Integrated Circuits (ASICs) that provide the signals, controllers, interfaces and buffers that the system needs to operate.

30 Chipset

31 Main functions of the Chipset A System Controller handles timing, interrupt and DMA control, and power management. A Memory Controller provides interconnection and control of memory systems. A Peripheral Controller connects the MPU to internal and external devices such as disk drives, buses, and peripherals.

32 Super I/O Controller Super I/O Controller

33 Super I\O Controller Interface to the floppy drive. Interface to serial ports. Interface to parallel ports.

34 Keyboard Controller Keyboard Controller

35 Keyboard Controller Communicates with the microprocessor in the keyboard. Performs a parity check. Converts serial data from the keyboard into the parallel data needed by the computer. Generates an interrupt to alert the system that a key has been depressed.

36 ROM BIOS ROM BIOS

37 Identifying the ROM BIOS. R3.60 Socket Version #

38 Electrically-Erasable PROM… EEPROM

39 Real Time Clock Real Time Clock

40 The Real Time Clock (RTC) contains: Clock CMOS memory And in some cases the battery.

41 CMOS is used to hold SETUP information.

42 The FRUs on the AT Motherboard include: The MPU Any board plugged into the PCI bus. Any board plugged into the ISA bus. The SIMMs/DIMMs The ROM BIOS

43 ATX Mother- board

44 Early ATX Motherboard 9.6 ” 12 ”

45

Power Distribution

47 ATX-Motherboard Power Connector

48 Motherboard Power Connector

49 Power Connector Power Connector

50 Power Supply Output Voltages ATX-Type +5 Volts +12 Volts -12 Volts -5 Volts +3.3 Volts

51 Pentium 4, Heat Sink & Fan Pentium 4, Heat Sink & Fan

52 PCI Bus

53 AGP

54 Accelerated Graphics Port (AGP) Operates at twice the speed of the PCI bus or at 66MHz. Even higher speed versions are being developed. Mostly used by Video Cards

55 DIMMs

56 Dual In-line Memory Modules (DIMMs) have components and pin connections on both sides of board.

57 Chipset

58 Super I/O Controller Super I/O Controller

59 ROM BIOS Battery

60 I/O Ports

61 ATX Mother- board Pentium D Processor Pentium D Processor PCI Bus

62 ATX Mother- board PCI Express X1 PCI Express X16

63 ATX Mother- board DDR DIMM

I/O Ports

The motherboard is the heart and soul of the computer.

Copyright © 2007 Heathkit Company, Inc. All Rights Reserved PC Fundamentals End