Exercise 2
The Motherboard
1
Motherboard Form Factors
 AT-Type
 Baby
or Mini AT
 ATX-Type
 Proprietary
Designs
2
Proprietary Motherboard
3
ATX
Motherboard
4
Some motherboards are designed
for the original Pentium Processor
5
Others are designed for the
Pentium II Processor
6
AT Motherboard with
Pentium CPU
7
Power Distribution
8
Black
Wires
AT-Motherboard Power Connectors
9
10
Edge View of Motherboard
11
Voltages supplied to the
motherboard
+
+
-
5 Volts
5 Volts
12 Volts
12 Volts
12
Voltage Regulator
13
CPU Socket
14
The MPU
15
The Pin Grid Array (PGA) Socket.
16
MPU
Lever
17
2.
1.
18
3.
19
4.
20
Fan
Heat Sink
CPU
21
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.
22
ISA BUS
23
16-bit Cards
8-bit Cards
24
ISA boards installed.
16-Bit
8-Bit
Motherboard
25
Peripheral Component
Interconnect (PCI) Bus

33 MHz

Handles 32-bit and 64-bit data transfers

Processor independent

Supports Plug and Play
26
PCI BUS
27
SIMMs
28
Single In-line Memory Module (SIMM)
29
Cache
Memory
30
The Chip Set

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.
31
Chipset
32
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.
33
Super I/O
Controller
34
Super I\O Controller

Interface to the floppy drive.

Interface to serial ports.

Interface to parallel ports.
35
Keyboard
Controller
36
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.
37
ROM
BIOS
38
Identifying the ROM BIOS.
Socket
Version #
R3.60
39
Electrically-Erasable
PROM… EEPROM
40
Real Time
Clock
41
The Real Time Clock (RTC)
contains:

Clock

CMOS memory

And in some cases the battery.
42
CMOS is used to hold SETUP
information.
43
The FRUs on the Motherboard
include:

The MPU

Any board plugged into the PCI bus.

Any board plugged into the ISA bus.

The SIMMs

The ROM BIOS
44
9.6 ”
ATX
Motherboard
12 ”
45
Power Distribution
46
ATX-Motherboard Power Connector
47
Motherboard Power Connector
48
49
Power Supply Output Voltages
ATX-Type
 +5
Volts
 +12
 -12
 -5
Volts
Volts
Volts
 +3.3
Volts
50
Pentium 4,
Heat Sink & Fan
51
ISA Bus?
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.

Presently used only 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
59
ROM BIOS
Battery
60
I/O Ports
61
I/O Ports
10101
10101
62
The motherboard is the heart and
soul of the computer.
63