ASUS P2B User Manual

R

P2B

Pentium® II Motherboard

USER’S MANUAL

USER'S NOTICE

No part of this manual, including the products and software described in it, may be repro­duced, transmitted, transcribed, stored in a retrieval system, or translated into any language in
any form or by any means, except documentation kept by the purchaser for backup purposes,
without the express written permission of ASUSTeK COMPUTER INC. (“ASUS”).

ASUS PROVIDES THIS MANUAL “AS IS” WITHOUT WARRANTY OF ANY KIND,
EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED T O THE IMPLIED
WARRANTIES OR CONDITIONS OF MERCHANT ABILITY OR FITNESS FOR A PAR­TICULAR PURPOSE. IN NO EVENT SHALL ASUS, ITS DIRECTORS, OFFICERS,
EMPLOYEES OR AGENTS BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDEN­TAL, OR CONSEQUENTIAL DAMAGES (INCLUDING DAMAGES FOR LOSS OF
PROFITS, LOSS OF BUSINESS, LOSS OF USE OR DATA, INTERRUPTION OF BUSI­NESS AND THE LIKE), EVEN IF ASUS HAS BEEN ADVISED OF THE POSSIBILITY
OF SUCH DAMAGES ARISING FROM ANY DEFECT OR ERROR IN THIS MANUAL
OR PRODUCT.

Product warranty or service will not be extended if: (1) the product is repaired, modified or
altered, unless such repair, modification of alteration is authorized in writing by ASUS; or (2)
the serial number of the product is defaced or missing.

Products and corporate names appearing in this manual may or may not be registered trade­marks or copyrights of their respective companies, and are used only for identification or
explanation and to the owners’ benefit, without intent to infringe.

• Intel, LANDesk, and Pentium are registered trademarks of Intel Corporation.

• IBM and OS/2 are registered trademarks of International Business Machines.

• Symbios is a registered trademark of Symbios Logic Corporation.

• Windows and MS-DOS are registered trademarks of Microsoft Corporation.

• Sound Blaster AWE32 and SB16 are trademarks of Creative Technology Ltd.

• Adobe and Acrobat are registered trademarks of Adobe Systems Incorporated.
The product name and revision number are both printed on the product itself. Manual revi-

sions are released for each product design represented by the digit before and after the period
of the manual revision number. Manual updates are represented by the third digit in the manual
revision number.

For previous or updated manuals, BIOS, drivers, or product release information, contact ASUS
at http://www.asus.com.tw or through any of the means indicated on the following page.

SPECIFICATIONS AND INFORMATION CONTAINED IN THIS MANUAL ARE FUR­NISHED FOR INFORMATIONAL USE ONLY, AND ARE SUBJECT TO CHANGE AT
ANY TIME WITHOUT NOTICE, AND SHOULD NOT BE CONSTRUED AS A COM­MITMENT BY ASUS. ASUS ASSUMES NO RESPONSIBILITY OR LIABILITY FOR
ANY ERRORS OR INACCURACIES THAT MA Y APPEAR IN THIS MANUAL, INCLUD­ING THE PRODUCTS AND SOFTWARE DESCRIBED IN IT.

Copyright © 1998 ASUSTeK COMPUTER INC. All Rights Reserved.

Product Name: ASUS P2B
Manual Revision: 1.03 E302
Release Date: November 1998

2

ASUS P2B User’s Manual

ASUS CONTACT INFORMATION

ASUSTeK COMPUTER INC.

Marketing

Address: 150 Li-Te Road, Peitou, Taipei, Taiwan 112
Telephone: [phone]
Fax: [phone]
Email: [e-mail]

Technical Support

Fax: [phone]
BBS: [phone]
Email: [e-mail]
WWW: www.asus.com.tw
FTP: ftp.asus.com.tw/pub/ASUS

ASUS COMPUTER INTERNATIONAL

Marketing

Address: 6737 Mowry Avenue, Mowry Business Center, Building 2

Newark, CA 94560, USA
Fax: [phone]
Email: [e-mail]

Technical Support

Fax: [phone]
BBS: [phone]
Email: [e-mail]
WWW: www.asus.com
FTP: ftp.asus.com.tw/pub/ASUS

ASUS COMPUTER GmbH

Marketing

Address: Harkort Str. 25, 40880 Ratingen, BRD, Germany
Telephone: [phone]
Fax: [phone]
Email: [e-mail]

Technical Support

Hotline: [phone]
BBS: 49-2102-448690
Email: [e-mail]
WWW: www.asuscom.de
FTP: ftp.asuscom.de/pub/ASUSCOM

ASUS P2B User’s Manual 3

CONTENTS

I. INTRODUCTION 7

How this Manual is Organized ........................................................... 7

Item Checklist ..................................................................................... 7

II. FEATURES 8

Features of the ASUS P2B Motherboard ............................................ 8

The ASUS P2B Motherboard ........................................................ 9

III. INSTALLATION 10

Layout of the ASUS P2B Motherboard ............................................ 10

Installation Steps............................................................................... 12

1. Jumpers ......................................................................................... 12

Jumper Settings ........................................................................... 13

2. System Memory (DIMM) ............................................................. 17

DIMM Memory Installation Procedures: .............................. 18

3. Central Processing Unit (CPU).................................................... 19

Universal Retention Mechanism ........................................... 19

Heatsinks ............................................................................... 19

Installing the Processor ............................................................... 20

ASUS Smart Thermal Solutions............................................ 22

Recommended Heatsinks for Slot 1 Processors .................... 23

4. Expansion Cards ........................................................................... 24

Expansion Card Installation Procedure ................................. 24

Assigning IRQs for Expansion Cards.................................... 24

Assigning DMA Channels for ISA Cards.............................. 25

ISA Cards and Hardware Monitor ......................................... 25

5. External Connectors..................................................................... 26

Power Connection Procedures .......................................................... 33

IV. BIOS SOFTWARE 34

Flash Memory Writer Utility ............................................................ 34

Main Menu .................................................................................. 34

Managing and Updating Your Motherboard’s BIOS................... 36

6. BIOS Setup .................................................................................. 37

Load Defaults ........................................................................ 38

Standard CMOS Setup ................................................................ 38

Details of Standard CMOS Setup:......................................... 38

BIOS Features Setup ................................................................... 41

Details of BIOS Features Setup............................................. 41

4

ASUS P2B User’s Manual

CONTENTS

Chipset Features Setup ................................................................ 44

Details of Chipset Features Setup.......................................... 44

Power Management Setup........................................................... 47

Details of Power Management Setup .................................... 47

PNP and PCI Setup ..................................................................... 50

Details of PNP and PCI Setup ............................................... 50

Load BIOS Defaults .................................................................... 52

Load Setup Defaults .................................................................... 52

Supervisor Password and User Password ................................... 53

IDE HDD Auto Detection ........................................................... 54

Save & Exit Setup ....................................................................... 55

Exit Without Saving .................................................................... 55

V. DESKTOP MANAGEMENT 56

Desktop Management Interface (DMI)............................................. 56

Introducing the ASUS DMI Configuration Utility ................ 56

System Requirements ............................................................ 56

Using the ASUS DMI Configuration Utility ......................... 57

Using the ASUS DMI Configuration Utility ......................... 57

VI. ASUS LAN Card 59

ASUS PCI-L101 Fast Ethernet Card ................................................ 59

Features ............................................................................................. 60

Software Driver Support ............................................................. 60

Question and Answer .................................................................. 60

ASUS P2B User’s Manual 5

FCC & DOC COMPLIANCE

Federal Communications Commission Statement

This device complies with FCC Rules Part 15. Operation is subject to the following
two conditions:

• This device may not cause harmful interference, and

• This device must accept any interference received, including interference that
may cause undesired operation.

This equipment has been tested and found to comply with the limits for a Class B
digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to
provide reasonable protection against harmful interference in a residential installa­tion. This equipment generates, uses and can radiate radio frequency energy and, if
not installed and used in accordance with manufacturer's instructions, may cause
harmful interference to radio communications. However , there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause
harmful interference to radio or television reception, which can be determined by
turning the equipment off and on, the user is encouraged to try to correct the inter­ference by one or more of the following measures:

• Re-orient or relocate the receiving antenna.

• Increase the separation between the equipment and receiver.

• Connect the equipment to an outlet on a circuit different from that to which
the receiver is connected.

• Consult the dealer or an experienced radio/TV technician for help.

WARNING! The use of shielded cables for connection of the monitor to the

graphics card is required to assure compliance with FCC regulations. Changes
or modifications to this unit not expressly approved by the party responsible for
compliance could void the user's authority to operate this equipment.

Canadian Department of Communications Statement

This digital apparatus does not exceed the Class B limits for radio noise emissions
from digital apparatus set out in the Radio Interference Regulations of the Cana­dian Department of Communications.

6

ASUS P2B User’s Manual

I. INTRODUCTION

How this Manual is Organized

This manual is divided into the following sections:

I. Introduction: Manual information and checklist
II. Features: Information and specifications concerning this product
III. Installation: Instructions on setting up the motherboard
IV. BIOS Software: Instructions on setting up the BIOS software
V. Support Software: Information on the included support software

Item Checklist

Please check that your package is complete. If you discover damaged or missing
items, please contact your retailer.

(1) ASUS Motherboard
(1) Universal Retention Mechanism for SECC/SECC2/SEPP

Manual / Checklist

I. INTRODUCTION

(1) IDE ribbon cable for master and slave drives
(1) Floppy ribbon cable for (1) 5.25inch floppy and (2) 3.5inch floppies
(1) Bag of spare jumper caps
(1) Support CD with drivers and utilities
(1) User’s manual

S-P2FAN or P2T-Cable for Slot 1 processors
IrDA-compliant infrared module (optional)
ASUS PCI-L101 Wake-on-LAN 10/100 Ethernet Card (optional)

ASUS P2B User’s Manual 7

Features of the ASUS P2B Motherboard

The ASUS P2B is carefully designed for the demanding PC user who wants ad­vanced features processed by the fastest CPU.

• Multi-Speed: Supports Intel Pentium® II (233 to 450M H z) and CeleronTM (266MHz and

• Multi-Cache: Supports processors with or without Pipelined Burst Level 2 cache.

• Intel AGPset: Features Intel’s 440BX AGPset with I/O subsystems and front-side bus (FSB)

II. FEATURES

Specifications

• Enhanced ACPI and Anti-Boot Virus BIOS: Features a programmable BIOS, offering en-

• PC100 Memory Support: Equipped with three DIMM sockets to support Intel PC100-

• Thermal Sensor Connector with Optional Sensor: Accurately detects the CPU

II. FEATURES

faster) processors.

platform, which boosts the traditional 66-MHz internal bus speed to 100MHz.

hanced ACPI for Windows 98 compatibility, built-in hardware-based virus protection through
Trend ChipAway Virus, and autodetection of most devices for virtually automatic setup.

compliant SDRAMs (8, 16, 32, 64, or 128MB) up to 384MB. These new SDRAMs are
necessary to meet the enhanced 100MHz bus speed requirement.

temperature of processors with the ASUS Smart Fan or the Intel boxed proces­sor heatsink with fan when connected to an ASUS P2T-Cable.

• Wake-On-LAN: Supports Wake-On–LAN activity with special network cards, such as

the ASUS PCI-L101 10/100 Fast Ethernet PCI card.

• AGP Slot: Supports Accelerated Graphics Port cards for high performance, component

level interconnect targeted at 3D graphical display applications.

• SB-Link™: Features Creative’s SB-Link™, allowing SB16 compatibility, using Intel’s

PC-PCI DMA and serialized IRQ protocols, to AWE64D or compatible PCI audio cards.

• SMBus: Features the System Management Bus interface, which is used to physically

transport commands and information between SMBus devices.

• PCI & ISA Expansion Slots: Provides four 32-bit PCI and three 16-bit ISA slots.

• Intelligence: Supports Keyboard Power Up, Fan Status Monitoring and Alarm, Tem-

perature Monitoring and Alert, Voltage Monitoring and Alert, System Resources Alert,
Intel LANDesk Client Manager (LDCM), and ASUS PC Probe software.

• Super Multi-I/O: Provides two high-speed UAR T compatible serial ports and one parallel

port with EPP and ECP capabilities. UART2 can also be directed from COM2 to the Infra­red Module for wireless connections.

• Desktop Management Interface (DMI): Supports DMI through BIOS, which allows

hardware to communicate within a standard protocol creating a higher level of compat­ibility. (Requires DMI-enabled components.) (See section V)

• Ultra DMA/33 Bus Master IDE: Comes with an onboard PCI Bus Master IDE controller with

two connectors that support four IDE devices in two channels, supports UltraDMA/33, PIO
Modes 3 and 4 and Bus Master IDE DMA Mode 2, and supports Enhanced IDE devices, such
as T ape Backup, CD-ROM, and LS-120 drives.

• Universal Retention Mechanism: Supports a Pentium® II processor packaged in a Single

Edge Contact Cartridge (SECC/SECC2) or a CeleronTM processor packaged in a Single
Edge Processor Package (SEPP).

• SCSI BIOS: Supports optional ASUS SCSI controller cards through onboard SYMBIOS firmware.

• IrDA: Supports an optional infrared port module for wireless interface.

• Concurrent PCI: Allows multiple PCI transfers from PCI master buses to memory to CPU.

8 ASUS P2B User’s Manual

II. FEATURES

The ASUS P2B Motherboard

T: PS/2 Mouse
B: PS/2 Keyboard

T: USB Port 1
B: USB Port 2

B: COM 1

T: Parallel
B: Serial

B: COM 2

Universal Folding
Retention Mechanism

Accelerated
Graphics Port

Wake-On-LAN
Connector
4 PCI Slots

ATX Power

Connector

CPU

Slot 1

Intel 440BX AGPset

3 DIMM Sockets

II. FEATURES

Motherboard Parts

Programmable
2Mbit Flash EEROM

Hardware
Monitoring ASIC

3 ISA Slots

ASUS P2B User’s Manual 9

III. INSTALLATION

Layout of the ASUS P2B Motherboard

III. INSTALLATION

Board Layout

TOP:

PS/2

USB

Mouse

BOTTOM:

Keyboard

TOP:

USB 1

BOTTOM:

USB 2

COM 1

Parallel Port

COM 2

PWR_FAN

ATX Power Conenctor

Keyboard Power

CPU Slot 1

CPU_FAN

Intel

440BX

AGPset

BUS FREQ

FS2
FS1
FS0

DIMM Socket 1 (64/72 bit, 168 pin module)

DIMM Socket 2 (64/72 bit, 168 pin module)

DIMM Socket 3 (64/72 bit, 168 pin module)

Multi-I/O

SBLINK

JTPWR

Hardware

Monitor

Flash EEPROM

(Programable BIOS)

SMB Connector

JTCPU

Wake-On-LAN

CHASIS

Connector

Accelerated Graphics Port

PCI Slot 1

PCI Slot 2

PCI Slot 3

PCI Slot 4

ISA Slot 1

R

ISA Slot 2

ISA Slot 3

CR2032 3V
Lithium Cell
(BIOS Power)

Intel PIIX4E

PCIset

Infrared Connector

FLOPPY

SECONDARY IDE

BF3
BF2
BF1
BF0

BUS FREQ

ASUS

ASIC

IDE LED

Panel Connectors

PRIMARY IDE

CLRTC

CHA_FAN

10 ASUS P2B User’s Manual

III. INSTALLATION

Jumpers

1) CLR TC p. 13 Clear Real T ime Clock (R TC) RAM (Short/Clear CMOS)

2) KBPWR p. 13 Keyboard Power

3) FS0, FS1, FS2 p. 14 CPU External Clock (BUS) Frequency Selection

4) BF0, BF1, BF2, BF3 p. 14 CPU Core:BUS Frequency Multiple

Expansion Slots/Sockets

1) System Memory p. 17 System Memory Support

2) DIMM Sockets p. 18 DIMM Memory Module Support

3) CPU Slot 1 p. 19 Pentium II/Celeron CPU Support

4) SLOT1, SLOT2, SLOT3 p. 24 16-bit ISA Bus Expansion Slots

5) PCI1, PCI2,PCI3, PCI4 p. 24 32-bit PCI Bus Expansion Slots

6) AGP p. 25 Accelerated Graphics Port

Hardware Monitor

1) JTPWR, JTCPU p. 23 Thermal Sensor Connector

Connectors

1) PS2KBMS p. 26 PS/2 Keyboard Connector (6-pin female)

2) PS2KBMS p. 26 PS/2 Mouse Connector (6-pin female)

3) PARALLEL p. 27 Parallel (Printer) Port Connector (25-pin female)

4) COM1, COM2 p. 27 Serial Port COM1 & COM2 (two 9-pin male)

5) FLOPPY p. 2 7 Floppy Drive Connector (34-pin block)

6) USB p. 28 Universal Serial BUS Ports 1 & 2 (two 4-pin female)

7) Primary/Secondary IDE p. 28 Primary/Secondary IDE Connector (40-pin blocks)

8) IDELED p. 28 IDE LED Activity Light (2 pins)

9) CHA_, PWR_, CPU_FAN p. 29 Chassis, Power Supply, CPU Fan Power Lead (3-pin block)

10) CHASIS p. 29 Chassis Intrusion Alarm Lead (4-1 pins)

*

Board Layout

III. INSTALLATION

11) IR p. 30 Infrared Port Module Connector (5 pins)

12) ATXPWR p. 30 ATX Motherboard Power Connector (20-pin block)

13) WOL_CON p. 31Wake on LAN Connector (3 pins)

14) SBLINK p. 31 SB-Link™ Connector (6-1 pins)

15) SMB p. 31 SMBus Connector (5-1 pins)

16) MSG.LED (PANEL) p. 32 System Message LED (2 pins)

17) SMI (PANEL) p. 32 SMI Switch Lead (2 pins)

18) PWR.SW (PANEL) p. 32 ATX Power & Soft-Off Switch Lead (2 pins)

19) RESET (PANEL) p. 32 Reset Switch Lead (2 pins)

20)

PWR.LED (

21)

KEYLOCK (

22) SPEAKER (PANEL) p. 32 Speaker Output Connector (4 pins)

*

The onboard hardware monitor uses the address 290H-297H so legacy ISA cards must not

use this address otherwise conflicts will occur.

PANEL

PANEL)p. 32 Keyboard Lock Switch Lead (2 pins)

)

p. 32 System Power LED Lead (3 pins)

ASUS P2B User’s Manual 11

III. INSTALLATION

Jumpers

III. INSTALLATION

Installation Steps

Before using your computer, you must complete the following steps:

1. Set Jumpers

2. Install Memory Modules

3. Install the Central Processing Unit (CPU)

4. Install Expansion Cards

5. Connect Ribbon Cables, Cabinet Wires, and Power Supply

6. Setup the BIOS Software

1. Jumpers

WARNING! Computer motherboards and expansion cards contain very delicate

Integrated Circuit (IC) chips. To protect them against damage from static electric­ity, you should follow some precautions whenever you work on your computer.

1. Unplug your computer when working on the inside.

2. Use a grounded wrist strap before handling computer components. If you do
not have one, touch both of your hands to a safely grounded object or to a
metal object, such as the power supply case.

3. Hold components by the edges and try not to touch the IC chips, leads or
connectors, or other components.

4. Place components on a grounded antistatic pad or on the bag that came with
the component whenever the components are separated from the system.

12 ASUS P2B User’s Manual

III. INSTALLATION

Jumper Settings

1. Clear Real Time Clock (RTC) RAM (CLRTC)

The CMOS RAM is powered by the onboard button cell battery. To clear the
R TC data: (1) Turn off your computer and unplug your AC power , (2) Short the
two points labeled CLRTC, (3) Turn on your computer, (4) Hold down
<Delete> during bootup and enter BIOS setup to re-enter user preferences.

R

P2B Clear RTC RAM

Short small solder points to clear CMOS

CLRTC

2. Keyboard Power Up (KBPWR)

This allows you to disable or enable the keyboard power up function. Set to
Enable if you want to use your keyboard (by pressing <Spacebar>) to power up
your computer. This feature requires an ATX power supply that can supply at
least 300mA on the +5VSB lead and the new ACPI BIOS support. The default is
set to Disable because not all computers have the appropriate ATX power sup­ply. Your computer will not function if you set this to Enable and if you do not
have the right ATX power supply.

KBPWR

123

R

Disable

123

Enable

Jumpers

III. INSTALLATION

P2B Keyboard Power Up

ASUS P2B User’s Manual 13

III. INSTALLATION

3. CPU Bus Frequency (FS0, FS1, FS2)

This option tells the clock generator what frequency to send to the CPU, DRAM, and
440BX AGPset. This allows the selection of the CPU’s External frequency (or BUS
Clock). The BUS Clock multiplied by the BUS Ratio equals the CPU’s Internal fre-
quency (the advertised CPU speed).

4. CPU Core:BUS Frequency Multiple (BF0, BF1, BF2, BF3)

This option sets the frequency ratio between the Internal frequency of the CPU
and the CPU’ s External frequency . These must be set in conjunction with the CPU

Bus Frequency.

III. INSTALLATION

Jumpers

BF3

BF2

BF3

BF2

FS2

1
2
3

133MHz

33.3MHz/

44.3MHz

1
2

3

1
2

3

FS0

BF0

BF0

FS1

BF1

BF1

FS2

BF2

BF2

BF3

1
2

3

BF3

CPU
PCI

BF0

BF1

BF2

R

P2B CPU

BF3

BF2

1
2

3

BF3

BF2

1
2

3

FS1

FS0

1
2
3

83.3MHz

41.65MHz

BF0

BF1

BF0

BF1

FS2

FS0

1
2
3

100.2MHz

33.3MHz

BF2

BF2

FS1

BF3

1
2

3

BF3

1
2

3

FS2

BF0

BF1

BF0

BF1

FS0

1
2
3

103MHz

33.4MHz

FS1

BF0

BF1

2.0x (2/1)

BF0

BF1

5.5x (11/2)

CPU Core:BUS Frequency Multiple

FS1

FS0

66.8MHz

33.4MHz

CPU External Clock (BUS) Frequency Selection

BF0

BF1

BF3

BF2

1
2

3

2.5x (5/2) 3.0X (3/1) 3.5X (7/2) 4.0X (4/1) 4.5X (9/2) 5.0X (5/1)

BF0

BF1

BF3

BF2

1
2

3

6.0x (6/1) 6.5X (13/2) 7.0X (7/1) 7.5X (15/2) 8.0X (8/1)

FS2

FS1

FS2

FS0

1
2
3

75MHz

37.5MHz

BF2

BF2

FS2

BF3

1
2

3

BF3

1
2

3

FS0

1
2
3

112MHz

37.3MHz

BF0

BF0

BF1

BF1

FS1

WARNING! Frequencies above 1 00MHz exceed the specifications for the on-

board Intel Chipset and are not guaranteed to be stable.

Set the jumpers by the Internal speed of your processor as follows:

BF3

(BUS Freq.) (Freq. Ratio)

Intel CPU Model Freq. Ratio BUS F. FS0 FS1 FS2 BF0 BF1 BF2 BF3

Pentium II 450MHz 4.5x 100MHz [1-2] [1-2] [1-2] [1-2] [2-3] [1-2] [2-3]
Pentium II 400MHz 4.0x 100MHz [1-2] [1-2] [1-2] [2-3] [2-3] [1-2] [2-3]
Pentium II 350MHz 3.5x 100MHz [1-2] [1-2] [1-2] [1-2] [1-2] [2-3] [2-3]

Pentium II/Celeron 333MHz 5.0x 66MHz [1-2] [1-2] [2-3] [2-3] [1-2] [1-2] [2-3]
Pentium II/Celeron 300MHz 4.5x 66MHz [1-2] [1-2] [2-3] [1-2] [2-3] [1-2] [2-3]
Pentium II/Celeron 266MHz 4.0x 66MHz [1-2] [1-2] [2-3] [2-3] [2-3] [1-2] [2-3]

NOTES: Overclocking your processor is not recommended. It may result in a slower

speed. Voltage Regulator Output Selection (VID) is not needed for the Pentium II
processor because it sends a VID signal directly to the onboard power controller.

14 ASUS P2B User’s Manual

(This page was intentionally left blank.)

ASUS P2B User’s Manual 15

(This page was intentionally left blank.)

16 ASUS P2B User’s Manual

III. INSTALLATION

2. System Memory (DIMM)

This motherboard uses only Dual Inline Memory Modules (DIMMs). Three sockets
are available for 3.3Volt (power level) unbuffered Synchronous Dynamic Random
Access Memory (SDRAM) of either 8, 16, 32, 64, 128 or 256MB to form a memory
size between 8MB to 768MB. One side (with memory chips) of the DIMM takes up
one row on the motherboard.

To utilize the chipset’s Error Checking and Correction (ECC) feature, you must use a
DIMM module with 9 chips per side (standard 8 chips/side + 1 ECC chip) and make
the proper settings through “Chipset Features Setup” in IV. BIOS SOFTWARE.

Memory speed setup is recommended through SDRAM Configuration under “Chipset
Features Setup”.

IMPORTANT (see General DIMM Notes below)

• SDRAMs used must be compatible with the current Intel PC100 SDRAM
specification.

Install memory in any combination as follows:

DIMM Location 168-pin DIMM Total Memory

Socket 1 (Rows 0&1) SDRAM 8, 16, 32, 64, 128, 256MB x1
Socket 2 (Rows 2&3) SDRAM 8, 16, 32, 64, 128, 256MB x1
Socket 3 (Rows 4&5) SDRAM 8, 16, 32, 64, 128, 256MB x1

Total System Memory (Max 768MB) =

General DIMM Notes

• Use only PC100-compliant DIMMs. This motherboard operates at 100MHz, thus most

systems will not even boot if non-compliant modules are used because of the strict tim­ing issues involved under this speed.

• Two possible memory chips are supported: SDRAM with and without ECC.

• SDRAM chips are generally thinner with higher pin density than EDO (Extended Data
Output) chips.

• BIOS shows SDRAM memory on bootup screen.

• 8 chips/side modules do not support ECC, only 9 chips/side modules support ECC.

• Single-sided modules come in 16, 32, 64 ,128MB; double-sided come in 32, 64, 128, 256MB.

System Memory

III. INSTALLATION

ASUS P2B User’s Manual 17

III. INSTALLATION

DIMM Memory Installation Procedures:

Insert the module(s) as shown. Because the number of pins are different on either
side of the breaks, the module will only fit in the orientation as shown. DRAM
SIMM modules have the same pin contacts on both sides. SDRAM DIMMs have
different pin contacts on each side and therefore have a higher pin density.

III. INSTALLATION

System Memory

P2B 168-Pin DIMM Memory Sockets

The DIMMs must be 3.3Volt unbuffered SDRAMs. To determine the DIMM type,
check the notches on the DIMMs (see figure below).

168-Pin DIMM Notch Key Definitions (3.3V)

R

DRAM Key Position

RFU

Buffered

Unbuffered

20 Pins 60 Pins 88 Pins

FRONT

Voltage Key Position

5.0V

Reserved

3.3V

Lock

The notches on the DIMM will shift between left, center, or right to identify the type
and also to prevent the wrong type from being inserted into the DIMM slot on the
motherboard. You must tell your retailer the correct DIMM type before purchasing.
This motherboard supports four clock signals.

18 ASUS P2B User’s Manual

III. INSTALLATION

3. Central Processing Unit (CPU)

Your motherboard provides a Slot 1 connector for a Pentium
in a Single Edge Contact Cartridge (SECC/SECC2) or a Celeron™ processor pack­aged in a Single Edge Processor Package (SEPP).

®

II processor packaged

CPU

Heatsinks

The recommended heatsinks (see section on recommended heatsinks for Pentium II
processors for more information) for the boxed Pentium II and Celeron processors
are those with three-pin fans that can be connected to the fan connectors on the
motherboard.

III. INSTALLATION

WARNING! Be sure that there is sufficient air circulation across the processor’ s

heatsink by regularly checking that your CPU fan is working. W ithout sufficient
circulation, the processor could overheat and damage both the processor and the
motherboard. You may install an auxiliary fan, if necessary.

ASUS P2B User’s Manual 19

III. INSTALLATION

Installing the Processor

1. Unlock the URM’s Folding Support Arms:

The folding support arms of the URM are
locked when shipped.

III. INSTALLATION

CPU

The URM is now ready for the installation
of your processor.

Unlocked Folding
Support Arms

2. Attach the Heatsink
NOTE: Follow carefully the heatsink attachment instructions included with your

heatsink or processor. The following steps are provided only as a general guide
and may not reflect those for your heatsink.

®

SECC with Pentium

II

Place the SECC face down on a flat surface
and lay the heat sink flush on the back (metal
side) of the SECC. Check the orientation of
the heatsink against the illustration below.
The thicker fin must be orientated toward the

®

SECC2 with Pentium

II/SEPP with Celeron™

Insert the heatsink clip through the holes at the
SECC2/SEPP’s back, making sure that the bot­tom of the clip plate sits against the processors’s
back. Remove the tab from the thermal grease,
which is located on the bottom of the heatsink)

20 ASUS P2B User’s Manual