Asus P2B User manual

R
P2B
Pentium®II Motherboard
USER’S MANUAL

ASUS P2B User’s Manual
2
USER'S NOTICE
Product Name: ASUS P2B
Manual Revision: 1.00
Release Date: MARCH 1998
No part of this manual, including the products and software described in it, may be repro-
duced, 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 TO THE IMPLIED
WARRANTIES OR CONDITIONS OF MERCHANTABILITYOR FITNESS FORAPAR-
TICULAR PURPOSE. IN NO EVENT SHALL ASUS, ITS DIRECTORS, OFFICERS,
EMPLOYEES OR AGENTS BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDEN-
TAL, OR CONSEQUENTIAL DAMAGES (INCLUDING DAMAGES FOR LOSS OF
PROFITS, LOSS OF BUSINESS, LOSS OF USE OR DATA, INTERRUPTION OF BUSI-
NESS 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 byASUS; 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 trade-
marks 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, contactASUS
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 FUR-
NISHED FOR INFORMATIONAL USE ONLY, AND ARE SUBJECT TO CHANGE AT
ANY TIME WITHOUT NOTICE, AND SHOULD NOT BE CONSTRUED AS A COM-
MITMENT BY ASUS. ASUS ASSUMES NO RESPONSIBILITY OR LIABILITY FOR
ANYERRORS OR INACCURACIESTHATMAYAPPEARINTHISMANUAL, INCLUD-
ING THE PRODUCTS AND SOFTWARE DESCRIBED IN IT.
Copyright © 1998 ASUSTeK COMPUTER INC. All Rights Reserved.

ASUS P2B User’s Manual 3
ASUS CONTACT INFORMATION
ASUSTeK COMPUTER INC.
Marketing
Address: 150 Li-Te Road, Peitou, Taipei, Taiwan 112
Telephone: [phone]
Fax: [phone]
Email: [email protected]
Technical Support
Fax: [phone]
BBS: [phone]
Email: [email protected]
WWW: www.asus.com.tw
FTP: ftp.asus.com.tw/pub/ASUS
ASUS COMPUTER INTERNATIONAL
Marketing
Address: 6737 Mowry Ave, Mowry Business Center, Building 2,
Newark, CA 94560, USA
Fax: [phone]
Email: [email protected]
Technical Support
Fax: [phone]
BBS: [phone]
Email: [email protected]
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: [email protected]
Technical Support
Hotline: [phone]
BBS: 49-2102-448690
Email: [email protected]
WWW: www.asuscom.de
FTP: ftp.asuscom.de/pub/ASUSCOM

ASUS P2B User’s Manual
4
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
Pentium II Processor.............................................................. 19
AAVID Heatsink ................................................................... 23
Elan Vital Heatsink ................................................................ 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
Support Software .............................................................................. 34
Flash Memory Writer Utility....................................................... 34
Main Menu ............................................................................ 34
Main Menu ............................................................................ 34
Support Software .............................................................................. 34
Flash Memory Writer Utility....................................................... 34
Advanced Features Menu ...................................................... 35
Advanced Features Menu ...................................................... 35
Managing and Updating Your Motherboard’s BIOS................... 36
Managing and Updating Your Motherboard’s BIOS................... 36
6. BIOS Setup .................................................................................. 37
Load Defaults ........................................................................ 38

ASUS P2B User’s Manual 5
CONTENTS
Standard CMOS Setup ................................................................ 38
Details of Standard CMOS Setup:......................................... 38
BIOS Features Setup ................................................................... 41
Details of BIOS Features Setup............................................. 41
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
VI. ASUS PCI SCSI Cards 59
Symbios SCSI BIOS and Drivers ..................................................... 59
ASUS PCI-SC200 & PCI-SC860 SCSI Cards ................................. 59
Setting Up the ASUS PCI-SC200 & PCI-SC860........................ 60
Setting the INTAssignment for the ASUS PCI-SC200 .............. 60
Terminator Requirements for SCSI Devices ............................... 60
Terminator Settings for the ASUS PCI-SC860 ........................... 61
Terminator Settings for the ASUS PCI-SC200 ........................... 61
SCSI ID Numbers for SCSI Devices .......................................... 62
SCSI ID Priority .......................................................................... 62
VII. ASUS LAN Card 63
ASUS PCI-L101 Fast Ethernet Card ................................................ 63
Features ............................................................................................. 64
Software Driver Support ............................................................. 64
Question and Answer .................................................................. 64

ASUS P2B User’s Manual
6
FCC & DOC COMPLIANCE
FederalCommunications 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 installa-
tion. 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 inter-
ference 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.
CanadianDepartment 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 Cana-
dian Department of Communications.

ASUS P2B User’s Manual 7
I. INTRODUCTION
I. INTRODUCTION
Manual / Checklist
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
VI. ASUS SCSI Cards: Installation of ASUS SCSI cards (optional)
VII. ASUS L101 Card: Installation of the ASUS LAN card (optional)
Item Checklist
Please check that your package is complete. If you discover damaged or missing
items, please contact your retailer.
(1) ASUS Motherboard
(1)Retentionmechanism&heatsinksupportforCPUandheatsinkfor440BXAGPset
(2) Attach mount bridges (factory installed)
(1) 9pin male serial + 25pin male serial external connector set
(1) 25pin female parallel + 6pin female PS/2 mouse external connector set
(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 jumpers
(1) diskette or CD with support drivers and utilities:
• Flash Memory Writer utility to update the onboard programmable BIOS
• LANDesk Client Manager (LDCM) Software
• ASUS PC Probe Utility
• Desktop Management Interface (DMI) utility
• Readme files for descriptions and use of the files
• Technical Support Form
(1) User’s Manual
PS/2 Mouse, Infrared, USB1, and USB2 external connector module (optional)
ASUS PCI-SC200 Fast-SCSI or PCI-SC860 Ultra-Fast SCSI card (optional)
ASUS PCI-L101 Wake-on-LAN 10/100 Ethernet Card (optional)

8 ASUS P2B User’s Manual
Features of the ASUS P2B Motherboard
The ASUS P2B is carefully designed for the demanding PC user who wants ad-
vanced features processed by the fastest CPU. This motherboard:
•Versatile Processor Support: Intel Pentium
®
II (233MHz–400MHz) processor.
•Intel AGPset: Features Intel’s 440BX AGPset with I/O subsystems and featuring
Intel’s“front-side bus(FSB)platform”,whichboasts a100-MHzinternalbusspeed.
•Programmable Flash ROM: 2Mbit programmable bios (Flash EEPROM), offer-
ing built-in, hardware-based virus protection and enhanced ACPI for Windows 98
compatibility, autodetection of hard drives, PS/2 mouse, and Plug and Play devices
for virtually automatic setup of hard drives, expansion cards, and other devices.
•AGPSlot:SupportsAccelerated Graphics Port cards forhighperformance, com-
ponent level interconnect targeted at 3D graphical display applications.
•ISA & PCI Expansion Slots: Provides three 16-bit ISA and four 32-bit PCI slots.
•Super Multi-I/O: Provides two high-speed UART compatible serial ports and
oneparallelportwithEPPand ECPcapabilities. UART2can 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)
•PCI Bus Master IDE Controller: Comes with an onboard PCI Bus Master IDE
controller with two connectors that supports 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 Tape Backup and CD-ROM drives.
Two floppy drives of either 5.25inch or 3.5inch (1.44MB or 2.88MB) are also
supported without an external card. Supports Japanese standard “Floppy 3 mode”
(3.5-inch disk drive: 1.2MB) and LS-120 floppy disk drives (3.5-inch disk drive:
120 MB, 1.44MB, 720K). BIOS supports IDE CD-ROM or SCSI device boot-up.
•CPU Built-In Level 2 Cache: 512KB or less Pipelined Burst Level 2 cache in
the Pentium II Single Edge Contact (SEC) cartridge.
•Versatile Memory Support: Is equipped with three DIMM sockets to support
(8,16,32,64,or 128MB) 168-pin SDRAM/EDO memory modules up to 384MB.
•SCSI BIOS: Supports optional ASUS SCSI controller cards through onboard
SYMBIOS firmware.
•IrDA: Supports an optional infrared port module for wireless interface.
•Concurrent PCI: Concurrent PCI allows multiple PCI transfers from PCI mas-
ter busses to memory to CPU.
•Intelligence: Supports Fan Status Monitoring and Alarm, Temperature Moni-
toring and Alert, Voltage Monitoring and Alert, System Resources Alert, and
Virus Write Protection through the onboard Hardware Monitor, Intel LANDesk
Client Manager (LDCM), and ASUS PC Probe software.
II. FEATURES
Specifications
II. FEATURES

ASUS P2B User’s Manual 9
The ASUS P2B Motherboard
II. FEATURES
II. FEATURES
Motherboard Parts
T: USB Port 1
B: USB Port 2
B: COM 1
B: COM 2
Programmable
2Mbit Flash ROM
Accelerated
Graphics Port
3ISA Slots
T: PS/2 Mouse
B: PS/2 Keyboard
T: Parallel
B: Serial
3 DIMM SocketsIntel 440BXAGPset
SEC CPU Socket
(PENTIUM II)
ATX Power
Connector
4 PCI Slots

10 ASUS P2B User’s Manual
III. INSTALLATION
Layout of the ASUS P2B Motherboard
FLOPPY
SECONDARY IDE
PRIMARY IDE
CR2032 3V
Lithium Cell
(BIOS Power)
CPU_FAN
DIMM Socket 1 (64 bit, 168 pin module) DIMM Socket 2 (64 bit, 168 pin module) DIMM Socket 3 (64 bit, 168 pin module)
Accelerated Graphics Port
PCI Slot 4
ISA Slot 3
Intel PIIX4
PCIset
Intel
440BX
AGPset
2Mbit Flash EEPROM
(Programable BIOS)
PWR_FAN
CHA_FAN
Hardware
Monitor
ATX Power Conenctor
Single Edge Contact CPU Slot
Panel Connectors
Infrared Connector
IDE LED
USB
PS/2
TOP:
USB 1
BOTTOM:
USB 2
Multi-I/O
R
Wake on LAN
Connector
BUS FREQ
BF2
BF3
BF1
BF0
CLRTC
BUS FREQ
FS1
FS2
FS0
ISA Slot 1
ISA Slot 2
PCI Slot 3
PCI Slot 2
PCI Slot 1
COM 1
Parallel Port
COM 2
TOP:
Mouse
BOTTOM:
Keyboard
Keyboard Power
ASUS
ASIC
Board Layout
III. INSTALLATION

ASUS P2B User’s Manual 11
III. INSTALLATION
Jumpers
1) CLRTC p. 13 Clear Real Time Clock (RTC) 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) SEC CPU Slot p. 19 Single Edge Contact 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
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. 27 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. 29 IDE LED Activity Light (2 pins)
9) CHA_, PWR_, CPU_FAN p. 29 Chassis, Power Supply, CPU Fan Power Lead (3-pin block)
10) IR p. 30 Infrared Port Module Connector (5 pins)
11) ATXPWR p. 30 ATX Motherboard Power Connector (20-pin block)
12) WOL_CON p. 31Wake on LAN Connector (3 pins)
13) MSG.LED (PANEL) p. 32 System Message LED (2 pins)
14) SMI (PANEL) p. 32 SMI Switch Lead (2 pins)
15) PWR.SW (PANEL) p. 32 ATX Power & Soft-Off Switch Lead (2 pins)
16) RESET (PANEL) p. 32 Reset Switch Lead (2 pins)
17)
PWR.LED ( PANEL ) p. 32 System Power LED Lead (3 pins)
18)
KEYLOCK ( PANEL ) p. 32 Keyboard Lock Switch Lead (2 pins)
19) 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.
†
PCI slots 4&5 share the same interrupt number (INT#) so PCI cards on these two slots must be
able to share an INT# or make sure that one of these PCI cards does not use an INT#.
(Board Layout)
III. INSTALLATION

12 ASUS P2B User’s Manual
III. INSTALLATION
Jumpers
III. INSTALLATION
Installation Steps
Before using your computer, you must complete the following steps:
1. Set Jumpers
2. Install DRAM 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
Several hardware settings are made through the use of jumper caps to connect jumper
pins (JP) on the motherboard. See motherboard layout on page 10 for locations of
jumpers. The jumper settings will be described numerically such as [----], [1-2],
[2-3] for no connection, connect pins 1&2, and connect pins 2&3 respectively. Pin 1
for our motherboards is always on top
PIN 1
or on the left
PIN 1
when holding the
motherboard with the keyboard connector away from yourself. A “1” is written be-
sides pin 1 on jumpers with three pins. The jumpers will also be shown graphically
such as to connect pins 1&2 and to connect pins 2&3. Jumpers with
two pins will be shown as for Short (On) and for Open (Off). For manu-
facturing simplicity, the jumpers may be sharing pins from other groups. Use the dia-
grams in this manual instead of following the pin layout on the board. Settings with
two jumper numbers require that both jumpers be moved together. To connect the
pins, simply place a plastic jumper cap over the two pins as diagramed.
WARNING! Computer motherboards and expansion cards contain very delicate
Integrated Circuit (IC) chips. To protect them against damage from static electric-
ity, 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.

ASUS P2B User’s Manual 13
III. INSTALLATION
III. INSTALLATION
Jumpers
Jumper Settings
1. Clear Real Time Clock (RTC) RAM (CLRTC)
The CMOS RAM is powered by the onboard button cell battery. To clear the
RTC data: (1) Turn off your computer and unplug yourAC 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.
Short small solder points to clear CMOS
P2B Clear RTC RAM
CLRTC
R
2. Keyboard Power (KBPWR)
This allows you to disable or enable the keyboard wakeup function. Set to Enable if
you want to use your keyboard (by typing <SPACE>) to wake up your computer.
This feature requires an ATX power supply that can supply at least 300mA on the
+5VSB lead and new BIOS support. The default is set to Disable because not all
computershave the appropriateATX power supply.Your computer will notfunction
if you set this to Enable and if you do not have the rightATX power supply.
R
P2B Keyboard Power
Disable
1 2 3
KBPWR
Enable
1 2 3

14 ASUS P2B User’s Manual
III. INSTALLATION
Jumpers
III. INSTALLATION
BF2
BF1
BF3
CPU Core:BUS Frequency Multiple
P2B CPU
R
BF0
BF2
BF1
BF3
BF0
BF2
BF1
BF3
BF0
BF2
BF1
BF3
BF0
BF2
BF1
BF3
BF0
BF2
BF1
BF3
BF0
BF2
BF1
BF3
BF0
2.0x (2/1) 2.5x (5/2) 3.0X (3/1) 3.5X (7/2) 4.0X (4/1) 4.5X (9/2) 5.0X (5/1)
FS1 FS2 FS0
1
2
3
FS1 FS2 FS0
1
2
3
FS1 FS2 FS0
1
2
3
2
1
3
2
1
32
1
32
1
32
1
32
1
3
FS1 FS2 FS0
1
2
3
FS1 FS2 FS0
1
2
3
FS1 FS2 FS0
103MHz
33.4MHz
CPU External Clock (BUS) Frequency Selection
CPU
PCI
66.8MHz
33.4MHz 75MHz 37.5MHz 83.3MHz 41.65MHz 100.2MHz 33.3MHz 112MHz 37.3MHz
BF2
BF1
BF3
BF0
BF2
BF1
BF3
BF0
BF2
BF1
BF3
BF0
BF2
BF1
BF3
BF0
BF2
BF1
BF3
BF0
BF2
BF1
BF3
BF0
5.5x (11/2) 6.0x (6/1) 6.5X (13/2) 7.0X (7/1) 7.5X (15/2) 8.0X (8/1)
2
1
3
2
1
32
1
32
1
32
1
3
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.
Intel Pentium II Processor in an SEC Cartridge
(233-400MHz 256/512KB L2 Cache)
WARNING! Frequencies above 100Mhz exceed the specifications for the on-
board Intel Chipset and are not guaranteed to be stable.
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.
Set the jumpers by the Internal speed of your processor as follows:
(BUS Freq.) (Freq. Ratio)
CPU Model Freq. Ratio BUS F. FS0 FS1 FS2 BF0 BF1 BF2 BF3
Intel Pentium II 400MHz 4.0x 100MHz [1-2] [1-2] [1-2] [2-3] [2-3] [1-2] [2-3]
Intel Pentium II 350MHz 3.5x 100MHz [1-2] [1-2] [1-2] [1-2] [1-2] [2-3] [2-3]
Intel Pentium II 300MHz 3.0x 100MHz [1-2] [1-2] [1-2] [2-3] [1-2] [2-3] [2-3]
Intel Pentium II 333MHz 5.0x 66MHz [1-2] [1-2] [2-3] [2-3] [1-2] [1-2] [2-3]
Intel Pentium II 300MHz 4.5x 66MHz [1-2] [1-2] [2-3] [1-2] [2-3] [1-2] [2-3]
Intel Pentium II 266MHz 4.0x 66MHz [1-2] [1-2] [2-3] [2-3] [2-3] [1-2] [2-3]
Intel Pentium II 233MHz 3.5x 66MHz [1-2] [1-2] [2-3] [1-2] [1-2] [2-3] [2-3]

ASUS P2B User’s Manual 15
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16 ASUS P2B User’s Manual
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ASUS P2B User’s Manual 17
III. INSTALLATION
System Memory
2. System Memory (DIMM)
Only Dual Inline Memory Modules (DIMM’s) can be used with this motherboard.
Three sockets are available for 3.3Volt (power level) Unbuffered Synchronous
DRAMs (SDRAMs) or EDO DRAMs of either 8, 16, 32, 64, or 128MB to form a
memory size between 8MB to 512MB. One side (with memory chips) of the DIMM
module takes up one Row on the motherboard.
IMPORTANT: Do not mix SDRAMs and EDO DRAMs.
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 parity chip) and
make the proper settings in the BIOS Chipset Features Setup.
IMPORTANT: Memory speed setup is required through “Auto Configuration” in
BIOS Chipset Features Setup.
Install memory in any combination as follows:
DIMM Location 168-pin DIMM Memory Modules Total Memory
Socket 1 (Rows 0&1) SDRAM/EDO 8, 16, 32, 64, 128MB x1
Socket 2 (Rows 2&3) SDRAM/EDO 8, 16, 32, 64, 128MB x1
Socket 3 (Rows 4&5) SDRAM/EDO 8, 16, 32, 64, 128MB x1
Total System Memory (Max 384MB) =
General DIMM Notes (not true for all memory modules)
•Four possible memory chips are supported: EDO or SDRAM with and without parity.
Mixing SDRAMs with EDO DRAMs, or vice-versa, is, however, not allowed.
• SDRAM chips are generally thinner with higher pin density than EDO chips.
• BIOS shows EDO or SDRAM memory on bootup screen.
• 8 chips/side modules do not support parity, only 9 chips/side modules support parity.
• Singlesidedmodulesare usually16,32,or64MB,doublesidedareusually32,64,or128MB.
ASUS Memory Examples:
III. INSTALLATION
Parity EDO DIMM (9 chips)
Non-Parity SDRAM DIMM (8 chips)

18 ASUS P2B User’s Manual
System Memory
III. INSTALLATION
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 contact on both sides. SDRAM DIMM modules
have different pint contact on each side and therefore have a higher pin density.
Lock
P2B 168-Pin DIMM Memory Sockets
20 Pins 60 Pins 88 Pins
R
FRONT
The Dual Inline Memory Module (DIMM) memory modules must be 3.3Volt Un-
buffered Synchronous DRAM (SDRAM) or Extended Data Output (EDO) . You
can identify the type of DIMM module by the illustration below:
168-Pin DIMM Notch Key Definitions (3.3V)
DRAM Key Position Voltage Key Position
Unbuffered
RFU
Buffered Reserved
3.3V
5.0V
The notch on the DIMM module will shift between left, center, or right to identify
the type and also to prevent the wrong type to be inserted into the DIMM slot on the
motherboard. You must ask your retailer for the specifications before purchasing.
Four clock signals are supported on this motherboard.

ASUS P2B User’s Manual 19
3. Central Processing Unit (CPU)
This motherboard provides a Single Edge Contact (SEC) slot for a Pentium II pro-
cessor packaged in an SEC cartridge.
Pentium II Processor
WARNING! Be sure that sufficient air circulation is available across the processor’s pas-
siveheatsink.Withoutsufficientcirculation, theprocessorcouldoverheatanddamageboth
the processor and the motherboard.You may install an auxiliary fan, if necessary.
You should check to see that you have the following 9 items.
NOTE: The pictures in the following pages will have the same item numbers next to
them for your reference. The design and color of your items may be slightly different.
Attach Mount Bridges (Items 1,2)
(1)
(2)
Pentium II Retention Mechanism (Item 3)
Lock Holes
Captive Nut
(3)
Pentium II Processor Heatsink (Item 8)
(8)
Heatsink bottom Groove
for the Support Top Bar
Larger Fin should
be on the bottom.
Heatsink Support Base/Top Bar (Items 4-7)
Top Bar (4)
Base (7)
Posts
Pin
(5)
(6)
Intel Pentium II Processor in an SEC Cartridge
(233-400MHz 256/512KB L2 Cache)
CPU (Item 9)
III. INSTALLATION
CPU
III. INSTALLATION

20 ASUS P2B User’s Manual
III. INSTALLATION
CPU
III. INSTALLATION
The Motherboard As Shipped
Four screws should be showing next to each corner of the SEC CPU Slot using two
attach mount bridges from the underside of the motherboard.
Installing the Pentium II Processor:
1. Mount the Pentium II Retention Mechanism: The retention mechanism is
designed to fit into the SEC slot only one way.
TIP: Orient the mechanism’s lock holes toward the motherboard’s chipsets see
motherboard layout for the location of the Intel chipset).
Be sure to align the notch in the mechanism with the small rib on one side of the
slot and that the mechanism is properly seated on the board. Then, screw the
captive nuts in place.
WARNING! Do not overtighten the captive nuts. Doing so could damage your
motherboard. Tighten captive nuts to no more than 6±1 inch/pound.
Lock holes
Captive nut
Captive nut
NOTE: Encircled items are screws
from the mount bridges (1 & 2)
SEC CPU slot