Pentium Super7 Motherboard

USERS 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 TO THE IMPLIED WARRANTIES OR CONDITIONS OF MERCHANTABILITY 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 HAc 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.
ALi and Aladdin are trademarks of Acer Laboratories Inc. (ALi) Adobe and Acrobat are registered trademarks of Adobe Systems Incorporated. AMD, K6, and combinations thereof are trademarks of Advanced Micro Devices, Inc. Cyrix, M II, and combinations thereof are trademarks of National Semiconductor Corporation. IBM is a registered trademark of IBM Corporation. Intel, LANDesk, and Pentium are registered trademarks of Intel Corporation. Windows and MS-DOS are registered trademarks of Microsoft Corporation.
The product name and revision number are both printed on the product itself. Manual revisions 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 MAY APPEAR IN THIS MANUAL, INCLUDING THE PRODUCTS AND SOFTWARE DESCRIBED IN IT. Copyright 1999 ASUSTeK COMPUTER INC. All Rights Reserved.
Product Name: Manual Revision: Release Date:
ASUS P5A-B 1.07 E381 April 1999

ASUS P5A-B Users Manual

ASUS CONTACT INFORMATION
ASUSTeK COMPUTER INC. (Asia-Pacific)

Marketing

Address: Telephone: Fax: Email: Tel (English): Tel (Chinese): Fax: Email: Newsgroup: WWW: FTP: 150 Li-Te Road, Peitou, Taipei, Taiwan 112 +886-2-2894-3447 +886-2-2894-3449 info@asus.com.tw +886-2-2894-3447 ext. 706 +886-2-2894-3447 ext. 111 +886-2-2895-9254 tsd@asus.com.tw news2.asus.com.tw www.asus.com.tw ftp.asus.com.tw/pub/ASUS

Technical Support

ASUS COMPUTER INTERNATIONAL (America)
Address: Fax: Email: Fax: BBS: Email: WWW: FTP: 6737 Mowry Avenue, Mowry Business Center, Building 2 Newark, CA 94560, USA +1-510-608-4555 info-usa@asus.com.tw +1-510-608-4555 +1-510-739-3774 tsd-usa@asus.com.tw www.asus.com ftp.asus.com.tw/pub/ASUS
ASUS COMPUTER GmbH (Europe)
Address: Telephone: Fax: Email: Hotline: BBS: Email: WWW: FTP: Harkort Str. 25, 40880 Ratingen, BRD, Germany 49-2102-445011 49-2102-442066 sales@asuscom.de 49-2102-499712 49-2102-448690 tsd@asuscom.de www.asuscom.de ftp.asuscom.de/pub/ASUSCOM

CONTENTS

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 users 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.

I. INTRODUCTION

I. II. III. IV. V. VI. VII. Introduction Features Installation BIOS Software Support Software ASUS CIDB ASUS L101 Card APPENDIX Manual information and checklist Information and specifications concerning this product Instructions on setting up the motherboard Instructions on setting up the BIOS software Information on the included support software Installation of the ASUS CIDB Chassis Sensor (optional) Installation of the ASUS LAN card (optional) Glossary of Terms I. INTRODUCTION Sections/Checklist 7
How this Manual is Organized

Item Checklist

Check that your package is complete. If you discover damaged or missing items, contact your retailer. (1) ASUS Motherboard (2) 9-pin male serial external connector set (1) 25-pin female parallel + 6-pin female PS/2 mouse external connector set (1) IDE ribbon cable for master and slave drives (1) Ribbon cable for (1) 5.25 and (2) 3.5 floppy disk drives (1) Bag of spare jumpers (1) CD disc with support drivers and utilities (1) Users Manual Audio Bracket (only available with ISA audio option) ASUS CIDB chassis sensor module (optional) PS/2 Mouse, Infrared, USB1, and USB2 external connector module (optional) ASUS PCI-L101 Wake-On-LAN 10/100 Ethernet Card (optional)

II. FEATURES

ASUS P5A-B Motherboard
ALi AGPset: ALi (Acer Laboratories Inc.) Aladdin V AGPset with support for a 100MHz Front Side Bus (FSB), Accelerated Graphics Port (AGP), and all current Socket-7 processors. Multi-Processor/Multi-Speed Support: AMD K6-III /400 & faster, AMD K62/266 & faster, AMD K6/166 & faster, AMD K5/90133, IBM/Cyrix 6x86MX/ M II (PR166 & faster), IDT WinChip 2/240 & faster, IBM/Cyrix 6x86-PR166+ (Rev 2.7 or later), Intel Pentium 90233MHz (P55C-MMX, P54C/P54CS). Level 2 Cache SRAM/Tag RAM: Supports 512KB/1MB pipelined-burst SRAM/L2 memory cache and integrated Tag RAM to make using the 100MHz bus speed possible. Enhanced ACPI and Anti-Boot Virus BIOS: Features a programmable BIOS, offering enhanced ACPI for Windows 98 compatibility, built-in hardware-based virus protection through Trend ChipAwayVirus, and autodetection of most devices for virtually automatic setup. PC100 Memory Support: Equipped with three DIMM sockets to support Intel PC100-compliant SDRAMs (8, 16, 32, 64, 128, or 256MB) up to 768MB. These new SDRAMs are necessary to meet the 95MHz/100MHz bus speed requirement. AGP Slot: Supports AGP cards for high performance, component level interconnection targeted at 3D graphical display applications. ISA Audio (optional): Features C-Medias 3D positional sound chip, which provides such cutting edge features as wavetable music synthesizer, 3D surround audio, and SPDIF I/O interface in addition to the usual compatibility with games written for both Windows 95/98 and DOS. UltraDMA/33 BM IDE: 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. Supports two drives of either 5.25-inch (360KB or 1.2MB) or 3.5-inch (720KB, 1.44MB, or 2.88MB) disk drives. Supports Japanese 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. Wake-On-LAN: Supports Wake-OnLAN activity with special network cards, such as the ASUS PCI-L101 10/100 Fast Ethernet PCI card. PC Health Monitoring (optional): Provides a convenient utility to monitor your systems vital components/activities, such as fan rotations, voltages, and temperatures. Super Multi-I/O: Provides two high-speed UART 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) USB, PS/2 Mouse, IrDA Connector: Supports an optional cable and bracket set to mount the connectors to an unused expansion slot on the system chassis. A second IrDA connector is available for a standard individual infrared cable set.

II. FEA TURES P5A-B Series 10
Parts of the ASUS P5A-B Motherboard
Serial Parallel Ports Port

3 DIMM Sockets

ALi Aladdin V AGPset

ATX Power

AT Connector

CPU ZIF Socket 7

Keyboard
USB/MIR Floppy/IDE Connectors 512KB/1024KB Pipelined Burst L2 Cache Accelerated Graphics Port

3 PCI Slots

2 ISA Slots

Programmable Flash ROM

C-Media 3D Positional Sound Chip (optional)
II. FEA TURES Motherboard Parts

III. INSTALLATION

ASUS P5A-B Motherboard Layout

Parallel Port

AT Keyboard Connector

FS3 FS2 FS1 FS0

AT Power Connector

PWR_FAN

VIO1 VIO0

ATX Power Connector

BF2 BF1 BF0

USB, PS/2 Mouse, IrDA

DIMM Socket 1 (64-bit, 168-pin module) DIMM Socket 2 (64-bit, 168-pin module) DIMM Socket 3 (64-bit, 168-pin module)

Primary IDE

Floppy Drive
512KB/ 1MB Pipelined Burst L2 Cache

Temp Sensor

III. INST ALLATION Motherboard Layout 12

Secondary IDE

Accelerated Graphics Port

CR2032 3V Lithium Cell

PCI Slot 1
Chassis Intrusion Alarm Lead

WOLCON

SMBus Connector

CD1 CPU_FAN

ALi M1543 Chip

PCI Slot 2

VID3 VID2 VID1 VID0

Audio Connectors

PCI Slot 3 ISA Slot 1
1Mbit Flash EEPROM (Programmable BIOS)

CHA_FAN

SPDI SPDO TTL

Panel Connectors

ISA Slot 2

IDELED

Jumpers
1) 2) 4) 5) 6) CLRTC VIO FS0, FS1, FS2, FS3 BF0, BF1, BF2 VID0, VID1, VID2, VID3 p. 15 p. 15 p. 16 p. 16 p. 18 Real Time Clock (RTC) RAM Voltage Input/Output Selection CPU External (BUS) Frequency Selection CPU to BUS Frequency Ratio Voltage Regulator Output Selection

Expansion Slots

1) 2) 3) 4) DIMM Sockets CPU ZIF Socket 7 SLOT 1, 2 PCI 1, 2, 3 p. 19 p. 21 p. 23 p. 23 168-Pin DIMM Memory Expansion Sockets Central Processing Unit (CPU) Socket 16-bit ISA Bus Expansion Slots* 32-bit PCI Bus Expansion Slots

Connectors

1) KB 2) FLOPPY 3) PRINTER 4) COM1, COM2 5) FAN 6) CHASIS 7) PRIMARY/SECOND. IDE 8) IDELED 9) ATX 10) PS/2 11) USB/MIR 12) IR 13) MSG.LED (PANEL) 14) PWR SW. (PANEL) 15) RESET (PANEL) 16) PWR.LED (PANEL) 17) KEYLOCK (PANEL) 18) SPEAKER (PANEL) 19) WOLCON 20) SMB 21) AUDIOCON 22) SPD0/SPD1/TTL 23) AUX 24) CD1

p. 25 p. 25 p. 26 p. 26 p. 27 p. 27 p. 28 p. 28 p. 29 p. 29 p. 31 p. 31 p. 31 p. 31 p. 31 p. 31 p. 31 p. 31 p. 32 p. 32 p. 33 p. 33 p. 34 p. 34
Keyboard Connector (5-pin Female) Floppy Drive Connector (34-1 pins) Parallel (Printer) Port Connector (26-1 pins) Serial Port COM1 & COM2 (10-1 pins) Power Supply, Chassis, CPU Fan Power Leads (3 pins) Chassis Open Alarm Lead (4-1 pins) Primary/Secondary IDE Connector (40-1 pins) IDE LED Activity Light (2 pins) ATX Motherboard Power Connector (20 pins) AT Motherboard Power Connector (12 pins) USB, Infrared, PS/2 Mouse Module Connector (18-1 pins) IrDA-compliant Infrared Module Connector (5 pins) System Message LED (2 pins) ATX Power Switch/Soft Power Switch Lead (2 pins) Reset Switch Lead (2 pins) System Power LED Lead (3 pins) Keyboard Lock Switch Lead (2 pins) Speaker Output Connector (4 pins) Wake-On-LAN Activity Connector (3 pins) SMBus Connector (5-1 pins) Audio Jack Connector (26 pins) Digital Audio Interface (6 pins) Stereo Audio In Connector (4 pins) Stereo Audio In Connector (4 pins)
The onboard hardware monitor uses the address 290H-297H so legacy ISA cards must not use this address or else conflicts will occur.
III. INST ALLATION Map of Board

Installation Steps

Before using your computer, you must complete the following steps: 1. 2. 3. 4. 5. 6. Set Jumpers on the Motherboard Install System Memory Modules Install the Central Processing Unit (CPU) Install Expansion Cards Connect Ribbon Cables, Cabinet Wires, and Power Supply Setup the BIOS Software

1. Jumpers

WARNING! Computer motherboards, baseboards and components, such as SCSI 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. III. INST ALLATION Jumpers 14

Jumper Settings

1. 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, (2) Short solder points using a small metalic object, (3) Turn on your computer, (4) Hold down <Delete> during bootup and enter BIOS setup to re-enter user preferences.

P5A-B Clear RTC RAM

2. Voltage Input/Output Selection (VIO) This jumper allows you to select the voltage supplied to the DRAM, chipset, and AGP.

VIO0 VIO1

3 3.5Volts 3.6Volts 3.8Volts 4.0Volts

(DEFAULT)

P5A-B Voltage Input/Output Selection
WARNING! Using a higher voltage may help when overclocking but may result in the shortening of your computer components life. Use default setting.
III. INST ALLATION Jumpers
Short solder points to Clear CMOS
3. CPU External (BUS) Frequency Selection (FS0, FS1, FS2, FS3) These jumpers tell the clock generator what frequency to send to the CPU. These allow the selection of the CPUs External frequency (or BUS Clock). The BUS Clock times the BUS Ratio equals the CPU's Internal frequency (the advertised CPU speed). 4. CPU to BUS Frequency Multiple (BF0, BF1, BF2) These jumpers set the frequency ratio between the Internal frequency of the CPU and the External frequency (called the BUS Clock) within the CPU. These must be set in conjunction with the jumpers for CPU External (BUS) Frequency Selection.
FS0 FS1 FS2 FS3 FS0 FS1 FS2 FS3

3 CPU AGP PCI

60MHz 60MHz 30MHz

66.8MHz 66.8MHz 33.4MHz

FS0 FS1 FS2 FS3
75MHz 75MHz 37.5MHz 100MHz 66.6MHz 33.3MHz 120MHz 80MHz 40MHz
3 CPU 83.3MHz AGP 66.6MHz PCI 33.3MHz 3 CPU 110MHz AGP 73MHz PCI 36.6MHz

95MHz 63.3MHz 31.6MHz

115MHz 77.6MHz 38.3MHz
CPU External Clock (BUS) Frequency Selection
BF0 BF1 BF2 BF0 BF1 BF2 BF0 BF1 BF2
2.5x(5/2) 2.5x(5/2) 2.5x(5/2) 2.5x(5/2) 1.0x(1/1) 2.5x(5/2) 3 CPU A 3.5x(7/2) 6.0x(6/1) CPU B 3.5x(7/2) 2.0x(2/1) CPU C 1.5x(3/2) 2.0x(2/1) CPU D 3.5x(7/2) 2.0x(2/1) CPU E 3.0x(3/1) 2.0x(2/1) CPU F 3.5x(7/2) 3.33x(10/3)
Match the Mult. (Multiple) column of the table on the opposite page to these CPU types: CPU A: CPU B: CPU C: CPU D: AMD-K6-III, AMD-K6-2/400&faster AMD-K6-2/380&slower, AMD-K6 Intel Pentium P54C, AMD-K5 Intel Pentium P55C, IBM/Cyrix 6x86MX, IBM/Cyrix M II CPU E: IBM/Cyrix 6x86, IBM/Cyrix 6x86L CPU F: IDT WinChip 2
3.0x(3/1) 3.0x(3/1) 3.0x(3/1) 3.0x(3/1) 3.0x(3/1)

BF0 BF1 BF2

5.0x(5/1) 5.0x(5/1) 2.33x(7/3)
3 CPU A 4.0x(4/1) CPU B 4.0x(4/1) CPU C CPU D CPU E CPU F 4.0x(4/1) 4.5x(9/2) 4.5x(9/2) 4.5x(9/2) 5.5x(11/2) 5.5x(11/2) 2.66x(8/3)
CPU : BUS Frequency Multiple

WARNING! Frequencies above 100MHz exceed the specifications for the onboard chipset and are not guaranteed to be stable. The table on the following page is for general reference purposes only. Always refer to the instructions included with your CPU when possible.
75MHz 60MHz 30MHz 105MHz 70MHz 35MHz
Set the jumpers by the Internal speed of your CPU as follows:
CPU Model AMD-K6-III/450 AMD-K6-III/400 AMD-K6-2/475 AMD-K6-2/450 AMD-K6-2/400 AMD-K6-2/380 AMD-K6-2/366 AMD-K6-2/350 AMD-K6-2/333 AMD-K6-2/300 AMD-K6-2/266 AMD-K6/300 AMD-K6/266 AMD-K6/233 AMD-K6/200 AMD-K6/166 AMD-K5/133 AMD-K5/120 AMD-K5/100 AMD-K5/90 Intel Pentium P54C Intel Pentium P54C Intel Pentium P54C Intel Pentium P54C Intel Pentium P54C Intel Pentium P54C Intel Pentium P55C Intel Pentium P55C Intel Pentium P55C IBM/Cyrix M II-PR333 IBM/Cyrix M II-PR300 IBM/Cyrix M II-PR300 Freq. 450MHz 400MHz 475MHz 450MHz 400MHz 380MHz 366MHz 350MHz 333MHz 300MHz 266MHz 300MHz 266MHz 233MHz 200MHz 166MHz 100MHz 90MHz 100MHz 90MHz 166MHz 150MHz 133MHz 120MHz 100MHz 90MHz 233MHz 200MHz 166MHz 333MHz 300MHz 300MHz Mult. BUS F. (BUS Freq.) FS0 FS1 FS2 FS3 [1-2] [1-2] [1-2] [2-3] [1-2] [1-2] [1-2] [2-3] (Freq. Mult.) BF0 BF1 BF2 [2-3] [2-3] [2-3] [2-3] [1-2] [2-3] [1-2] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [1-2] [2-3] [2-3] [1-2] [1-2] [1-2] [1-2] [2-3] [2-3] [2-3] [1-2] [1-2] [2-3] [1-2] [1-2] [1-2] [1-2] [2-3] [2-3] [2-3] [2-3] [1-2] [1-2] [1-2] [1-2] [1-2] [1-2] [2-3] [1-2] [2-3] [1-2] [1-2] [2-3] [2-3] [1-2] [1-2] [1-2] [1-2] [2-3] [2-3] [1-2] [1-2] [1-2] [1-2] [2-3] [2-3] [----] [----] [----] [2-3] [2-3] [2-3] [----] [----] [----] [----] [----] [----] [----] [----] [----] [----] [----] [----] [----]
A-4.5x 100MHz A-4.0x 100MHz
A-5.0x 95MHz [2-3] [1-2] [1-2] [2-3] A-4.5x 100MHz [1-2] [1-2] [1-2] [2-3] A-4.0x 100MHz [1-2] [1-2] [1-2] [2-3] B-4.0x B-5.5x B-3.5x B-3.5x B-3.0x B-4.0x B-4.5x B-4.0x B-3.5x B-3.0x B-2.5x C-1.5x C-1.5x C-1.5x C-1.5x C-2.5x C-2.5x C-2.0x C-2.0x C-1.5x C-1.5x 95MHz 66MHz 100MHz 95MHz 100MHz 66MHz 66MHz 66MHz 66MHz 66MHz 66MHz 66MHz 60MHz 66MHz 60MHz 66MHz 60MHz 66MHz 60MHz 66MHz 60MHz [2-3] [1-2] [1-2] [2-3] [1-2] [1-2] [1-2] [1-2] [1-2] [1-2] [1-2] [1-2] [2-3] [1-2] [2-3] [1-2] [2-3] [1-2] [2-3] [1-2] [2-3] [1-2] [2-3] [1-2] [1-2] [1-2] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [1-2] [2-3] [1-2] [1-2] [1-2] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3]

Pin 1 Orient the red stripe on your cable to Pin 1
P5A-B Floppy Disk Drive Connector
3. Parallel Connector (PARALLEL, 26-1 pin block) This connector supports the included parallel port ribbon cable with mounting bracket. Connect the ribbon cable to this connection and mount the bracket to the case on an open slot. A PS/2 mouse connector is included for the USB/ Mouse/IR onboard connector if the optional USB/MIR connector is not used. You can make available the parallel port and choose the IRQ through the Onboard Parallel Port in Chipset Features of the BIOS SOFTWARE. (Pin 26 is removed to prevent inserting in the wrong orientation when using ribbon cables with pin 26 plugged). NOTE: Serial printers must be connected to the serial port.
Orient the red stripe on your cable to Pin 1
III. INST ALLATION Connectors 26
P5A-B Parallel Port Connector
4. Serial Port Connectors (COM1/COM2, two 10-1 pin blocks) These connectors support the provided serial port ribbon cables with mounting bracket. Connect the ribbon cables to these connectors and mount the bracket to the case on an open slot. You can make available the parallel port and choose the IRQ through the Onboard Serial Port in Chipset Features of the BIOS SOFTWARE. (Pin 10 is removed to prevent inserting in the wrong orientation when using ribbon cables with pin 10 plugged).

COM 1 Pin 1 COM 2

P5A-B Onboard Serial Port Connectors
For this connector to be available, you must connect the included parallel (25-pin female) cable set to a free expansion slot opening. TIP: You may also remove the bracket connectors and mount them directly to the case to save expansion slot space.
For these connectors to be available, you must connect the included Serial cable set from COM1 (using the 9-Pin male) & COM2 (using the 25-Pin male) to a free expansion slot opening. TIP: You may also remove the bracket connectors and mount them directly to the case to save expansion slot space.
5. CPU Cooling Fan Connectors (FAN, 3 pins) This connector supports a 3-pin CPU cooling fan of 500mA (6W) or less with a minimum of 3,500RPM. Depending on the fan manufacturer, the wiring and plug may be different. The red wire should be Positive, the black should be Ground, and the yellow wire should be Rotation signal. WARNING! The CPU and/or motherboard will overheat if there is no airflow across the CPU. Damage may occur to the motherboard and/or the CPU fan if these pins are incorrectly used. These are not jumpers, do not place jumper caps over these pins.

Power Supply Fan

Ground +12 Volt Rotation
P5A-B Power Supply, CPU, Chassis Fan Power
6. Chassis Intrusion Alarm Lead (4-1 pin CHASIS) This lead is for a chassis intrusion monitor or sensor. The sensor is triggered when a high level signal is sent to the chassis signal lead. This occurs when a panel switch or light detector is triggered. This function requires the optional ASUS CIDB Chassis Sensor to be installed (see VI. ASUS CIDB). NOTE: When the chassis is opened, connect/short the Chassis Signal pin to the +5VSB pin. When the chassis is closed, connect/short the Chassis Signal pin to the Ground pin.
+5Volt (Power Supply Stand By) Chassis Signal Ground
P5A-B Chassis Open Alarm Lead
III. INST ALLATION Connectors
Chassis Fan Power CPU Fan Power

Rotation +12 Volt Ground

7. Primary / Secondary IDE connectors (Two 40-1 pin block) These connectors support the provided IDE hard disk ribbon cable. After connecting the single end to the board, connect the two plugs at the other end to your hard disk(s). If you install two hard disks on the same channel, you must set the second drive to Slave mode. Refer to the documentation of your hard disk for the jumper settings. BIOS now supports SCSI device or IDE CD-ROM bootup (see HDD Sequence SCSI/IDE First & Boot Sequence in the BIOS Features Setup of the BIOS SOFTWARE) (Pin 20 is removed to prevent inserting in the wrong orientation when using ribbon cables with pin 20 plugged).
Secondary IDE Connector Pin 1 Primary IDE Connector
NOTE: Orient the red stripe on your cable to Pin 1
III. INST ALLATION Connectors 28

P5A-B IDE Connectors

TIP: You may configure two hard disks to be both Masters using one ribbon cable on the primary IDE connector and another ribbon cable on the secondary IDE connector. You may install one operating system on an IDE drive and another on a SCSI drive and select the boot disk through BIOS Features Setup. 8. IDE activity LED (IDELED, 2 pins) This connector supplies power to the cabinets IDE activity LED. Read and write activity by devices connected to the Primary or Secondary IDE connectors will cause the LED to light up.
TIP: If the case-mounted LED does not light, try reversing the 2-pin plug. IDELED +

P5A-B IDE Activity LED

9. ATX Power Supply Connector (ATX, 20-pin block) This connector connects to an ATX power supply. The plug from the power supply will only insert in one orientation because of the different hole sizes. Find the proper orientation and push down firmly making sure that the pins are aligned. IMPORTANT: Make sure that your ATX power supply can supply at least 10mAmp on the 5-volt standby lead (+5VSB). You may experience difficulty in powering on your system if your power supply cannot support the load. For Wake on LAN support, your ATX power supply must supply at least 720mA.

P5A-B ATX Power Connector
10. AT Power Supply Connector (PS/2, 12-pin block) This connector connects to a standard 5 Volt power supply. To connect the leads from the power supply, ensure first that the power supply is not plugged. Most power supplies provide two plugs (P8 and P9), each containing six wires, two of which are black. Orient the connectors so that the black wires are together.

PG +12V +5V -12V GND

ORG RED YLW BLU BLK BLK BLK BLK WHT RED RED RED
Power Connector on Motherboard
Power Plugs from Power Supply

P5A-B AT Power Connector

At a slight angle, align the plastic guide pins on the lead to their receptacles on the connector. Once aligned, press the lead onto the connector until the lead locks into place.
+12.0 Volts +5V Standby Power Good Ground +5.0 Volts Ground +5.0 Volts Ground +3.3 Volts +3.3 Volts
+5.0 Volts +5.0 Volts -5.0 Volts Ground Ground Ground Power Supply On Ground -12.0 Volts +3.3 Volts
11. USB, Infrared, PS/2 Mouse Module Connector (USB/MIR, 18-1 pin block) If you want to use PS/2 mouse, USB, or infrared (IrDA) devices, you need to purchase an external connector set. The external connector set connects to the 18-pin block and mounts to an open slot on your computers chassis. The system will direct IRQ12 to the PS/2 mouse if one is detected. If not detected, expansion cards can use IRQ12. See PS/2 Mouse Control in BIOS Features Setup and USB Function in PnP and PCI Setup of the BIOS SOFTWARE. See Second IrDA. connector for details on the infrared connector.
1: USB +5 Volt 2: USB Port 0 3: USB Port 0 + 4: Ground 5: (no connection) 6: PS/2 Mouse Clock 7: Ground 8: (no connection) 9: +5 Volt
10: USB +5 Volt 11: USB Port 1 12: USB Port 1 + 13: Ground 14: (no connection) 15: PS/2 Mouse Data 16: Ground 17: Infrared Receive 18: Infrared Transmit
Infrared PS/2 Mouse USB 0 USB 1
III. INST ALLATION Connectors 30

Optional USB/MIR

P5A-B PS/2 USB, Mouse, IrDA Module Connector
12. IrDA-Compliant Infrared Module Connector (IR, 5-pin block) This connector supports the optional wireless transmitting and receiving infrared module. This module mounts to a small opening on system cases that support this feature. You must also configure the setting through UART2 Use Infrared in Chipset Features Setup to select whether UART2 is directed for use with COM2 or IrDA. Use the five pins as shown below (Back View) and connect a ribbon cable from the module to the motherboard according to the pin definitions.

IV. BIOS Chipset Features
Parallel Port Mode (ECP+EPP) This field allows you to set the operation mode of the parallel port. The setting Normal, allows normal-speed operation but in one direction only; EPP allows bidirectional parallel port operation at maximum speed; ECP allows the parallel port to operate in bidirectional mode and at a speed faster than the maximum data transfer rate; ECP+EPP allows normal speed operation in a two-way mode. ECP DMA Select (3) This selection is available only if you select ECP or ECP+EPP in the Parallel Port Mode. Select either DMA Channel 1, 3, or Disabled. Onboard IR (Disabled) When enabled, this field activates the onboard infrared feature and sets the second serial UART to support the infrared module connector on the motherboard. If your system already has a second serial port connected to the onboard COM2 connector, it will no longer work if you enable the infrared feature. By default, this field is set to Disabled, which leaves the second serial port UART to support the COM2 serial port connector. IR Mode (IrDA SIR) This motherboard supports IrDA compatible Serial Infrared (SIR) and Fast Infrared (FIR) communication modes. The FIR mode has two options: FIR/HP and FIR/ IBM, for computers or peripherals using HP and IBMs infrared transceivers, respectively. When using either FIR option, FIR DMA Select must be configured to reflect the DMA channel used by the port. FIR DMA Select (1) This allows you to configure the DMA channel used by the FIR port. Options are DMA 1 (default) or DMA 3. Onboard PCI IDE Enable (Both) You can select to enable the Primary IDE channel, Secondary IDE channel, Both, or Disable both channels (for systems with only SCSI drives). IDE Ultra DMA Mode (Auto) This sets the IDE UltraDMA to be active when using UltraDMA-capable IDE devices. The BIOS will automatically adjust or disable this setting for slower IDE devices so that Auto or high settings will not cause problems for older IDE devices. Choose Disable if you do not want this feature for all devices. IDE 0 Master/Slave PIO/DMA Mode, IDE 1 Master/Slave PIO/DMA Mode (Auto) Each channel (0 and 1) has both a master and a slave making four IDE devices possible. Because each IDE device may have a different Mode timing (0, 1, 2, 3, 4), it is necessary for these to be independent. PIO and DMA timings can be independently set. The default setting of Auto will allow autodetection to ensure optimal performance.
IV. BIOS Chipset Features IV. BIOS Chipset Features 48

VII. ASUS LAN Card Information 66

Software Driver Support

NetWare ODI Drivers - Novell Netware 3.x, 4.x, DOS, OS/2 Client NDIS 2.01 Drivers - Microsoft LAN Manager, Microsoft Windows 3.11, IBM LAN Server NDIS 3.0 Drivers - Microsoft Windows NT, Microsoft Windows 95, Microsoft Windows 3.11

Question and Answer

Q: What is Wake-On-LAN ? A: The Wake-On-LAN feature provides the capability to remotely power on systems supporting Wake-On-LAN by simply sending a wake-up frame. With this feature, remotely uploading/downloading data to/from systems during off-peak hours will be feasible. Q: What can Wake-On-LAN do for you ? A: Wake-On-LAN is a remote management tool with advantages that can reduce system management workload, provide flexibility to the system administrators job, and then of course save you time-consuming efforts and costs. Q: What components does Wake-On-LAN require to be enable? A: To enable Wake-On-LAN function, your system requires Ethernet LAN adapter card that can activate Wake-On-LAN function, a client with Wake-On-LAN capability, and software such as LDCM Rev. 3.10 or up that can trigger wake-up frame.

APPENDIX

Glossary
AGP (Accelerated Graphics Port) An interface specification that enables high-performance 3D graphics on mainstream PCs. AGP offers a higher throughput than PCI by providing the graphics controller with direct access to system memory. Bus PCI AGP 1X AGP 2X AGP 4X Bus Frequency 33MHz 66MHz 133MHz 266MHz Bus Speed 133MB/s 200-300MB/s 528MB/s 1 GB/s
AUTOEXEC.BAT AUTOEXEC.BAT is a special-purpose file that is automatically executed by DOS whenever the computer is turned ON or restarted. This file contains important commands that help configure the system to work with certain software and devices. Windows 95 and later has its own startup files and may not use or may ignore parts of the AUTOEXEC.BAT file. BIOS (Basic Input/Output System) BIOS is a set of routines that affect how the computer transfers data between computer components, such as memory, disks, and the display adapter. The BIOS instructions are built into the computers read-only memory. BIOS parameters can be configured by the user through the BIOS Setup program. The BIOS can be updated using the provided utility to copy a new BIOS file into the EEPROM. Bit (Binary Digit) Represents the smallest unit of data used by the computer. A bit can have one of two values: 0 or 1. Boot Boot means to start the computer operating system by loading it into system memory. When the manual instructs you to boot your system (or computer), it means to turn ON your computer. Reboot means to restart your computer. When using Windows 95 or later, selecting Restart from Start | Shut Down. will reboot your computer. Bus Master IDE PIO (Programmable I/O) IDE requires that the CPU be involved in IDE access and waiting for mechanical events. Bus master IDE transfers data to/from the memory without interrupting the CPU. Bus master IDE driver and bus master IDE hard disk drives are required to support bus master IDE mode.

APPENDIX Glossary

Byte (Binary Term) One byte is a group of eight contiguous bits. A byte is used to represent a single alphanumeric character, punctuation mark, or other symbol. COM Port COM is a logical device name used by to designate the computer serial ports. Pointing devices, modems, and infrared modules can be connected to COM ports. Each COM port is configured to use a different IRQ and address assignment. CPU (Central Processing Unit) The CPU, sometimes called Processor, actually functions as the brain of the computer. It interprets and executes program commands and processes data stored in memory. Currently, there are socket 370 (for Pentium Celeron-PPGA), socket 7 (for Pentium, AMD, Cyrix, IBM), slot 1 (for Pentium II and III), and slot 2 (for Xeon) processors. Device Driver A device driver is a special set of instructions that allows the computers operating system to communicate with devices such as VGA, audio, ethernet, printer, or modem. DOS (Disk Operating System) DOS is the foundation on which all other programs and software applications operate, including Windows. DOS is responsible for allocating system resources such as memory, CPU time, disk space, and access to peripheral devices. For this reason, DOS constitutes the basic interface between you and your computer. Hardware Hardware is a general term referring to the physical components of a computer system, including peripherals, such as printers, modems, and pointing devices. IDE (Integrated Drive Electronics) IDE devices integrate the drive control circuitry directly on the drive itself, eliminating the need for a separate adapter card (in the case for SCSI devices). UltraDMA/ 33 IDE devices can achieve up to 33MB/Sec transfer. LPT Port (Line Printer Port) Logical device name reserved by DOS for the computer parallel ports. Each LPT port is configured to use a different IRQ and address assignment. MMX A set of 57 new instructions based on a technique called Single Instruction, Multiple Data (SIMD), which is built into the new Intel Pentium PP/MT (P55C) and Pentium II (Klamath) CPU as well as other x86-compatible microprocessors. The MMX instructions are designed to accelerate multimedia and communications applications, such as 3D video, 3D sound, video conference.

APPENDIX Glossary 68

PCI Bus (Peripheral Component Interconnect Local Bus) PCI bus is a specification that defines a 32-bit data bus interface. PCI is a standard widely used by expansion card manufacturers. Peripherals Peripherals are devices attached to the computer via I/O ports. Peripheral devices allow your computer to perform an almost limitless variety of specialized tasks. POST (Power On Self Test) When you turn on the computer, it will first run through the POST, a series of software-controlled diagnostic tests. The POST checks system memory, the motherboard circuitry, the display, the keyboard, the diskette drive, and other I/O devices. PS/2 Port PS/2 ports are based on IBM Micro Channel Architecture. This type of architecture transfers data through a 16-bit or 32-bit bus. A PS/2 mouse and/or keyboard may be used on ATX motherboards. RAID (Redundant Array of Independent Disks) RAID can be set up to provide mirroring (for fault tolerance), parity (for data guarding), or striping (for data distribution over several drives for increased performance). A RAID card is required to setup a RAID system. RAM (Random Access Memory) There are several different types of RAM such as DRAM (Dynamic RAM), EDO DRAM (Extended Data Output DRAM), SDRAM (Synchronous DRAM). ROM (Read Only Memory) ROM is nonvolatile memory used to store permanent programs (called firmware) used in certain computer components. Flash ROM (or EEPROM) can be reprogrammed with new programs (or BIOS). SCSI (Small Computer System Interface) High speed parallel interface defined by the X3T9.2 committee of the American National Standards Institute (ANSI) for connecting many peripheral devices. System Disk A system disk contains the core file of an operating system and is used to boot up the operating system. Ultra DMA/33 Ultra DMA/33 is a new specification to improve IDE transfer rates. Unlike traditional PIO mode, which only uses the rising edge of IDE command signal to transfer data, the DMA/33 uses both rising edge and falling edge. Hence, the data transfer rate is double of the PIO mode 4 or DMA mode 2. (16.6MB/s x2 = 33MB/s). APPENDIX Glossary 69

ASUS P5A-B Users Manual

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 manufacturers 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 users 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.
ALi Serial Parallel 3 DIMM Aladdin V Sockets AGPset Ports Port

ATX Power

AT Connector

CPU ZIF Socket 7

Keyboard USB/ MIR Floppy/IDE Connectors 512KB/ 1024KB Pipelined Burst L2 Cache Accelerated Graphics Port

3 PCI Slots

2 ISA Slots

Programmable Flash ROM

IrDA C-Media 3D Positional Sound Chip (optional)

Parallel Port

AT Keyboard Connector

FS3 FS2 FS1 FS0

AT Power Connector

PWR_FAN

VIO1 VIO0

ATX Power Connector

BF2 BF1 BF0

USB, PS/2 Mouse, IrDA

DIMM Socket 1 (64-bit, 168-pin module) DIMM Socket 2 (64-bit, 168-pin module) DIMM Socket 3 (64-bit, 168-pin module)

Primary IDE

Floppy Drive

ALi Aladdin V AGPset

512KB/ 1024KB Pipelined Burst L2 Cache

Temp Sensor

Secondary IDE
Accelerated Graphics Port

CR2032 3V Lithium Cell

PCI Slot 1
Chassis Intrusion Alarm Lead

WOLCON

SMBus Connector

CD1 CPU_FAN

ALi M1543 Chip

PCI Slot 2

VID3 VID2 VID1 VID0

Audio Connectors

PCI Slot 3 ISA Slot 1
1Mbit Flash EEPROM (Programmable BIOS)

CHA_FAN

C-Media 3D Positional Sound Chip (optional)

SPDI SPDO TTL

Panel Connectors

ISA Slot 2

IDELED

P5A-B Clear RTC RAM

VIO0 VIO1
3 3.5Volts 3.6Volts 3.8Volts 4.0Volts

(DEFAULT)

P5A-B Voltage Input/Output Selection
Short solder points to Clear CMOS

FS0 FS1 FS2 FS3

3 CPU AGP PCI

60MHz 60MHz 30MHz

66.8MHz 66.8MHz 33.4MHz
FS0 FS1 FS2 FS3 75MHz 75MHz 37.5MHz 100MHz 66.6MHz 33.3MHz 120MHz 80MHz 40MHz
3 CPU 83.3MHz AGP 66.6MHz PCI 33.3MHz 3 CPU 110MHz AGP 73MHz PCI 36.6MHz

95MHz 63.3MHz 31.6MHz

115MHz 77.6MHz 38.3MHz BF0 BF1 BF2
CPU External Clock (BUS) Frequency Selection
BF0 BF1 BF2 BF0 BF1 BF2 2.5x(5/2) 2.5x(5/2) 2.5x(5/2) 1.0x(1/1) 2.5x(5/2) BF0 BF1 BF2 5.0x(5/1) 2.33x(7/3) 3 CPU A 3.5x(7/2) 2.0x(2/1) CPU B 1.5x(3/2) 2.0x(2/1) CPU C 3.5x(7/2) 2.0x(2/1) CPU D 3.0x(3/1) 2.0x(2/1) CPU E 3.5x(7/2) 3.33x(10/3) BF0 BF1 BF2 BF0 BF1 BF2 BF0 BF1 BF2 3.0x(3/1) 3.0x(3/1) 3.0x(3/1) 3.0x(3/1) BF0 BF1 BF2 5.5x(11/2) 2.66x(8/3)
Match the Mult. (Multiple) column of the table on the opposite page to these CPU types: CPU A: AMD-K6-2, AMD-K6 CPU B: Intel Pentium P54C, AMD-K5 CPU C: Intel Pentium P55C, IBM/Cyrix 6x86MX, IBM/Cyrix M II CPU D: IBM/Cyrix 6x86, IBM/Cyrix 6x86L CPU E: IDT WinChip 2
3 CPU A 4.0x(4/1) CPU B CPU C CPU D CPU E 4.0x(4/1) 4.5x(9/2) 4.5x(9/2)
CPU : BUS Frequency Multiple
FS0 FS1 FS2 FS3 75MHz 60MHz 30MHz 105MHz 70MHz 35MHz
FS0 FS1 FS2 FS3 AMD-K6-2-PR350 AMD-K6-2-PR333 AMD-K6-2-PR300 AMD-K6-2-PR266 AMD-K6-PR300 AMD-K6-PR266 AMD-K6-PR233 AMD-K6-PR200 AMD-K6-PR166 AMD-K5-PR133 AMD-K5-PR120 AMD-K5-PR100 AMD-K5-PR90 Intel Pentium P54C Intel Pentium P54C Intel Pentium P54C Intel Pentium P54C Intel Pentium P54C Intel Pentium P54C Intel Pentium P55C Intel Pentium P55C Intel Pentium P55C IBM/Cyrix M II-PR333 IBM/Cyrix M II-PR300 IBM/Cyrix M II-PR300 IBM/Cyrix 6x86MX-PR233 IBM/Cyrix 6x86MX-PR200 IBM/Cyrix 6x86MX-PR166 350MHz 333MHz 300MHz 266MHz 300MHz 266MHz 233MHz 200MHz 166MHz 100MHz 90MHz 100MHz 90MHz 166MHz 150MHz 133MHz 120MHz 100MHz 90MHz 233MHz 200MHz 166MHz 333MHz 300MHz 300MHz 200MHz 166MHz 150MHz A-3.5x A-3.5x A-3.0x A-4.0x A-4.5x A-4.0x A-3.5x A-3.0x A-2.5x B-1.5x B-1.5x B-1.5x B-1.5x B-2.5x B-2.5x B-2.0x B-2.0x B-1.5x B-1.5x C-3.5x C-3.0x C-2.5x C-3.0x C-3.0x C-3.5x C-3.0x C-2.5x C-2.5x 100MHz 95MHz 100MHz 66MHz 66MHz 66MHz 66MHz 66MHz 66MHz 66MHz 60MHz 66MHz 60MHz 66MHz 60MHz 66MHz 60MHz 66MHz 60MHz [1-2] [2-3] [1-2] [1-2] [1-2] [1-2] [1-2] [1-2] [1-2] [1-2] [2-3] [1-2] [2-3] [1-2] [2-3] [1-2] [2-3] [1-2] [2-3] [1-2] [1-2] [1-2] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [1-2] [1-2] [1-2] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3]

BF0 BF1 BF2 [1-2] [1-2] [1-2] [2-3] [2-3] [2-3] [1-2] [1-2] [2-3] [1-2] [1-2] [1-2] [1-2] [2-3] [2-3] [2-3] [2-3] [1-2] [1-2] [1-2] [1-2] [2-3] [1-2] [2-3] [1-2] [1-2] [2-3] [2-3] [1-2] [1-2] [1-2] [1-2] [2-3] [2-3] [1-2] [1-2] [1-2] [1-2] [----] [----] [----] [2-3] [2-3] [2-3] [----] [----][----] [----] [----] [----] [----] [----] [----] [----] [----] [----] [----]
66MHz [1-2] [2-3] [2-3] [2-3] 66MHz [1-2] [2-3] [2-3] [2-3] 66MHz [1-2] [2-3] [2-3] [2-3] 83MHz [1-2] [2-3] [1-2] [2-3] 75MHz [1-2] [1-2] [2-3] [2-3] 66MHz [1-2] [2-3] [2-3] [2-3] 66MHz [1-2] [2-3] [2-3] [2-3] 66MHz [1-2] [2-3] [2-3] [2-3] 60MHz [2-3] [2-3] [2-3] [2-3]
[1-2] [1-2] [----] [1-2] [2-3] [----] [2-3] [2-3] [----] [1-2] [2-3] [----] [1-2] [2-3] [----] [1-2] [1-2] [----] [1-2] [2-3] [----] [2-3] [2-3] [----] [2-3] [2-3] [----] [2-3] [1-2] [----] [2-3] [1-2] [----] [2-3] [1-2] [2-3]
*IBM/Cyrix 6x86-PR166+ 133MHz *IBM/Cyrix 6x86L-PR166+ 133MHz IDT WinChip 2TM * 240MHz
D-2.0x 66MHz [1-2] [2-3] [2-3] [2-3] D-2.0x 66MHz [1-2] [2-3] [2-3] [2-3] E-4.0x 60MHz [2-3] [2-3] [2-3] [2-3]
AMD-K6-2 (PR266 & faster)
AMD-K6 (PR166 & faster)
Pentium MMX (P55C) AMD-K5 (150MHz-233MHz) (PR75-PR133)
IBM/Cyrix 6x86 (M1) IBM/Cyrix 6x86 (M1) (PR166 & faster) (PR166 & faster)
Manufacturer CPU Type AMD (.25micron) K6-233,266,300 K6-2-266,300,333 AMD K5 IBM/Cyrix 6x86 Intel P54C/P54CS AMD K5 Intel P54C/P54CS AMD (.35micron) K6-PR233 AMD (.35micron) K6-166,200 IBM/Cyrix 6x86MX Intel P55C-MMX
Single Plane ---3.5V(VRE) 3.5V(VRE) 3.5V(VRE) 3.4V(STD) 3.4V(STD) ------------VID0 VID1 VID2 VID3
Dual Plane 2.2V(Dual) --------------3.2V(Dual) 2.9V(Dual) 2.9V(Dual) 2.8V(Dual)
VID0 VID1 VID2 VID3 [1-2] [2-3] [1-2] [1-2] [2-3] [2-3] [2-3] [1-2] [1-2] [1-2] [2-3] [2-3] [1-2] [2-3] [2-3] [2-3] [2-3] [2-3] [1-2] [1-2] [1-2] [1-2] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [1-2] [1-2] [1-2] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3] [2-3]

VID0 VID1 VID2 VID3

VID0 VID1 VID2 VID3 2.3Volts 2.8Volts 3.3Volts

3 2.0Volts

2.1Volts

2.2Volts

3 2.5Volts 3 3.0Volts 3.1Volts 3 3.5Volts 3.2Volts 3.4Volts 2.6Volts 2.7Volts 2.9Volts
P5A-B CPU Vcore Voltage Selection
VID0 VID1 VID2 VID3 2.4Volts
Install memory in any combination as follows:
DIMM Location Socket 1 (Rows 0&1) Socket 2 (Rows 2&3) Socket 3 (Rows 4&5) 168-pin DIMM SDRAM 8, 16, 32, 64, 128, 256MB SDRAM 8, 16, 32, 64, 128, 256MB SDRAM 8, 16, 32, 64, 128, 256MB x1 x1 x1 Total Memory
Total System Memory (Max 768MB) =

ECC EDO DIMM (9 chips)

Non-ECC SDRAM DIMM (8 chips)

88 Pins

60 Pins

20 Pins

P5A-B 168-Pin DIMM Memory Sockets
168-Pin DIMM Notch Key Definitions (3.3V)

DRAM Key Position Unbuffered RFU Buffered
Voltage Key Position 5.0V 3.3V Reserved

Blank Lever

P5A-B ZIF Socket 7
P5A-B Accelerated Graphics Port (AGP)
Keyboard Connector (5-pin female)
This motherboard accepts an AT Keyboard Connector Plug as shown here.

P5A-B Keyboard Connector

Pin 1 Orient the red stripe on your cable to Pin 1
P5A-B Floppy Disk Drive Connector
Orient the red stripe on your cable to Pin 1
For this connector to be available, you must connect the included parallel (25-pin female) cable set to a free expansion slot opening. TIP: You may also remove the bracket connectors and mount them directly to the case to save expansion slot space.
P5A-B Parallel Port Connector

COM 1 Pin 1 COM 2

For these connectors to be available, you must connect the included Serial cable set from COM1 (using the 9-Pin male) & COM2 (using the 25-Pin male) to a free expansion slot opening. TIP: You may also remove the bracket connectors and mount them directly to the case to save expansion slot space.
P5A-B Onboard Serial Port Connectors

Power Supply Fan

Ground +12 Volt Rotation
Chassis Fan Power CPU Fan Power

Rotation +12 Volt Ground

P5A-B Power Supply, CPU, Chassis Fan Power
P5A-B Chassis Open Alarm Lead
+5Volt (Power Supply Stand By) Chassis Signal Ground
Secondary IDE Connector Pin 1 Primary IDE Connector
NOTE: Orient the red stripe on your cable to Pin 1

P5A-B IDE Connectors

TIP: If the case-mounted LED does not light, try reversing the 2-pin plug. IDELED +

P5A-B IDE Activity LED

+12.0 Volts +5V Standby Power Good Ground +5.0 Volts Ground +5.0 Volts Ground +3.3 Volts +3.3 Volts
+5.0 Volts +5.0 Volts -5.0 Volts Ground Ground Ground Power Supply On Ground -12.0 Volts +3.3 Volts
P5A-B ATX Power Connector

PG +12V +5V -12V GND

ORG RED YLW BLU BLK BLK BLK BLK WHT RED RED RED
Power Connector on Motherboard
Power Plugs from Power Supply

P5A-B AT Power Connector

1: USB +5 Volt 2: USB Port 0 3: USB Port 0 + 4: Ground 5: (no connection) 6: PS/2 Mouse Clock 7: Ground 8: (no connection) 9: +5 Volt
10: USB +5 Volt 11: USB Port 1 12: USB Port 1 + 13: Ground 14: (no connection) 15: PS/2 Mouse Data 16: Ground 17: Infrared Receive 18: Infrared Transmit
Infrared PS/2 Mouse USB 0 USB 1

Optional USB/MIR

P5A-B PS/2 USB, Mouse, IrDA Module Connector

Front View FIRRX GND

Back View

+5V IRRX IRTX

IRTX GND IRRX

+5V FIRRX

For the infrared feature to be available, you must connect an optional Infrared module to the motherboard.
P5A-B Infrared Module Connector

Message LED

+5V GND
ATX Power Switch Reset SW
+5V NC GND LOCK GND +5V GND GND SPKR
System Power LED Keyboard Lock Speaker Connector
*Requires an ATX power supply, optional ATX to
AT power connector adapter, and a momentary switch button.
P5A-B System Panel Connectors
P5A-B Wake-On-LAN Connector

P5A-B SMBus Connector

+5V Standby Ground PME
SMBCLK Ground SMBDATA +5V

Audio connector

Game/MIDI Port (15 pins)

Red marking along edge

P5A-B Audio Jack Connector
P5A-B Digital Audio Interface
Line Output (1/8 phono) Microphone In (1/8 phono) Line Input (1/8 phono)
TTL: Short this, if output device is TTL level SPDIFO: Digital Signal OUT SPDIFI: Digital Signal IN
P5A-B Stereo Audio In Connector
AUX Left Audio Channel Ground Ground Right Audio Channel
Left Audio Channel Ground Ground Right Audio Channel CD1
Chipset Features 46 ASUS P5A-B Users Manual

......

IV. BIOS Chipset Features
IV. BIOS Chipset Features 48 ASUS P5A-B Users Manual

Power Manage-

IV. BIOS Load Setup
530h,E80h,F40h 8h 530h 388h-3F8h 8h 388h 5,7,9,10,11,0,1,-----
300h-330h 2h 330h ------5,7,9,10,11,---------
200h-FE0h 8h 200h -------------------
220h,240h 10h 220h ------5,7,9,10,11,0,1,5,7 5
LAN Activity Output Signal

Intel Chipset

Wake on LAN Output Signal

Motherboard type