AOpen AX59PRO User Manual

AX59PRO

User's Guide

Printed in Taiwan

PART NO.:49.87801.311

DOC. NO.:AX59P-1-E9903G

AX59PRO

Mainboard

User's Guide

Document Number : AX59P-1-E9809F

Model and Revision : For AX59PRO revision 1.xx

Manual Revision : English, revision F

Release Date : Sep 21, 1998

More help for latest information:

Taiwan http://www.aopen.com.tw

USA http://www.aopen-usa.com

http://www.aopenusa.com

http://www.aopenamerica.com

Europe http://www.aopen.nl

Copyright

Copyright © 1998 by this company. All rights reserved. No part of this
publication may be reproduced, transmitted, transcribed, stored in a retrieval
system, or translated into any language or computer language, in any form or
by any means, electronic, mechanical, magnetic, optical, manual or otherwise,
without the prior written permission of this company.

ii

Disclaimer

This company makes no representations or warranties, either expressed or
implied, with respect to the contents hereof and specifically disclaims any
warranties, merchantability or fitness for any particular purpose. Any software
described in this manual is sold or licensed "as is". Should the programs prove
defective following their purchase, the buyer (and not this company, its
distributor, or its dealer) assumes the entire cost of all necessary servicing,
repair, and any incidental or consequential damages resulting from any defect
in the software. Further, this company reserves the right to revise this
publication and to make changes from time to time in the contents hereof
without obligation to notify any person of such revision or changes.

Intel and Pentium are registered trademarks of Intel Corporation.

XT/AT is a registered trademark of International Business Machines Corporation.

AMI is a registered trademark of American Megatrends Inc.

AWARD is a registered trademark of Award Software Inc.

Other brand and product names are trademarks and/or registered trademarks of their
respective holders.

iii

FCC Class B Radio Frequency

Declaration of Conformity

This equipment has been tested and found to comply with the limits for a Class
B Subassembly -CPU Board device, pursuant to Part 15 of FCC Rules.
Operation is subject to the following two conditions: 1. This device may not
cause harmful interference, and 2. This device must accept any interference
received, including interference that may cause undesired operation.

Equipment Classification : FCC Class B Subassembly - CPU Board
Type of Product : Intel Pentium PCI/ISA/AGP ATX Motherboard
Chipset(s) : VIA MVP3

AX59PRO

Test To Comply
With FCC Standards

FOR HOME OR OFFICE USE

The limits of FCC Part 15 Class B 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 the 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:

1. Reorient or relocate the receiving antenna.

2. Increase the separation between the equipment and receiver.

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

4. Consult the dealer or an experienced radio/television technician for help.

iv

Notice 1:

The changes or modifications not expressly approved by the party responsible
for compliance could void the user's authority to operate the equipment.

Notice 2:

Shielded interface cables, if any, must be used in order to comply with emission
limits.

v

Organization

Chapter 1, Overview, covers the introduction and specifications of the system
board and special features.

Chapter 2, Hardware Installation, describes hardware jumpers, connectors and
memory configuration. There are user friendly drawings to locate jumper and
connector.

Chapter 3, AWARD BIOS, explains the system BIOS and tells how to configure
the system by setting the BIOS parameters.

Appendix A, Frequently Asked Question, collects most frequently asked
question of this product.

Appendix B, Troubleshooting Guide, includes first aid information you need if
you meet trouble, the WWW address and worldwide service telephone/fax are
also included.

Appendix C, Jumper Table Summary, gives you a tabular summary of the
jumper settings discussed in Chapter 2.

vi

Conventions

The following conventions are used in this manual:

Text entered by user,
default settings,
recommended selections

<Enter>, <Tab>,<Ctl>, <Alt>,
<Ins>, <Del>, etc

Represent text input by the user, default
settings and recommended selections

Represent the actual keys that you
have to press on the keyboard.

Note:

Gives bits and pieces of additional
information related to the current topic.

Warning:

Alerts you to any damage that might
result from doing or not doing specific
actions.

Caution:

Suggests precautionary measures to
avoid potential hardware or software
problems.

Important:

Reminds you to take specific action
relevant to the accomplishment of the
procedure at hand.

Tip:

Tells how to accomplish a procedure
with minimum steps through little
shortcuts.

vii

Contents

Chapter 1 Overview

1.1 Specifications..................................................................3

1.2 Overclocking ...................................................................5

1.3 Zero Voltage Modem Wake Up ......................................8

1.4 System Voltage Monitoring..........................................10

1.5 Fan Monitoring ..............................................................10

1.6 CPU Thermal Protection ..............................................11

chapter 2 Hardware Installation

2.1 Jumper and Connector Locations ................................2

2.2 Jumpers ........................................................................... 4

2.2.1 Setting the CPU Voltage...........................................5

2.2.2 Selecting the CPU Frequency ..................................8

2.2.3 DRAM Clock ...........................................................12

2.2.4 Clearing the CMOS................................................. 13

2.3 Connectors ....................................................................14

2.3.1 Power Cable ...........................................................14

2.3.2 ATX Soft-Power Switch Connector......................... 14

2.3.3 Fan………………………………………………………15

2.3.4 PS/2 Mouse ............................................................15

2.3.5 Keyboard.................................................................16

2.3.6 Serial Devices (COM1/COM2)................................16

2.3.7 Printer .....................................................................17

2.3.8 USB Device.............................................................17

2.3.9 Floppy Drive............................................................17

2.3.10 IDE Hard Disk and CD ROM ................................18

2.3.11 Hard Disk LED ......................................................19

2.3.12 Panel Connector ................................................... 20

2.3.13 IrDA Connector ..................................................... 21

2.3.14 Wake-up Connector..............................................22

viii

2.3.15 LAN Wake-up Connector......................................22

2.4 Configuring the System Memory.................................23

2.5 Windows 98 Installation ............................................... 29

chapter 3 Award BIOS

3.1 Entering the Award BIOS Setup Menu .........................2

3.2 Standard CMOS Setup....................................................3

3.3 BIOS Features Setup ...................................................... 6

3.4 Chipset Features Setup................................................ 11

3.5 Power Management Setup ........................................... 15

3.6 PNP/PCI Configuration Setup......................................20

3.7 Load Setup Defaults ..................................................... 23

3.8 Load Turbo Defaults.....................................................23

3.9 Integrated Peripherals..................................................24

3.10 Password Setting........................................................ 29

3.11 IDE HDD Auto Detection ............................................29

3.12 Save & Exit Setup .......................................................29

3.13 Exit without Saving.....................................................30

3.14 NCR SCSI BIOS and Drivers ......................................30

3.15 BIOS Flash Utility........................................................30

Appendix A Frequently Asked Question

Appendix B Troubleshooting

Appendix C Jumper Table Summary

ix

Chapter 1

Overview

AX59 Pro is a high-performance Pentium®-based system board that utilizes
VIA MVP3 AGPset on ATX PCI/ISA platform. This motherboard supports new
architectures such as high speed AGP, SDRAM, Ultra DMA/33, Bus master
IDE and USB port. It has 512KB or 1MB (optional) pipelined-burst second­level cache onboard and support two single in-line memory module (SIMM)
plus three Dual in-line memory module (DIMM) that allows to mix EDO and
SDRAM memory and expansion up to a maximum of 1GB.

Not only above features, AX59 Pro implements most advanced technology as
following.

Zero Voltage Modem Wake Up In conjunction with ATX soft power On/Off, it
is possible to have system totally power off and wakeup to automatically
answer a phone call such as answering machine or to send/receive fax. The
most important break through is not only external box modem but also internal
modem card can be used to support Modem Wake Up. The AX59 Pro and
MP56 internal modem card implement special circuit (patent applied) to make
sure the modem card work properly without any power.

LAN Wake Up This feature is very similar as Modem Wake Up, but it is through
local area network. To use LAN Wake Up function, you must have a network
card that supports this feature and also need to install a network management
software.

RTC Wake Up Timer The Wake Up Timer is more like an alarm, which wakes
up and power on your system at a pre-defined time for specific application. It
can be set to wake up everyday or on specific date within a month. The
date/time accurate is second.

High Efficient Synchronous Switching Regulator Most of the current
switching designs are Asynchronous mode, which from the technical point of
view, still consumes very high power as well as heat. AX59 Pro implements
high efficient synchronous switching design that the temperature of MOS FET
is far less than Schottky diode of Asynchronous design.

1-1

Overview

CPU Thermal Protection AX59 Pro has a special thermal detection circuit to
have warning through application software when the temperature is higher than
a predefined value.

CPU core current protection AX59 Pro implements CPU core voltage 15A
over-current protection to prevent any accident short circuit and prevent system
damage.

CPU and Housing Fan Monitoring AX59 Pro has one more "fan monitoring"
function to prevent system overheat. There are two fan connectors, one is for
CPU and the other can be a extra housing fan. The system will report and
alarm fan malfunction though utility software such as Hardware Monitor utility
(named AOhw100, where 100 means version number).

System Voltage Monitoring Further more, AX59 Pro implements a voltage
monitoring system, As you turn on your system, this smart design will continue
to monitor your system working voltage. If any of the system voltage is over the
component's standard. There will be alarm though software such as Hardware
Monitor utility for a warning to user.

Full-range CPU core voltage This motherboard supports the CPU core
voltage from 1.3V to 3.5V, that can be applied to various CPU type in future.

Resetable Fuse AX59 Pro implements resetable fuses to prevent any
accidental short circuit caused by keyboard or USB devices hot plug.

FCC DoC certificate AX59 Pro has passed FCC DoC test. The radiation is
very low, you can use any kind of housing.

Powerful utility software supported AOpen Bonus Pack companion CDROM
contains many useful utilities, such as Norton Anti-virus, AOchip, Hardware
Monitor utility, and BIOS flash utility.

1-2

1.1 Specifications

Overview

Form Factor

Board Size

CPU

System Memory

Second-level Cache

Chipset

Expansion Slots

Serial Port

Parallel Port

Floppy Interface

IDE Interface

USB Interface

PS/2 Mouse

Keyboard

RTC and Battery

BIOS

ATX

305 mm x 202 mm

Intel Pentium Processor P54C, PP/MT (P55C), AMD
K5/K6/K6-2, Cyrix 6x86/M2 and IDT WinChip C6
family.

72-pin SIMM x2, and SDRAM 168-pin x3,
maximum 1GB.

512KB or 1MB (optional) pipeline-burst cache
onboard

VIA MVP3 AGPset

ISA x2, PCI x4 and AGP x1

Two serial ports UART 16C550 compatible, and the
3rd UART for IR function.

One parallel port supports standard parallel port
(SPP), enhanced parallel port (EPP) or extended
capabilities port (ECP).

Floppy interface supports 3.5 inches drives with
720KB, 1.44MB or 2.88MB format or 5.25 inches
drives with 360KB, 1.2MB format.

Dual-channel IDE interface support maximum 4 IDE
hard disks or CDROM, mode 4 , bus master hard disk
drives and Ultra DMA/33 mode hard drives are also
supported.

Two USB ports supported by USB bracket, the BIOS
also supports USB driver to simulate legacy
keyboard.

Mini-Din PS/2 mouse connector onboard.

Mini-Din PS/2 keyboard connector onboard.

RTC build in MVP3 chipset, Lithium (CR-2032)
battery.

AWARD Plug-and-Play, 2M bit Flash ROM BIOS.

1-3

Overview

Zero Voltage Modem
Wake Up

LAN Wake Up

RTC Wake Up Timer

Synchronous
Switching Regulator

Over-current
Protection

CPU Thermal
Protection

Fan Monitoring

System Voltage
Monitoring

Special circuit (patent applied) to support modem
wake up by external box modem or internal AOpen
F56/MP56 modem card.

By using a network card that supports this feature
and a network management software, you can wake
up a system through a local area network.

Program the date/time to wake up your system.

High efficient synchronous switching regulator for
future CPU.

CPU core voltage 15A over-current protection to
prevent any accident short circuit.

Warning when CPU temperature is higher than a
predefined value.

Three fan connectors, warning when CPU or housing
fan is malfunction.

Warning when system voltage (5V,12V,3.3V,2.8V)
are abnormal.

1-4

Overview

1.2 Overclocking

As a leading manufacturer in motherboard industry, AOpen always listens to
what customers want and develop products to fit different user's requirements.
Reliability, compatibility, leading technology and friendly features are our basic
goals when designing motherboards. Other than above mentioned design
criteria, there are power users who are always seeking to push the limitation of
the system performance by overclocking which we call them "Overclocker".

This section is dedicated to Overclockers.

This high performance AX59 Pro motherboard is designed for maximum
100MHz CPU bus clock. But it comes with clock generator of 112MHz and
124MHz when we design it to accommodate future CPU bus clock. Our lab test
results shown that 112MHz is achievable when proper setting and quality
components were presented, we feel quite comfortable overclocking to 112MHz.
Not only that, AX59 Pro has 32 Vcore (CPU core voltage) settings and up to

5.5x CPU ratio, that supports almost all of Socket 7 CPUs in the future and

provides flexibility for overclockers. As for 124MHz, we do not recommend at
this time. For your reference, the following configurations are what we feel
comfortable at 112 MHz bus clock. But not guaranty.☺

Warning: The design of this product follows CPU and chipset
vendor's design guideline. Any attempts to push beyond product
specification are not recommended and you are taking your own risk
to damage your system or important data. Before doing overclocking,
you must make sure your components are able to tolerate such
abnormal setting, especially CPU, DRAMs, hard disks, and AGP VGA
cards.

Warning: Note that overclocking may also cause thermal problem.
Please make sure that the cooling fan and the heatsink were
adequate to dissipate excessive heat that's generated by
overclocking the CPU.

VGA and HDD are key components for overclocking, for your reference, the
following list are what have been successful overclocked in our lab. Please note
that AOpen can not guaranty they can be successful overclocked again.

1-5

Overview

VGA Card

VGA model/ Vendor Chipset model Driver

Asus S3 –Virge/dx(86c375) Asus

VENUS T-775 S3 Trio 64V2(86C775) Venus

VENUS 67TV Trident 9685 Venus

GALAXIE Trident 9685 (PS-68) Venus

ATI MACH 64 210888GX00 Win95 default

MATROX MY220P/4+ MGA

MATROX MGA-MIL/4+ MGA

MATROX MIL2P/4+ MGA

Hard Disk:

Vender Model Size

Maxtor 90680D4 6.8G

Maxtor 90845D5 8.4G

Maxtor 72004AP 2.0G

Maxtor 82560A4 2.5G

Seagate ST36530A 6.5G

Seagate ST31277A 1.2G

Quantum FireballST4320AT 4.3G

Quantum T-Rex Bigfoot TX6.0AT 6.0G

Quantum T-Rex Bigfoot TX8.0AT 8.0G

Quantum T-Rex Bigfoot TX12.0AT 12.0G

IBM DHEA-34330 4.3G

IBM DTTA-351010 10.1G

IBM DTTA-350840 8.4G

IBM DTTA-350640 6.4G

IBM DAQA-32160 2.1G

1-6

Overview

AX59 Pro Overclocking Settings

The following table lists the overclocking settings in AOpen’s lab for your
reference.

CPU

DRAM

HDD

VGA

OS

BIOS

Intel MMX-233MHz

SEC KOREA 801

KM48S2020CT-GH 32MB

IBM DHEA-34330

ATI 3D RAGE PRO AGP 2X

Windows 95 OSR2

R2.00d

Load BIOS Setup Default for

112MHz * 2.5 = 280MHz (O.K.)

112MHz * 2 = 224MHz (O.K.)

Load BIOS Turbo Default for

100MHz * 2.5 = 250MHz (O.K.)

1-7

Overview

p

(

)

p

1.3 Zero Voltage Modem Wake Up

The Modem Wake Up discussed here is to wakeup from true power off
(identified by fan of power supply is off), This motherboard still supports
traditional green PC suspend mode but it is not discussed here.

With the help ATX soft power On/Off, it is possible to have system totally power
off (The traditional suspend mode of power management function does not
really turn off the system power supply), and wakeup to automatically answer a
phone call such as answering machine or to send/receive fax. You may identify
the true power off by checking fan of your power supply. Both external box
modem and internal modem card can be used to support Modem Wake Up, but
if you use external modem, you have to keep the box modem always power-on.
AOpen AX59 Pro and internal modem card implement special circuit (patent
applied) and make sure the modem card works properly without any power. We
recommend you choose AOpen modem card (MP56) for Modem Wake Up
applications.

TEL Line

COM port

External Box Modem

External Modem Wake U

TEL Line

Internal Modem Card Wake U

1-8

such as MP56

Overview

For Internal Modem Card (AOpen MP56):

1. Go into BIOS setup , Power Management  Modem Wake Up, select

Enable.

2. Setup your application, put into Windows 95.

3. Turn system power off by soft power switch.

4. Connect 4-pin Modem Ring-On cable from MP56 RING connector to AX59

Pro connector WKUP.

5. Connect telephone line to MP56. You are now ready to use Modem Ring-

On.

For External Box Modem:

1. Go into BIOS setup , Power Management  Modem Wake Up, select

Enable.

2. Setup your application, put into Windows 95 Start Up.

3. Turn system power off by soft power switch.

4. Connect RS232 cable of external box Modem to COM1 or COM2.

5. Connect telephone line to external box Modem. Turn on Modem power (you

must keep Modem power always on). You are now ready to use Modem
Ring

Tip: External modem wake up signal is detected through
COM1 or COM2. Internal modem card wake up signal is
detected through cable from connector RING (on modem
card) to WKUP (on mainboard).

Note: If you use external modem, the power of external
modem must be kept on to receive signal from telephone
line. Internal modem card has no such limitation.

1-9

Overview

1.4 System Voltage Monitoring

This motherboard implements a voltage monitoring system. As you turn on your
system, this smart design will continue to monitor your system working voltage.
If any of the system voltage is over the component's standard. There will be
alarm through application software such as Hardware Monitor utility for a
warning to user. System voltage monitoring function monitors CPU core voltage.
It is automatically implemented by BIOS and Hardware Monitor utility (the file
name is like aohw100.exe, where 100 means the version number, no hardware
installation is needed.

1.5 Fan Monitoring

There are three fan connectors, two is for CPU, the other can be a housing fan.
The fan monitoring function is implemented by connecting fan to 3-pin fan
connector CPUFAN2 and installing Hardware Monitor utility.

Note: You need 3-pin fan that supports SENSE
signal for fan monitoring function to work properly.

1-10

Overview

1.6 CPU Thermal Protection

This motherboard implements special thermal protection circuit below the CPU.
When temperature is higher than a predefined value, the CPU speed will
automatically slow down and there will be warning from BIOS and also
Hardware Monitoring Utility software.

CPU Thermal Protection is automatically implemented by BIOS and utility
software, no hardware installation is needed.

1-11

Chapter 2

Hardware Installation

This chapter gives you a step-by-step procedure on how to install your system.
Follow each section accordingly.

Caution: Electrostatic discharge (ESD) can
damage your processor, disk drives, expansion
boards, and other components. Always
observe the following precautions before you
install a system component.

1. Do not remove a component from its
protective packaging until you are ready
to install it.

2. Wear a wrist ground strap and attach it to
a metal part of the system unit before
handling a component. If a wrist strap is
not available, maintain contact with the
system unit throughout any procedure
requiring ESD protection.

2-1

Hardware Installation

R

2.1 Jumper and Connector Locations

The following figure shows the locations of the jumpers and connectors on the
system board :

I
S

A

SPWR

I
S

A

PANEL

MODEM WKUP

HDD
LED

P
C

I
4

BIOS

P
C
I
3

LAN WKUP

FAN

FDC

IrDA

P

P

C

C

I

I

2

JP14

1

A
G
P

PWR2

JP23

JP24

JP25

COM2

PRINTE

SIMM2

SIMM1

JP5

IDE2

IDE1

COM1

USB

DIMM3

DIMM2

DIMM1

CPUFAN2

KB/PS2

CPUFAN1

2-2

Hardware Installation

Jumpers:

SW1:

JP4,JP5,JP6,
JP25:

JP23,JP24

JP14:

Connectors:

PS2: PS/2 mouse connector
KB: PS/2 keyboard connector
COM1: COM1 connector
COM2: COM2 connector
PRINTER: Printer connector
PWR2: ATX power connector
USB: USB connector
FDC: Floppy drive connector
IDE1: IDE1 primary channel
IDE2: IDE2 secondary channel
CPUFAN1: CPU Fan connector
CPUFAN2: CPU Fan connector
FAN: Fan Connector
IrDA: IrDA (Infrared) connector
HDD LED: HDD LED connector
PANEL: Front panel (Multifunction) connector
SPWR: ATX Soft-Power Switch Connector
MODEM-WKUP: MODEM Wake Up Connector
LAN-WKUP: LAN Wake Up Connector

DIP Switch for CPU voltage and clock ratio

CPU external (bus) clock

DRAM Clock

Clear CMOS

2-3

Hardware Installation

2.2 Jumpers

Jumpers are made by pin headers and plastic connecting caps for the purpose
of customizing your hardware. Doing so requires basic knowledge of computer
hardware, be sure you understand the meaning of the jumpers before you
change any setting. The onboard jumpers are normally set to their default with
optimized settings.

On the mainboard, normally there is a bold line marked beside pin 1 of the
jumper, sometimes, there are numbers also. If we connect (short) plastic cap to
pin 1 and 2, we will say set it at 1-2, and when we say jumper is open, that
means no plastic cap connected to jumper pins.

Open

1
2

Short

1
2

Jumper set at 1-2

1
2
3

Jumper set at 2-3

For your convenience to install a CPU, this motherboard also use a DIP switch
to set CPU voltage and frequency ratio. The following figure simply shows you
how to set this DIP switch, please see also to next sections for more details.

ON

12345678

1
2
3

2-4

OFF ON

Hardware Installation

2.2.1 Setting the CPU Voltage

S4

ON

OFF

OFF

ON

OFF

OFF

OFF

S5

ON

ON

OFF

OFF

OFF

OFF

ON

S6

S7

S8

Vcore

ON

ON

OFF

ON

ON

OFF

ON

ON

OFF

OFF

ON

OFF

OFF

ON

OFF

ON

OFF

OFF

OFF

OFF

OFF

3.52V

3.45V

3.2V

2.9V

2.8V

2.4V

2.2V

SW1 is used to select CPU core
voltage (Vcore) and ratio, there
are totally eight switches on the
DIP. After installing CPU, set
the switch 4-8 to specify a
proper Vcore.

ON

1 2 3 4 5 6 7 8

3.2V

K6-233

ON

1 2 3 4 5 6 7 8

2.9V

K6-166/200 or M2

ON

1 2 3 4 5 6 7 8

3.52V

6x86 or K5

ON

1 2 3 4 5 6 7 8

3.45V

P54C

ON

1 2 3 4 5 6 7 8

3.3V

IDT C6

ON

1 2 3 4 5 6 7 8

2.8V

P55C (MMX)

ON

1 2 3 4 5 6 7 8

2.4V

K6-2 400/450 and K6-III

ON

1 2 3 4 5 6 7 8

2.2V

K6-266/300 and K6-2

2-5

Hardware Installation

Following table lists possible settings of current CPU available on the market.
Note that the correct setting may vary because of new CPU product, refer to
your CPU specification for more details.

CPU Type Vcore S4 S5 S6 S7 S8

INTEL P54C Single Voltage 3.45V OFF ON ON ON OFF

INTEL P55C Dual Voltage 2.8V OFF OFF OFF ON OFF

AMD K5 Single Voltage 3.52V ON ON ON ON OFF

AMD K6-166/200 Dual Voltage 2.9V ON OFF OFF ON OFF

AMD K6-233 Dual Voltage 3.2V OFF OFF ON ON OFF

AMD K6-266/300 Dual Voltage 2.2V OFF ON OFF OFF OFF

AMD K6-2 Dual Voltage 2.2V OFF ON OFF OFF OFF

AMD K6-2 400/450 Dual Voltage 2.4V OFF OFF ON OFF OFF

AMD K6-III Dual Voltage 2.4V OFF OFF ON OFF OFF

Cyrix 6x86 Single Voltage 3.52V ON ON ON ON OFF

Cyrix 6x86L Dual Voltage 2.8V OFF OFF OFF ON OFF

Cyrix M2 Dual Voltage 2.9V ON OFF OFF ON OFF

IDT C6 Single Voltage 3.52V

3.3V

Warning: This high performance AX59 Pro motherboard that AOpen
presented to you has a capability to overclock to 112MHz external
clock while still conforming the design guide from VIA. This overclock
scheme is accomplished by AOpen's technical expertise as well as
manufacturing capabilities. However, please understand that some of
the add-on cards might not work with this board properly when
overclock scheme is engaged. Please use designated speed when
you encountered such a problem

ON
ON

ON
OFF

ON
ON

ON
ON

OFF
OFF

2-6

Warning: Note that overclocking may cause thermal problem. Please

make sure that the cooling fan and the heatsink were adequate to
dissipate excessive heat that's generated by overclocking the CPU.

Tip: Normally, for single voltage CPU, Vcpuio (CPU I/O Voltage) is
equal to Vcore, but for CPU that needs dual voltage such as PP/MT
(P55C) or Cyrix 6x86L, Vcpuio is different from Vcore and must be
set to Vio (PBSRAM and Chipset Voltage). The single or dual voltage
CPU is automatically detected by hardware circuit.

Tip: For supporting more different CPUs in future, this motherboard
uses five switches to specify Vcore. There are 32 settings totally, and
the range is from 1.3V to 3.5V.

Hardware Installation

This motherboard supports the CPU core voltage from 1.3V to 3.5V, that can
be applied to the various CPU type in future. For your reference, all settings are
listed in the following table.

Vcore

1.30V

1.35V

1.40V

1.45V

1.50V

1.55V

1.60V

1.65V

1.70V

1.75V

1.80V

1.85V

1.90V

1.95V

2.00V

2.05V

2.1V

2.2V

2.3V

2.4V

2.5V

2.6V

2.7V

2.8V

2.9V

3.0V

3.1V

3.2V

3.3V

3.4V

3.5V

S4

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON
ON
OFF

ON
OFF

ON
OFF

ON
OFF

ON
OFF

ON
OFF

ON
OFF

ON

S5

OFF
OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON

OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON

S6

OFF
OFF
OFF
OFF

ON
ON
ON

ON
OFF
OFF
OFF
OFF

ON

ON

ON

ON

OFF

OFF
OFF

ON

ON

ON

ON
OFF
OFF
OFF
OFF

ON

ON

ON

ON

S7

OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF

ON
ON
ON
ON
ON
ON
ON
ON

OFF

OFF
OFF
OFF
OFF
OFF
OFF

ON
ON
ON
ON
ON
ON
ON
ON

S8

ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON

ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF

2-7

Hardware Installation

2.2.2 Selecting the CPU Frequency

S1

OFF

ON

ON

OFF

ON

ON

OFF

OFF

S2

OFF

OFF

ON

ON

OFF

ON

ON

OFF

S3

OFF

OFF

OFF

OFF

ON

ON

ON

ON

CPU Frequency

Ratio

1.5x (3.5x)

2x

2.5x (1.75x)

3x

4x

4.5x

5x

5.5x

Intel Pentium, Cyrix 6x86 and
AMD K5/K6 CPU are designed
to have different Internal (Core)
and External (Bus) frequency.
The ratio of Core/Bus frequency
is selected by the switch 1-3 of
SW1.

Note: Intel PP/MT MMX 233MHz is using 1.5x jumper setting
for 3.5x frequency ratio, and AMD PR166 is using 2.5x setting
for 1.75x frequency ratio.

Core frequency = Ratio * External bus clock

ON

1 2 3 4 5 6 7 8

ON

1 2 3 4 5 6 7 8

ON

1 2 3 4 5 6 7 8

1.5x (3.5x)

ON

1 2 3 4 5 6 7 8

4.5x

3x

4x

2-8

ON

1 2 3 4 5 6 7 8

2x

ON

1 2 3 4 5 6 7 8

2.5x (1.75x)

ON

1 2 3 4 5 6 7 8

5x

ON

1 2 3 4 5 6 7 8

5.5x

Hardware Installation

CPU CLK

66MHz

68MHz

75MHz

83MHz

95MHz

100MHz

112MHz

124MHz

JP4, JP5, JP6 and J25 are the selections of CPU external clock (bus clock),
AGP Clock and PCI Clock.

JP4

JP5

JP6

JP23

JP4

JP5

JP6

JP23

1 2 3

1 2 3

AGP CLK

66MHz

68MHz

75MHz

56MHz

64MHz

66MHz

75MHz

83Mhz

JP24

JP25

66MHz

JP24

JP25

68MHz

1 2 3

1 2 3

PCI CLK

33MHz

34MHz

38MHz

28MHz

32MHz

33MHz

37MHz

41MHz

JP4

JP5

JP6

JP23

JP4

JP5

JP6

JP23

JP4

1-2

2-3

1-2

2-3

2-3

1-2

1-2

2-3

JP4

JP5

JP6

JP23

JP5

1-2

2-3

2-3

2-3

1-2

1-2

2-3

1-2

1 2 3

1 2 3

1 2 3

JP6

1-2

2-3

1-2

1-2

2-3

2-3

2-3

1-2

JP24

JP25

75MHz

JP24

JP25

83MHz

JP24

JP25

95MHz

JP25

1-2

1-2

1-2

2-3

2-3

2-3

2-3

2-3

1 2 3

1 2 3

1 2 3

2-9