ASUS MEL-B User Manual

R

MEL-B

Socket 370 Baby AT Motherboard

USER’S MANUAL

USER'S NOTICE

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

ASUS PROVIDES THIS MANUAL “AS IS” WITHOUT WARRANTY OF ANY KIND,
EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED T O THE IMPLIED
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EMPLOYEES OR AGENTS BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDEN­TAL, OR CONSEQUENTIAL DAMAGES (INCLUDING DAMAGES FOR LOSS OF
PROFITS, LOSS OF BUSINESS, LOSS OF USE OR DATA, INTERRUPTION OF BUSI­NESS AND THE LIKE), EVEN IF ASUS HAS BEEN ADVISED OF THE POSSIBILITY
OF SUCH DAMAGES ARISING FROM ANY DEFECT OR ERROR IN THIS MANUAL
OR PRODUCT.

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

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

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

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

• Symbios is a registered trademark of Symbios Logic Corporation.

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

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

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

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

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

Copyright © 1999 ASUSTeK COMPUTER INC. All Rights Reserved.

Product Name: ASUS MEL-B
Manual Revision: 1.00 E336
Release Date: January 1999

2 ASUS MEL-B User’s Manual

ASUS CONTACT INFORMATION

ASUSTeK COMPUTER INC. (Asia-Pacific)

Marketing

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

Technical Support

Tel (English): [phone] ext. 706
Tel (Chinese): [phone] ext. 701
Fax: [phone]
Email: [e-mail]
Newsgroup: news2.asus.com.tw
WWW: www.asus.com.tw
FTP: ftp.asus.com.tw/pub/ASUS

ASUS COMPUTER INTERNATIONAL (America)

Marketing

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

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

Technical Support

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

ASUS COMPUTER GmbH (Europe)

Marketing

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

Technical Support

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

ASUS MEL-B User’s Manual 3

CONTENTS

I. INTRODUCTION.............................................................................. 7

How this manual is organized............................................................. 7

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

II. FEATURES ....................................................................................... 8

The ASUS MEL-B Motherboard ........................................................ 8

Parts of the ASUS MEL-B Motherboard .......................................... 11

III. HARDWARE SETUP .................................................................... 12

ASUS MEL-B Motherboard Layout................................................. 12

Hardware Setup Steps ....................................................................... 14

1. Motherboard Settings.................................................................... 14

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

DIMM Memory Installation .................................................. 18

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

4. Expansion Cards ........................................................................... 20

Expansion Card Installation Procedure ................................. 20

Assigning IRQs for Expansion Cards.................................... 20

Assigning DMA Channels for ISA Cards.............................. 21

ISA Cards and Hardware Monitor ......................................... 21

5. External Connectors..................................................................... 22

Using the ASUS CIDB .......................................................... 31

The ASUS CIDB Chassis Sensor ................................................ 31

Setting up the ASUS CIDB ................................................... 32

ASUS CIDB Additional Considerations ............................... 32

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

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

IV. BIOS SETUP................................................................................... 34

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

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

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

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

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

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

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

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

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

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

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

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

4 ASUS MEL-B User’s Manual

CONTENTS

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. SOFTWARE SETUP ....................................................................... 57

VI. SOFTWARE REFERENCE.......................................................... 69

APPENDIX ........................................................................................... 83

ASUS MEL-B User’s Manual 5

FCC & DOC COMPLIANCE

Federal Communications Commission Statement

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

• This device may not cause harmful interference, and

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

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

• Re-orient or relocate the receiving antenna.

• Increase the separation between the equipment and receiver.

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

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

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

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

Canadian Department of Communications Statement

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

6 ASUS MEL-B User’s Manual

I. INTRODUCTION

How this manual is organized

This manual is divided into the following sections:

I. Introduction Manual information and checklist
II. Features Information and specifications concerning this product
III. Hardware Setup Instructions on setting up the motherboard
IV. BIOS Setup Instructions on setting up the BIOS software
V. Software Setup Information on setting up the included support software
VI. Software Reference Reference material for the included support software

Item Checklist

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

(1) ASUS Motherboard

Sections/Checklist

I. INTRODUCTION

(1) IDE ribbon cable for master and slave drives
(1) Ribbon cable for (1) 5.25” and (2) 3.5” floppy disk drives
(1) Serial cable connector set
(1) Parallel + PS/2 mouse connector set
(1) Bag of spare jumper caps
(1) Support CD with drivers and utilities
(1) This Motherboard User’s Manual

ASUS IrDA-compliant infrared module (optional)
ASUS USB/MIR module (optional)
ASUS CIDB chassis sensor module (optional)
ASUS PCI-L101 Wake-On-LAN 10/100 Fast Ethernet Card (optional)

ASUS MEL-B User’s Manual 7

II. FEATURES

Features

II. FEATURES

The ASUS MEL-B Motherboard

The ASUS MEL-B motherboard is carefully designed for the demanding PC user
who wants many intelligent features in a small package.

Specifications

• Intel Processor Support: Supports Intel Celeron processors (300MHz and faster)

designed for Socket 370 and packaged in a Plastic Pin Grid Array (PPGA).

• Intel AGPset: Features Intel’s 440LX AGPset with a 66MHz Front Side Bus

and I/O subsystems.

• Enhanced ACPI & Anti-Boot Virus BIOS: Programmable BIOS (Flash

EEPROM), offering enhanced ACPI for W indows 98 compatibility , built-in firm­ware-based virus protection, and autodetection of most devices for virtually au­tomatic setup.

• Versatile Memory: Equipped with three DIMM sockets to support Intel PC66-

compliant SDRAMs (8, 16, 32, 64, 128, or 256MB) up to 768MB.

• AGP Slot: Supports an Accelerated Graphics Port card for high performance,

component level interconnect targeted at 3D graphical display applications sup­porting a 1X or 2X mode bus.

• PCI & ISA Expansion: Provides three 32-bit PCI and two 16-bit ISA expan-

sion slots.

• PC Health Monitoring: Provides an easier way to examine and manage system

status information such as CPU and system voltages, temperatures, and fan sta­tus through the onboard hardware ASIC and bundled LDCM or ASUS PC Probe.

• Wake-On-LAN Header: Supports W ake-On-LAN activity through an optional

ASUS PCI-L101 Fast Ethernet card or a similar ethernet card.

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

ing Intel’ s PC-PCI and serialized IRQ protocols, to A WE64D or compatible PCI
audio cards.

• Super Multi-I/O: Provides two high-speed UART compatible serial ports and

one parallel port with EPP and ECP capabilities.

• 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.)

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

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

• Easy Installation: Equipped with BIOS that supports autodetection of hard

drives, PS/2 mouse, and Plug and Play devices to make setup of hard drives,
expansion cards, and other devices virtually automatic.

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

• Quick Adjustments: Easy-to-access DIP switches make changing CPU and

onboard feature settings a snap.

8 ASUS MEL-B User’s Manual

II. FEATURES

Performance

• ACPI Ready: ACPI (Advanced Configuration and Power Interface) is also imple-

mented on all ASUS smart series motherboards. ACPI provides more Energy
Saving Features for future operating systems (OS) supporting OS Direct Power
Management (OSPM) functionality . W ith these features implemented in the OS,
PCs can be ready around the clock, yet satisfy all the energy saving standards.
T o fully utilize the benefits of ACPI, an ACPI-supported OS such as the succes­sor of Windows 95 must be used.

• Double the IDE Transfer Speed: IDE transfers using UltraDMA/33 Bus Mas-

ter IDE can handle rates up to 33MB/sec. The best of all is that this new technol­ogy is compatible with existing AT A-2 IDE specifications so there is no need to
upgrade current hard drives or cables.

• Concurrent PCI: Concurrent PCI allows multiple PCI transfers from PCI mas-

ter buses to memory to CPU.

• PC’98 Compliant: Both the BIOS and hardware levels of the motherboard meets

PC’98 compliancy . The new PC’98 requirements for systems and components are
based on the following high-level goals: Support for Plug and Play compatibility
and power management for configuring and managing all system components,
and 32-bit device drivers and installation procedures for Windows 95/98/NT.

Features

II. FEATURES

• SDRAM Optimized Performance: ASUS smart series motherboards support

the new generation memory, Synchronous Dynamic Random Access Memory
(SDRAM), which increases the data transfer rate from 264MB/s max using EDO
memory to 528MB/s max using SDRAM.

ASUS MEL-B User’s Manual 9

II. FEATURES

Features

II. FEATURES

Intelligence (some features require the optional Hardware/Thermal Monitor)

• Fan Status Monitoring and Alarm: To prevent system overheat and system

damage, the CPU, power supply, and system fans can be monitored for RPM
and failure. All the fans are set for its normal RPM range and alarm thresholds.

• Temperature Monitoring and Alert: To prevent system overheat and system

damage, there are heat sensors to monitor the CPU and system temperatures to
warn of damaging temperatures.

• Voltage Monitoring and Alert: System voltage levels are monitored to ensure

stable current to critical motherboard components. Voltage specifications are
more critical for future processors, so monitoring is necessary to ensure proper
system configuration and management.

• System Resources Alert: T oday’ s operating systems such as W indows 95, W in-

dows NT , and OS/2, require much more memory and hard drive space to present
enormous user interfaces and run large applications. The system resource moni­tor will warn the user before the system resources are used up to prevent pos­sible application crashes. Suggestions will give the user information on manag­ing their limited resources more efficiently.

• Auto Fan Off: The system fans will power off automatically even in sleep
mode. This function reduces both energy consumption and system noise, and

is a important feature to implement silent PC systems.

• Dual Function Power Button: The system can be in one of two states, one is
Sleep mode and the other is the Soft-Off mode. Pushing the power button for
less than 4 seconds places the system into Sleep mode. When the power button
is pressed for more than 4 seconds, it enters the Soft-Off mode.

• Remote Ring On (requires modem): This allows a computer to be turned on
remotely through an internal or external modem. With this benefit on-hand, any
user can access vital information from their computer from anywhere in the world!

• Message LED (requires ACPI OS support): Chassis LEDs now act as infor­mation providers. Through the way a particular LED illuminates, the user can
determine the stage the computer is in. A simple glimpse provides useful infor­mation to the user.

• Keyboard Power Up: Keyboard Power Up can be enabled or disabled to allow
the computer to be powered on by pressing the space bar on the keyboard.

• Chassis Intrusion Detection: Supports chassis-intrusion monitoring through
LDCM and the optional ASUS CIDB chassis sensor module.

10 ASUS MEL-B User’s Manual

II. FEATURES

Parts of the ASUS MEL-B Motherboard

Keyboard
Connector

Serial Connectors
COM 1/COM 2

Parallel Connector
PS/2 Mouse,USB,
IrDA Header

AGP Port
Wake-On-LAN Header

3 PCI Slots

Multi-I/O Chip

AT Power Connector
ATX Power Connector

Intel 440LX

AGPset

3 DIMM
Sockets

Socket 370

DIP

Switches

II. FEATURES

Motherboard Parts

Hardware Monitor

2 ISA Slots

SB-Link

Header

TM

Intel PIIX4

PCIset

Programmable

Flash EEPROM

Wake-On-Ring

Header

ASUS MEL-B User’s Manual 11

III. HARDWARE SETUP

ASUS MEL-B Motherboard Layout

PS/2

KB-PS2KB

P8

CPU_FAN

Keyboard

KBPWR

COM 1

Serial Ports

Motherboard Layout

III. H/W SETUP

USB/MIR

Multi-I/O

&
Keyboard
Controller

Hardware

Monitor

COM 2

PARALLEL

RT1A

P9

SBLINK

ATX Power Connector

PWR_FAN

FLOPPY

WOL_CON

Intel

440LX

AGPset

DIMM Socket 1 (64/72-bit, 168-pin module)
DIMM Socket 2 (64/72-bit, 168-pin module)
DIMM Socket 3 (64/72-bit, 168-pin module)

Accelerated Graphics Port

PCI Slot 1

PCI Slot 2

PCI Slot 3

ISA Slot 1

SMB

Intel

PIIX4

Chipset

CR2032 3V
Lithium Cell

CMOS Power

CL_RTC

Thermal Sensor

Socket 370

IDE2

IDE1

CHA_FAN

WOR

IDELED

IR

Row

0
1

2
3

4
5

DIP

Switches

ISA Slot 2

12 ASUS MEL-B User’s Manual

CHASIS

2Mbit Flash EEPROM
(Programmable BIOS)

Panel Connectors

III. HARDWARE SETUP

Motherboard Settings

1) KBPWR p. 14 Keyboard Power Up (Enable/Disable)

2) DIP6 p. 15 VIO Setting

3) DIP1,2,3 p. 16 CPU Bus Frequency

4) DIP7,8,9,10 p. 16 CPU Core:Bus Frequency Multiple

Expansion Slots

1) DIMM1,2,3 p. 18 168-Pin DIMM Memory Support

2) Socket 370 p. 19 Central Processing Unit (CPU) Socket

3) SLOT1, SLOT2 p. 20 16-bit ISA Bus Expansion Slots

4) PC I 1,2,3 p. 20 32-bit PCI Bus Expansion Slots

5) AGP p. 21 Accelerated Graphics Port

Connectors

1) KB-PS2KB p. 22 Keyboard Port Connector (6-pin female)

2) FLOPPY p. 22 Floppy Disk Drive Connector (34-1 pins)

3) PARALLEL p. 23 Parallel Port Connector (25-pin female)

4) COM1, COM2 p. 23 Serial Port COM1 and COM2 Connectors (9-pi n male)

5) IDE 1/IDE2 p. 24 Primary/Secondary IDE Connectors (T wo 40-1pins)

6) IDELED p. 24 IDE LED Activity Light (2 pins)

7) CHA_, CPU_, PWR_FAN p. 25 Chassis, CPU, Power Supply Fan Connectors (Three 3-pin)

8) WOL_CON p. 25 Wake-On-LAN Header (3 pins)

9) MSG.LED (PANEL) p. 26 System Message LED (2 pins)

10) SMI (PANEL) p. 26 SMI Switch Lead (2 pins)

11) PWR.SW (PANEL) p. 26 ATX Power & Soft-Off Switch Lead (2 pins)

12) RESET (PANEL) p. 26 Reset Switch Lead (2 pins)

13)

PWR.LED (

14)

KEYLOCK (

15) SPEAKER (PANEL) p. 26 System Warning Speaker Connector (4 pins)

16) USB/MIR P. 27 PS/2 Mouse/USB/IR Combo-Connector (18-1 pins)

17) IR p. 27 IrDA-Compliant Infrared Module Connector (5 pins)

18) ATXPWR p. 28 ATX Power Supply Connector (20 pins)

19) PS/2 p. 28 AT Power Supply Connector (20 pins)

20) SBLINK p. 29 SB-LinkTM Connector (6-1 pins)

21) SMB p. 29 SMBus Connector (5-1 pins)

22) WOR p. 30 Wake-On-Ring Header (2 pins)

23) CHASIS p. 30 Chassis Intrusion Sensor Lead (4-1 pins)

PANEL

PANEL

)

)

p. 26 System Power LED Lead (3-1 pins)
p. 26 Keyboard Lock Switch Lead (2 pins)

*

III. H/W SETUP

Layout Contents

*

The onboard hardware monitor uses the address 290H-297H so legacy ISA cards

must not use this address; otherwise, conflicts will occur.

ASUS MEL-B User’s Manual 13

Hardware Setup Steps

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

1. Make Motherboard Settings

2. Install System Memory Modules

3. Install the Central Processing Unit (CPU)

4. Install Expansion Cards

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

6. Setup the BIOS Software

1. Motherboard Settings

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

Motherboard Settings

III. H/W SETUP

work on your computer .

1. Unplug your computer when working on the inside.

III. HARDWARE SETUP

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 o r
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.

1. Keyboard Power Up (3-pin KBPWR)

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

KBPWR

3
2
1

Disable

(Default)

KBPWR

3
2
1

Enable

MEL-B Keyboard Power Up

14 ASUS MEL-B User’s Manual

III. HARDWARE SETUP

Motherboard Feature Settings (DIP Switches)

The motherboard’ s onboard features can be adjusted through the DIP switches. The
white block represents the switch’s position. The example below shows all the
switches in the OFF position.

OFF

12345678910

MEL-B DIP Switch

ON

ON

<Frequency Selector 1
<Frequency Selector 2
<Frequency Selector 3
<Reserved
<Reserved
<VIO Setting
<Frequency Ratio 1
<Frequency Ratio 2
<Frequency Ratio 3
<Frequency Ratio 4

2. VIO Setting (DIP6)

The onboard voltage regulator allows you to select the voltage supplied to the
DRAM, chipset, AGP, and the CPU’s I/O buffer. IMPORTANT! Setting this
jumper to Add 0.1 Volt may cause your system to become unstable. It is strongly
recommended that you leave this jumper on its default setting of Normal (3.5V).

Normal Add 0.1Volt

ON

123456 78910

ON

123456 78910

III. H/W SETUP

Motherboard Settings

MEL-B Voltage I/O

ASUS MEL-B User’s Manual 15

III. HARDWARE SETUP

3. CPU External (BUS) Frequency Selection (DIP1, 2, 3)

These DIP switches tell the clock generator what frequency to send to the CPU.
These allow the selection of the CPU’ s External frequency (or BUS Clock). The
BUS Clock times the BUS Ratio equals the CPU's Internal frequency (the ad­vertised CPU speed).

CPU/AGP
PCI BUS

MEL-B CPU BUS Frequency Selection

Motherboard Settings

III. H/W SETUP

4. CPU to BUS Frequency Multiple (DIP7, 8, 9, 10)

These DIP switches set the frequency multiple between the Internal frequency
of the CPU and the External frequency (called the BUS Clock) within the CPU.

3.0x(3/1) 5.5x(11/2)

12345678910

6.0x(6/1)

12345678910

ON

ON

→

50MHz

→

25MHz

12345678910

3.5x(7/2)

ON

12345678910

6.5x(13/2)

ON

12345678910

ON

4.0x(4/1)

ON

12345678910

7.0x(7/1)

ON

12345678910

83.3MHz
41MHz

12345678910

4.5x(9/2)

12345678910

7.5x(15/2)

12345678910

ON

ON

ON

68.4MHz

34.2MHz

ON

12345678910

5.0x(5/1)

ON

12345678910

8.0x(8/1)

ON

12345678910

75MHz

37.5MHz

12345678910

ON

12345678910

ON

66.8MHz

33.4MHz

ON

12345678910

60MHz
30MHz

12345678910

ON

MEL-B CPU : BUS Frequency Multiple

Set the DIP switches by the Internal speed of your processor as follows:

(BUS Frequency) (Frequency Multiple)

Intel CPU Model Speed Mult Freq. DIP1 DIP2 DIP3 DIP7 DIP8 DIP9 DIP10

Celeron (PPGA) 400MHz 6.0x 66MHz [OFF] [OFF] [OFF] [ON] [ON] [ON] [OFF]
Celeron (PPGA) 366MHz 5.5x 66MHz [OFF] [OFF] [OFF] [OFF] [OFF] [OFF] [ON]
Celeron (PPGA) 333MHz 5.0x 66MHz [OFF] [OFF] [OFF] [ON] [OFF] [OFF] [ON]
Celeron (PPGA) 300MHz 4.5x 66MHz [OFF] [OFF] [OFF] [OFF] [ON] [OFF] [ON]

16 ASUS MEL-B User’s Manual

III. HARDWARE SETUP

2. System Memory (DIMM)

NOTE: No hardware or BIOS setup is required after adding or removing memory.
This motherboard uses only Dual Inline Memory Modules (DIMMs). Sockets are

available for 3.3Volt (power level) unbuffered Synchronous Dynamic Random Ac-
cess Memory (SDRAM) of either 8, 16, 32, 64, 128MB, or 256MB. One side (with
memory chips) of the DIMM takes up one row on the motherboard.

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

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

W ARNING! Memory modules must have 18 chips or less. Memory modules with

more than 18 chips exceed specifications and may cause unstable operation.

Install memory in any combination as follows:

DIMM Location 168-pin DIMM Total Memory

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

Total System Memory (Max 768MB) =

General DIMM Notes

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

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

• BIOS shows SDRAM memory on bootup screen.

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

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

III. H/W SETUP

System Memory

ASUS MEL-B User’s Manual 17

DIMM Memory Installation

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. DIMM
modules are longer and have different pin contact on each side and therefore have a
higher pin density. SIMM modules have the same pin contact on both sides.

System Memory

III. H/W SETUP

III. HARDWARE SETUP

Lock

20 Pins 60 Pins 88 Pins

MEL-B 168-Pin DIMM Memory Sockets

The DIMMs must be 3.3V Unbuffered for this motherboard. T o determine the DIMM
type, check the notches on the DIMMs (see figure below).

168-Pin DIMM Notch Key Definitions (3.3V)

DRAM Key Position

RFU

Buffered

Unbuffered

Voltage Key Position

5.0V

Reserved

3.3V

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

18 ASUS MEL-B User’s Manual

III. HARDWARE SETUP

3. Central Processing Unit (CPU)

The motherboard provides a ZIF Socket 370. The CPU that came with the mother­board should have a fan attached to it to prevent overheating. If this is not the case
then purchase a fan before you turn on your system.

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

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

To install a CPU, first turn off your system and remove its cover. Locate the ZIF
socket and open it by first pulling the lever sideways away from the socket then
upwards to a 90-degree right angle. Insert the CPU with the correct orientation as
shown. The notched corner should point towards the end the of the lever. Because
the CPU has a corner pin for two of the four corners, the CPU will only fit in the one
orientation as shown. The picture is for reference only; you should have a CPU fan
that will cover the face of the CPU. W ith the added weight of the CPU fan, no force
is required to insert the CPU. Once completely inserted, close the socket’s lever
while holding down the CPU.

CPU

III. H/W SETUP

NOTE: Set the bus frequency and multiple for your Socket 370 processor.

Socket 370 CPU (Top)

Notch

MEL-B Socket 370

Socket 370 CPU (Bottom)

ASUS MEL-B User’s Manual 19

III. HARDWARE SETUP

4. Expansion Cards

WARNING! Make sure that you unplug your power supply when adding or

removing expansion cards or other system components. Failure to do so may
cause severe damage to both your motherboard and expansion cards.

Expansion Card Installation Procedure

1. Read the documentation for your expansion card and make any necessary hard­ware or software settings for your expansion card, such as jumpers.

2. Remove your computer system’s cover and the bracket plate on the slot you
intend to use. Keep the bracket for possible future use.

3. Carefully align the card’s connectors and press firmly.

4. Secure the card on the slot with the screw you removed above.

Expansion Cards

III. H/W SETUP

5. Replace the computer system’s cover.

6. Set up the BIOS if necessary

7. Install the necessary software drivers for your expansion card.

Assigning IRQs for Expansion Cards

Some expansion cards need to use an IRQ to operate. Generally, an IRQ must be
exclusively assigned to one use. In a standard design, there are 16 IRQs available
but most of them are already in use, leaving 6 IRQs free for expansion cards.

Both ISA and PCI expansion cards may require the use IRQs. System IRQs are
available for cards installed in the ISA expansion bus first, then the remaining IRQs
are available for PCI cards. Currently , there are two types of ISA cards. The original
ISA expansion card design, now referred to as legacy ISA cards, requires that you
configure the card’ s jumpers manually and then install it in any available slot on the
ISA bus. You may use the Microsoft Diagnostics (MSD.EXE) utility located in the
Windows directory to see a map of your used and free IRQs. If you use W indows 95,
the Resources tab under Device Manager displays the resource settings being used
by a particular device (to gain access, double-click the System icon under the Con-
trol Panel program). Ensure that no two devices share the same IRQs or your com­puter will experience problems when those two devices are in use at the same time.

(such as IRQ xx Used By ISA: Yes in PNP AND PCI SETUP)

20 ASUS MEL-B User’s Manual

III. HARDWARE SETUP

T o simplify this process this motherboard has complied with the Plug and Play (PNP)
specification which was developed to allow automatic system configuration when­ever a PNP-compliant card is added to the system. For PNP cards, IRQs are as­signed automatically from those available.

If the system has both Legacy and PNP ISA cards installed, IRQs are
assigned to PNP cards from those not used by Legacy cards. The PCI and PNP
configuration of the BIOS setup utility can be used to indicate which IRQs are being
used by Legacy cards. For older Legacy cards that do not work with the BIOS, you
can contact your vendor for an ISA Configuration Utility.

An IRQ number is automatically assigned to PCI expansion cards after those used
by Legacy and PNP ISA cards. In the PCI bus design, the BIOS automatically as­signs an IRQ to a PCI slot that has a card in it that requires an IRQ. To install a PCI
card, you need to set something called the INT (interrupt) assignment. Since all the
PCI slots on this motherboard use an INTA #, be sure that the jumpers on your PCI
cards are set to INT A.

Assigning DMA Channels for ISA Cards

Some ISA cards, both legacy and PnP, may also need to use a DMA (Direct Memory
Access) channel. DMA assignments for this motherboard are handled the same way
as the IRQ assignment process described earlier. You can select a DMA channel in
the PCI and PnP configuration section of the BIOS Setup utility.

IMPORTANT: To avoid conflicts, reserve the necessary IRQs and DMAs for legacy

ISA cards (under PNP AND PCI Setup of BIOS SETUP, choose Yes in IRQ xx Used By
ISA and DMA x Used By ISA for those IRQs and DMAs you want to reserve).

ISA Cards and Hardware Monitor

The onboard hardware monitor uses the address 290H-297H so legacy ISA cards
must not use this address or else conflicts will occur.

Accelerated Graphics Port

This motherboard provides an accelerated graphics port (AGP) slot to support a new
generation of graphics cards with ultra-high memory bandwidth, such as an ASUS
3D hardware accelerator.

DMA Channels

III. H/W SETUP

MEL-B Accelerated Graphics Port (AGP)

ASUS MEL-B User’s Manual 21

III. H/W SETUP

Connectors

III. HARDWARE SETUP

5. External Connectors

WARNING! Some pins are used for connectors or power sources. These are

clearly separated from jumpers in “Layout Contents.” Placing jumper caps over
these will cause damage to your motherboard.

IMPORTANT: Ribbon cables should always be connected with the red stripe on Pin
1 side of the connector. The four corners of the connectors are labeled on the
motherboard. Pin 1 is the side closest to the power connector on hard drives and some
floppy drives. IDE ribbon cables must be less than 18 in. (46 cm), with the second
drive connector no more than 6 in. (15 cm) from the first connector.

1. Keyboard Connector (5-pin)

This connector supports either a standard IBM-compatible, 101/102-key , or 104­key keyboard (Windows 95-compatible). Use a PS/2 keyboard adapter in order
to connect a PS/2 keyboard to this AT connector.

Keyboard Connector (5-pin female)

This motherboard accepts an AT Keyboard
Connector Plug as shown here.

MEL-B Keyboard Connector

2. Floppy drive connector (34-1 pin FLOPPY)

This connector supports the provided floppy drive ribbon cable. After connect­ing the single end to the board, connect the two plugs on the other end to the
floppy drives. (Pin 5 is removed to prevent inserting in the wrong orienta-

tion when using ribbon cables with pin 5 plugged).

Pin 1

Floppy Disk Drive Connector

MEL-B Floppy Disk Drive Connector

22 ASUS MEL-B User’s Manual

III. HARDWARE SETUP

3. Parallel Printer Connector (26-1 pin PARALLEL)

This connector supports the included parallel and PS/2 mouse connector set.
Connect the parallel ribbon cable to this connector and mount the bracket to the
case on an open slot. A PS/2 mouse connector is included for the USB/IR/Mouse
onboard connector if the optional USB/MIR connector is not used. You can
make available the parallel port and choose the IRQ through “Onboard Parallel
Port” in Chipset Features of BIOS SETUP. (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.

PARALLEL

Parallel Connector

PS/2 Mouse Connector

Pin 1

Connect the Red
stripe to Pin 1

MEL-B Parallel Connector

4. Serial Port Connectors (10-1 pin COM1/COM2)

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 serial port and choose the
IRQ through “Onboard Serial Port” in Chipset Features of BIOS SETUP. (Pin

10 is removed to prevent inserting in the wrong orientation when using
ribbon cables with pin 10 plugged).

Pin 1

COM 2

Pin 1

COM 1

Connectors

III. H/W SETUP

MEL-B Serial Port Connectors

ASUS MEL-B User’s Manual 23

5. Primary / Secondary IDE connectors (Two 40-1 pin IDE)

III. H/W SETUP

Connectors

III. HARDWARE SETUP

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, you must configure the
second drive to Slave mode by setting its jumper accordingly . Please 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 BIOS Features Setup of BIOS SETUP) (Pin 20 is removed

to prevent inserting in the wrong orientation when using ribbon cables with
pin 20 plugged).

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 up to four operating systems on each IDE drive
and select the boot disk through “Boot Sequence” in BIOS Features Setup.

Secondary IDE Connector

Pin 1

Primary IDE Connector

NOTE: Orient the red markings (usually zigzag)

MEL-B IDE Connectors

on the IDE ribbon cable to pin 1

6. IDE activity LED (2-pin IDELED)

This connector supplies power to the cabinet’s 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

MEL-B IDE Activity LED

24 ASUS MEL-B User’s Manual

III. HARDWARE SETUP

7. Chassis, CPU , & Power Supply Fan Connectors (3-pin CHA_, CPU_, PWR_F AN)

These connectors support cooling fans of 500mA (6 Watts) or less. Orientate
the fans so that the heat sink fins allow airflow to go across the onboard heat
sink(s) instead of the expansion slots. Depending on the fan manufacturer , the
wiring and plug may be different. The red wire should be positive, while the
black should be ground. Connect the fan’ s plug to the board taking into consid­eration the polarity of the this connector . NOTE: The “Rotation” signal is to

be used only by a specially designed fan with rotation signal.

WARNING! These connectors have power. Damage may occur to the mother-

board and/or the CPU fan if these connectors are incorrectly used.

CPU Fan Power

GND
+12V
Rotation

Power Supply Fan

GND

+12V

Rotation

Chassis Fan Power

MEL-B 12Volt Cooling Fan Power

8. Wake-On-LAN Connector (3-pin WOL_CON)

This connector connects to a LAN card with a Wake-On-LAN output, such as
the ASUS PCI-L101. The LAN card powers up the system when a wakeup
packet or signal is received from the network.

IMPORTANT: This feature requires that the W AKE On LAN Power Up Con­trol is set to Enabled (see Power Management Setup under BIOS SETUP) and

that your system has an ATX power supply with at least 720mA +5V standby
power.

Ground

Connectors

III. H/W SETUP

MEL-B Wake-On-LAN Connector

ASUS MEL-B User’s Manual 25

+5VSB

PME

9. Message LED Lead (2-pin MSG.LED)

10. System Management Interrupt Lead (2-pin SMI)

III. H/W SETUP

Connectors

11. ATX Power Switch/Soft Power Switch Lead (2-pin PWR.SW)

III. HARDWARE SETUP

This indicates whether a message has been received from a fax/modem. The
LED will remain lit when there is no signal and blink when there is data transfer
or messages waiting in the inbox. This function requires ACPI OS support.

This allows the user to manually place the system into a suspend mode or “Green”
mode where system activity will be instantly decreased to save electricity and
expand the life of certain components when the system is not in use. This 2-pin
connector (see the figure below) connects to the case-mounted suspend switch.
If you do not have a switch for the connector, you may use the “Turbo Switch”
since it does not have a function. SMI is activated when it detects a short to
open moment and therefore leaving it shorted will not cause any problems. May
require one or two pushes depending on the position of the switch. W ake-up can
be controlled by settings in the BIOS but the keyboard will always allow wake­up (the SMI lead cannot wake-up the system). If you want to use this connector,
“Suspend Switch” in Power Management Setup of BIOS SETUP section should
be on the default setting of Enable.

The system power can be controlled by a momentary switch connected to this
lead. Pushing the button once will switch the system between ON and SLEEP.
Pushing the switch while in the ON mode for more than 4 seconds will turn the
system off. The system power LED shows the status of the system’s power.

12. Reset Switch Lead (2-pin RESET)

This 2-pin connector connects to the case-mounted reset switch for rebooting
your computer without having to turn off your power switch This is a preferred
method of rebooting in order to prolong the life of the system’s power supply.

13. System Power LED (3-1 pin PWR.LED)

This 3-pin connector connects the system power LED, which lights when the
system is powered on and flashes when it is in sleep mode.

14. Keyboard Lock Switch Lead (2-pin KEYLOCK)

This 2-pin connector connects to the case-mounted key switch to allow key­board locking.

15. Speaker Connector (4-pin SPEAKER)

This 4-pin connector connects to the case-mounted speaker.

Speaker
Connector

Keyboard Lock

Power LED

Reset Switch

ATX Power Switch

SMI Lead

Message LED

*

Requires an ATX power supply.

MEL-B System Panel Connections

26 ASUS MEL-B User’s Manual

III. HARDWARE SETUP

16. USB, Infrared, PS/2 Mouse Module Connector (18-1 pin USB/MIR)

If you want to use USB or infrared (IrDA) devices, you need to purchase an exter­nal connector set. Otherwise, a PS/2 mouse connector is provided with the parallel
connector . The external connector set, which also includes a PS/2 mouse connec­tor, connects to the 18-pin block and mounts to an open slot on your computer’s
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 BIOS SETUP. See
IrDA-Compliant... connector for details on the infrared connector.

USB/MIR

9

18

1

10

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

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

Parallel Connector

PS/2 Mouse Connector

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

17. IrDA-Compliant infrared module connector (5-pin IR)

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 on the Back V iew and connect a ribbon cable
from the module to the motherboard according to the pin definitions.

Connectors

III. H/W SETUP

GND

(NC)

MEL-B Infrared Module Connector

ASUS MEL-B User’s Manual 27

IRTX

IRRX

+5V

Front View

Back View

IRTX
GND

IRRX

+5V

(NC)