Asus MEL-B User manual

R
MEL-B
Socket 370 Baby AT Motherboard
USER’S MANUAL

2ASUS MEL-B User’s Manual
USER'S NOTICE
Product Name: ASUS MEL-B
Manual Revision: 1.00 E336
Release Date: January 1999
No part of this manual, including the products and software described in it, may be repro-
duced, transmitted, transcribed, stored in a retrieval system, or translated into any language in
any form or by any means, except documentation kept by the purchaser for backup purposes,
without the express written permission of ASUSTeK COMPUTER INC. (“ASUS”).
ASUS PROVIDES THIS MANUAL “AS IS” WITHOUT WARRANTY OF ANY KIND,
EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
WARRANTIES OR CONDITIONS OF MERCHANTABILITYOR FITNESS FORAPAR-
TICULAR PURPOSE. IN NO EVENT SHALL ASUS, ITS DIRECTORS, OFFICERS,
EMPLOYEES OR AGENTS BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDEN-
TAL, OR CONSEQUENTIAL DAMAGES (INCLUDING DAMAGES FOR LOSS OF
PROFITS, LOSS OF BUSINESS, LOSS OF USE OR DATA, INTERRUPTION OF BUSI-
NESS AND THE LIKE), EVEN IF ASUS HAS BEEN ADVISED OF THE POSSIBILITY
OF SUCH DAMAGES ARISING FROM ANY DEFECT OR ERROR IN THIS MANUAL
OR PRODUCT.
Product warranty or service will not be extended if: (1) the product is repaired, modified or
altered, unless such repair, modification of alteration is authorized in writing byASUS; or (2)
the serial number of the product is defaced or missing.
Products and corporate names appearing in this manual may or may not be registered trade-
marks or copyrights of their respective companies, and are used only for identification or
explanation and to the owners’ benefit, without intent to infringe.
• Intel, LANDesk, and Pentium are registered trademarks of Intel Corporation.
• IBM and OS/2 are registered trademarks of International Business Machines.
• Symbios is a registered trademark of Symbios Logic Corporation.
• Windows and MS-DOS are registered trademarks of Microsoft Corporation.
• Adobe and Acrobat are registered trademarks of Adobe Systems Incorporated.
The product name and revision number are both printed on the product itself. Manual revi-
sions are released for each product design represented by the digit before and after the period
of the manual revision number. Manual updates are represented by the third digit in the manual
revision number.
For previous or updated manuals, BIOS, drivers, or product release information, contactASUS
at http://www.asus.com.tw or through any of the means indicated on the following page.
SPECIFICATIONS AND INFORMATION CONTAINED IN THIS MANUALARE FUR-
NISHED FOR INFORMATIONAL USE ONLY, AND ARE SUBJECT TO CHANGE AT
ANY TIME WITHOUT NOTICE, AND SHOULD NOT BE CONSTRUED AS A COM-
MITMENT BY ASUS. ASUS ASSUMES NO RESPONSIBILITY OR LIABILITY FOR
ANYERRORSORINACCURACIESTHATMAYAPPEARINTHIS MANUAL, INCLUD-
ING THE PRODUCTS AND SOFTWARE DESCRIBED IN IT.
Copyright © 1999 ASUSTeK COMPUTER INC. All Rights Reserved.

ASUS MEL-B User’s Manual 3
ASUS CONTACT INFORMATION
ASUSTeK COMPUTER INC. (Asia-Pacific)
Marketing
Address: 150 Li-Te Road, Peitou, Taipei, Taiwan 112
Telephone: [phone]
Fax: [phone]
Email: [email protected]
Technical Support
Tel (English): [phone] ext. 706
Tel (Chinese): [phone] ext. 701
Fax: [phone]
Email: [email protected]
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: [email protected]
Technical Support
Fax: [phone]
BBS: [phone]
Email: [email protected]
WWW: www.asus.com
FTP: ftp.asus.com.tw/pub/ASUS
ASUS COMPUTER GmbH (Europe)
Marketing
Address: Harkort Str. 25, 40880 Ratingen, BRD, Germany
Telephone: [phone]
Fax: [phone]
Email: [email protected]
Technical Support
Hotline: [phone]
BBS: 49-2102-448690
Email: [email protected]
WWW: www.asuscom.de
FTP: ftp.asuscom.de/pub/ASUSCOM

4ASUS MEL-B User’s Manual
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

ASUS MEL-B User’s Manual 5
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

6ASUS MEL-B User’s Manual
FCC & DOC COMPLIANCE
FederalCommunications Commission Statement
This device complies with FCC Rules Part 15. Operation is subject to the following
two conditions:
• This device may not cause harmful interference, and
• This device must accept any interference received, including interference that
may cause undesired operation.
This equipment has been tested and found to comply with the limits for a Class B
digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to
provide reasonable protection against harmful interference in a residential installa-
tion. This equipment generates, uses and can radiate radio frequency energy and, if
not installed and used in accordance with manufacturer’s instructions, may cause
harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause
harmful interference to radio or television reception, which can be determined by
turning the equipment off and on, the user is encouraged to try to correct the interfer-
ence 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. Without sufficient
circulation, the processor could overheat and damage both the processor and the
motherboard. You may install an auxiliary fan, if necessary.
CanadianDepartment of Communications Statement
This digital apparatus does not exceed the Class B limits for radio noise emissions
from digital apparatus set out in the Radio Interference Regulations of the Canadian
Department of Communications.

ASUS MEL-B User’s Manual 7
I. INTRODUCTION
I. INTRODUCTION
Sections/Checklist
How this manual is organized
This manual is divided into the following sections:
I. Introduction Manual information and checklist
II. Features Information and specifications concerning this product
III. 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
(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)

8ASUSMEL-BUser’sManual
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
•IntelProcessorSupport:SupportsIntelCeleronprocessors(300MHzandfaster)
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),offeringenhancedACPI forWindows 98 compatibility, built-infirm-
ware-based virus protection, and autodetection of most devices for virtually au-
tomatic 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 sup-
porting 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 sta-
tus through the onboard hardwareASIC and bundled LDCM orASUS PC Probe.
•Wake-On-LAN Header: Supports Wake-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, toAWE64D 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 ManagementInterface (DMI): Supports DMI through BIOS, which
allows hardware to communicate within a standard protocol creating a higher
level of compatibility. (Requires DMI-enabled components.)
•UltraDMA/33BM 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.

ASUS MEL-B User’s Manual 9
II. FEATURES
II. FEATURES
Features
Performance
• ACPIReady:ACPI(Advanced Configuration and Power Interface) isalsoimple-
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. With these features implemented in the OS,
PCs can be ready around the clock, yet satisfy all the energy saving standards.
To fully utilize the benefits ofACPI, anACPI-supported OS such as the succes-
sor 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 technol-
ogy is compatible with existingATA-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’98Compliant: BoththeBIOSand 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.
• 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.

10 ASUSMEL-BUser’sManual
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.
• SystemResourcesAlert:Today’s operating systems such as Windows 95, Win-
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 moni-
tor will warn the user before the system resources are used up to prevent pos-
sible application crashes. Suggestions will give the user information on manag-
ing 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
usercanaccessvitalinformationfromtheircomputerfrom anywhere in the world!
• Message LED (requires ACPI OS support): Chassis LEDs now act as infor-
mation providers. Through the way a particular LED illuminates, the user can
determine the stage the computer is in.A simple glimpse provides useful infor-
mation 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.

ASUS MEL-B User’s Manual 11
Parts of the ASUS MEL-B Motherboard
II. FEATURES
II. FEATURES
Motherboard Parts
Serial Connectors
COM 1/COM 2
Multi-I/O Chip
Wake-On-Ring
Header
Intel 440LX
AGPset
ATX Power Connector
AT Power Connector
Keyboard
Connector
Parallel Connector
PS/2 Mouse,USB,
IrDAHeader
AGP Port
Socket 370
3 DIMM
Sockets
Hardware Monitor
2 ISA Slots
3 PCI Slots
DIP
Switches
Wake-On-LAN Header
SB-Link
TM
Header Intel PIIX4
PCIset Programmable
Flash EEPROM

12 ASUSMEL-BUser’sManual
III. HARDWARE SETUP
ASUS MEL-B Motherboard Layout
Motherboard Layout
III. H/W SETUP
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)
Row
CHASIS
Accelerated Graphics Port
FLOPPY
ATX Power Connector
2Mbit Flash EEPROM
(Programmable BIOS)
PCI Slot 1
PCI Slot 2
PCI Slot 3
ISA Slot 2
ISA Slot 1
CR2032 3V
Lithium Cell
CMOS Power
IDE1
IDE2
Socket 370
Thermal Sensor
PWR_FAN
KBPWR
IR
IDELED
Panel Connectors
CPU_FAN
CHA_FAN
CL_RTC
SMB
KB-PS2KB
Intel
440LX
AGPset
3
2
1
0
5
4
Keyboard
PARALLEL
USB/MIR
WOL_CON
SBLINK
PS/2
P8
P9
Serial Ports
COM 2
COM 1
Hardware
Monitor
DIP
Switches
Multi-I/O
&
Keyboard
Controller
Intel
PIIX4
Chipset
RT1A
WOR

ASUS MEL-B User’s Manual 13
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) PCI1,2,3 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 SerialPortCOM1and COM2 Connectors (9-pinmale)
5) IDE1/IDE2 p. 24 Primary/Secondary IDE Connectors (Two 40-1pins)
6) IDELED p. 24 IDE LEDActivity Light (2 pins)
7) CHA_, CPU_, PWR_FAN p.25 Chassis,CPU,PowerSupplyFanConnectors(Three3-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 ( PANEL ) p. 26 System Power LED Lead (3-1 pins)
14) KEYLOCK ( PANEL ) p. 26 Keyboard Lock Switch Lead (2 pins)
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-Link
TM
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)
*
The onboard hardware monitor uses the address 290H-297H so legacy ISA cards
must not use this address; otherwise, conflicts will occur.
Layout Contents
III. H/W SETUP

14 ASUS MEL-B User’s Manual
III. HARDWARE SETUP
Motherboard Settings
III. H/W SETUP
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 asSCSI
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.
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 300mAon 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.
MEL-B Keyboard Power Up
KBPWR KBPWR
Enable
1
2
3
Disable
(Default)
1
2
3

ASUS MEL-B User’s Manual 15
III. HARDWARE SETUP
III. H/W SETUP
Motherboard Settings
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.
MEL-B DIP Switch
OFF
ON
12345678910
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).
ON
12345678910
ON
12345678910
MEL-B Voltage I/O
Normal Add 0.1Volt

16 ASUS MEL-B User’s Manual
III. HARDWARE SETUP
Motherboard Settings
III. H/W 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 ad-
vertised CPU speed).
MEL-B CPU BUS Frequency Selection
CPU/AGP
PCI BUS →
→66.8MHz
33.4MHz
ON
12345678910
60MHz
30MHz
ON
12345678910
ON
12345678910
83.3MHz
41MHz 68.4MHz 34.2MHz
ON
12345678910
75MHz
37.5MHz
ON
12345678910
50MHz
25MHz
ON
12345678910
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.
MEL-B CPU : BUS Frequency Multiple
8.0x(8/1)
ON
12345678910
7.5x(15/2)
ON
12345678910
7.0x(7/1)
ON
12345678910
6.5x(13/2)
ON
12345678910
ON
12345678910
6.0x(6/1)
5.0x(5/1)
ON
12345678910
4.5x(9/2)
ON
12345678910
4.0x(4/1)
ON
12345678910
3.5x(7/2)
ON
12345678910
ON
12345678910
3.0x(3/1) 5.5x(11/2)
ON
12345678910
Set the DIP switchesbythe 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]

ASUS MEL-B User’s Manual 17
III. HARDWARE SETUP
System Memory
III. H/W SETUP
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 (Ex-
tended Data Output) chips.
• BIOS shows SDRAM memory on bootup screen.
• 8chips/sidemodulesdonot support ECC, only 9 chips/sidemodulessupportECC.
• Single-sided DIMMs come in 16, 32, 64,128MB; double-sided come in 32, 64,
128, 256MB.
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.
Memoryspeedsetup is recommended through SDRAM Configuration under “Chipset
Features Setup” in BIOS SETUP.
WARNING!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) =

18 ASUS MEL-B User’s Manual
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.
MEL-B 168-Pin DIMM Memory Sockets
20 Pins 60 Pins 88 Pins
Lock
TheDIMMsmustbe3.3VUnbufferedfor this motherboard.To determine the DIMM
type, check the notches on the DIMMs (see figure below).
168-Pin DIMM Notch Key Definitions (3.3V)
DRAM Key Position Voltage Key Position
Unbuffered
RFU
Buffered Reserved
3.3V
5.0V
The notches on the DIMM module will shift between left, center, or right to identify
the typeand alsoto prevent the wrongtype from being inserted intothe DIMM slot on
the motherboard.You must ask your retailer the correct DIMM type before purchas-
ing. This motherboard supports four clock signals.
III. HARDWARE SETUP
System Memory
III. H/W SETUP

ASUS MEL-B User’s Manual 19
III. HARDWARE SETUP
CPU
III. H/W SETUP
3. Central Processing Unit (CPU)
The motherboard provides a ZIF Socket 370. The CPU that came with the mother-
board 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. Without sufficient
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. With 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.
NOTE: Set the bus frequency and multiple for your Socket 370 processor.
Socket 370 CPU (Top) Socket 370 CPU (Bottom)
Notch
MEL-B Socket 370

20 ASUS MEL-B User’s Manual
III. HARDWARE SETUP
Expansion Cards
III. H/W 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 hard-
ware 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.
5. Replace the computer system’s cover.
6. Set up the BIOS if necessary
(such as IRQ xx Used By ISA: Yes in PNPAND PCI SETUP)
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 ISAcards. 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 useWindows 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 com-
puter will experience problems when those two devices are in use at the same time.