American Megatrends MegaRUM User manual

MegaRUM
Dual Pentium® II
PCI ISA Motherboard
User's Guide
MAN-758
6/5/97

MegaRUM PCI Motherboard User’s Guideii
© Copyright 1997 American Megatrends, Inc.
All rights reserved.
American Megatrends, Inc.
6145F Northbelt Parkway
Norcross, GA 30071
This publication contains proprietaryinformation which is protected by copyright. No part of this publication may be reproduced,
transcribed, stored in a retrieval system, translated into any language or computer language, or transmitted in any form whatsoever
without the prior written consent of the publisher, American Megatrends, Inc.
Limited Warranty
Buyer agrees if this product proves to be defective, that American Megatrends, Inc. is only obligated to replace or refund the purchase
price of this product at American Megatrend's discretion according to the terms and conditions on the motherboard warranty card.
American Megatrends shall not be liable in tort or contract for any loss or damage, direct, incidental or consequential. Please see the
Warranty Registration Card shipped with this product for full warranty details.
Limitations of Liability
In no event shall American Megatrends be held liable for any loss, expenses, or damages of any kind whatsoever, whether direct,
indirect, incidental, or consequential, arising from the design or use of this product or the support materials provided with the product.
Trademarks
VESA is a registered trademark of the Video Electronics Standards Association.
Intel, Pentium. Pentium Pro, and Pentium II are registered trademarks of Intel Corporation.
MS-DOS, Microsoft Word, and Microsoft are registered trademarks of Microsoft Corporation. Microsoft
Windows, Windows NT, and Windows 95 are trademarks of Microsoft Corporation.
IBM, AT, XT, CGA, VGA, PS/2, OS/2, and EGA are registered trademarks of International Business Machines
Corporation.
Fujitsu is a registered trademark of Fujitsu America, Inc.
Motorola is a registered trademark of Motorola Corporation.
Hitachi is a registered trademark of Hitachi America, Ltd.
PNY is a registered trademark of PNY Corporation.
Oki is a registered trademark of Oki America, Inc.
NEC is a registered trademark of NEC Corporation.
Samsung is a registered trademark of Samsung Electronics Corporation.
Siemens is a trademark of Siemens Corporation.
Mitsubishi is a registered trademark of Mitsubishi Electronics of America.
Micron is a registered trademark of Micron Corporation.
SCO, Unix, and UnixWare are registered trademarks of the Santa Cruz Operation, Inc.
Toshiba is a registered trademark of Kabushiki Kaisha Toshiba.
All other brand and product names are trademarks or registered trademarks of their respective companies.
Revision History
6/5/97 Initial release of preliminary version.

Preface iii
Preface
To the OEM Thank you for purchasing the high performance American Megatrends
MegaRUM Dual Pentium II PCI ISA motherboard. This product is a state of the
art motherboard that includes the famous AMIBIOS. It is assumed that you
have also licensed the rights to use the American Megatrends documentation
for the American Megatrends MegaRUM motherboard.
This manual was written for the OEM to assist in the proper installation and
operation of this motherboard. This manual describes the specifications and
features of the MegaRUM PCI motherboard. It explains how to assemble a
system based on the MegaRUM PCI motherboard and how to use the
AMIBIOS that is specifically designed for this motherboard.
This manual is not meant to be read by the computer owner who purchases a
computer with this motherboard. It is assumed that you, the computer
manufacturer, will use this manual as a sourcebook of information, and that
parts of this manual will be included in the computer owner's manual.
Technical SupportIf an American Megatrends motherboard fails to operate as described or you
are in doubt about a configuration option, please call technical support at 770-
246-8600.
Web Site We invite you to access the American Megatrends world wide web site at:
http://www.ami.com.

MegaRUM PCI Motherboard User’s Guideiv
Packing List
You should have received the following:
•aMegaRUMDualPentiumIIPCIISAmotherboard,
•twoserialcables,
•oneparallelcable,
•oneVGAcable,
•twoVGAdriverdiskettesforWindows95andWindowsNTV3.5x,
•5SCSIdriverdiskettes,
•adiskettecontainingtheAmericanMegatrendsDMIWizard95softwareutility,
•TheDMI Wizard 95 User’s Guide,
•the SystemGuru User’s Guide,
•4diskettescontainingtheSystemGuruServerManagementSoftwareforWindowsNT,
•aWarrantyCard,and
•theAmerican Megatrends MegaRUM Dual Pentium II PCI ISA Motherboard User's Guide.
Warning
Do not use 16 MB x 36 (64 MB) SIMMs that have 36 chips per SIMM.
This type of 16 MB SIMM does not work reliably because of
excessive loading on the motherboard circuitry. If you must use 64
MB SIMMs, use only SIMMs thathave 12 or 8 chips per SIMM.
Do not use 70 ns SIMMs. The system memory timing cycle onthis
motherboard are very sensitive. This motherboard does not work
reliably with 70 ns SIMMs.

Chapter 1 Hardware Installation 1
1Hardware Installation
Overview
The American Megatrends MegaRUM PCI Dual Pentium II ISA motherboard
features include:
•two Intel Pentium II CPUs operating at 120, 133, 150, 166, 180, 200, 210, 233,
240, 266 MHz or higher speeds ,
•up to 1 GB of system memory on the motherboard,
•parity checking or ECC (Error Checking and Correction),
•PCI local bus throughput of 132 megabytes per second,
•two Ultra Wide SCSI channels operating at 40 MBs,
•specially designed for the American Megatrends RAID Upgrade controller
cards,
•onboard ATI Rage II PCI VGA controller with 2 MB of synchronous
graphics RAM,
•the American Megatrends SystemGuru server management software,
•two ISA expansion slots, and
•sixPCIexpansionslots.
CPUs The MegaRUM motherboard will support all Intel Slot1 CPUs operating at 233
MHz, 266 MHz, or faster speeds.
PCI Bus Speed AMIBIOS automatically configures the PCI slots. The PCI slots are
synchronous with the CPU clock:
CPUExternalClockFrequency PCIExpansionSlotFrequency
66MHz 33MHz
60MHz 30MHz
Cont’d

MegaRUM PCI Motherboard User’s Guide2
Overview, Continued
Onboard I/O The MegaRUM motherboard includes:
•an onboard ATI Rage II PCI VGA controller with 2 MB of synchronous
graphics memory,
•two onboard Symbios Logic 53C875 SCSI controllers that provide 2 40
MBs ultra wide SCSI channels and one ultra wide/narrow SCSI channel,
•two 40-pin IDE connectors for 1 – 4 IDE drives,
•a 34-pin floppy drive connector,
•two serial port connectors,
•a 25-pin parallel port connector,
•a keyboard DIN connector,
•two 4-pin USB ports, and
•a9-pinbergmouseconnector.
Server Management Software The American Megatrends SystemGuru server management
software is included with the MegaRUM motherboard. SystemGuru uses the
I2C interface to constantly monitor and report the CPU temperature, fan speed,
ECC memory errors, ambient temperature, CPU voltage, system voltage and
other user-specified system status information to any remote client computer.
See the American Megatrends SystemGuru User’s Guide for additional
information.
Onboard PCI VGA The PCI VGA on the MegaRUM motherboard is supported by the ATI 3D
RAGE II 264GT PCI Graphics Controller chip. The PCI VGA features are:
•2MBSGRAM(notupgradable),
•aVGAcableisincluded,and
•videodriversforWindows95andWindowsNTwillbeprovided.
You can download video drivers for all other operating systems from the ATI
BBS at 905-764-9404. Make sure you load the ATI 3D RAGE II drivers from the
diskette provided. Windows95 auto detection tries to load the ATI Mach 64
drivers, which will not function properly.

Chapter 1 Hardware Installation 3
MegaRUM PCI Dimensions
The motherboard is approximately 12.25” by 13.8”. The motherboard height
restrictions are shown below:
Warning
This motherboard contains sensitive electronic components
that can be easily damaged by static electricity. Follow the
antistatic instructions carefully to ensure correct installation
and to avoid damage.

MegaRUM PCI Motherboard User’s Guide4
MegaRUM PCI Motherboard Layout

Chapter 1 Hardware Installation 5
Step 1 Unpack the Motherboard
Step Action
1Inspect the cardboard carton for obvious damage. If
damaged, call 770-246-8645. Leave the motherboard in its
original packing.
2Perform all unpacking and installation procedures on a
ground-connected anti-static mat. Wear an anti-static
wristband grounded at the same point as the anti-static
mat. Or use a sheet of conductive aluminum foil grounded
through a 1 megohm resistor instead of the anti-static mat.
Similarly, a strip of conductive aluminum foil wrapped
around the wrist and grounded through a 1 megohm
resistor serves the same purpose as the wristband.
3Inside the carton, the motherboard is packed in an
anti-static bag, and sandwiched between sheets of
sponge. Remove the sponge and the anti-static bag. Place
the motherboard on a grounded anti-static surface
component side up. Save the original packing material.
4Inspect the motherboard for damage. Press down on all
ICs mounted in sockets to verify proper seating. Do not
apply power to the motherboard if it has been damaged.
5If the motherboard is undamaged, it is ready to be
installed.
Set Jumpers Set all jumpers and install the CPU before placing the motherboard in the
chassis.
Avoid Static Electricity
Static electricity can damage the motherboard and other computer components.
Keep the motherboard in the anti-static bag until it is to be installed. Wear an
anti-static wrist grounding strap before handling the motherboard. Make sure
you stand on an anti-static mat when handling the motherboard.
Avoid contact with any component or connector on any adapter card, printed
circuit board, or memory module. Handle these components by the mounting
bracket.

MegaRUM PCI Motherboard User’s Guide6
Step 2 Configure CPU Speed
If using two CPUs with different speed ratings, set the motherboard jumpers to
the lower CPU speed. J21 and J24 select the CPU speed. The drawings on the
next screens show how J24 and J21 should look for each possible CPU speed:
CPUSpeed J21 J24
120MHz OPEN ShortPins1-2,
ShortPins3-4
ShortPins5-6
ShortPins7-8
133MHz Shorted ShortPins1-2,
ShortPins3-4
ShortPins5-6
ShortPins7-8
150MHz OPEN ShortPins3-4
ShortPins5-6
ShortPins7-8
166MHz Shorted ShortPins3-4
ShortPins5-6
ShortPins7-8
180MHz OPEN ShortPins1-2
ShortPins5-6
ShortPins7-8
200MHz Open ShortPins1-2
ShortPins5-6
ShortPins7-8
210MHz OPEN ShortPin5-6
ShortPin7-8
233MHz Shorted ShortPin5-6
ShortPin7-8
240MHz OPEN ShortPins1-2
ShortPins3-4
ShortPins7-8
266MHz Shorted ShortPins1-2
ShortPins3-4
ShortPins7-8
Important
Please contact American Megatrends technical support at
770-246-8645 to support a CPU running at other speeds.
Cont’d

Chapter 1 Hardware Installation 7
Step 2 Configure CPU Speed, Continued
Cont’d

MegaRUM PCI Motherboard User’s Guide8
Step 2 Configure CPU Speed, Continued

Chapter 1 Hardware Installation 9
Step 3 Configure CPU Voltage
J5 and J15 Each CPU can be independently set to the correct CPU core voltage. J5 sets the
voltage for the CPU in CPU Slot1. J15 sets the voltage for the CPU in Slot2.
CoreCPUVoltage J5andJ15Setting
3.50V ShortPins3-4
ShortPins5-6
ShortPins7-8
ShortPins9-10
3.40V ShortPins3-4
ShortPins5-6
ShortPins7-8
3.3V(FactorySetting) ShortPins3-4
ShortPins5-6
ShortPins9-10
3.2V ShortPins3-4
ShortPins5-6
3.1V ShortPins3-4
ShortPins7-8
ShortPins9-10
3.0V ShortPins3-4
ShortPins7-8
2.9V ShortPins3-4
ShortPins9-10
2.8V ShortPins3-4
2.7V ShortPins5-6
ShortPins7-8
ShortPins9-10
2.6V ShortPins5-6
ShortPins7-8
2.5V ShortPins5-6
ShortPins9-10
2.4V ShortPins5-6
2.3V ShortPins7-8
ShortPins9-10
2.2V ShortPins7-8
2.1V ShortPins9-10
2.05V ShortPins1-2
ShortPins3-4
ShortPins5-6
ShortPins7-8
ShortPins9-10
2.0V ShortPins1-2
ShortPins3-4
ShortPins5-6
ShortPins7-8
1.95V ShortPins1-2
ShortPins3-4
ShortPins5-6
ShortPins9-10
1.90V ShortPins1-2
ShortPins3-4
ShortPins5-6
1.85V ShortPins1-2
ShortPins3-4
ShortPins7-8
ShortPins9-10
1.8V ShortPins1-2
ShortPins3-4
ShortPins7-8
NoCPU None

MegaRUM PCI Motherboard User’s Guide10
Step 4 Install Additional Voltage Regulator
One Voltage Regulator Module (VRM) is shipped with every MegaRUM
motherboard. You need another VRM if you install two CPUs. You can order
VRMs for Intel Pentium II CPUs from:
Manufacturer PartNumber AMIPartNumber
VXI 073-20715-02 MDL-P681-V5A140
Corsair SPX560KM MDL-P681-V5A140

Chapter 1 Hardware Installation 11
Step 5 Connect CPU Fans
J1 and J7 (shown below) are 3-pin bergs that connect the fan on the CPU heat
sink to the motherboard power. J1 is the CPU fan connector for the CPU in CPU
Slot1. J7 is the CPU fan connector for the CPU in CPU Slot2.
J1, J7, and
J23 pinout
+12V
Ground Pin 1
Fan Sense
All Pentium II CPUs are shipped witha heat sink and a CPU fan. The
connector from the CPU fan usually has three leads (has red, yellow, and black
leads). Connect the Red lead to Pin 3 (+12V). Make sure that you use fans
that have 3 leads. The 3rd (yellow) lead should provide a tachometer output to
permit the fan speed to be monitored by the onboard server management
hardware. If you must use fans with only 2 leads, connect the red lead to Pin 3.
J23 Chassis Fan J23 is a 3-pin berg located near the VRM for the CPU 2 socket. The pinout is
the same for J23 as it is for J1 and J7. J23 provides +12V power to the main
chassis fan. The chassis fan should provide a tachometer output on Pin 3 so it
can be monitored by the onboard server management hardware.
Step 6 Install CPU
The Pentium II CPUs are on Intel Slot1 adapter cards. Insert the Slot1 cards into
the CPU card sockets on the motherboard. The CPU Slot1 sockets are below
the SIMM sockets.
Warning
Improper CPU installation can damage the CPU and the
motherboard. You must follow the procedures in this section
exactly as documented. Make sure you wear an antistatic
wristband while installing the CPU. Follow all antistatic
procedures.

MegaRUM PCI Motherboard User’s Guide12
Step 7 Install Memory
System Memory There are eight 32-bit SIMM (Single Inline Memory Module) sockets. System
memory must be populated one bank at a time. Each bank has two sockets.
Each bank must be populated with the same type of SIMM. If a 4 MB SIMM is
installed in the first socket in Bank0, then the same type of 4 MB SIMM must
be installed in the second Bank0 SIMM socket. The minimum amount of
system memory supported by the MegaRUM PCI is 8 MB. Each socket can
hold one SIMM. You can use:
•1MBx32(or36),
•2MBx32(or36),
•4MBx32(or36),
•8MBx32(or36),
•16MBx32(or36),or
•32MBx32(or36)SIMMs.
The MegaRUM motherboard will support 128 MB SIMMs when they become
available, permitting up to 1 GB of system memory to be installed on the
motherboard.
Fast Page Mode, EDO, and Burst EDO SIMMs cannot be mixed. The
motherboard supports SIMMs operating at 60 or 70 ns (RAS access time). Set
the Chipset SetupDRAM Speed (ns)option correctly.
Memory Display System memory is reported by AMIBIOS as it boots and again when the
AMIBIOS System Configuration Screen is displayed just before the operating
system boots. The memory displayed by AMIBIOS on the System
Configuration Screen is 384 KB less than the total memory installed.
Cont’d

Chapter 1 Hardware Installation 13
Step 7 Install Memory, Continued
Select SIMMs SIMMs must meet the following specifications:
Parameter Specification
PageMode FAST
Refresh CASbeforeRAS
tCAC ≤20ns
tRAC ≤80ns
tAA ≤45ns
tRP 70ns
tCPA ≤45ns
SIMM Part Numbers
Type Manufacturer PartNumber
1MBx36 Micron MT12D136M-7
“Mitsubishi MH1M36ADJ-7
“PNY P361000-70
“Motorola MCM36100AS-70
“Oki MSC2355-70YS12
“Samsung KMM5361000AV-7
2MBx36 PNY P362000-70
“Samsung EMM53620036-70
4MBx36 Micron MT12D436M-7
“Mitsubishi MH4M36SAJ-7
“Motorola MCM36400S-70
“PNY P364000-70
“Samsung KMM5364100-7
8MBx36 Motorola MCM36800S-70
“PNY P368000-707
“Samsung KMM5368100-7
16MBx36 Samsung KMM53616000AKG-6
Cont’d

MegaRUM PCI Motherboard User’s Guide14
Step 7 Install Memory, Continued
Installing SIMMs The four SIMM sockets on the motherboard can be filled with either 1 MB x 32
(or 36), 2 MB x 32 (or 36), 4 MB x 32 (or 36), 8 MB x 32 (or 36), or 16 MB x 32 (or
36) SIMMs.
Place the motherboard on an anti-static mat. With the component side of the
SIMM facing you, firmly push the SIMM into the socket at an angle, then push
it up. When properly inserted, the SIMM clicks into place as the latching pins
engage. The SIMM installation process is shown below:

Chapter 1 Hardware Installation 15
Step 8 Install the Motherboard
The motherboard mounting hole pattern is shown below. Standoffs and
mounting screws are not supplied with the motherboard. The chassis
manufacturer should supply these parts.
Step Action
1Placethechassisonananti-staticmat.Connectthechassistogroundtoavoidstatic
damageduringinstallation.Connectanalligatorclipwithawireleadtoany
unpaintedpartofthechassis.Groundtheotherendoftheleadatthesamepointas
thematandthewristband.
2Rotatethechassissothefrontistotheright,andtherearistotheleft.Thesidefacing
youiswherethemotherboardismounted.Thepowersupplyismountedatthefarend
ofthechassis.
3Holdthemotherboard,component-sideup,withtheedgewiththeSIMMsockets
towardyouandtheedgewiththepowersupplyconnectorawayfromyou.The
keyboard,mouse,andvideoconnectorsshouldbetotheleft.
4Carefullyslidethemotherboardintothechassis.Makecertaintheedgeconnectorsfit
theportsintherearofthechassis.Themotherboardshouldrestlevelwiththe
chassis.
5Placethemountingscrewsintheholesprovidedandtightenthem.Ifnecessary,shift
themotherboardslightlytoalignthemountingholesonthemotherboardwiththe
holesonthechassis,
Warning
If using metallic screws, make sure you use them only in
the plated mounting holes.
If using metallic screws, make sure the head of the screw
fits completely inside the plated mounting holes.

MegaRUM PCI Motherboard User’s Guide16
Step 9 Attach Cables
Connectors The MegaRUM PCI motherboard includes many connectors. Connection
instructions, illustrations of connectors, and pinouts are supplied in the
following pages. A list of all connectors described in this section follows:
Connector
PowersupplyconnectorsP1,P2,P3,andP4
DrainCMOSRAMpower–J35
KeyboardconnectorJ12
PS/2mouseconnectorJ2
ChassisintrusionLED–J29
ExternalSMIconnector–J18
DisableonboardVGA–J14
HardwareresetswitchJ28
SpeakerJ46
SCSIactivityLED–J40
KeyboardlockconnectorJ41
TurboLEDconnectorJ33
IDELEDconnectorJ38
USBport1connectorJ19
USBport2connectorJ20
Systemoverride–J47
AMI-specificVGAcable–J16
DisableVGAinterrupt–J13
Serialport1connectorJ9
Serialport2connectorJ8
ParallelportconnectorJ3
FloppyconnectorJ4
IDEchannel0connectorJ10
IDEchannel1connectorJ11
SCSIchannel1(Wide)–J44
SCSIchannel1(Narrow)–J36
SCSIchannel2(Wide)–J45
SCSIchannel2(Narrow)–J37
Cont’d