American Megatrends Enterprise-II User manual

American Megatrends, Inc.
Series 16
Enterprise-II
80486 EISA
Motherboard
User's Guide
MAN-616
10/21/92

© Copyright 1992 American Megatrends, Inc.
All rights reserved.
American Megatrends, Inc.
6145F Northbelt Parkway
Norcross, GA 30071
This publication contains proprietary information 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 Enterprise-II 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
Fujitsu is a registered trademark of Fujitsu America, Inc.
IBM, AT, VGA, OS/2, PS/2, and EGA are registered trademarks of International Business Machines
Corporation. XT and CGA are trademarks of International Business Machines Corporation.
Intel and i486 are registered trademarks of Intel Corporation.
MS-DOS, Xenix, and Microsoft are registered trademarks of Microsoft Corporation.
Mitsubishi is a registered trademark of Mitsubishi Electronics of America.
NEC is a registered trademark of NEC Corporation.
Oki is a registered trademark of Oki America, Inc.
Siemens is a trademark of Siemens Corporation.
Toshiba is a registered trademark of Kabushiki Kaisha Toshiba.
Unix is a registered trademark of American Telephone and Telegraph Company Bell Laboratories.
Weitek is a trademark of Weitek, Inc.
Revision History
March 3, 1992 Added documentation for Rev G
features.

American Megatrends Enterprise-II Motherboard User's Guide
iii
Table of Contents
Chapter 1 System Overview............................................................................ 1
Chapter 2 Installation...................................................................................... 9
Unpacking the Motherboard............................................................... 9
Installation Steps.............................................................................. 11
Step 1 Set Switch and Jumper Options............................. 12
Step 2 Install Memory....................................................... 15
Step 3 Install Coprocessor................................................ 19
Step 4 Install the Motherboard.......................................... 20
Step 5 Connect the Power Supply .................................... 21
Step 6 Connect the Keyboard Cable................................. 25
Step 7 Connect the Mouse................................................ 25
Step 8 Connect Cables..................................................... 26
Step 9 Install Adapter Cards ............................................. 30
Step 10 Test and Configure .............................................. 36
Chapter 3 BIOS Power-On Self Test (POST)................................................. 39
POST Phases................................................... 39
BIOS Error Reporting........................................ 39
Beep Codes...................................................................... 40
AMIBIOS Displayed Error Messages ................................ 41
EISA Error Messages ....................................................... 43
ISA BIOS NMI Messages.................................................. 43
EISA BIOS NMI Error Messages ...................................... 43
BIOS Configuration Summary Screen............................... 44
POST Memory Test.......................................................... 44
Chapter 4 AMIBIOS Setup.............................................................................. 45
Section 1 Running AMIBIOS Setup .................................................. 47
Setup Key Use.................................................................. 48
Auto Configuration With BIOS Defaults............................. 49
Auto Configuration With Power-On Defaults ..................... 50
Write to CMOS and Exit.................................................... 50
Do Not Write to CMOS RAM and Exit............................... 50
Section 2 STANDARD CMOS SETUP.............................................. 51
Date And Day Configuration.............................. 51
Hard Disk Configuration.................................... 52
Hard Disk Parameter Table............................... 53
Monitor.............................................................. 54
Keyboard........................................................... 54
Section 3 ADVANCED CMOS SETUP ............................................. 55
Typematic Rate Programming, Rate,
and Delay.......................................... 56
Extended Memory Test ..................... 57
Memory Test Tick Sound ................................. 57
Hit <DEL> Message Display ............................ 57
System Boot Up Num Lock .............................. 59

Preface
iv
Table of Contents, Continued
Chapter 4 AMIBIOS Setup, cont'd
Numeric Processor .......................................... 59
Floppy Drive Seek At Boot ............................... 59
System Boot Up Sequence .............................. 59
Fast Gate A20................................................... 59
Password Check Option.................... 60
Video or Adaptor ROM
Shadow ............................................ 60
Section 4 AMIBIOS Password Support............................................. 61
Section 5 Hard Disk Utility................................................................ 63
When to Use AMIBIOS Hard Disk Utilities........................ 64
Hard Disk Format Utility.................................................... 65
Auto Interleave Utility........................................................ 67
Hard Disk Utility Error Messages ...................................... 69
Appendix A 32-Bit Enterprise-II Memory Card.............................................. 71
Appendix B EISA Configuration Worksheets ............................................... 73
Appendix C Heat Dissipation......................................................................... 91
Index................................................................................................................ 93

American Megatrends Enterprise-II Motherboard User's Guide
v
Preface
To the OEM
Thank you for purchasing the high performance Enterprise-II
80486 EISA motherboard. This product is a state of the art
80486-based motherboard that includes the famous AMIBIOS. It
is assumed that you have also licensed the rights to use the
American Megatrends documentation for the Enterprise-II.
This manual was written for the OEM to assist in the proper
installation, and operation of the Enterprise-II motherboard
and AMIBIOS. This manual is not meant to be read by the
computer owner who purchases a computer with the Enterprise-
II 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 Support
If an Enterprise-II motherboard fails to operate as
described or you are in doubt about a configuration option,
please call technical support at 404-246-8600.
Acknowledgments
This manual was written by Robert Cheng and Paul Narushoff.
The writers gratefully acknowledge the assistance of Rex
Wade and Sukha Ghosh.
New in Series 16 Revision G
New Jumpers
There are several additional jumpers: J35, J36, and
J37. These jumpers select the processor type and
speed.
Support for Additional Processors
Rev G of the Enterprise-II now support the Intel
80486SX, 80487SX, P23T, P24, and the 80486DX.
Support for Additional Processor Speeds

Preface
vi
Rev G of the Enterprise-II will now support the
following processor speeds:
80486DX 25, 33, and 50 MHz
80486SX 25 MHz
80487SX 25 MHz

American Megatrends Enterprise-II Motherboard User's Guide
vii
New in Series 16 Revision G, Continued
Selecting the Processor Speed
A table on page 14 documents the jumper settings for
selecting the processor speed.
Selecting the Processor Type
A table on page 14 describes how to set jumpers to select
the processor speed.
J22 Name Change
The name of J22 has been changed to Interrupt Latch Disable.
This jumper is always shorted.
American Megatrends BBS
The American Megatrends BBS permits OEMs, VARs, and system
integrators to access technical information about
motherboard and BIOS products. Product Engineering Change
Notices, Tech Tips, Technical Notes, and technical manuals
are available on the BBS.
Data Transmission Rates
The BBS automatically handles modems with data transmission
rates from 1,200 to 14,400 bps. If using an HST modem, call
404-246-8780. If using a non-HST modem, call 404-246-8782.
BBS Phone Numbers
The following table lists the characteristics of the BBS
phone numbers. The BBS requires no parity, 8 data bits, and
1 stop bit.
Phone Number Characteristics
404-246-8780 Supports HST and v.42.
404-246-8781 Supports HST and v.42.
404-246-8782 Dual standard. Can handle 2400 or 9600 bps. Supports v.32 and
v.42. Can handle up to 14,400 baud.
404-246-8783 Supports v.32 and v.42.

American Megatrends Enterprise-II Motherboard User's Guide
11
Chapter 1
System Overview
The American Megatrends Series 16
Enterprise-II is an EISA (Extended
Industry Standard Architecture)
motherboard. It is approximately 13.8
inches wide by 12 inches long (identical
in size to a standard IBM AT motherboard
with similar mounting hole locations). The
following graphic illustrates the
dimensions of the Enterprise-II
motherboard and identifies the height
restrictions.

Chapter 1 - System Overview
2
Description
Processor Type and Speed
The Enterprise-II EISA motherboard comes
with either an 80486DX operating at 25,
33, or 50 MHz or an 80486SX operating at
25 MHz. The Enterprise-II also supports
future Intel processors and upgradable
processors. 80486SX-equipped Enterprise-II
motherboards support an 80487SX operating
at 25 MHz.
Heat Sink for 50 MHz CPUs
All Enterprise-II EISA motherboards with
50 MHz 80486DX CPUs are also equipped with
a heat sink to help dissipate the
additional heat.
Processor Speed
All Enterprise-II motherboards have two
clock speeds: high or low. The high clock
speed is factory-set to 25, 33, or 50 MHz.
The low clock speed is achieved by adding
the appropriate number of software delays,
depending on the speed of the processor
used on the motherboard, and emulates an
IBM AT running at 8 MHz.
Speed selection is through the turbo
switch or the keyboard (<Ctrl> <Alt> <+>
or <Ctrl> <Alt> <->).

American Megatrends Enterprise-II Motherboard User's Guide
3
Description, Continued
Cache Memory
The Enterprise-II supports 128 KB of
direct mapped, write-through external
cache memory. The Intel 80486 processors
have 8 KB of internal cache.
All system memory can be cached. The cache
read has 0 wait states. Burst mode is
supported. Cache memory is enabled and
disabled through the keyboard: <Ctrl>
<Alt> <Shift> <+> enables cache and <Ctrl>
<Alt> <Shift> <-> disables it.
Main Memory
The Enterprise-II motherboard supports up
to 32 MB of onboard memory. It also
supports up to 64 MB of additional
offboard system memory on the 32-bit
memory expansion slot.
The Enterprise-II supports up to 96 MB of
system RAM. Up to 4 gigabytes of memory
are supported on the EISA bus.
SIMMs
The Enterprise-II supports 1 MB x 9 or 4
MB x 9 fast page mode SIMMs operating at
70 ns (RAS access time), fast page mode at
25, 33, and 50 MHz.
Shadow RAM
The Enterprise-II system BIOS is always
shadowed. The video BIOS is shadowed
through AMIBIOS Setup. Adaptor ROM BIOS is
also shadowed via AMIBIOS Setup.

Chapter 1 - System Overview
4
Description, Continued
BIOS
The Enterprise-II has a 128 KB EISA
AMIBIOS located at E000–FFFFh with built-
in Setup, hard disk drive diagnostics, and
user-definable hard disk drive types. The
EISA AMIBIOS allows you to bypass error
messages for missing video, keyboard, or
floppy drives to facilitate the building
of file server systems
CMOS RAM
The Enterprise-II has 8 KB of nonvolatile
SRAM with built-in battery backup for EISA
configuration. The battery is on the CMOS
RAM/RTC chip itself.
Real Time Clock
The Enterprise-II has a real time clock
and CMOS RAM with built-in battery backup
for ISA BIOS Setup. The battery is on the
CMOS/RTC chip.
Math Coprocessor
The Enterprise-II has a socket for an
optional Weitek® 4167 numeric coprocessor.
EISA Integrated Peripheral Controller
The Enterprise-II has an Intel 82357 EISA
Integrated System Peripheral Controller.

American Megatrends Enterprise-II Motherboard User's Guide
5
Description, Continued
Seven DMA Channels
The Enterprise-II has seven DMA channels.
In accordance with the EISA
specifications, any DMA channel may be
programmed for 8, 16, or 32-bit DMA device
size and ISA compatible, type A, type B,
or burst type C modes.
Fifteen Interrupt Levels
The Enterprise-II has 15 hardware
interrupt levels. Of course, NMIs take
precedence over the following hardware
interrupts.
Priority Label Typical Interrupt Source
1 IRQ 0 Interval Timer 1, Counter 0 OUT
2 IRQ 1 Keyboard
3-10 IRQ 2 Used internally for IRQ 8 through IRQ 15
3 IRQ 8 Real-TIme-Clock
4 IRQ 9 EISA bus
5 IRQ 10 EISA bus
6 IRQ 11 EISA bus
7 IRQ 12 Mouse on EISA bus
8 IRQ 13 Coprocessor Error
9 IRQ 14 EISA bus (Hard disk drive controller)
10 IRQ 15 EISA bus
11 IRQ 3 EISA bus (Serial Port 2)
12 IRQ 4 EISA bus (Serial Port 1)
13 IRQ 5 EISA bus (Parallel Port 2)
14 IRQ 6 EISA bus and floppy disk controller
15 IRQ 7 EISA bus (Parallel Port 1)

Chapter 1 - System Overview
6
Description, Continued
Timer Features
The Enterprise-II has five programmable
16-bit counter/timers.
System Arbiter
The Enterprise-II has standard EISA
arbitration features.
Refresh Generation
The Enterprise-II has a refresh generation
feature.
I/O Capability
The Enterprise-II accesses 32-, 16-, 8-bit
memory devices and 32-, 16-, 8-bit I/O
devices on the EISA bus.
EISA Bus
The EISA Bus in the Enterprise-II has a
system clock that is generated by the EISA
bus clock (BCLK) and operates at 8.33 MHz.
I/O Slots
The Enterprise-II has one 32-bit
proprietary memory card slot and seven 32-
bit EISA bus slots (fully compatible with
ISA adapter cards). It also has one 8-bit
XT-compatible slot. If the memory slot is
used, the 8-bit slot cannot be used.

American Megatrends Enterprise-II Motherboard User's Guide
7
Description, Continued
I/O Address Space
The Enterprise-II uses I/O addresses x100h
through x3FFh for ISA compatible I/O (x=
a "don't care" character which does not
affect mapping location. For example, I/O
port addresses 0100h, 1100h, 2100h, and
3100h map to the same location).
The Enterprise-II also uses the following
EISA I/O port addresses:
•s000h through s0FFh for EISA
expansion slot
•s400h through s4FFh for EISA
expansion slot
•s800h through s8FFh for EISA
expansion slot
•sC00h through sCFFh for EISA
expansion slot
(s= EISA bus slot number,
s= 0 for motherboard)
Addresses
The Enterprise-II uses 32-bit memory
addresses to access 4 gigabytes of memory
address space on the EISA expansion slots.
I/O Channel Check
The Enterprise-II supports the use of the
I/O channel check to generate NMIs.

Chapter 1 - System Overview
8
Description, Continued
I/O Wait State Generation
The Enterprise-II has an open bus
structure (allowing multiple
microprocessors to share the system
resources, including memory). The
Enterprise-II supports refresh of system
memory from channel microprocessors.
Keyboard
The Enterprise-II uses a 5-pin IBM AT-
compatible DIN connector and has a
keyboard lock to prevent unauthorized
access.
Mouse
The Enterprise-II has a 6-pin IBM PS/2®-
compatible mini-DIN connector.
Speaker
The Enterprise-II has a standard speaker
attachment.

American Megatrends Enterprise-II Motherboard User's Guide
9
Chapter 2
Installation
Unpacking the Motherboard
Step Action
1 Inspect the cardboard carton for obvious damage. If damaged, call
Technical Support at 404-236-8600.
Leave the Enterprise-II motherboard in its original packing.
2 Perform all unpacking and installation procedures on a ground
connected anti-static mat. The operator should 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.
3 Inside the carton, the Enterprise-II motherboard is packed in an
anti-static bag, and sandwiched between sheets of sponge.
Remove the sponge and remove the anti-static bag. Place the
Enterprise-II motherboard on a grounded anti-static surface
component side up. Save the original packing material in case of
reshipment.
4 Inspect 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.
5 If the motherboard is undamaged, it is ready to be installed.

Chapter 2 - Installation
10

American Megatrends Enterprise-II Motherboard User's Guide
11
Installation Steps
The steps for assembling a system that
uses the 80486 Enterprise-II motherboard
and CPU card are shown in the following
table. Each step is discussed in detail in
the following pages.
Step Action Turn to
1 Set switch and jumper options Page 12
2 Install memory Page 15
3 Install coprocessors Page 19
4 Install motherboard Page 21
5 Connect the power supply Page 22
6 Connect the keyboard Page 26
7 Connect the mouse Page 26
8 Connect cables Page 27
9 Install adapter cards Page 33
10 Test and configure Page 40
Warning
The Enterprise-II motherboard contains sensitive electronic
components which can be easily damaged by static electricity.
Follow the instructions carefully to ensure correct installation
and to avoid static damage.

Chapter 2 - Installation
12
Step 1 Set Switch and Jumper Options
Set all user-configurable jumpers and
switches and install coprocessors before
installing the motherboard in the chassis.
There are two user-configurable switches
and five jumpers.
SW
SW is a dual 2-bit DIP switch. SW-1 is
used for manufacturing diagnostics. The
motherboard is shipped with this switch
Off. The switch should remain Off.
The COL/MONO (SW-2) switch sets the type
of video display adapter card in the
system. This switch is factory-set to Off,
for a monochrome display adapter (MDA).
Set On for a color graphics adapter (CGA).
This switch has no effect on EGA and VGA
adapters.
J12 Floppy Disk Type
J12 is a 3 pin single-inline berg. This
jumper selects the floppy disk drive type
when using the onboard floppy controller.
Some 3½" drives (PS/2 compatible) have
inverted DENSEL (density select) signals.
Short Pins 1-2 for normal XT and AT style
drives (default). Short Pins 2-3 for PS/2
compatible drives (inverted DENSEL). When
using PS/2-compatible drives, resistor
network RN13 must be changed from 150Ωto
10KΩ.