American Megatrends Baby EISA User manual

American Megatrends, Inc.
Series 64
Baby EISA
80486 EISA Motherboard
User's Guide
MAN-664
3/15/93

© Copyright 1993 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 Baby EISA 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
Intel and i486 are registered trademarks of Intel Corporation.
MS-DOS, Xenix, and Microsoft are registered trademarks of Microsoft Corporation.
IBM, AT, VGA, OS/2, and EGA are registered trademarks of International Business Machines Corporation. XT and CGA are trademarks of International Business Machines
Corporation.
Fujitsu is a registered trademark of Fujitsu America, Inc.
Motorola is a registered trademark of Motorola 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.
Unix is a registered trademark of American Telephone and Telegraph Company Bell Laboratories.
Weitek is a trademark of Weitek, Inc.
Toshiba is a registered trademark of Kabushiki Kaisha Toshiba.
Revision History
12/2/92 Initial release.
3/15/93 Minor changes to manual.

American Megatrends 80486 Baby EISA 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............................ 11
Step 2 Install Memory....................................................... 14
Step 3 Install Upgrade Processor..................................... 16
Step 4 Install the Motherboard ......................................... 17
Step 5 Connect the Power Supply.................................... 18
Step 6 Connect the Keyboard Cable ................................ 22
Step 7 Connect the Mouse............................................... 23
Step 8 Connect Cables .................................................... 24
Step 9 Install Adapter Cards............................................. 26
Step 10 Test and Configure.............................................. 31
Chapter 3 BIOS Power-On Self Test ..................................................... 33
Beep Codes ..................................................................... 34
Troubleshooting System Problems................................... 34
AMIBIOS Displayed Error Messages................................ 35
EISA Error Messages....................................................... 37
ISA BIOS NMI Messages................................................. 37
EISA BIOS NMI Error Messages...................................... 37
Chapter 4 AMIBIOS Setup ..................................................................... 39
Section 1 Running AMIBIOS Setup.................................................. 41
AMIBIOS Setup Key Use ................................................. 42
AMIBIOS Setup Main Menu ............................................. 43
Auto Configuration With BIOS Defaults............................ 43
Auto Configuration With Power-On Defaults..................... 44
Write to CMOS and Exit................................................... 44
Do Not Write to CMOS RAM and Exit .............................. 44
Section 2 STANDARD CMOS SETUP............................................. 45
Date And Day Configuration............................. 45
Hard Disk Configuration.................................... 46
Hard Disk Drive Types...................................... 47
Monitor............................................................. 48
Keyboard.......................................................... 48
Section 3 ADVANCED CMOS SETUP............................................. 49
Typematic Rate Programming.......................... 51
Typematic Rate................................................ 51
Typematic Rate Delay...................................... 51
Above 1 MB Memory Test................................ 51
Memory Test Tick Sound.................................. 51
Hit <DEL> Message Display ............................ 52
System Boot Up Num Lock ............................. 53
Floppy Drive Seek At Boot ............................... 53

Preface
iv
Table of Contents, Continued
Chapter 4 AMIBIOS Setup, cont'd
System Boot Up Sequence .............................. 53
Fast Gate A20.................................................. 54
Password Check Option................................... 55
Boot Sector Virus Protection ............................ 56
Section 4 ADVANCED CHIPSET SETUP........................................ 57
Hidden Refresh ................................................................ 57
Non-Cache Size - Block 0 ................................................ 58
Non-Cache Start - Block 0................................................ 58
Cacheable Region............................................................ 58
BCLK Stretch................................................................... 59
Back-to-Back I/O.............................................................. 59
CPU Time-Slice Priority.................................................... 59
Fast Keyboard Reset........................................................ 60
Section 5 AMIBIOS Password Support ............................................ 61
Section 6 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 Temperature and Power.................................................... 71
Appendix B EISA Configuration Worksheets....................................... 73
Index....................................................................................................... 91

American Megatrends 80486 Baby EISA Motherboard User's Guide
v
Preface
To the OEM
Thank you for purchasing the high performance Baby EISA 80486 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 Baby EISA motherboard.
This manual was written for the OEM to assist you in the proper installation
and operation of the Baby EISA motherboard. This manual also describes the
specifications and features of the Baby EISA motherboard. It explains how to
assemble a system based on the Baby EISA 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 the Baby
EISA 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 Baby EISA 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.

Preface
vi
American Megatrends BBS
The BBS permits OEMs, VARs, system integrators, and end users to access
technical information about motherboard and BIOS products. Product Engineering
Change Notices, Tech Tips, Technical Notes, and complete 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.
Packing Slip
You should have received:
• a Series 64 Baby EISA Motherboard,
• a floppy disk with the AMIECU and EISA CFG file,
• the American Megatrends Series 64 Baby EISA Motherboard User's Guide,
and
• the American Megatrends ECU Version 2.00 User's Guide.

American Megatrends 80486 Baby EISA Motherboard User's Guide
1
Chapter 1
System Overview
Dimensions
The American Megatrends Series 64 Baby EISA is an EISA (Extended
Industry Standard Architecture) motherboard. It is approximately 8.6
inches wide by 13 inches long (approximately the size of a standard Baby
AT motherboard with similar mounting hole locations). The following
graphic illustrates the dimensions of the Baby EISA motherboard and
identifies the height restrictions.

Chapter 1 - System Overview
2
Description
Processor Type and Speed
The Baby EISA motherboard can be configured with any of the following
Intel® microprocessors:
Processor Speeds
80486SX 20, or 25 MHz
80486DX 25, 33, 50 MHz
80486DX2 50, 66 MHz
80487SX or Overdrive 50 MHz
The Baby EISA motherboard also supports future Intel processors and
upgradeable processors. Intel Overdrive replacement processors can also
be used.
Heat Sink
All Baby EISA motherboards with a 50 or 66 MHz 80486DX, 80486DX2, or
Overdrive processor are equipped with a heat sink to help dissipate the
additional heat.
Processor Speed
All Baby EISA motherboards have two clock speeds: high or low. The high
clock speed is factory-set to the rated speed of the installed
microprocessor (20, 25, 33, 50, or 66 MHz).
Low clock speed is achieved by adding the appropriate number of software
delays, depending on the speed of the processor used on the motherboard.
Low speed emulates an IBM AT running at 8 MHz.
Speed selection is through the keyboard via the following keychords:
<Ctrl><Alt><+> switches to High speed;
<Ctrl><Alt><-> switches to Low speed.

American Megatrends 80486 Baby EISA Motherboard User's Guide
3
Description, Continued
Cache Memory
The Baby EISA motherboard supports 64 KB or 256 KB direct mapped, write-
back external (secondary) cache memory. The Intel 80486 processors have
8 KB of internal cache memory.
Eight 8 KB x 8 or 32 KB x 8 15 ns SRAM chips are used for cache memory.
Tag memory is 15 ns 16 KB x 4 SRAM chips.
System BIOS and video BIOS can be cached via the Cacheable RAM Area
option in ADVANCED CMOS SETUP.
All system memory can be cached. Up to three non-cacheable areas from 64
KB – 512 KB can be defined via AMIBIOS ADVANCED CHIPSET SETUP.
The cache read and write has 0 wait states (1 wait state is used for
write operations if a 50 or 66 MHz microprocessor is installed). Burst
mode is supported. Cache memory is enabled and disabled via the keyboard
or a hardware turbo switch. The hardware turbo switch can be enabled or
disabled via ADVANCED CMOS SETUP. The keychords that control cache
memory are:
<Ctrl><Alt><Shift><+> enables internal and external (secondary) cache memory
<Ctrl><Alt><Shift><-> disables internal and external (secondary) cache memory.
System Memory
The Baby EISA motherboard supports up to 128 MB of DRAM onboard system
memory using eight 16 MB x 9 SIMMs. The Baby EISA motherboard has two
banks (with four sockets each) of SIMM sockets. Up to 4 GB of system
memory is supported on the EISA bus.

Chapter 1 - System Overview
4
Description, Continued
SIMMs
The motherboard uses 1 MB x 9, 4 MB x 9, or 16 MB x 9 fast page mode
SIMMs with 70 ns RAS access time.
Shadow RAM
Shadowing can be performed on three areas in the Baby EISA motherboard
and is controlled by ADVANCED CMOS SETUP options in AMIBIOS Setup (see
page 56). The areas are:
• system BIOS (128 KB at E0000h – FFFFFh),
• video BIOS (32 KB at C0000h – C7FFFh), and
• adaptor ROM BIOS (C8000h - DFFFFh) can be shadowed in 16 KB
increments.
ROM
The Baby EISA motherboard has 128 KB of ROM that contains the system
EISA AMIBIOS at memory location E0000h – FFFFFh.
BIOS
The Baby EISA motherboard has a 128 KB EISA AMIBIOS at E0000h – FFFFFh
with built-in AMIBIOS Setup, hard disk drive diagnostics, and user-
definable hard disk drive types. AMIBIOS allows you to bypass error
messages for missing video, keyboard, or floppy drives for file servers.
EISA Extended CMOS RAM
The Baby EISA motherboard has 4 KB of nonvolatile EISA Extended CMOS RAM
with built-in battery backup for EISA configuration.

American Megatrends 80486 Baby EISA Motherboard User's Guide
5
Description, Continued
ISA CMOS RAM
The Baby EISA motherboard has a Dallas RAMified Real Time Clock+RAM chip
(DS1387) or equivalent that includes the Real Time Clock and 64 bytes of
built-in battery-backed standard ISA CMOS RAM.
EISA Configuration Utility
The American Megatrends EISA Configuration Utility (ECU) is shipped with
the motherboard.
Real Time Clock
The Baby EISA motherboard has a real time clock and CMOS RAM with built-
in battery backup. The battery is on the CMOS/Real Time Clock chip.
Performance Upgrade Socket
The Baby EISA motherboard has an Intel Performance Upgrade Socket for an
optional 80487SX numeric coprocessor or Intel Overdrive processor.
EISA Integrated Peripheral Controller
The Baby EISA motherboard has an OPTi 82C686 EISA Integrated Peripheral
Controller.
OPTi EISA Chipset
The Baby EISA motherboard uses the OPTI 82C681 EISA chipset:
82C681 EISA Bus Controller
82C682 Memory and Cache Controller
82C686 Integrated System Peripheral
82C867 Data Bus Controller

Chapter 1 - System Overview
6
Description, Continued
Seven DMA Channels
The Baby EISA motherboard has seven DMA channels. Any DMA channel may be
programmed for 8, 16, or 32-bit DMA device size and ISA compatible, type
A, type B, or burst modes.
Fifteen Interrupt Levels
The motherboard has 15 hardware interrupt levels. The NMI takes
precedence over 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)
Timer Features
The Baby EISA motherboard has five programmable 16-bit counter/timers.
System Arbiter
The Baby EISA motherboard has standard EISA arbitration features.

American Megatrends 80486 Baby EISA Motherboard User's Guide
7
Description, Continued
Refresh Generation
The Baby EISA motherboard has a hidden refresh generation feature that
saves CPU cycles.
I/O Capability
The motherboard accesses 32-, 16-, 8-bit memory and I/O devices on the
EISA bus.
EISA Bus
The EISA Bus in the Baby EISA motherboard has a system clock that is
generated by the EISA bus clock (BCLK) and operates at approximately
8.33 MHz.
Expansion Slots
The motherboard has eight 188-pin, 32-bit EISA expansion slots, fully
compatible with ISA adapter cards. The first six EISA slots are bus
mastering slots.
Maximum Supported Memory Addresses
The Baby EISA motherboard uses 32-bit memory addresses to access 4
gigabytes of memory address space on the EISA expansion slots.
I/O Channel Check
The Baby EISA motherboard supports the use of the I/O channel check to
generate NMIs.
EISA Supports Multiple Processors
The Baby EISA motherboard has an open bus structure (allowing multiple
microprocessors to share the system resources, including memory).

Chapter 1 - System Overview
8
Description, Continued
I/O Address Space
The Baby EISA motherboard uses I/O addresses x100h through x3FFh for ISA
compatible I/O (xdoes not affect mapping location — I/O port addresses
0100h, 1100h, 2100h, and 3100h map to the same location). It also uses
the following EISA I/O port addresses:
s000h – s0FFh EISA expansion slot
s400h – s4FFh EISA expansion slot
s800h – s8FFh EISA expansion slot
sC00h – sCFFh EISA expansion slot
s= EISA bus slot number (0 for motherboard)
Memory Refresh from Bus
The Baby EISA motherboard supports refresh of system memory from channel
microprocessors.
Keyboard
A standard five-pin AT-compatible DIN connector is supplied for the
keyboard. A five-pin berg connector for a keyboard lock connector is
also provided. Any AT- or XT-compatible keyboard can be used.
Mouse
A 10-pin header is used for the mouse. A PS/2®-type mouse can be
attached via a serial port cable.
Hardware Reset Switch
The Baby EISA motherboard has a two-pin berg connector for a standard
hardware reset switch.
Speaker
The Baby EISA motherboard has a standard four-pin speaker attachment.

American Megatrends 80486 Baby EISA 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 404-246-8600. Leave
the 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 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 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 damaged.
5. If the motherboard is undamaged, it is ready to be installed.

Chapter 2 Installation
10

American Megatrends 80486 Baby EISA Motherboard User's Guide
11

Chapter 2 Installation
12

American Megatrends 80486 Baby EISA Motherboard User's Guide
13
Installation Steps
Step Action
Turn to
1 Set switch and jumper options Page 13
2 Install memory Page 16
3 Install upgrade processor Page 18
4 Install motherboard Page 19
5 Connect the power supply Page 20
6 Connect the keyboard Page 24
7 Connect the mouse Page 25
8 Connect cables Page 26
9 Install adapter cards Page 28
10 Test and configure Page 33
Warning
The Baby EISA 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.
Step 1 Set Switch and Jumper Options
Set all user-configurable jumpers and switches before installing the
motherboard in the chassis.
SW
SW is a dual two-position DIP switch. SW-1 (DIAG) is OFF when shipped
and it should remain OFF. The COL/MONO (SW-2) switch sets the type of
video 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 if an EGA or VGA adapter is
installed. SW is in the same end of the motherboard as the CPU but in
the opposite corner. See the figure on page 15.

Chapter 2 Installation
14
Step 1 Set Switch and Jumper Options, Continued
All jumpers are located on the half of the motherboard that includes the
CPU. Refer to the figure on the next page for the exact placement of the
jumpers.
Selecting the Frequency
Jumper Type 20 MHz 25 MHz 33 MHz 50 MHz
J3 three-pin Short 1-2 Short 1-2 Short 1-2 Short 2-3
J6 two-pin Short 1-2 OPEN OPEN OPEN
J16 two-pin OPEN OPEN OPEN Short 1-2
J17 two-pin OPEN OPEN Short 1-2 Short 1-2
J27 three-pin Short 2-3 Short 1-2 Short 1-2 Short 1-2
J3 2x or 1x CLK Select
J6 Flush or Burst Write
J16 Speed Input to EBC
J17 Speed Input to EBC
J27 Synchronous BCLK Select
J9 Set CPU Type
J9 is a four-pin berg that selects the CPU type. When Pins 3-4 of J9 are
shorted, it is IGNNE# Pin Select. When Pins 1-2 of J9 are shorted, it is
NMI Pin Select. See the graphic on the next page for the location of J9.
CPU Pins Shorted
80486SX Short 2-3.
80486DX or
80486DX2 Short pins 1-2 and 3-4.