American Megatrends Atlas EISA User manual

American Megatrends, Inc.
Atlas PCI Pentium
EISA Motherboard
User's Guide
MAN-717
7/11/94

© Copyright 1994 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 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, Pentium, and Overdrive are registered trademarks of Intel Corporation.
MS-DOS, Xenix, and Microsoft are registered trademarks of Microsoft Corporation. Microsoft Windows and Windows NT are trademarks of Microsoft Corporation.
SMC is a registered trademark of SMC Corporation.
IBM, AT, VGA, PS/2, 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.
Boca is a registered trademark of Boca Research Inc.
Antec is a registered trademark of Antec 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.
Unix is a registered trademark of American Telephone and Telegraph Company Bell Laboratories.
Weitek is a trademark of Weitek, Inc.
National Semiconductor is a registered trademark of National Semiconductor Corporation.
Toshiba is a registered trademark of Kabushiki Kaisha Toshiba.
Revision History
7/11/94 Initial release.

Atlas PCI Pentium EISA Motherboard User's Guide
iii
Table of Contents
1 System Overview ........................................................................................................1
Features...............................................................................................................................................................................2
2 Specifications .............................................................................................................3
Atlas PCI Motherboard Dimensions.................................................................................................................................8
Onboard I/O ...............................................................................................................................................................9
3 PCI Local Bus............................................................................................................ 11
4 Installation.................................................................................................................15
Unpacking the Motherboard...........................................................................................................................................15
Installation Steps ..............................................................................................................................................................17
Step 1 Set Switches and Jumpers .............................................................................................................................17
Step 2 Install System Memory .................................................................................................................................22
Step 3 Install the Motherboard...................................................................................................................................4
Step 4 Connect the Power Supply ..............................................................................................................................6
Step 5 Connect the Keyboard Cable.........................................................................................................................32
Step 6 Connect the Mouse........................................................................................................................................33
Step 7 Connect Cables .............................................................................................................................................34
Step 8 Connect Onboard I/O ....................................................................................................................................40
Step 9 Install Floppy Drive ......................................................................................................................................45
Step 10 Install Hard Disk .........................................................................................................................................47
Step 11 Install Adapter Cards ..................................................................................................................................48
Step 12 Test and Configure......................................................................................................................................55
5 WinBIOS Power-On Self Test ....................................................................................1
Beep Codes ................................................................................................................................................................2
WinBIOS Displayed Error Messages.........................................................................................................................3
WinBIOS Displayed Error Messages.........................................................................................................................4
Other Messages ..........................................................................................................................................................5
EISA NMI Messages..................................................................................................................................................5
WinBIOS Configuration Summary Screen.................................................................................................................6
POST Memory Test ...................................................................................................................................................6
6 WinBIOS Setup ...........................................................................................................9
Starting WinBIOS Setup ............................................................................................................................................9
7 Flash ROM Programming......................................................................................... 37
A Temperature and Power........................................................................................... 45
Temperature Ranges.................................................................................................................................................45
Humidity ..................................................................................................................................................................45
B EISA Configuration Worksheets..............................................................................47
Index ..................................................................................................................................... 60

Preface
iv
Preface
To the OEM
Thank you for purchasing the high performance American Megatrends Atlas PCI Pentium EISA motherboard.
This product is a state of the art Pentium-based motherboard that includes the famous WinBIOS. It is
assumed that you have also licensed the rights to use the American Megatrends documentation for the
American Megatrends Atlas PCI 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
Atlas PCI motherboard. It explains how to assemble a system based on the Atlas PCI motherboard and how to
use the WinBIOS that is specifically designed for this motherboard.
This manual is not addressed to the computer owner who purchases this motherboard or 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 Support
If an American Megatrends motherboard fails to operate as described or you are in doubt about a
configuration option, please call technical support at 770-246-8645.

Atlas PCI Pentium EISA Motherboard User's Guide
v
Preface, Continued
Packing Slip
You should have received:
•an American Megatrends Atlas PCI Pentium EISA motherboard,
•the Atlas PCI Pentium EISA Motherboard User's Guide,
•a diskette containing the American Megatrends ECU and EISA configuration files.
•the American Megatrends ECU User's Guide, and
•the AMIFlash Utility program.
•a Warranty Card for the Atlas PCI Pentium EISA motherboard,
•two 10-pin to DB9 connector serial cables (American Megatrends Part Number CBL-SUB-1-10), and
•one 26-pin to DB25 connector parallel cable (American Megatrends Part Number CBL-SUB-2-25).
The cable that attaches to the PS/2 mouse connector is the same as the serial cables listed above (American
Megatrends Part Number CBL-SUB-1-10).
If using the Green PC features of this motherboard, you will also need a 10-pin to 25-pin Green PC cable
(American Megatrends Part Number CBL-SUB-12-10) that is not supplied with the motherboard.
Call the American Megatrends Sales Department at 800-828-9264 to order the serial cables or Green PC
cable.

Preface
vi
American Megatrends BBS
The 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 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 770-246-8780.
If using a non-HST modem, call 770-246-8782.
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
770-246-8780 Supports HST and v.42.
770-246-8781 Supports HST and v.42.
770-246-8782 Dual standard. Can handle 2400 or 9600 bps.
Supports v.32 and v.42. Can handle up to 14,400
baud.
770-246-8783 Supports v.32 and v.42.

Atlas PCI Pentium EISA Motherboard User's Guide
1
1 System Overview
The American Megatrends Atlas PCI (Peripheral Component Interconnect) is a full AT-size PCI EISA
motherboard that supports a P54C Pentium® CPU operating at 60 or 66 MHz externally and 90 or 100 MHz
internally.
This motherboard has three PCI Local Bus expansion slots. All three slots can be used for bus mastering PCI
adapter cards.
The motherboard also has six EISA bus mastering expansion slots. The motherboard height restrictions are
shown below.

Chapter 1 System Overview
2
Features
The American Megatrends Atlas PCI Pentium EISA motherboard has the following features:
•Supports 256 or 512 KB of direct-mapped write-back (or write-through) secondary cache memory.
•Supports from 2 to 192 MB of non-interleaved system memory via two to six x 36 single-sided or
double-sided SIMMs on the motherboard.
•Supports up to four IDE hard disk drives through two IDE connectors on the motherboard on the fast PCI
local bus. IDE Modes 0, 1, 2, and 3 with 32-bit read/write, and write posting are supported.
•Includes an SMC® FDC37C665 100-pin PQFP Universal Peripheral Controller that supports two
National Semiconductor NS16C550 serial ports, a parallel port with ECP (Extended Capabilities Port)
and EPP (Enhanced Parallel Port) support, and a floppy controller,
•Includes a 128 KB flash EPROM for the system BIOS.
•Includes a battery-backed Real Time Clock with 114 bytes of CMOS RAM to store system configuration
data. It also has an additional 8 KB of EISA Extended CMOS RAM.
•Has six bus mastering EISA and three PCI bus mastering expansion slots. All expansion slots are bus
mastering slots.

Atlas PCI Pentium EISA Motherboard User's Guide
3
2 Specifications
The American Megatrends Atlas PCI is a full AT-size motherboard. The motherboard has an onboard fast
IDE controller on the PCI local bus that supports IDE Modes 0, 1, 2 and 3 with 32-bit read/write, readahead,
and write posting. The motherboard has an I/O Controller that supports floppy drives, serial ports, and a
parallel port with ECP and EPP capabilities.
Motherboard Frequency
The Atlas PCI motherboard operates at either High or Low speed. High speed is the same as the speed of the
CPU mounted on the motherboard (60/66 or 90/100 MHz). Low speed is approximately the same speed as
that of an 8 MHz IBM® AT. Low speed is achieved by emulation.
The end user can select the frequency by:
•selecting High or Low speed via an option in WinBIOS Setup Advanced Setup,
•after system boot, pressing <Ctrl> <Alt> <-> for Low speed or <Ctrl> <Alt> <+> for High speed, or
•after system boot, pressing the hardware Turbo switch mounted on the computer chassis.
Socketed CPU
The Atlas PCI Pentium EISA motherboard uses a 3.3V 90 or 100 MHz Intel P54C Pentium CPU operating
externally at 60 or 66 MHz in a ZIF socket.

Chapter 2 Specifications
4
Specifications, Continued
Internal Cache Memory
The Pentium CPU includes both an 8 KB code cache and an 8 KB write-back data cache referred to as L1
internal cache memory. All onboard memory can be stored in internal cache memory on the CPU.
Internal cache memory can be enabled via Advanced Setup in WinBIOS Setup.
Secondary Cache Memory
The Atlas PCI motherboard has 256 KB or 512 KB of factory-installed L2 secondary (external) cache
memory. The cache memory is direct-mapped programmable in write-through or write-back mode. The cache
memory chips are:
Cache Memory Description
256 KB L2 cache memory uses eight 32 KB x 8 standard SRAMs. Cache data
RAM operates at 15 ns.
256 KB L2 cache memory uses four 32 KB x 18 burst SRAMs operating at 9 ns.
512 KB L2 cache memory uses 64 KB x 18 asynchronous SRAMs. The cache data
RAM operates at 15 ns.
512 KB L2 cache memory uses four 64 KB x 18 burst SRAMs operating at 9 ns.
4 KB L2 cache memory Tag
RAM
Integrated into the chipset.
The L2 secondary cache memory supports CPU burst reads and writes. The L2 secondary cache memory can
be implemented in synchronous or asynchronous burst SRAMs.
The Intel Pentium is supported in both write-back and write-through modes. The external cache memory can
also be in write-back or write-through mode.
L2 Secondary (External)l cache memory can be enabled via WinBIOS Setup Advanced Setup.

Atlas PCI Pentium EISA Motherboard User's Guide
5
Specifications, Continued
Cacheable Memory
All of system memory on the motherboard (up to 192 MB) can be read from or written to both L1 internal
cache memory and L2 secondary cache memory.
Non-Cacheable Memory
Up to two blocks of system memory can be defined as non-cacheable. The contents of these areas cannot be
read from or written to either L1 or L2 cache memory. The size of this area can be 64 KB to 512 KB and is
defined through WinBIOS Setup Advanced Setup.
Storing BIOS ROM in Cache Memory
Both the contents of the system BIOS ROM and the video BIOS ROM can be read from or written to both L1
and L2 cache memory. The contents of both system BIOS ROM and the video BIOS ROM can also be write-
protected. Options in WinBIOS Setup Advanced Setup control these features.
Chipset
The Atlas EISA motherboard uses the Intel Mercury chipset and EISA chipset consisting of the following
ICs: 82434LX PCI, Cache, and Memory Controller (PCMC), 82433LX Local Bus Accelerator (LBX),
82375EB PCI to EISA bridge (PCEB), and the 82374EB EISA System Controller (ESC).
Other Connectors
•a four-pin berg connector attaches to a speaker,
•a two-pin connector connects a hardware reset switch,
•a five-pin connector connects a keyboard lock switch,
•a two-pin connector connects a turbo switch
•there are three 5V six-pin power supply connectors and two 3.3V power supply connectors,
•a 3.3V voltage regulator provides CPU power,
•a 34-pin dual inline header connects the floppy drives,
•two 40-pin headers connect up to four IDE drives on the PCI bus, and
•two 10-pin serial connectors and a 26-pin parallel connector.

Chapter 2 Specifications
6
Specifications, Continued
Onboard System Memory
•The Atlas PCI motherboard supports from 2 to 192 MB of system memory via six 72-pin SIMM sockets.
Either single-sided or double-sided SIMMs can be used.
•The system BIOS automatically detects and configures all onboard DRAM memory.
•Slave memory devices can be added on the PCI bus and the EISA bus for additional memory.
•The Atlas PCI motherboard can have two, four, or six 36 SIMMs in six SIMM sockets.
•The Atlas PCI motherboard supports 256 KB x 36, 1 MB x 36, and 4 MB x 36 single-sided SIMMs and
512 KB x 36, 2 MB x 36, and 8 MB x 36 double-sided SIMMs.
•70 ns fast page mode DRAMs are required for onboard DRAM. Parity is checked on all system memory
reads to ensure data integrity. The memory architecture is paged and non-interleaved.
•WinBIOS Setup Chipset Setup provides two options that permit the end user to configure up to two holes
in memory. These holes will be available to devices on the PCI bus.
System Memory Buffers
The Atlas PCI Pentium EISA motherboard has five integrated write posting and read prefetch buffers:
Type of Memory Buffer Buffer Size
CPU to memory posted write buffer four quadwords deep
PCI to memory posted write buffer eight quadwords deep
PCI to memory read prefetch buffer four quadwords deep
CPU to PCI posted write buffer four doublewords deep
CPU to PCI read prefetch buffer four doublewords deep

Atlas PCI Pentium EISA Motherboard User's Guide
7
Specifications, Continued
PCI Expansion Slots
The motherboard has three bus mastering PCI slots operating at 30 or 33 MHz synchronous with the CPU
clock.
EISA Expansion Slots and Bus Speed
The motherboard has six EISA expansion slots operating at 7.5 or 8.0 MHz.
CMOS RAM
The motherboard has 114 bytes of CMOS RAM on the Real Time Clock. The contents of CMOS RAM are
configured by WinBIOS Setup, resident with the system BIOS on the Flash EPROM. There is also an
additional 8 KB of EISA Extended CMOS RAM.
System BIOS
The system BIOS resides on a 128 KB boot block flash ROM. The system BIOS can be updated through the
AMIFlash software utility. The system BIOS is shadowed to RAM and can be read from or written to L1 and
L2 cache memory, as controlled through Advanced Setup.
Adaptor ROM BIOS
The Adaptor ROM BIOS between C0000h - EFFFFh can be shadowed to RAM. The contents can be read
from or written to secondary cache memory and the contents can be write-protected with 16 KB granularity
via WinBIOS Setup Advanced Setup.
SCSI Support
SCSI support is optional. The motherboard may have an NCR 53C810 PCI SCSI controller, if the customer
orders it.

Chapter 2 Specifications
8
Specifications, Continued
Mouse
The Atlas PCI motherboard supports a PS/2- compatible mouse interface through a 10-pin dual-inline
connector.
Keyboard
The standard Atlas PCI motherboard has a five-pin DIN keyboard connector.
Green PC Monitor Connector
The Atlas PCI motherboard has a 10-pin dual-inline connector for Green PC monitor support.
Atlas PCI Motherboard Dimensions
The Atlas PCI motherboard is approximately 12.1 inches wide by 13.8 inches long (the standard full AT®
size with similar mounting hole locations). The following graphic shows the dimensions and height
restrictions.

Atlas PCI Pentium EISA Motherboard User's Guide
9
Onboard I/O
Universal Peripheral Controller
The Atlas PCI EISA motherboard has an SMC FDC37C665 Universal Peripheral Controller that supports up
to two floppy drives (360 KB, 1.2 MB, 720 KB, 1.44 MB, or 2.88 MB), two serial ports (using National
Semiconductor 16C550s), and one parallel port with ECP (Extended Capabilities Port) and EPP (Enhanced
Parallel Port) capability.
Onboard PCI IDE Support
The onboard IDE is on the PCI bus. The IDE controller supports up to four IDE hard disk drives through two
IDE connectors on the motherboard.
The IDE controller supports IDE Mode 0, Mode 1, Mode 2, and Mode 3. It also supports IDE read data
prefetch and write posting. The WinBIOS supports 32-bit data transfers as well as the following cycle times
for each IDE Mode.
IDE Mode Cycle Time (in nanoseconds)
0 600
1 383
2 240
3 180
PCI IDE Support on the PCI Expansion Slots
PCI IDE adapter cards are supported on all PCI expansion slots.

Chapter 2 Specifications
10

Atlas PCI Pentium EISA Motherboard User's Guide
11
3 PCI Local Bus
The PCI specification provides the electrical specifications for peripheral chip makers and the logic
requirements for a PCI Controller. PCI also defines a local bus standard and a standard common I/O
component-level interface.
The Atlas PCI EISA Motherboard conforms to the Intel PCI specifications. The PCI Local Bus Specification
is a standard set of interface, architecture, timings, electrical, and physical specifications that permits all PCI
Local Bus products to be totally interchangeable. PCI is a multiplexed extension of the CPU bus. In PCI, the
CPU bus control mechanisms have been extended to optimize I/O support.
PCI is a specification for a local bus standard. PCI establishes a local bus standard in which a large variety of
I/O components can be directly connected without using any glue logic.
What PCI Accomplishes
PCI is a way to physically interconnect highly integrated peripheral components and processor/memory
systems.
PCI Features
Up to ten PCI loads can be used in the same system on the PCI bus, including the PCI Controller and an
expansion bus controller for EISA, ISA, or MCA®. PCI decouples the CPU from the expansion bus.
The local bus defined in the current PCI specification works at 33 MHz and can use either a 32-bit or 64-bit
data connection path to the CPU.

Chapter 3 PCI
12
PCI, Continued
PCI Features
•is processor-independent,
•has a multiplexed address, command, and data bus and supports burst mode operation on reads and
writes,
•runs synchronous with the CPU at speeds up to 33 MHz,
•has a maximum data transfer rate of 120 MBs (with a peak rate of 132 MBs on a 32-bit data path),
•has a maximum data transfer rate of 240 MBs (with a peak rate of 264 MBs on a 64-bit data path),
•has an optional 64-bit data path that is transparently interoperable with the 32-bit data path,
•has low latency random accesses (about 60 ns write access latency) to slave registers from a PCI bus
master on the PCI bus,
•is capable of full concurrency with the processor and PCI bus masters,
•has full multimaster capability, allowing any PCI Master peer-to-peer access to any PCI slave,
•has hidden and overlapped central arbitration,
•has a low pin count (master - 47; slave - 45),
•has address and data parity, and
•uses three physical address spaces: 32-bit memory, 32-bit I/O, and a 256 byte-per-agent configuration
space.

Atlas PCI Pentium EISA Motherboard User's Guide
13
PCI, Continued
PCI Diagram
A typical PCI motherboard system block diagram follows.
Buffered Reads and Writes
The PCI Controller buffers reads and writes between the memory and the CPU and between PCI peripheral
devices.
PCI Component Classes
PCI components must be one of three classes: bus master, slave, or master/slave combination.
Bus Mastering
PCI devices can be bus masters, slaves, or a combination of bus master and slave.

Chapter 3 PCI
14
PCI, Continued
Concurrent Operation
The CPU in a PCI system runs concurrently with PCI bus mastering peripherals. Although bus mastering
peripheral devices are arbitrated, significant improvements in data transfer rates can be achieved without
splitting resource utilization between the CPU and a bus mastering device. Peripheral devices can operate at
speeds up to 33 MHz in a PCI environment.
Burst Mode
The PCI specification also provides for burst mode of any length for both reads and writes.
Multiplexing
PCI is a multiplexed bus. Multiplexing allows more than one signal to be sent on the same electrical path. The
PCI control mechanisms have been modified and extended to optimize I/O support.
Using PCI Adapter Cards
The Atlas PCI EISA motherboard has three PCI expansion slots. The PCI expansion slots can accept any
adapter card that complies with the PCI Revision 2.0 specification.
P16 (Slot E), P17 (Slot F), and P18 (Slot D) are all bus master PCI slots.