Intel 301 System board (PBA 149422-xxx), 301 System board (PBA 451213-xxx) iSBC 386AT User Guide

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iSBC 386AT USER'S GUIDE

Order Number: 149568-002

Intel Corporation

3065 Bowers Avenue

Santa Clara, California 95051

Copyright0 1987, Intel Corporation, All Rights Reserved

Additional copies of this manual or other Intel literature may by obtained from:

Literature D epartm ent
Intel Corporation
3065 Bowers Avenue
Santa Clara, CA 95051

The information in this document is subject to change w ithout notice.

Intel Corporation makes no w arranty of any kind with regard to this m aterial, including, but not
limited to, the im plied w arranties of m erchantability and fitness for a particular purpose. Intel
Corporation assumes no responsibility for any errors that may appear in this document. Intel
Corporation makes no com m itment to update or to keep current the information contained in this
document.

Intel Corporation assumes no responsibility for the use of any circuitry other than c ircuitry
embodied in an Intel product. No other circuit patent licenses are implied.

Intel software products are copyrighted by and shall remain the property of Intel Corporation.
Use, duplication or disclosure is subject to restrictions stated in Intel's software license, or as
defined in ASPR 7-104.9 (a) (9).

No part of this document may be copied or reproduced in any form or by any means without prior
written consent of Intel Corporation.

The following are tradem ark s of Intel Corporation and its affiliates and may be used only to
identify Intel products:

Above
BITBUS
COMMputer

iLBX
Lm

iMDDX

iPSC
iRMX ONCE

iSBC
CREDIT iMMX iSBX
Data Pipeline Insite
Genius in tel

4

i

intelBOS
i Intelevision
I2ICE

in teligent Identifier MCS RMX/80

ICE inteligent Programming
iCEL
iCS
iDBP
iDIS

Intellec

Intellink

iOSP

iPDS

iSDM Prom ware
iSSB
iSXM
Library Manager Ripplemode

Megachassis
MICROMAINFRAME
MULTIBUS
MULTICHANNEL
MULTIMODULE

OpenNET

Plug-A-Bubble
PROMPT

QUEST
QueX

RUPI
Seamless
SLD

UPI
VLSiCEL

iPSB

XENIX, MS-DOS, M ultiplan, and Microsoft are trademarks of Microsoft Corporation. UNIX is a
trademark of Bell Laboratories. E thernet is a trademark of Xerox Corporation. Centronics is a
trademark of Centronics D ata Computer Corporation. Chassis Trak is a trad em ark of G eneral
Devices Company, Inc. VAX is a tradem ark of D igital Equipment Corporation. Smartmodem 1200
and Hayes are tradem ark s of Hayes Microcomputer Products, Inc. IBM is a registered tradem ark
of International Business Machines.

Copyright 1987, Intel Corporation

11

REV.

REVISION HISTORY

DATE

-001 Original Issue. Documents product number
PBA 149422-003 to -009.

-002 Revision documents product number PBA 04/87

451213.

11/86

CAUTION

This board generates and uses energy of about the same frequency as radio and
TV broadcasts. Installed incorrectly, it may interfere with reception of radio
and TV broadcasts.

The board has been verified to be within energy emission limits for Class B
computing devices as defined in the FCC Rules, Part 15, Subpart J. Installed
correctly, it probably will not interfere with your radio or TV. However, we do

not guarantee the absence of interference.
Peripherals (computer input/output devices, terminals, printers, etc.) attached

to this board must be certified to comply with the Class B limits. Operation
with non-certified peripherals is likely to result in interference with radio and

TV reception. NOTE: shielded, grounded cables must be used.

You might find the following booklet helpful:

"How to Identify and Resolve Radio-TV Interference Problems”

You can order the booklet from the U.S. Government Printing Office,
Washington, DC 20402. Ask for stock number 004-000-00345-4.

iii/iv

TABLE OF CONTENTS

inter

CHAPTER 1
INTRODUCTION

Features...........................................................................................................................1-1

How to Use This M anual

___________________________________________

1-2

Revision Differences

_____________________________________________

1-3
Organization______________________________________________________ 1-4

Symbols and Terms..................................................................................................1-5

CHAPTER 2
FEATURES OF THE iSBC® 386AT BOARD

80386 Microprocessor

_______________________________________

2-4

Math Coprocessor Socket.............................................................................................2-6

Timers

_____________________________________________________________

2-7

Memory____________________________________________________________ 2-7

System Board RAM................................................................................................2-7

32-bit Memory Boards........................................................................................... 2-10

Memory to Fill 640 KB

..........................................................................................

2-11

System ROM

_________________________________________________

2-12

Expansion Slots..........................................................................................................2-13

8-Bit Expansion Slots.............................................................................................2-15

16-Bit Expansion Slots........................................................................................... 2-16

High-Speed 32-Bit RAM Expansion Slots____________________________ 2-17

I/O Address Map........................................................................................................ 2-19

Interrupt Controllers.................................................................................................2-21

DMA Controllers.......................................................................................................2-22

Real-Time Clock.......................................................... 2-23

Keylock Interface......................................................................................................2-24

Speaker Interface.......................................................................................................2-24

Serial Communications Port.....................................................................................2-25

Parallel Printer Port..................................................................................................2-26

Power Connectors...................................................................................................... 2-27

Keyboard Connector

.................................................................................................

2-29

Keyclick Volume....................................................................................................... 2-30

iSBC® 386AT

v

Contents

CHAPTER 3
CONFIGURING THE iSBC® 386AT BOARD

Jumper Locations.........................................................................................................3-1

Monitor Type...............................................................................................................3-3

Memory Configuration Selection

..............................................................................

3-3
ROM Size Selection______________________________________________ 3-6

Serial Communications Port Selection...................................................................... 3-7

Parallel Printer Port Selection................................................................................... 3-8

Printer Acknowledge Signal

___________________________________________

3-9

Keyboard Reset............................................................................................................3-9

Math Coprocessor

.................

3-10

CHAPTER 4
INSTALLATION

Building a System

..........

..............................................................................................4-1

Installing Intel Memory Boards............................... 4-2

Installing the Math Coprocessor.................................................................................4-3

Installing the 80387 Math Coprocessor
Installing the SBCMATH Module

Installing the Power Connectors

_______________________________________

________________________

4-4

_________________________________

4-5

4-6

CHAPTER 5
SETUP PROGRAM

Preparing the System To Run SETUP......................................................................5-1

Running the SETUP Program

__________________________

5-2

Setting the Date and Time.....................................................................................5-3

Setting the Current Options

...............

5-4
SETUP Option Screens_____________________________________________5-4

Rebooting the System............................................................................................5-14

SETUP Error Messages.............................................................................................5-14

CHAPTER 6
POWER-ON SELF TEST

POST Operation...........................................................................................................6-1

POST Error Messages................................................................................................. 6-2

Screen Messages.......................................................................................................6-2

System Board Errors............................................................................................... 6-9

CHAPTER 7
BIOS INFORMATION

APPENDIX A
SPECIFICATIONS

vi iSBC® 386AT

Contents

APPENDIX B
JUMPERS

APPENDIX C
TESTED SOFTWARE AND HARDWARE

Business Management________________________________________________ C-l
Communications_____________________________________________________C-l
Database and File Management________________________________________C-2
Disk and Tape Systems

_______________________________________________

C-2

Educational, Recreational, and Training

________________________________

C-2

General-Purpose Enhancements

_______________________________________

C-3

Graphics

.................

C-3

Input Devices.............................................................................................................. C-3

Integrated Packages................................................................................................... C-4

Monitors and Video Cards

____________________________________________

C-4

Networks

__________________________________________________________

C-4
Operating Systems___________________________________________________C-4
Spreadsheets

........

........................................................................................................C-5

Utilities and Languages_______________________________________________C-5
Word Processors, Editors, and Spelling Checkers

______________________

C-6

APPENDIX D
RELATED PUBLICATIONS

APPENDIX E

SERVICE INFORMATION

Services Provided......................................................................................................... E-l

When You Call______________________________________________________E-l
Packaging Requirements___________________________________________ E-2
Shipping Address____________________________________________________ E-2

Obtaining DRA or RRA Service..............................................................................E-2

iSBC® 386AT vii

Contents

intel® TABLES

Table 1-1. Comparison of System Board Functions.......

Table 2-1. System Board Memory Access Times
Table 2-2. Expansion Slot Types

________________________________

...

...........................................

1-2

...................................................2-9

2-14

Table 2-3. Pin-Out Spec for 8-Bit Expansion Slot...................................................2-15

Table 2-4. Pin-Out Spec for 16-Bit Expansion Slot.................................................2-16

Table 2-5. Pin-Out Spec for 32-Bit RAM Expansion Slot......................................2-17

Table 2-6. I/O Address Map......................................................................................2-19

Table 2-7. Bits in I/O Address 61H..........................................................................2-20

Table 2-8. Interrupt Lines.........................................................................................2-21

Table 2-9. DMA Channels
Table 2-10. Battery Connector Pin-Out Specification

.................

2-22

..................

2-23

Table 2-11. Keylock Connector Pin-Out Specification...........................................2-24

Table 2-12. Speaker Connector Pin-Out Specification
Table 2-13. Integral Serial Port Connector Pin-Out Specification
Table 2-14. Integral Printer Port Connector Pin-out Specification
Table 2-15. Power Consumption of System Board
Table 2-16. System Current Requirements

__________________________

Table 2-17. Keyboard Connector Pin-Out Specification

..........................................

-----------------
___________

...........

.....................................

______________

2-24

2-25
2-26

2-27

2-28

2-29

Table 5-1. Types for Example Fixed Disks..............................................................5-7

Table 5-2. Fixed Disk Types..................................................................................... 5-7

Table 6-1. Beep Codes for Fatal Errors.................................................................. 6-10

Table 6-2. Beep Codes for Non-Fatal Errors

_____________________________

6-11

Table 7-1. BIOS Functions................................. 7-1

Table A-l. Specifications...........................................................................................A-l

Table B-l. Jumper Descriptions

________________________________________

B-l

viii

iSBC® 386AT

Contents

inter FIGURES

Figure 1-1. Installing J13 and J14 on PBA149422 Boards
Figure 2-1. Layout of the iSBC® 386AT Board

.........................................................

Figure 2-2. Functional Diagram of the iSBC® 386AT Board

.........................................

..................................

1-3

2-2

2-3

Figure 2-3. Programmatically Setting Deturbo Mode..............................................2-5

Figure 2-4. Programmatically Setting Turbo Mode

.................................................

2-6

Figure 2-5. Memory Map............................................................................................ 2-8

Figure 2-6. 32-Bit Memory Board

.............................................................................

2-10

Figure 2-7. Expansion Slot Locations.......................................................................2-14

Figure 2-8. Keyboard Connector

..............................................................................

2-30

Figure 3-1. 386AT Jumper Locations..........................................................................3-2

Figure 3-2. Jumper Options for Standard Board......................................................3-4

Figure 3-3. Jumper Options for 16 MB RAM Option

..............................................

3-5

Figure 3-4. Jumpers for ROM.....................................................................................3-6

Figure 4-1. Location of Pin 1 on the 80387 ............................................................... 4-4

Figure 4-2. Installing the SBCMATH Module

.........................................................

4-5

Figure 4-3. Power Connector Pins..............................................................................4-6

Figure 5-1. Memory Map........................................................................................... 5-12

iSBC® 386AT

IX

CHAPTER 1

intel® INTRODUCTION

The iSBC® 386AT board is a high-performance system board that provides
the primary elements for building advanced personal computers. The board
is functionally compatible with the system board in the IBM AT. However,
it contains an 80386 microprocessor, 32-bit access to data, and other features

that give it over twice the performance of an 8MHz IBM AT.

NOTE This manual describes boards that have a product number

PBA451213. If your board has a product number PBA149422—003
to —009, please read the section in this chapter called "Revision
Differences." If your board does not have one of these numbers,
contact your sales representative for documentation.

FEATURES

Major features of the iSBC 386AT board include:

• Intel 16MHz 80386 central processor and support circuits

• Socket for the Intel 80387 math coprocessor or iSBC® MATH
(SBCMATH) module

• ROM BIOS compatible with the IBM AT BIOS

• RAM memory (Sixteen 64Kx4 chips for a total of 512K bytes of
conventional memory on the system board)

• Keyboard interface compatible with IBM AT

• Keylock interface

• Real-time clock with battery-backed CMOS memory

• Sixteen interrupts

• Seven Direct Memory Access (DMA) channels

• One configurable IBM-compatible serial RS-232 communications port

• One configurable Centronics-compatible parallel printer port

• Expansion bus interface

-two 8-bit slots exclusively for PC-compatible expansion boards

-four 16-bit slots for both AT- and PC-compatible boards

-two expansion slots for high-speed, 32-bit RAM expansion boards
(or for PC-compatible expansion boards)

• Speaker drive

Table 1-1 compares the features of the iSBC 386AT board with those of the

IBM AT and XT system boards.

iSBC® 386AT

1-1

Introduction

Table 1-1. Comparison of System Board Functions

Functions

Processor 80386 80286 8088
Math coprocessor

Maximum RAM on board
ROM
DMA Channels
Timer/Counter 3 3 3

Interrupt levels

Keyboard interface

Speaker driver

Expansion slots 8 (4 with 16-bit)
Serial interface Standard

Clock/calendar
Parallel printer port Standard

386AT

80387/80287 ‘ 80287 8087
512 KB

128 KB

7 7

16 16 8
8742 8042 8255

yes

Standard

PC-AT

512 KB
128 KB

yes

8 (6 with 16-bit)

option board

Standard
option board

256 KB
48 KB
4

yes
8 (all 8-bit)
option board
option board
option board

PC-XT

CPU/Memory bus 32 bit 16 bit 8 bit

‘The 386AT uses an optional 80387 or 10 MHz 80287 math module.

HOW TO USE THIS MANUAL

This manual is intended for the original equipment manufacturer (OEM)
who plans to build computer systems based on the iSBC 386AT board. It
describes the major features of the board, lists the pin-out specifications for
all the connectors on the board, provides instructions for installing and
configuring the board, and describes the system and setup software available

with the board. The OEM can use this information when designing the
system interfaces. Relevant information can also be included in the OEM’s
end-user documentation.

1-2

iSBC® 386AT

Revision Differences

A board numbered PBA149422-003 to -009 differs from PBA451213, the
standard board discussed in this manual, in these ways:

PBA 451213 (this manual)

• Can use either an 80387 or its own SBCMATH module

• Has no stake pins numbered 4, 5, or 6; requires M146818AP for real-time

clock

PBA 149422 (-003 and up)

• Can use an SBCMATH module; cannot use an 80387

• A jumper on stake pins 4 to 5 selects M146818AP for the real-time clock
chip; jumper 5 to 6 selects M146818P.

Introduction

• Power connector J14 has the same pinout as J14 on PBA451213. However,
the connector is turned 180 degrees.

CAUTION If you use J14 on PBA149422, do not use Figure 4—3, "Power

Connector Pins." Use Figure 1—1. If the key is broken and the

power connector installed incorrectly, the power connector will

deliver -f 5V to the ground plane of the board and damage
components on the board.

PIN

•

1

SYSRST*

•

+ 5V

2

•

+ 12V

3

•

4

-12V

•

5

GROUND

6•| GROUND

! GROUND

•

7

•

8

GROUND

9 l•' - 5 V

•

10
11
12

+ 5V

•

+ 5V

•

+ 5V

+ 5V
+ 5V

+ 5V
GROUND
GROUND
GROUND

• 1

• 2

• 3

• 4

i

• 5

! • ! 6

PIN

iSBC® 386AT

Figure 1-1. Installing J13 and J14 on PBA149422 Boards

1-3

Introduction

Organization

The manual has the following chapters and appendixes:
Chapter 1. Introduction - Introduction to the board, list of differences

between revisions, and description of the organization of the manual.

Chapter 2. Features of the iSBC 386AT Board - High-level descriptions of the

major items on the board, including the pin-out specifications for all of
the connectors.

Chapter 3. Configuring the iSBC 386 AT Board -- Descriptions of all the

jumper settings on the board.

Chapter 4. Installation -- Recommendations for building a system based on

the iSBC 386AT board, plus instructions for installing the math
coprocessor and the 32-bit memory boards.

Chapter 5. SETUP Program - Description of the SETUP program that can

store system configuration information in the CMOS memory of the
real-time clock chip.

Chapter 6. Power-On Self Test -- Brief description of the power-on self test

and list of the screen messages and audible tones that can occur when
error conditions are present.

Chapter 7. BIOS Information -- Table of BIOS interrupts and the functions

they perform.

Appendix A. Specifications -- Table of board specifications.
Appendix B. Jumpers -- Table of jumper settings.
Appendix C. Tested Software and Hardware-- Table of tested software and

hardware.

Appendix D. Related Publications -- List of publications that might be of

interest to the reader of this manual.

Appendix E. Service Information -- How to get boards repaired.

1-4

iSBC® 386AT

Symbols and Terms

The following symbols and terms are used in this manual:
* Indicates an active low signal, such as IOCHECK*.

Introduction

<>

H

Cautions

Notes
Default

Indicates special keys on the keyboard. For example, <Enter>
indicates the Enter key.

Denotes hexadecimal numbers. All addresses are listed in
hexadecimal notation.

indicate potential for software or hardware damage.
simply emphasize information.

is the configuration of the board when shipped from the

factory. Default usually refers to the factory setting of jumpers
on the stake pins.

iSBC® 386AT

1-5

inte

CHAPTER 2

FEATURES OF THE iSBC® 386AT BOARD

This chapter briefly describes each of the major features of the iSBC 386AT

board. It covers the following topics:

• 80386 processor

• Math coprocessor socket

• Timers

• Memory

• Expansion slots

• I/O address map

• Interrupt controllers

• DMA controllers

• Real-time clock with battery backup

• Keylock interface

• Speaker interface

• Serial communications port

• Parallel printer port

• Power connectors

• Keyboard connector

• Keyclick volume
Figure 2-1 shows the layout of the board with callouts identifying most of

these items. Figure 2-2 is a functional diagram of the board.

iSBC® 386AT

2-1

Features of the iSBC® 386AT Board

Figure 2-1. Layout of the iSBC® 386AT Board

2-2

iSBC® 386AT

Features of the iSBC® 386AT Board

2576

Figure 2-2. Functional Diagram of the iSBC® 386AT Board

iSBC® 386AT

2-3

Features o f the iSBC® 386AT Board

80386 MICROPROCESSOR

The central processing unit of the iSBC 386AT board is the Intel 80386
microprocessor, a high-performance, 32-bit microprocessor that is upward
compatible with Intel’s 8088, 8086, and 80286 processors. Included in the extra
features offered by the 80386 are the following:

32 data lines, enabling it to access 32 bits of data in a single instruction.
32 address lines, with a physical address space of 2 bytes (4 gigabytes)

in protected mode and a virtual address space of 2 ^ bytes (64 terabytes).
Address lines 0-23 and 31 are connected on the iSBC 386AT board,

limiting the actual physical address space to 16M bytes.

• Virtual 8086 mode addressing that permits concurrent execution of
multiple applications written specifically for the 8088 or 8086.

• Paged memory support that permits memory to be mapped anywhere in
the 16M-byte address space recognized by the iSBC 386AT board.

The 80386 runs at a clock speed of 16MHz in the iSBC 386AT board, resulting
in system clock cycles of 62.5 ns. This gives the system board over twice the
performance of an 8MHz IBM AT. However, for those applications that
require slower operation (such as installing some copy-protected software),
the iSBC 386AT board offers a "deturbo" mode that enables the board to
simulate the performance of a 8MHz IBM AT. The deturbo mode is
enabled and disabled from the keyboard with the following key sequences:

Key Sequence

Description

Ctrl-Alt-1 Holding down the Ctrl and Alt keys and pressing 1

on the numeric keypad places the board in deturbo
mode (emulating the performance of an 8MHz AT).

Ctrl-Alt-2 Holding down the Ctrl and Alt keys and pressing 2

on the numeric keypad places the board in turbo
mode (resuming full processor speed).

After every system (power-on) reset, the deturbo logic is reset, causing the
system board to run at full processor speed. A software reset does not
change the processor speed.

2-4

The deturbo mode does not affect the clock rate at which the 80386 executes

instructions, nor does it affect the clock rate of the math coprocessor.
Rather, it inserts processor hold states between each instruction, causing an
effective processor speed of 8MHz.

iSBC® 386AT

Features o f the iSBC® 386AT Board

When a speaker is connected to the system board, an audible tone occurs

when you change the processor mode. Pressing Ctrl-Alt-1 (for deturbo mode)
emits a low-pitched tone. Pressing Ctrl-Alt-2 (for full speed) emits a high-
pitched tone.

CPU speed can also be set programmatically. Figure 2-3 lists the assembly
language code needed to place the board in deturbo mode. Figure 2-4 shows
the code to return the board to 16MHz operation.

; slow

/
code
assume

start: jmp
msg
begin:

done:

code

end

— put iSBC 386AT into DETURBO mode (simulated 8MHz)

segment public

cs:code,

org lOOh

db
mov
mov
mov

out
mov

mov

int 21h

mov

int
ends
start

ds:code

begin

'iSBC 386AT in DETURBO mode','$'

ax, cs ;set up ds

ds,ax

ax,OeaH
64H,ax

dx,offset msg ;address of deturbo message

ah,09h ;display string function request

;call DOS
ah,4ch
21h ;call DOS

;terminate process funct request

;start is the entry point

Figure 2-3. Programmatically Setting Deturbo Mode

iSBC® 386AT

2-5

Features of the iSBC® 386AT Board

fast — put iSBC 386AT into TURBO mode (16MHz)

code
assume

start: jmp
msg
begin: mov

segment

cs:code,

org
db

mov

public

ds:code

lOOh

begin

'iSBC 386AT in TURBO mode','$'
ax, cs ;set up ds
ds,ax

mov ax,0e5H

done:
code

end

out
mov
mov

int
mov

int

ends

start ;start is the entry point

64H,ax

dx,offset msg

ah,09h
21h ;call DOS
ah,4ch
21h ;call DOS

Figure 2-4. Programmatically Setting Turbo Mode

MATH COPROCESSOR SOCKET

;address of turbo message
;display string function request

;terminate process funct request

The math coprocessor socket is a 68-pin PGA (pin grid array) socket that can
contain either an 80387 math coprocessor or an 80287-based SBCMATH

module. The SBCMATH module is a small board containing an 80287 and
support circuitry. The SBCMATH module physically adapts the 40-pin
80287, enabling it to plug into the 68-pin 80387 socket.

When an 80387 is plugged into the socket, it uses the CPU clock as its clock

source and operates synchronously with the 80386. Therefore, it also

operates at 16MHz. When the SBCMATH module is inserted, the 80287

operates at 10MHz, asynchronously to the 80386.

CA U T IO N Before inserting an 80387 in the board, read the instructions in

Chapter 4. If the chip is inserted incorrectly, the chip and the
system will be damaged.

2-6

iSBC® 386AT

TIMERS

An on-board 8254A chip provides three programmable timers, each with the
same timing frequency of 1.19MHz. The timers are used for the following
operations:

Features of the iSBC® 386AT Board

Timer

0

1

2

MEMORY

The iSBC 386AT board contains 512K bytes of RAM for system access and
64K bytes of ROM that contains the BIOS. It also contains two 32-bit

expansion slots for extended memory boards. Figure 2-5 shows the memory
map.

System Board RAM

Function

The output of this timer is tied to interrupt request
0 (IRQ 0).

This timer is used to trigger memory refresh cycles.

The BIOS loads this timer with a value of 012H to
set the RAM refresh period.

This timer provides the speaker tone. Application
programs can load different counts into this timer

to generate various sound frequencies.

The system board contains 512K bytes of RAM that the processor can access

a full 32 bits at a time. Sixteen 64Kx4 chips are used for memory access, and
eight 64Kxl chips are used for the parity bits (with one parity bit for each
byte of data). All of the RAM chips have 120ns access times.

The system board RAM is arranged into two 256K byte banks of memory.
The memory addresses alternate between the banks (the first 32 bits of
memory are in bank 0, the next 32 bits are in bank 1, the next 32 bits in bank

0, etc.). With this two-bank arrangement, the memory chips in one bank can

recharge while the CPU accesses memory from the other bank. By
overlapping the recharge of one bank with access in another, the CPU
requires only one wait state to access memory in alternating banks. This
would be the normal case for sequential memory accesses.

iSBC® 386AT

2-7

Features of the iSBC® 386AT Board

PROM (128 KB)

Extended RAM (0 to 15 MB)

PROM (128 KB)

Reserved for extensions to BIOS

(128 KB)

Reserved (128 KB)

Conventional RAM

(128KB offboard)

Conventional RAM
(512 KB onboard)

Figure 2-5. Memory Map

2-8

iSBC® 386AT

Features of the iSBC® 386AT Board

If the CPU makes consecutive memory accesses to the same bank, it must
wait for the RAM to recharge. This performance penalty is approximately

2 wait states (125 ns).

Table 2-1 shows the access times for 32-bit read and write operations using
the RAM on the system board. The table shows the times for both busy and
nonbusy banks of memory. A busy bank is one to which the CPU has made
consecutive accesses. When alternating between banks, the memory is
nonbusy. For comparison, the table also lists the ROM access times and the
access times for boards plugged into the 8-bit (PC-compatible) and 16-bit
(AT-compatible) slots.

Table 2-1. System Board Memory Access Times

Operation CPU Clock Cycles (16MHz) Time (ns)

32-bit read of system board RAM

Read from nonbusy bank 3
Read from busy bank

32-bit write of system board RAM

Write to nonbusy bank 4

Write to busy bank
32-bit ROM read (two 16-bit accesses) 12
8-bit read/write of expansion slot

8-bit (PC-compatible) slot

16-bit (AT-compatible) slot

131

81

16-bit read/write of expansion slot

8-bit (PC-compatible) slot

16-bit (AT-compatible) slot

251

81

32-bit read/write of expansion slot

8-bit (PC-compatible) slot
16-bit (AT-compatible) slot

501

161

187.5

5 312.5

250

6

373.75

747.5

812.5
500

1562.5
500

3125

1000

^ Depending on the previous cycle, this access
clock cycle (62.5 ns).

iSBC® 386AT

might take one

additional

2-9

Features o f the iSBC® 386AT Board

32—bit Memory Boards

Two of the expansion slots on the iSBC 386AT board are 32-bit slots that can
contain 32-bit memory boards. The iSBC 386AT board can recognize as

much as 15M bytes of extended memory (starting at address 100000H and
going to address OFFFFFFH). Intel provides the iSBC® 386MEM020 and
iSBC® 386MEM080 memory boards for these slots. Each MEM020 board
contains 2M bytes of RAM and uses 256Kxl chips. Each MEM080 board
contains 8M bytes of RAM and uses lMxl chips. On both boards, there is a
parity bit for each byte of data.

Like the memory on the system board, the RAM on these boards is arranged
into two banks of alternating addresses (see Figure 2-6). Thus the CPU can
access the memory on these boards 32 bits at a time with only one wait state

when accessing alternate banks. The access times for memory on the boards
are the same as for the memory on the system board. Table 2-1 lists the
times.

2-10

Figure 2-6. 32-Bit Memory Board

iSBC® 386AT

The jumpers on the system board are set at the factory to assume that two
MEM020 boards will be used. If your system has a different configuration,
you must change the memory jumpers on the system board. You can
configure the system board for 0, 2, 4 or 10 megabytes on the 32-bit boards.
The MEM080 board is shipped with a replacement PAL for U59; use the
replacement if your system has 8 or 16 megabytes on the 32-bit boards.

Refer to Chapter 3 for information on configuring the system board.

Memory to Fill 640 KB

To get the total 640K byte conventional memory recognized by DOS, you

need to add 128K byte of offboard memory to supplement the 512K byte
onboard. You can do this in one of two ways: with software, now on the
market, that assigns 128K bytes from a 32-bit board to this area, or with a
memory card such as an Intel AboveBoard in one of the AT-compatible 16-
bit slots.

Features of the iSBC® 386AT Board

Extended and Expanded Memory

Sections of memory on the 32-bit boards or the 16-bit AboveBoard can be
assigned as conventional, expanded, or extended. Conventional memory fills
the 128K byte area from 512 to 640K bytes. Expanded memory is memory
that adheres to the LIM (Lotus-Intel-Microsoft) specification, giving DOS
applications a window in which to access more memory than the 640K bytes
addressable in real mode. Extended memory is memory whose addresses
begin at 1M byte and continue up to 16M byte. Extended memory can be
accessed only when the processor is in protected mode.

Although most of the memory on the 32-bit boards is for extended memory,
several software packages now on the market can assign part of the 32-bit
boards to conventional and expanded memory. The software for the
expanded memory emulates the LIM specification.

The Intel AboveBoard uses switch settings to assign memory to the
conventional, expanded, and extended areas.

iSBC® 386AT

2-11

Features o f the iSBC® 386AT Board

System ROM

The system board contains 64K bytes of ROM that comprise the system
BIOS. This memory resides at the upper 64K bytes of address space in the

first megabyte and is also mapped to the upper 64K bytes of the 16M byte

space when the processor switches into protected mode. In protected mode,

the BIOS can be accessed at either location.
The CPU accesses ROM through a local I/O bus 16 bits at a time. The

system board will function correctly with ROM devices that have 250 ns
access times or shorter. Table 2-1 lists the time and the number of processor
clock cycles required to access the ROM.

The BIOS supplied with the iSBC 386AT board is compatible with the BIOS

in the IBM AT, as long as programs that access the BIOS use software
interrupts (as listed in Appendix B) and do not specify absolute memory
locations. Programs that refer to absolute locations in the IBM AT BIOS

will not function correctly when running on the iSBC 386AT board.
Unlike the IBM AT, the iSBC 386AT ROM does not contain code for the

BASIC interpreter. Therefore, the IBM BASIC and BASICA interpreters

will not run on this system board. Instead, users should acquire Microsoft’s

GW-BASIC interpreter for use in systems based on the iSBC 386AT board.

2-12

iSBC® 386AT

EXPANSION SLOTS

Expansion slots in IBM PC, XT, and AT computers and PC-compatibles
have evolved in size, giving greater performance by expanding the number
of bits of the data and address that can be accessed and sent through the bus.
The PC and XT slots provide 8 data bits and 20 address bits. The AT slots
provide 16 data bits and 24 address bits. The iSBC 386AT board contains
both of these types of slots. In addition, it expands the bus further by
supplying two slots with 32 data bits and 24 address bits. It contains eight

expansion slots of the following types:

• Two 8-bit slots for use exclusively by PC-compatible expansion boards

• Four 16-bit slots for use by both AT-compatible and PC-compatible
expansion boards

• Two 32-bit slots for use by both Intel 32-bit memory expansion boards
and by PC-compatible expansion boards.

Features of the iSBC® 386AT Board

The two 8-bit slots can handle any expansion boards that work in the IBM

PC or XT, including "drop cards" -- those boards that gain extra surface area
by dropping down immediately after the 8-bit connector. The drop cards
will not work in any 16-bit or 32-bit slot, because the longer slots interfere

with the dropped portion of the boards.

The 16-bit and 32-bit slots will accept other kinds of 8-bit PC-compatible

boards, but the 32-bit slots will not work with the 16-bit AT boards. The 32-
bit slots are keyed to prevent 16-bit AT boards from being inserted.

CA U T IO N Even if these keys are removed, do not insert a 16—bit AT board in

a 32—bit slot. It could damage the 80386.

Figure 2-7 identifies the slot locations on the iSBC 386AT board. Table 2-2

lists the type of slot and the number of bits it addresses.

iSBC® 386AT

2-13

Features o f the iSBC® 386AT Board

J2 J3 J4 J6 J7 J8 J9

J16 J17 J18

q

Keyboard
Connector

Figure 2-7. Expansion Slot Locations

Table 2-2. Expansion Slot Types

Data Address

Slot # Bits Bits Type

1 (J2/J16)
2 (J3/J17)

3 (J4/J18)
4(J5)
5 (J6)

16 24
16
16

8

24
24
20

8 20
6 (J7/J19) 32 24
7 (J8/J20)
8 (J9/J21)

32 24
16

24

AT/PC (no drop cards)
AT/PC (no drop cards)
AT/PC (no drop cards)
PC (including drop cards)
PC (including drop cards)
32-bit/PC (no drop cards)
32-bit/PC (no drop cards)
AT/PC (no drop cards)

2-14

iSBC® 386AT

8—Bit Expansion Slots

J2 through J9 are the IBM PC- and PC XT-compatible 62-pin expansion slots.
This 62-pin interface carries addresses to 1M byte and allows 8-bit data
transfers. When 8-bit expansion cards occupy the slots, the slots run with
8MHz bus cycles. Slots J7 and J8 also combine with slot extensions J19 and
J20 to form the 32-bit slots. When Intel MEM020 or MEM080 memory cards
occupy the 32-bit slots, those slots run with 16MHz bus cycles. Table 2-1 lists
the access times for these slots. Table 2-3 lists the pins for the 8-bit slots.

Table 2-3. Pin-Out Specification for 8-Bit Expansion Slot

Features of the iSBC® 386AT Board

I/O

o

-

I

-

I

-

I

-

-

o

SIGNAL

GND

RSTDEV

+5V

IRQ9 7 B4 A4

-5V
DRQ2

-12V
SRDY*
+12V
GND

MEMW*

o MEMR*
o
o
o

I

IOWC*
IORC* 27 B14
DACK3*
DRQ3

o DACK1*

I

I/O

o

I
I
I
I

I
o
o
o

-

o

-

DRQ1
MEMREF* 37
SYSCLK
IRQ7
IRQ6 43
IRQ5
IRQ4

IRQ3
DACK2*

TC

BUSALE
+5V
840SC
GND

PIN#

1
3 B2 A2 4 D7 I/O
5 B3 A3

9

11

13 B7 A7 14 D2

15

17

19
21
23 B12
25 B13 A13 26 A18

29

31
33 B17
35

39

41
45

47

49 B25 A25 50 A6

51
53 B27
55
57
59 B30 A30 60 A1
61 B31 A31 62

B# A# PIN#

B1 A1 2

6 D6

8
B5
B6 A6

B8
B9

BIO

Bll All

B15
B16 A16

B18 A18
B19 A19 38

B20

B21 A21 42
B22 A22
B23 A23 46 A8
B24 A24

B26
B28 A28 56

B29 A29 58

A5

A8

A9

A10 20
A12
A14 28

A15
A17

A20

A26
A27

10 D4 I/O
12 D3

16
18

22 AEN o

24

30 A16

32 A15
34 A14 I/O
36

40 All I/O
44
48

52 A5 I/O
54 A4 I/O

SIGNAL I/O

IOCHCK* I

D5 I/O

D1 I/O

DO I/O
IOCHRDY

A19
A17 I/O

A13 I/O
A12

A10
A9

A7 I/O

A3 I/O
A2

A0

I/O

I/O

I/O

I

I/O
I/O

I/O
I/O

I/O
I/O

I/O
I/O

I/O

I/O
I/O

I/O

iSBC® 386AT

2-15

Features of the iSBC® 386AT Board

16—Bit Expansion Slots

J16, J17, J18, and J21 are extensions to the 62-pin PC-compatible slots that
increase addressability to 16M bytes and enable 16-bit data transfers. These
32-pin slots extend in-line with the PC slots to form 16-bit slots that are
compatible with those available on the PC AT. The pin-out specification for
this slot extension is given in Table 2-4. The 16-bit expansion slots operate
with 8MHz bus cycles. Table 2-1 lists the access times for these slots.

Table 2-4. Pin-Out Specification for 16-Bit Expansion Slot Extension

I/O

I
I
I
I
I

I

I

o

I

o

I

o

I

o

I

-

I

-

SIGNAL PIN #

FMEM*

1
FIO* 3
IRQ10

5

IRQ11 7
IRQ12
IRQ15

IRQ14

DCCKO*
DRQO

DACK5*

9 D5 C5

11
13
15

17

19 DIO CIO 20 MWTC* I/O

DRQ5 21
DACK6* 23

DRQ6 25

DACK7*
DRQ7
+5V

27
29 D15

31

SECMAST* 33
GND

35

D#

C#

D1 Cl

PIN#

2 IOBHE*
D2 C2 4
D3 C3

D4 C4

6
8

10 P2A20

D6

D7

C6

Cl

D8 C8
D9 C9

Dll

D12

D13

D14

Cll
C12 24
C13
C14

12
14 P2A18 I/O

16

18 MRDC* I/O
22
26

28

C15 30

D16 C16
D17

C17 34

32 D13 I/O

D18 C18 36

SIGNAL

I/O

I/O
P2A23
P2A22
P2A21

I/O

I/O
I/O
I/O

P2A19
P2A17

D8

D9

I/O
I/O

I/O

I/O

DIO I/O

Dll
D12

D14

I/O

I/O

I/O
D15 I/O

2-16

iSBC® 386AT

High-Speed 32—Bit RAM Expansion Slots

Slots J7/J19 and J8/J20 are 86-pin slots available for high-speed, 32-bit RAM
expansion cards. The Intel MEM020 and MEM080 memory boards fit in
these slots. The slots operate at 16MHz, the same timing as the system board
RAM. See Table 2-1 for the access times. Table 2-5 lists the pin-out
specification for these slots.

Table 2-5. Pin-Out Specification for 32-Bit RAM Expansion Slot

Features of the iSBC® 386AT Board

I/O SIGNAL

o CPUA3

PIN # PIN #

1 2

SIGNAL I/O

EXPDO

I/O

o CPUA4 3 4 EXPD1 I/O
o CPUA5 5

-

o
o CPUA7
o
o CPUA12
o

-

o CPUA14
o
o
o CPUA17
o

-

o

GND
CPUA6

RA11
CPUA13 17

GND
CPUA15 23 24 EXPD10

CPUA16 25
CPUA18 29 30

+5V
CPUA19 33

7
9

11 12
13 14
15 16

19 20 EXPD8 I/O
21 22 EXPD9 I/O

27

31 32

o CPUA20 35
o

RA8

o RA9

37
39

6
8

10

18

26
28

34 EXPD15
36 NC
38
40

EXPD2 I/O
EXPD3

EXPD4
EXPD5
EXPD6
EXPD7 I/O
+5V

EXPD11 I/O
EXPD12 I/O
EXPD13
EXPD14

EXPD16 I/O

EXPD17

I/O
I/O
I/O
I/O

I/O

I/O
I/O
I/O

I/O

o RA10 41 42 EXPD18 I/O

-

-

iSBC® 386AT

(continued)

2-17

Features of the iSBC® 386AT Board

Table 2-5. Pin-Out Specification for 32-Bit RAM Expansion Slot (continued)

I/O SIGNAL

GND 43 44 EXPD19 I/O

o CPUA21

PIN # PIN #

45 46

o PI0_7 47

I

o

I

-

o

I P016_23

o PI24_31

I

POO_7 49
PI8 15 51 52 EXPD23 I/O
P08_15
GND

PI16 23 57

P024_31 62 63

53
55 56

59

61

o CPUA22 64 65

-

o CPUA23

-

-

o SLEBO*
o SLEBT

-

o
o
o

GND 67

69
NC 71 72
NC 73

75

77
GND

RMSELO*
RMSEL1* 83
MEMREF 85

79

81

SIGNAL I/O

EXPD20 I/O

48
50 EXPD22 I/O

54 EXPD24
58

60

62

68
70 +5V

74 LA21B0

76 LA19B1
78
80
82 WE_1
84
86

EXPD21

EXPD25 I/O
EXPD26 I/O
EXPD27
EXPD28
EXPD29
EXPD30
EXPD31 I/O

LA19B0

LA21B1 o
WE_0 o

WE_2 o
WE_3 o

I/O

I/O

I/O
I/O
I/O
I/O

-

o
o
o

0

2-18

Slots J7/J19 and J8/J20 can also contain standard 8-bit PC boards. However, if

you insert one 62-pin PC-compatible card and one 2M byte 86-pin memory
card in these two slots, you must place the memory card in slot J7/J19 and
rejumper the system board accordingly.

For example, suppose all the slots on the iSBC 386AT board are filled except
for slots J7/J19 and J8/J20. In addition, suppose you still need to insert a

MEM020 board and a video adapter board into your computer. In this
situation, you must insert the MEM020 board into slot J7/J19 and the video

adapter board into slot J8/J20. Then you must jumper the iSBC 386AT board

to specify that only one 2M-byte memory board is present. Chapter 3

describes the jumper settings.

iSBC® 386AT

I/O ADDRESS MAP

The 80386 CPU communicates with other devices via I/O ports. Table 2-6
lists the I/O port addresses used in the iSBC 386AT board. Table 2-7 lists the
uses of the bits of I/O port 61H.

Features of the iSBC® 386AT Board

Table 2-6. I/O Address Map

Address

(Hex)

00-1F

20-3F

40-5F Timer/Counter (8254)
60, 64

61

70,71

78 Reserved

80-9F DMA Page Register (74LS612)

AO-BF

CO-DF

F0

DMA Controller—(Direct Memory Access) (8237A-5)
(8-bit devices)

Master PIC—Programmable Interrupt Controller
(8259A)

Keyboard Controller (8742)
On-board Testing Registers
Clock/Calendar (MC146818AP) and NMI Mask

SlavePIC—Programmable Interrupt Controller (8259A)
DMA Controller—(Direct Memory Access) (8237A-5)

(16-bit devices)
Clear the Busy signal of the Math Coprocessor

Device

F8-FF

278-27F

2F8-2FF On-board serial port, if used as Port 2

378-37F

3F8-3FF On-board serial port, if used as Port 1

iSBC® 386AT

FI

Math Reset
Math Coprocessor

On-board printer port, if used as Port 2

On-board printer port, if used as Port 1

2-19

Features o f the iSBC® 386AT Board

Table 2-7. Bits in I/O Address 61H

Read

Bit Use

Bit = 0 Bit = 1

0

1 Speaker tone off enabled off

2 DRAM Parity Test off enabled off

3 I/O Channel Test

4

5
6

7

Speaker frequency

(off-board parity)

Refresh cycle not in

Speaker drive

I/O Channel Error
(off-board parity)

DRAM Parity Error no error

off enabled off enabled

off enabled off

process
off
no error

detected

detected

in process RESERVED RESERVED

on
detected

detected RESERVED

Write

Bit = 0 Bit = 1

enabled
enabled
enabled

RESERVED RESERVED
RESERVED

RESERVED

RESERVED

2-20

iSBC® 386AT

INTERRUPT CONTROLLERS

The system board contains two 8259A Programmable Interrupt Controllers
(PICs) that handle the hardware interrupts to the CPU. Table 2-8 lists the

interrupt lines, their priorities, and the devices to which the interrupts are
connected. If the interrupt line is accessible via an expansion slot, the table
lists the signal and the type of slot containing the signal. An 8-bit slot is a
62-pin, PC-compatible slot. A 16-bit slot is an AT-compatible, 36-pin
extension to the PC slot.

Table 2-8. Interrupt Lines

Features of the iSBC® 386AT Board

Interrupt

Level

NMI

0

1
2
3 PI Connector, IRQ3
4 PI Connector, IRQ4

5
6
7
8 Clock/Calendar

9 PI Connector, IRQ9 Slave PIC, Interrupt 1
10
11 P2 Connector, IRQ11

Parity error 80386 NMI input
Timer Channel 0 Master PIC, Interrupt 0
Keyboard Controller Master PIC, Interrupt 1
Slave PIC Master PIC, Interrupt 2

PI Connector, IRQ5
PI Connector, IRQ6
PI Connector, IRQ7

P2 Connector, IRQ10

Source

Master PIC, Interrupt 3
Master PIC, Interrupt 4
Master PIC, Interrupt 5
Master PIC, Interrupt 6
Master PIC, Interrupt 7
Slave PIC, Interrupt 0

Slave PIC, Interrupt 2
Slave PIC, Interrupt 3

Destination

12 P2 Connector, IRQ12
13 Math coprocessor busy signal

14 P2 Connector, IRQ14
15

iSBC® 386AT

Slave PIC, Interrupt 4
Slave PIC, Interrupt 5

(NPXBSY*)

Slave PIC, Interrupt 6

P2 Connector, IRQ15 Slave PIC, Interrupt 7

2-21

Features o f the iSBC® 386AT Board

DMA CONTROLLERS

The system board contains two 8237A-5 DMA (direct memory access)
controllers for byte and word DMA. These controllers operate at 4MHz (the

CPU clock divided by four), yielding a DMA clock cycle of 250ns. All DMA
transfer cycles consume 1250 ns (approximately 5 DMA clocks). In addition,
with a 16MHz CPU clock, 375ns are spent acquiring control and 500ns
relinquishing control of the expansion bus.

Table 2-9 lists the DMA channels and the corresponding signals on the PC
and AT expansion slots where these channels can be accessed.

Table 2-9. DMA Channels

Channel

DMA Controller U56 DMA Controller U57

(Byte Transfers) (Word Transfers)

0
1
2
3

4
5
6
7

Device

P2 Connector, DRQO
PI Connector, DRQ1
PI Connector, DRQ2
PI Connector, DRQ3
DMA Controller U56 into U57
P2 Connector, DRQ5
P2 Connector, DRQ6
P2 Connector, DRQ7

2-22

iSBC® 386AT

REA L-TIM E CLOCK

The system board contains an MC146818AP real-time clock component that
maintains date and time information in addition to storing configuration
information about the computer system.

Because the real-time clock uses CMOS technology, it consumes very little
power and can be maintained for long periods of time with inexpensive
batteries. (Batteries are not provided with the iSBC 386AT board.)

The real-time clock chip contains 14 bytes of clock and control registers. In
addition, it contains 50 bytes of general purpose RAM. This general purpose
RAM is used to store configuration information entered via the SETUP
program (see Chapter 5). When battery-backed power is provided for the
device, it maintains date, time, and configuration information even after the

computer system is turned off.
J10 is a battery connector that enables you to provide battery-backed power

for the real-time clock chip. The battery connector is a 1x4 header whose

pin assignments are shown in Table 2-10.

Features of the iSBC® 386AT Board

The real-time clock chip requires a 6V, 1-ampere-hour lithium battery, which
will last approximately two years with normal use.

Table 2-10. Battery Connector Pin-Out Specification

SIGNAL/FUNCTION J10 PIN #

Battery (plus) 1
Key (pin removed) 2
Ground (minus)
Ground (minus)

3
4

iSBC® 386AT

2-23

Features o f the iSBC® 386AT Board

KEYLOCK INTERFACE

Connector J23 provides the interface that enables you to connect an
electrical interlock, such as a key-activated switch, to lock out the keyboard.
The keylock connector is a 1x5 header whose pin assignments are shown in
Table 2-11.

Table 2-11. Keylock Connector Pin-Out Specification

SIGNAL/FUNCTION

Power for LED power-on light
Key (pin removed) 2
Ground 3

Keylock 4
Ground

SPEAKER INTERFACE

Connector J22 provides an interface that enables you to connect a speaker
for audible tone generation. The connector is a 1x4 header whose pin
assignments are shown in Table 2-12.

Table 2-12. Speaker Connector Pin-Out Specification

J23 PIN #

1

5

2-24

SIGNAL/FUNCTION

SPKOUT Speaker Drive Out

Key (pin missing)
Ground
+5V

J22 PIN #

1
2
3
4

iSBC® 386AT

SERIAL COMMUNICATIONS PORT

Connector J12 on the 386AT board is a 2x13 (26-pin) header that provides the
serial communication channel. This connector can map to either a DB25 (PC
style) RS-232 connector or a DB9 (AT style) connector according to the pin
out specification listed in Table 2-13.

Table 2-13. Integral Serial Port Connector Pin-Out Specification

Features of the iSBC® 386AT Board

J12 PIN #

1
2
3
4
5
6
7

DB9 PIN # DB25 PIN #

1
6 6
2 3
7 4

3

8 5
4

8 9 22

9 5
24
23

-

- -

2

20

7

25

SIGNAL/FUNCTION

DCD Carrier Detect
DSR Data Set Ready
RXD Receive Data
RTS Request to Send
TXD Transmit Data
CTS Clear to Send

DTR Data Terminal Ready
RI Ring Indicator
Ground
MGTEST Mfg. Test
Key (pin missing)

iSBC® 386AT

2-25

Features o f the iSBC® 386AT Board

PARALLEL PRINTER PORT

Connector Jll on the 386AT board is a 2x13 (26-pin) header that provides the
integral parallel printer port. You can use a cable to carry this port off the

system board and onto a standard DB25 connector using the IBM PC

parallel printer pin-out standard. The typical mating connector on a
Centronics-type printer is a 36-pin ribbon cable. The interface is TTL
compatible. The pin-out specification for this connector is shown in Table 2-

14.

Table 2-14. Integral Printer Port Connector Pin-out Specification

36-PIN RIBBON

Jll PIN #

DB25 PIN #

CABLE PIN #

SIGNAL/FUNCTION

1
3
5
7

9
11

13
15
17
19 10
21
23
25

2
4

6
8 17

10,12,14,

16,18,22,24

-

20
26

1

2 2

3 3

4 4

5 5
6
7 7
8 8
9 9

1

6

10

STROBE*

PRTD0 Data Bit 0
PRTD1 Data Bit 1
PRTD2 Data Bit 2
PRTD3 Data Bit 3
PRTD4 Data Bit 4

PRTD5 Data Bit 5
PRTD6 Data Bit 6
PRTD7 Data Bit 7

ACK* Acknowledge
11 11 BUSY
12
13
14

15
16 31

18-25

-

- -

-

19-30,33

12
13
14
32 ERROR*

36

17

-

PE Paper End

SLCT Select

AUTOFDXT* Auto Feed
INIT* Initializing Printer

SLCTIN* Select Input
Ground

Chassis ground

Key (pin missing)
No connection

2-26

iSBC® 386AT

POWER CONNECTORS

J13 and J14, the power connectors, are 12- and 6-pin connectors, respectively,

that supply power to the system board and to the eight expansion slots.
Each pin has a 7-amp current-carrying capacity. J13, the primary power
connector, can carry a maximum of 28 amps at 5 volts. If additional power is
required, up to 21 amps can be fed through J14. Chapter 4 discusses how to

install the power connectors. Table 2-15 lists the power consumption of the

iSBC 386AT board. Table 2-16 estimates the current requirements of an

example system based on an iSBC 386AT board.

Table 2-15. Power Consumption of System Board

Voltage and Tolerance Nominal Current Watts

Features of the iSBC® 386AT Board

+ 5 v +/- 5%
+12 v +/- 10%

-12 v +/- 10%
TOTAL 27.68

5.2 A 26.00

0.06A 0.72

0.08A

0.96

iSBC® 386AT

2-27

Features of the iSBC® 386AT Board

Table 2-16. System Current Requirements

Use

+ 5v + 12v

-12v

Baseboard 5.2 0.06 (EIA) 0.08 (EIA)

8 Expansion slots
Flexible disk drive

14.0

0.8 1.0
Hard disk drive 2.0
Streaming tape drive
Unspecified

4.0

—

TOTAL AMPS 32.6 26.0
TOTAL WATTS 206.5 W

130 W

0.24 (EIA) 0.32 (EIA)

—

2.1 (4.2 peak)

1.8 (5.0 peak)

—

—

0.3 0.6

5.5 (10.5 peak)

66 W

1.0
12 W

Note: All values in table are in amps, unless specified.

Older option boards may require -5volts.

-5v

—

—

—

“

—

0.1

0.1

0.5 W

2-28

iSBC® 386AT

KEYBOARD CONNECTOR

Jl, the keyboard connector, is a 5-pin DIN connector for the five signal pins
of keyboards that are compatible with the IBM AT keyboard. The pin
assignments are shown in Table 2-17. The cable shield contacts the case of Jl,
which is connected to the ground planes of the board with pins 6 and 7.
Signal ground (pin 4) also connects to the ground planes of the board.

The RST* pin is jumper configurable on the system board. In one setting,
this pin sends a reset pulse to the keyboard when a system reset occurs. In
the other setting (the default configuration), the pin is electrically
disconnected. Refer to Chapter 3 for the jumper settings.

The BIOS supports two kinds of keyboards: those that are compatible with
the original IBM AT keyboard and those that are compatible with IBM’s 101-
key enhanced keyboard. Programs that have difficulty running with IBM’s
enhanced keyboard will have the same difficulties when running on the

iSBC 386AT board.

Features o f the iSBC® 386AT Board

Table 2-17. Keyboard Connector Pin-Out Specification

SIGNAL/FUNCTION

KEYCLK (clock)
KEYDAT (data)

RST*

Jl PIN #

1
2

3
Ground 4
+5V

Cable shield (connector

5

6,7

case)

iSBC® 386AT

2-29

Features o f the iSBC® 386AT Board

The pin numbers of the keyboard connector are as follows:

Figure 2-8. Keyboard Connector

6 7

KEYCLICK VOLUME

Whenever you press a key, the 386AT system board emits a clicking sound to
give audio feedback for systems whose keyboards give little audio or tactile
feedback themselves. This keyclick feature has eight volume levels that can
be changed in a circular fashion. Holding down the Ctrl and Alt keys and
pressing + on the numeric keypad increases the volume to the next highest
level:

Ctrl-Alt-+ (on keypad)

When the volme is at the highest level, pressing the key sequence again
changes to the least audible setting (not audible). At power-up, the volume
is set to the second level.

2-30 iSBC® 386AT

CHAPTER 3

inteP

CONFIGURING THE iSBC® 386AT BOARD

The 386AT board has several jumper blocks that are used to set the
configuration of the board. The following configuration options can be
selected:

• Monitor type

• Memory configuration

• ROM size

• Serial communications port

• Parallel printer port

• Printer acknowledge signal

• Keyboard reset

• Math coprocessor

• Real-time clock
This chapter describes how to set the various configuration options.

JUMPER LOCATIONS

Figure 3-1 shows the locations of all the jumper blocks on the 386AT board.

Some pin numbers shown in this figure are silk-screened on the board so
that the pins can be located easily. This chapter refers to the individual pins
by these numbers. Appendix B summarizes all the options.

Setting board options involves placing the jumpers on the designated pins or
sometimes removing a jumper altogether. The following sections describe

the configuration options that can be set. An asterisk (*) marks the default

jumper.

iSBC® 386AT Board

3-1

Configuring the iSBC® 386AT Board

3-2

E37 - E38 Com1 Interrupt Line
E38 - E39 Com2 Interrupt Line
E40 - E41 Com2 is Serial Port
E41 - E42 Com1 is Serial Port
E43 - E44 LPT2 Interrupt Line
E4 4- E45 LPT1 Interrupt Line
E46 - E47 Math Coprocessor Installed
E48 - E49 No Math Coprocessor Installed x-1795

Figure 3-1. 386AT Jumper Locations

iSBC® 386AT Board

Configuring the iSBC® 386AT Board

MONITOR TYPE

Jumper pins E10 through E12 should be set depending on whether you will

be using a color or monochrome monitor. The options are:

Display Install Jumper

color E11-E12*
monochrome E10-E11

The factory setting is E11-E12 for the color monitor. If your monitor is a

monochrome, change the jumper to E10-E11.

MEMORY CONFIGURATION SELECTION

Jumper pins E28 through E36 identify the amount of memory installed. If
you install 16-bit memory cards, such as the Intel AboveBoard, to fill
conventional memory to its 640K limit or to add expanded memory, you do
not need to change any jumpers on the iSBC 386AT board.

Figure 3-2 shows the jumpers for 512K byte and 2, 4, and 10 M bytes.

default setting

iSBC® 386AT Board

3-3

Configuring the iSBC® 386AT Board

E28

I

E29 • * E30
E31 • f

E33 • 1

E35 •

E32
E34 E33 •
E36

-----

•

512 KB on System Board

• E28

E29 •

-----

• E30

E31 •

-----

• E32

E33 • • E34

-----

E35 •

• E36

512 KB on System Board
2 MB in Slot J7/J19
2 MB in Slot J8/J20*

‘ Default

• E28

E29 •

-----

• E30

E31 • t E32

1 E34

E35 •—- • E36

512 KB on System Board

2 MB in Slot J7/J19

• E28

-----

• E30

•

E29

-----

• E32

•

E31
E33

? • E34
1 • E36

E35

512 KB on System Board
2 MB in Slot J7/J19
8 MB in Slot J8/J20

x-1797

3-4

Figure 3-2. Jumper Options for Standard Board

(512 KB, 2 MB, 4 MB, 10 MB)

The factory setting has 512K byte of memory on the system board and 2M

bytes of extended memory in each of the 32-bit slots (slots J7/J19 and J8/J20).

This option assumes that two of Intel’s MEM020 memory boards are

installed. If you have fewer 32-bit memory boards installed, or a different
amount of memory on the boards, change the jumpers to match the memory
installed.

iSBC® 386AT Board

Configuring the iSBC® 386AT Board

If you want to use two 8M byte memory boards or one 8M byte board
without a 2M byte board, you need to change the jumpers and replace one
PAL device. The 8M byte boards ship with the PAL device and instructions
for changing it. Figure 3-3 shows the jumper settings for this option.

E28
E30

I

E31 • t E32
E33 • A E34

E35 •

----

• E36

512 KB on System Board

• E28
E29 • • E30
E31 •

----

• E32
E33 ♦ • E34

E35 1 • E36

512 KB on System Board
8 MB in Slot J7/J19

2 MB in Slot J8/J20

• E28

E29 •

-----

• E30
E31 • • E32
E33 • • E34
E35 • • E36

512 KB on System Board
8 MB in Slot J7/J19

• E28

E29 •

-----

• E30

-----

E31 •
E33 ♦ • E34

E35 A • E36

512 KB on System Board

8 MB in Slot J7/J19
8 MB in Slot J8/J20

• E32

x-1798

Figure 3-3. Jumper Options for 16 MB RAM Option

iSBC® 386AT Board

(512 KB, 8 MB, 10 MB, 16 MB)

3-5

Configuring the iSBC® 386AT Board

ROM SIZE SELECTION

Jumper pins E13 through E18 identify the size of ROMs used. Figure 3-4
shows the jumper settings for the three options.

E13 E14 E15

E16 E17 E18

32 K Bytes Total

(Two 27128 ROMs)

E13 E14 E15

»- » •

E16 E17 E18

64 K Bytes Total*

(Two 27256 ROMs)

* Default

(Two 27512 ROMs)

Figure 3-4. Jumpers for ROM

E13 E14 E15

• •

E16 E17 E18

128 K Bytes Total

x-1799

3-6

iSBC® 386AT Board

Configuring the iSBC® 386AT Board

SERIAL COMMUNICATIONS PORT SELECTION

Selecting the serial communications port on the 386AT board involves three
sets of jumpers: one set to select the port number, one set to enable or
disable the port, and one set to select the interrupt request (IRQ) line used
with the port.

Jumper pins E40 through E42 select the port number. The serial port can be
configured as either COM1 or COM2.

Option Install Jumper

Select COM1 E41-E42*
Select COM2 E40-E41

Jumper pins E19 through E21 enable or disable the serial port, regardless of
the one selected.

Option

Install Jumper

Disable serial port E19-E20
Enable serial port E20-E21*

Pins E37 through E39 select the interrupt request line. This setting must
correspond to the serial communications port you chose.

IRQ Line Install Jumper

IRQ4 (COM1) E37-E38*
IRQ3 (COM2) E38-E39

The factory setting is COM1 enabled (E41-E42, E20-E21, and E37-E38). If you
want to select COM2 or disable the serial port, set the jumpers accordingly.

default setting

iSBC® 386AT Board

3-7

Configuring the iSBC® 386AT Board

PARALLEL PRINTER PORT SELECTION

Selecting the parallel printer port involves two sets of jumper blocks, one to
select the port and one to select the interrupt request (IRQ) line used with
the port. Jumper pins E22 through E27 select the port. Jumper pins E43
through E45 select the interrupt request line.

Jumper pins E22 through E25 select the number of the 386AT board’s
parallel printer port and enable the port. Jumper pins E26 and E27 disable
the port. The parallel port can be configured as either LPT1 or LPT2.

CA U T IO N Only one of the following three jumper settings is permitted.

Installing jumpers in more than one position could damage the
system board.

Option

Install Jumper

Select LPT1 E22-E23
Select LPT2 E24-E25*

Disable printer port E26-E27
The factory setting is LPT2 (E24-E25). Move the jumper as indicated to

select LPT1 or to disable the printer port.
Jumper pins E43 through E45 select the interrupt request line that will be

used with the printer port. This jumper setting must correspond to the
parallel printer port you chose.

IRQ Line Install Jumper

IRQ7 (LPT1) E44-E45
IRQ5 (LPT2) E43-E44*

The factory setting is IRQ5 (E43-E44). If you selected printer port LPT1,
move the jumper to E44-E45 to select IRQ7.

3-8

default setting

iSBC® 386AT Board

PRINTER ACKNOWLEDGE SIGNAL

Jumper pins E7 through E9 select whether the leading or trailing edge of
the printer acknowledge signal is used to trigger the interrupt line selected
above.

Option Install Jumper

Leading edge of the acknowledge E8-E9
Trailing edge of the acknowledge E7-E8*

The factory setting is to use the trailing edge of the acknowledge signal (E7-
E8). Check your printer instructions to determine which acknowledge signal
is needed. If necessary, move the jumper to E8-E9 to select the leading edge.

KEYBOARD RESET

Configuring the iSBC® 386AT Board

Jumper pins El through E3 select whether the system sends a reset signal
(RST* signal) to the keyboard when a system reset occurs. Enabling the
keyboard reset might be necessary for keyboards that are not compatible
with the IBM AT keyboard. The options are:

Option Install Jumper

Keyboard reset enabled E1-E2

Keyboard reset disabled E2-E3*
The factory setting is E2-E3 to disable the keyboard reset. To enable the

keyboard reset signal, move the jumper to E1-E2.

default setting

iSBC® 386AT Board

3-9

Configuring the iSBC® 386AT Board

MATH COPROCESSOR

Jumper pins E46 through E49 select whether you have a math coprocessor
installed on the 386AT board. The math coprocessor can be either an 80387
math coprocessor or an SBCMATH module. The SBCMATH module is a
special circuit board that contains an 80287 math coprocessor, circuitry that
enables the 80287 to emulate the 80387, and pins that allow the board to plug
into the 80387 socket.

CA U T IO N Before inserting an 80387 in the board, read the instructions in

Chapter 4. If the chip is inserted incorrectly, the chip and the
system will be damaged.

CA U T IO N Only one of the following two jumper settings is permitted.

Installing jumpers in both positions could damage the system board.

Option Install Jumper

Math coprocessor installed E46-E47

Math coprocessor not installed E48-E49*
The factory setting is E48-E49, indicating that the coprocessor is not

installed. If you install a math coprocessor on the 386AT board, remove the
jumper from E48-E49 and move it to E46-E47.

default setting

3-10

iSBC® 386AT Board

CHAPTER 4

inter

This chapter describes the equipment you need to create a working system
around the iSBC 386AT board. It also describes how to install Intel’s

memory boards (2M byte MEM020 and 8M byte MEM080) into the 32-bit

expansion slots and how to install the math coprocessor.

BUILDING A SYSTEM

To build a system based on the iSBC 386AT board, you must obtain the

following equipment:

• A chassis to hold all the system components. The iSBC 386AT board
measures 12.0 inches by 13.8 inches (304.8 by 350.5 mm), so a chassis similar
in size to the one used with the IBM AT is appropriate. The holes for
mounting the iSBC 386AT board to the chassis are in the same locations
as on the IBM AT system board.

INSTALLATION

• A multi-voltage power supply similar to the one used in the IBM AT.
Appendix A shows the pin-out of the power supply connectors. Because

of the high-performance and high-capacity equipment that is expected

to be used in the system, Intel recommends that you use at least a 185
watt supply for a minimum system.

• A 6V battery to sustain the clock/calendar chip. Chapter 2 lists the pin
out for the battery connector.

• An 8 ohm speaker to provide sound capabilities for your system. The

pin-out for the speaker connector is listed in Chapter 2.

• A cable from the system board’s serial communication port to an IBM-
compatible DB25 or DB9 male connector. The pin-out for the serial port

is listed in Chapter 2.

• A cable from the system board’s parallel printer port to an IBM-

compatible DB25 female connector. The pin-out for the parallel port is
listed in Chapter 2. •

• A fixed disk/diskette controller.

iSBC® 386AT

4-1

Installation

• At least one diskette drive (360K or 1.2M).

• A fixed disk, if needed. Refer to Chapter 5 for a list of the drive types
that the BIOS supports.

• Cables between the fixed disk/diskette controller and the drives.

• A video controller and corresponding monitor.

• An AT-compatible keyboard. A PC- or XT-compatible keyboard will
not work with this board.

• Additional memory, if necessary. The iSBC 386AT board contains 512K

bytes of RAM as standard equipment. To fill conventional memory to
its 640K maximum, use a 32-bit memory board (MEM020 or MEM080) or
a 16-bit memory board such as the Intel AboveBoard. Use the remaining
memory on the add-in board(s) for expanded or extended memory, as
described in Chapter 2. The next section in this chapter describes how to

install the 32-bit boards.

• A math coprocessor, if needed. The iSBC 386AT board has a socket for
an 80387 coprocessor, but you can use Intel’s 80287-based SBCMATH
module. A later section in this chapter describes how to install the math
coprocessor and the SBCMATH module.

• MS-DOS version 3.10 or later, or PC-DOS version 3.10 or later.

INSTALLING INTEL MEMORY BOARDS

The 80386 processor can access memory 32 bits at a time. To enable 32-bit
memory accesses, the iSBC 386AT board provides a full 32-bit data path for
the 512K bytes of on-board memory. In addition, it provides two expansion
slots that also supply data 32 bits at a time to the processor. The 32-bit
expansion slots are slots J7/J19 and J8/J20.

To take advantage of the 32-bit data path, you must install Intel’s 2M-byte
MEM020 or 8M-byte MEM080 memory boards in these slots. If you install
only one 32-bit memory board, you must place it in slot J7/J19. If you install

two boards, place them in slots J7/J19 and J8/J20.
There are no switches or jumpers to set on the memory boards. However,

you need to set jumpers E28 through E36 on the iSBC 386AT board to
identify the amount of 32-bit memory in your system. These settings are
listed in Chapter 3.

4-2

iSBC® 386AT

Installation

The memory addresses of these boards are set automatically depending on

the slots in which the boards are inserted. The memory board in slot J7/J19
automatically starts the extended memory at 1M (100000H). If two memory
boards are installed, the memory on the second board (slot J8/J20) is located
immediately after the memory on the first.

CAUTION Use the replacement PAL shipped with the MEM080 board only in a

system that has 8M or 16M byte of RAM.

INSTALLING THE MATH COPROCESSOR

Socket U54 on the iSBC 386AT board is available for inserting a math
coprocessor chip. This socket can contain either an 80387 chip or Intel’s
80287-based SBCMATH module. The SBCMATH module contains an 80287
mounted on a special card with a connector that fits into the 80387 socket.

If you install either of the math coprocessors, you must set jumpers E46
through E49 on the iSBC 386AT board to indicate that a math coprocessor is
present. The jumper positions are as follows:

Option Jumper

Math coprocessor installed E46-E47
Math coprocessor not installed E48-E49*

The factory setting is E48-E49, indicating that the coprocessor is not
installed. When you install either math coprocessor, remove the jumper
from E48-E49 and move it to E46-E47.

CAUTION Installing jumpers in both positions could damage the system board.

Ensure that a jumper is on E46—E47 or on E48—E49, not on both.

iSBC® 386AT

4-3

Installing the 80387 Math Coprocessor

To install an 80387 math coprocessor, align the chip with socket U54, and
make sure that pin 1 of the math coprocessor chip corresponds to pin 1 of the
socket. Pin 1 of socket U54 is labeled. Pin 1 of the 80387 is designated with a
dot on the corner of the chip or with the corner of the chip cut off. Then
press the 80387 into socket U54. Figure 4-1 shows the location of pin 1 for the
80386 and for the 80387.

Installation

Figure 4-1. Location of Pin 1 on the 80387

CAUTION If the 80387 is not installed correctly, the 80387 and the system will

be damaged. Note that the 80387 and 80386 have different

orientations.

4-4

iSBC® 386AT

Installation

Installing the SBCMATH Module

The SBCMATH module contains an 80287 math coprocessor and has pins
designed to fit into the 80387 socket U54. To install the SBCMATH module,
first align the module as shown in Figure 4-2. In the correct alignment, the
long edge of the SBCMATH module is closest to the edge of the iSBC
386AT board and parallel to it. In this alignment, pin 1 of the 80287 chip
corresponds to pin 1 of socket U54.

Once the SBCMATH module is aligned, install the stress-relief standoffs and
press the SBCMATH module into socket U54.

iSBC® 386AT

Figure 4-2. Installing the SBCMATH Module

4-5

INSTALLING THE POWER CONNECTORS

Figure 4-3 shows the pin assignments, keys (protrusions), and standard wire
colors for power connectors J13 and J14.

When using an AT-compatible power supply, plug both of the power
supply’s connectors into J13. Pins 1 through 6 of one connector (the one that
supplies +12V, -12V, SYSRST*, and +5V) should match pins 1 through 6 of J13.
Pins 1 through 6 of the other connector (the one that supplies +5V, -5V and
ground) should match pins 7 through 12 of J13.

Some power supplies have a third plug with three 5V pins and three ground
pins. Pin 1 of this third power plug should match pin 1 of J14, which is

marked on the board.

Installation

PIN

1 '

2

+ 5V
+ 12V

3
4

-12V

GROUND

11
12

5

GROUND

6

7

GROUND

8

GROUND

9

10

- 5V
+ 5V
+ 5V
+ 5V

PIN

I 6

I 5
I 4
I 3

I 2

+ 5V

I 1

+ 5V

J14 J13

Figure 4-3. Power Connector Pins

CAUTION For the 5 volt supply to the system and adapter boards, do not

exceed 28 amps on J13 or 41 amps when using both J13 and J14.
Each power supply pin can handle a maximum of 7 amps.

x-1 7 94

4-6

iSBC® 386AT

CHAPTER 5

SETUP PROGRAMintel®

With the iSBC 386AT product, the OEM receives a diskette containing the
file SETUP.COM. This file is a program that stores system configuration
information in the battery-backed memory of the real-time clock chip. The
configuration information takes effect when you restart the system.

The following information is stored in the real-time clock/CMOS chip and
can be set with the SETUP program:

• Date and time

• Number and capacity of diskette drives

• Number and type of fixed disks

• Amount of base memory

• Amount of expansion (extended) memory

• Type of primary video adapter
You should run the SETUP program when you configure a system for the

first time, when you change the battery, and whenever you change any of
the items listed above. If you don’t run SETUP the first time you use the
system, you will get an invalid configuration message. If you press FI after
getting this message, the system boots with information for a minimum
default system and may not see all the installed memory.

This section provides step-by-step instructions for using the SETUP program
to configure the iSBC 386AT-based system.

PREPARING THE SYSTEM TO RUN SETUP

The SETUP program runs under the control of DOS. Therefore, you must

load DOS before invoking SETUP. Refer to the DOS manual for
instructions on loading DOS.

iSBC® 386AT

5-1

Setup Program

RUNNING THE SETUP PROGRAM

The SETUP program performs the following operations:

• Displays date, time, and a series of screens that list current values for
system options.

• Allows you to accept current values or enter different values for time,
date, and system options.

• Instructs you to re-boot the system so that the settings take effect.

When you turn on the system before you have run SETUP the first time,
the BIOS (Basic Input/Output System) sends a message that the
configuration information is not valid, and requests that SETUP be run.
Thereafter when the system is booted, it verifies the information you
entered previously and issues a message if the data does not agree with
actual system options.

CA U T IO N It is essential to configure your system with the correct fixed disk

drive type because the system cannot independently verify the fixed
disk drive type. Specifying an incorrect drive type could damage the
disk.

To run SETUP, load DOS, insert the SETUP diskette in drive A, and type:

A:SETUP (and press <Enter>)

The following screen appears:

Phoenix Technologies Ltd.
Configuration Setup Program Ver x.y

(c) Copyright 198x

This program is used to store system

configuration information into battery

backed memory in your computer. It is

necessary to run this program when
any memory, disk drives, or monitors

are added or removed from your system,
or to set the battery maintained time
or date.

5-2

Press <enter> to continue ...

iSBC® 386AT

Setting the Date and Time

Press <Enter>. SETUP displays the date and time as shown in the next
screen:

The battery maintained date is:

00/00/1900

The battery maintained time is:

00:00:51

Are these correct?

[Y or N]

If the date and time are correct, type Y and press <Enter> to indicate yes.

SETUP displays current settings for all system options as described in the
"Setting the Current Option" section of this chapter.

Setup Program

If the time or date is incorrect, type N and press <Enter> to indicate no.

SETUP displays the following message:

The battery maintained date is:

00/00/1900

If this date is not correct, type
the correct date using numbers
separated by slashes.

For example type 05/21/1985 <enter>
meaning May 21, 1985.

-?

Enter the correct date in the month/day/year format (mm/dd/yy or mm-dd-

yy). SETUP then prompts you to enter the correct time in the
hour:minute:second format (hh:mm:ss). It is not necessary to enter the
seconds.

iSBC® 386AT

5-3

Setup Program

Setting the Current Options

When the date and time information has been entered correctly, SETUP
displays the current option settings as in the following example:

The following information is required

for correct operation of your computer.

The current settings of your options:

Diskette Drive A:

Diskette Drive B: is 3 60K

Fixed Disk Drive C:

Fixed Disk Drive D:

System Base Memory is 512K

Extended Memory

Prime Video Adapter

Math Coprocessor

Are these options correct

(Reply Y or N then <enter>)

7

If the information is correct, type Y and press <Enter>. Then turn to the

"Rebooting the System" section of this chapter for further information.

If the current option settings are not correct, type N and press <Enter>.
Then continue with the "SETUP Option Screens" section.

SETUP Option Screens

is
is Type 7

is
is

is EGA
is

1.2M

NOT INSTALLED

OK
80387

5-4

If your system is not configured as indicated in the current options screen,
SETUP displays the first in a series of screens that list current setting
choices for each option. At each option, SETUP asks:

Is this correct (Y or N).

To change any setting, type N and press <Enter>. SETUP prompts for the
necessary information. If you type Y and press <Enter>, SETUP continues
with the next screen.

iSBC® 386AT

Diskette Drive Types

The first option screen asks for information on diskette drive types as

follows:

Your diskette drive types are set to

Diskette Drive A: is 1.2M
Diskette Drive B: is 360K

Are these drive types correct (Y or N)

7

Type Y and press <Enter> to accept the current information. Type N and
press <Enter> to change the drive types. If you type N, SETUP displays the

following prompts:

What type is diskette drive A:

Setup Program

(0,1,2,3 or 4) ?

Respond to the prompt with the correct type number and press <Enter>.
SETUP then repeats the prompt for drive B. Diskette types 1 and 2 are 5.25-
inch diskette drives; types 3 and 4 are 3.5-inch drives.

Fixed Disk Drive Types

After you correct the diskette settings as necessary, SETUP displays the
following screen:

Your fixed disk types are set to

Fixed Disk Drive C: is TYPE 7

Fixed Disk Drive D: is NOT INSTALLED

0 if this drive is not installed
1 if capacity is 360 kilobytes
2 if capacity is 1.2 megabytes
3 if capacity is 720 kilobytes
4 if capacity is 1.44 megabytes

iSBC® 386AT

Are these drive types correct (Y or N)

7

5-5

Setup Program

If listed information is correct, type Y and press <Enter> to accept it. Type

N and press <Enter> to enter different fixed drive type information. In this

case, SETUP issues the following prompts:

Enter the number of fixed disk drives in your system and press <Enter>.
Next, SETUP requests the information for the first drive, as follows:

How many fixed disk drives are installed

in your system ?

(0, 1, or 2) ?

What type is fixed drive C:

(Enter drive type indicated by label

affixed to drive)

For a list of disk types supported by
your computer enter a ? at prompt

(1 to 47 or ?)?

If you know the drive type associated with drive C, type that number and
press <Enter>. Table 5-1 lists the drive types for some drives that work with
the system board. Consult your vendor’s reference manual and Table 5-2 to
confirm these values.

5-6

iSBC® 386AT

Table 5-1. Types for Example Fixed Disks

VENDOR MODEL SIZE TYPE

(MB)

Setup Program

Fujitsu
Fujitsu
Fujitsu
Maxtor
Rodine
Seagate
Seagate
Toshiba
Quantum

M223SAS
B03B-4695

MKF3FB
XT1140

203E

ST225
ST4038
MKM0353E
Q540

2 0
2 0

86.5 37

140

90

2 0

33

86

40 7

13
13

9
3

2
8

37

If you do not know the drive type, type ? and press <Enter>. SETUP will

display a list of drive types and the specifications associated with each drive

type. By comparing this display with the specifications in your disk drive’s
hardware reference manual, you will be able to pick the correct drive type.

Table 5-2 lists the drive type specifications you will see.

TYPE

1

2

3
4

5

6

iSBC® 386AT

CYLIN

DERS

306 4

615
615

940

940
615 4

Table 5-2. Fixed Disk Types

HEADS

PRE

COMP

LAND
ZONE

128

4 300

6
8

6

300
512
512

-1

(continued)

SEC

TORS

305 17

615

615
940
940

615

17
17 30.6
17
17 46.8
17

SIZE

MEGS

10.1

20.4

62.4

20.4

5-7

Setup Program

Table 5-2. Fixed Disk Types (continued)

TYPE

CYLIN

7

8

9

10
11

12

13
14
16
17

18
19 1024

2 0

21

2 2

23
25
26
27
28
29

30" 615

35
36

37
38

39

40

41

42
43
44
45

46

4 7 * **

HEADS

DERS

462
733
900
820
855
855
306
733
612
977
977

733
733
733
306 4
615

1024

1024

1024

512

1024
1024

830
823

615
615
917

1023

823
820

1024

925
699 7

PRE

COMP

8

256

LAND

ZONE

SEC

TORS

511 17 30.6

5 -1 733 17

15 -1 901

3 -1 820 17
5 -1 855 17
7 -1

8

128 319

855

17

17 49.6
17 20.3

SIZE

MEGS

30.4

112.0

20.4

35.4

7 -1 733 17 42.5
4

0

663 17 20.3
5 300 977 17 40.5
7

-1 977
7 512 1023 17
5
7 300
5

4
4

5

8

8
2

300 732

732

300 733

0
0

336

615

-1 1023

-1 1023 17 42.5

-1 1023

256 512

615

615
9 1024 1024 17
5

10
10

4

8

15

512 1024 17

-1 830 17
256
128
128

-1

824
664
664 17 40.8

918

15 -1 1024

10

6

8

9 -1

512 823 17

-1 820

-1 1024 17
925 17 69.1

256

700 17 40.6

17
17

17
17 30.4
17
17 20.4
17 34.0

17
17 34.0
17

17 68.3
17 20.4

17
17 127.3

17

56.7

59.5

30.4

42.5

10.1

68 .0

10.2

76.5

42.5

68 .8

114.1

68.3

40.8

68 .0

* This type is available only on BIOS versions 3.06 or later.

** On BIOS versions earlier than 3.06, this type is:

47 1024 5 -1 1024 17 42.5

5-8

iSBC® 386AT

Setup Program

The column headings in Table 5-2 are the same column headings you will see

when SETUP displays the drive type information. These headings have the
following meanings:

TYPE

The drive type number that you must enter to
specify the type of fixed disk you have.

CYLINDERS

HEADS
PRECOMP

The number of cylinders in the drive.
The number of heads in the drive

The number of the cylinder at which the drive
begins performing write precompensation. A value
of 0 means precomp will start at 0 ; a value of -1
means precomp will not happen.

LAND ZONE

The number of the cylinder used for the head

landing zone.
SECTORS
SIZE MEGS

The number of sectors per track.

The size of the formatted drive in megabytes.
You can use the SETUP drive-type list in two ways:

• If your fixed drive has a label that specifies a type code (1-47), use the list

to confirm that SETUP supports your drive.

• If your fixed drive does not specify a type code, use the information on

For example, you can verify that your drive is a type 7 if it has the
following parameters:

Cylinders

Heads
Precompensation

Cylinder
Landing Zone
Sectors per track
Size (in megabytes)

iSBC® 386AT

the list and your drive specifications to identify the drive type.

462

8

256
511
17

30.6

5-9

Setup Program

NOTE If the list does not include your fixed—disk type, you can still use

SETUP to set system options, but you won’t be able to use the full
capacity of the fixed disk. In this case, choose the disk type that
most closely matches the specifications for your fixed disk, making
sure that the number of cylinders, number of heads, and disk
capacity are less than or equal to your disk’s values. Of course,

picking a disk type for a smaller disk means that your disk will have
a smaller usable capacity.

After you compare the SETUP display with the specifications for your fixed
disk, enter the correct drive type and press <Enter>. The SETUP program
then requests the same information for any other fixed disks in your system.

Base Memory

After you enter the fixed disk information, SETUP displays a screen similar
to the following one:

Base memory is that memory positioned
so as to be available to MS-DOS programs.

System Base Memory is 512K
Is this correct (Y or N) ?

As the display mentions, base memory is the amount of memory available to
DOS. Base memory is sometimes called conventional memory. It is limited

to a maximum of 640K bytes.

If the listed amount of base memory is correct, type Y and press <Enter>.
If your system contains a different amount of base memory, type N and

press <Enter>. SETUP then issues the following prompt:

What is the total size of the base

memory installed in your system in K

(Standard configurations are

256, 512, or 640)

7

In response, enter the base memory size and press <Enter>.

5-10

iSBC® 386AT

Extended Memory

After you correct the base memory information if necessary, SETUP
displays the following information concerning extended memory:

Extended memory is positioned at
a high address and available to MS-DOS
only for special functions.

Extended Memory is OK

Is this correct (Y or N) ?

When using the term extended memory, the SETUP program is referring to
memory whose address range begins at 1 megabyte. Figure 5-1 illustrates the

locations of extended memory, conventional (or base) memory, and
expanded memory.

Setup Program

If the information listed on the screen is correct, type Y and press <Enter>.
If your system contains a different amount of extended memory than listed,

type N and press <Enter>. The SETUP program prompts for the size, as
follows:

What is the total size of the extended
memory installed in your system in K

(Standard configurations are

512, 1024, ... )

7

In response, enter the correct memory size.

NO TE Some memory expansion cards add memory in increments of 256K

bytes. SETUP is NOT restricted to incremental sizes and accepts
any memory size.

iSBC® 386AT

5-11

Setup Program

I

/

/

/

/

/

/

EXPANDED
MEMORY

(USA BLE BY DOS
APPLIC ATION S
THAT ADHERE TO
TH E LOTU S/IN TEL /
MICR O SOF T
EXPANDED
MEMORY
SPECIF ICATIO N)

\

\

\

\

\

\

\

\

\

\

Figure 54. Memory Map

X-1612A

5-12

iSBC® 386AT

Primary Video Adapter

Next, SETUP displays the following information concerning video adapters:

The primary display is used by the

system following boot. If more than

one video adapter is installed in your

system you must select one as primary.

If you have an EGA installed, the EGA
option must be selected even if another
adapter is to be used as primary.
See your installation manual for details
of option switch settings that might
also be needed.

Prime Video Adapter is EGA

Is this correct (Y or N) ?

Setup P rogram

NOTE

If the listed video adapter is correct for your system, type Y and press

<Enter>.

If your system’s primary video adapter is not the type indicated in the this
screen, type N and press <Enter>. This causes SETUP to display the
following information:

Use the number code to indicate the

primary display adapter

0
1

2

3

EGA
Color graphic (40 columns)
Color graphic (80 columns)
Monochrome

In response, enter the number that corresponds to your primary video
adapter and press <Enter>.

If your system has an EGA monitor, answer with 0 (EGA), even if
another adapter is the primary one. This enables the SETUP
program to configure the EGA properly.

iSBC® 386AT

5-13

Setup Program

Rebooting the System

After you have modified the option settings as necessary, SETUP displays
the settings you have entered for all options, and asks if these options are
correct If there are any errors in the option settings, type N and press

<Enter>. This causes SETUP to take you through each option screen again.

If the option settings are correct, type Y and press <Enter>. SETUP then
prompts you to reboot the system as follows:

Your system must now be rebooted.

Insert DOS disk and Press <enter>

Remove the SETUP diskette, insert the DOS diskette in drive A, and press
<Enter>. The new configuration settings take effect upon booting.

SETUP ERROR MESSAGES

The SETUP program can report the following error messages. These
messages can also appear when you boot the system.

MESSAGE: ERRORS FOUND-

DISK X: FAILED INITIALIZATION

Explanation: SETUP reports that the fixed-disk configuration

information is incorrect.

Action: Rerun SETUP and enter correct fixed-disk information.

MESSAGE:

Explanation:

ERRORS FOUND-

INCORRECT CONFIGURATION INFO

MEMORY SIZE MISCOMPARE

SETUP reports that the size of base or expansion
(extended) memory does not agree with configuration

information.

Action:

Rerun SETUP and enter correct memory size.

5-14 iSBC® 386AT

CHAPTER 6

intel®

The Power-On Self Test (POST) is a diagnostic test that resides in the ROM-
BIOS and runs automatically whenever you turn on or reset your system.
The POST checks the processor, the memory, and the peripheral devices

connected to the computer (keyboard, monitor, disk drives, and others).

POST OPERATION

Each time you turn on the system unit, the POST performs the following
operations:

1. Blinks the keyboard status lights on and off.

2. Displays the following message on the screen:

Phoenix 80386 ROM BIOS Version x.yy
Copyright (c) 1985,1986 Phoenix Technologies Ltd

All Rights Reserved

POWER-ON SELF TEST

3. Tests system memory, displaying the amount of memory tested as the
test progresses. The POST takes from 3 to 15 seconds to complete,
depending on the amount of resident memory.

4. Tests the other devices in the system.

5. If the POST completes successfully, it begins the boot process. If the
POST detects an error, it sounds two beeps and displays a message on
the monitor or it sounds three sets of beeps. The following sections
list the errors that can occur.

iSBC® 386AT

6-1

Power-On Self Test

POST ERROR MESSAGES

If the Power-On Self Test (POST) can display an error message on the

monitor screen, it will beep the speaker twice as the message appears.

However, when an error occurs before the monitor is initialized, the POST
cannot display messages on the screen. Therefore, the POST will send out a
series of beeps instead.

The next two sections discuss the screen messages and beep codes.

Screen Messages

The POST may display one of the following messages during a normal test

or when it encounters a non-fatal system-board failure or an off-board

failure.

The Messages are in alphabetical order; the User Action suggests the reason

for the message or something for the user to do. The items in italics are

variable items that will differ from message to message.

Message: Hex—valuek Base Memory, hex—valuek Extended

User Action: Indication of the amount of memory that has been tested.

No action required.

Message: Decreasing available memory

User Action: This message immediately follows any memory error

message, informing you that memory chips are failing.

Check that each memory chip is installed correctly. If you

have a memory board with socketed chips, press each chip
to ensure it is seated well. If the message repeats, contact
your service representative.

Message: Diskette drive 0 seek failure

User Action: Check that Drive A is present and the diskette is inserted

properly. If they are, then Drive A may have failed.

6-2

iSBC® 386AT

Message: Diskette drive 1 seek failure

Power-O n Self Test

User Action:

Message:

User Action:

Message:

User Action:

Message:
User Action:

Check that Drive B is present and the diskette is inserted

properly. If they are, then Drive B may have failed.

Diskette subsystem failed

The diskette adapter (controller board) has failed. Check

the cable connections and reseat the adapter.

Diskette read failure —

strike FI to retry boot.

Replace the diskette and try again. Clean the drive heads.

Display adapter failed; using alternate

Check to ensure that the monitor type jumpers are set
correctly.

Message:

User Action:

Message:

User Action:

Gate A20 failure

The system cannot switch into protected mode. Check the
system board.

Hard disk configuration error

Run the SETUP utility

iSBC® 386AT

6-3

Power-On Self Test

Message:

User Action:

Message:

User Action:

Message:

User Action:

Hard disk controller failure

Check both ends of the controller’s cables, and reseat the

hard disk controller. If the message recurs, replace the
hard disk controller.

Hard disk failure

Check the system configuration and drive type, and rerun

the SETUP program. Check both ends of the controller’s
cable, and reseat the hard disk controller.

Hard disk read failure —

strike F I to retry boot

Check the system configuration and drive type, and rerun

the SETUP program. Check both ends of the controller’s
cables, and reseat the hard disk controller.

Message:

User Action:

Invalid configuration information — please run SETUP program

Check the system configuration and drive type, and rerun

the SETUP program.

Message:

User Action:

Keyboard clock line failure

Check the keyboard connection. If connection is good, the
keyboard may have failed.

Message: Keyboard controller failure

User Action:

Check the keyboard controller.

6-4

iSBC® 386AT

Power-On Self Test

Message:

User Action:

Keyboard data line failure

Check the keyboard connection. If the connection is good,
the keyboard may have failed.

Message: Keyboard is locked — please unlock

User Action:

Message: Keyboard stuck key failure

User Action:

Message:

User Action:

Unlock the keyboard and try again.

One of the keys is pressed. Release it and try again.

Memory address line failure at hex—value, read hex—value

expecting hex—value

The memory chip circuitry has failed. Contact your
service representative.

Message: Memory data line failure at hex—value—hex—value

User Action:

One of the memory chips or associated circuitry has failed.
Contact your service representative.

Message:

User Action:

Memory high address line failure at hex—value—hex—value

The memory chip circuitry has failed. Contact your
service representative.

iSBC® 386AT

6-5

Power-On Self Test

Message:

User Action:

Message:

User Action:

Message:

User Action:

Message:

Memory odd/even logic failure at hex—value—hex—value

The memory chip circuitry has failed. Contact your
service representative.

Memory parity failure at hex—value—hex—value

One of the parity or data memory chips has failed.
Contact your service representative.

Memory test terminated by keystroke

A key was pressed during the memory test. Reboot the

system to rerun to the POST.

Memory write/read failure at hex—value, read hex—value

expecting hex—value

User Action:

Message:

User Action:

One of the memory chips has failed. Contact your service
representative.

No boot device available —

strike FI to retry boot

Make sure that the diskette drive A contains a DOS
system diskette and that the door to the drive is closed.
Or, make sure the hard drive contains DOS. It could be a
problem with the disk controller board or the keyboard
interface.

6-6

iSBC® 386AT

Power-On Self Test

Message:

User Action:

Message:

User Action:

Message:

User Action:

No boot sector on hard disk —

strike FI to retry boot

The hard disk is not formatted as a system disk. Format

the disk with the /S option.

No timer tick interrupt

The timer chip on the system board may have failed.
Contact your service representative.

Not a boot diskette —

strike FI to retry boot

Replace the diskette with a DOS system diskette and try
again.

Message:

User Action:

hex—value Optional ROM bad Checksum = hex—value
A peripheral card contains a defective ROM. Replace the

ROM or the peripheral card.

Message:

User Action:

Message: Shutdown failure

User Action:

Phoenix 80386 ROM BIOS Version x.yy
Copyright (c) 1985, 1986 Phoenix Technologies Ltd

All Rights Reserved

Informational. No action required.

The keyboard controller or its associated logic has failed.
Check the keyboard controller.

iSBC® 386AT

6-7

Power-On Self Test

Message:

User Action:

Message: Time—of—day clock stopped

User Action:

Strike the F I key to continue

Follow the instructions to continue.

The battery is probably dead. Replace the battery and run
SETUP.

Message:

User Action:

Tim e—of—day not set —

Please run SETUP program

ROM BIOS startup program reports that date and time

information was to set in the real-time clock. Run SETUP
and configure the system

Message:

Timer chip counter 2 failed

User Action:

The timer chip on the system board may have failed.
Contact your service representative.

Message: Timer or Interrupt Controller Bad

User Action:

The timer chip or the interrupt controller on the system

board may have failed. Contact your service
representative.

6-8

iSBC® 386AT

System Board Errors

If the POST finds an error and cannot display a message on the monitor, the

POST issues a series of beeps to indicate the error.

For example, a failure of bit 3 in the first 64K of RAM is indicated by a 2-1-4

beep code (a burst of two beeps, a single beep, and a burst of four beeps). In

addition, the POST writes a value to I/O port 80H to enable debugging tools

to identify the area of failure.

Tables 6-1 and 6-2 list the beep codes and I/O port values that the POST

generates when it encounters error conditions. Table 6-1 lists fatal errors
(those that halt the system). Table 6-2 lists the non-fatal errors (those that
aren’t serious enough to halt the system). Both tables list other conditions

that have no beep codes.

One beep code is not listed in Tables 6-1 or 6-2: a long beep followed by 1 or

more short beeps indicates a video adapter failure.

Power-On Self Test

No beep code is sounded if a test is aborted while in progress.

iSBC® 386AT

6-9

Power-On Self Test

Beep Code

Description of Error

Table 6-1. Beep Codes for Fatal Errors

and I/O Port Contents for Errors and Status

Contents of
I/O Port 80H

none
1-1-3

1-1-4

1-2-1

1-2- 2

1-2-3
1-3-1

none

1-3-3

80386 register test in progress

Real-time clock write/read failure
ROM BIOS checksum failure
Programmable Interval Timer failure
DMA initialization failure
DMA page register write/read failure

RAM refresh verification failure
1st 64K RAM test in progress
1st 64K RAM chip or data line failure

multi-bit
1-3-4
1-4-1

1-4-2

2 -1-1
2 -1-2

2-1-3
2-1-4

2 -2-1
2 -2-2

2-2-3

2-2-4
2-3-1
2-3-2
2-3-3
2-34
2-4-1
2-4-2
2-4-3
2-4-4

3-1-1
3-1-2

1st 64K RAM odd/even logic failure
Address line failure 1st 64K RAM
Parity failure 1st 64K RAM
Bit 0 1st 64K RAM failure
Bit 11st 64K RAM failure

Bit 2 1st 64K RAM failure
Bit 3 1st 64K RAM failure
Bit 4 1st 64K RAM failure
Bit 5 1st 64K RAM failure
Bit 6 1st 64K RAM failure

Bit 7 1st 64K RAM failure
Bit 8 1st 64K RAM failure
Bit 9 1st 64K RAM failure
Bit A 1st 64K RAM failure
Bit B 1st 64K RAM failure
Bit C 1st 64K RAM failure

Bit D 1st 64K RAM failure
Bit E 1st 64K RAM failure
Bit F 1st 64K RAM failure
Slave DMA register failure

Master DMA register failure
3-1-3 Master interrupt mask register failure
3-1-4

Slave interrupt mask register failure

none Interrupt vector loading in progress

3-2-4

Keyboard controller test failure

none Real-time clock power failure and checksum

calculation in progress

01H

02H

03H

04H
05H
06H
08H
09H

OAH
OBH

OCH
ODH

10H

11H

12H

13H

14H
15H
16H
17H
18H
19H
1AH

1BH
1CH
1DH
1EH

1FH

20H

21H
22H
23H
25H
27H
28H

6-10

iSBC® 386AT

Beep Code

Table 6-2. Beep Codes for Non-Fatal Errors

and I/O Port Contents for Errors and Status

Description of Error

Power-On Self Test

Contents of
I/O Port 80H

none
3-3-4

3-4-1
3-4-2
none
none
none
none

none

none

Real-time clock configuration validation

in progress
Screen memory test failure
Screen initialization failure
Screen retrace test failure
Search for video ROM in progress
Screen believed operable
Screen believed running with video ROM
Monochrome display believed operable
Color display (40 column) believed operable
Color display (80 column) believed operable

29H
2BH
2CH
2DH
2EH
30H
30H
31H
32H
33H

iSBC® 386AT

6-11

CHAPTER 7

intel®

Interrupt
Number

02H

BIOS INFORMATION

The BIOS is available in ROM on the iSBC 386AT board and provides

input/output functions that are compatible with those provided in the BIOS
of the IBM AT. The programming interface to the BIOS is summarized in
Table 7-1.

Programs that access BIOS functions directly should always do so via
software interrupts and not by referring to procedure names or absolute

locations. Programs that violate these restrictions are not guaranteed to run

on other computers or on future versions of the iSBC 386AT BIOS.Table 7-1.

BIOS Functions

Function
Number

Description

Nonmaskable Interrupt

05H

08H
09H
OEH
10H

Print Screen
System Timer Interrupt Handler

Keyboard Hardware Interrupt
Diskette Hardware Interrupt
Video Functions

00H
01H
02H
03H Read current cursor position
04H Read light pen position
05H Select new video page
06H
07H

Set video mode
Set cursor type
Set cursor position

Scroll current page up
Scroll current page down

iSBC® 386AT

7-1

BIOS Inform ation

Table 7-1. BIOS Functions (continued)

Interrupt
Number

11H
12H

13H

Function
Number Description

08H Read character from screen
09H
OAH
OBH
OCH

Write character and attribute
Write character only
Set color palette

Write dot

ODH Read dot
OEH Teletype output function

OFH

Return video status

13H Display string

Equipment Check

Memory Size
Diskette Functions

00H
01H
02H
03H

04H

Reset diskette subsystem
Read diskette status

Read sectors
Write sectors

Verify sectors
05H Format track
15H
16H

Read diskette type
Detect media change

17H Set diskette type for format operation

7-2

13H

Fixed Disk Functions

00H
01H

All disk reset

Return status
02H Read sectors
03H
04H
05H

Write sectors

Verify sectors

Format track
06H Unused
07H Unused
08H

Return drive parameters
09H Initialize driver parameters
OAH Read long
OBH

Write long

iSBC® 386AT

Table 7-1. BIOS Functions (continued)

BIOS Inform ation

Interrupt
Number

14H

15H

Function
Number

OCH
ODH

10H
11H

14H

15H

00H
01H
02H
03H

80H
81H
82H
83H
84H
85H

8 6 H

87H

8 8 H

89H
90H
91H

Description

Disk seek
Fixed disk reset
Test drive ready
Disk recalibrate
Controller diagnostic
Return drive type

Serial Communication (RS232) Functions

Initialize communications adapter
Send character over communications line
Receive character from communications line
Return communications port status

Extended Functions

Device open
Device close
Program termination
Event wait
Joystick support
System Request key

Wait microseconds
Move block

Extended memory size

Set virtual mode

Device busy loop

Interrupt complete

16H

17H

19H

iSBC® 386AT

Keyboard Functions

00H
01H
02H

Get next keyboard character

Get keyboard status

Return shift flag status

Printer Functions

00H

Print a character
01H Initialize the printer port
02H Read the printer status

Bootstrap Load

7-3

BIOS Inform ation

Table 7-1. BIOS Functions (continued)

Interrupt
Number

1AH

1BH
1CH
1DH
1EH

Function
Number Description

Processor Clock Functions

00H

Read the "in RAM" system clock

01H Set the "in RAM" system clock
02H Read the time of the CMOS real-time clock
03H
04H
05H

06H
07H

Set the time of the CMOS real-time clock

Read the date of the CMOS real-time clock

Set the date of the CMOS real-time clock

Set the alarm

Reset the alarm

Ctrl-Break Address

Timer Tick

Video Parameter Table

Diskette Parameter Table

1FH
41H, 46H
50H
76H

Graphics Character Generator

Fixed Disk Drive Parameter Tables

Real-Time Clock Interrupt Handler

Fixed Disk Hardware Interrupt

7-4

iSBC® 386AT

APPENDIX A

intel®

CPU

Word Size Data Path:

Physical Addressing:

Virtual Addressing:

Clock Rates

Memory EPROM:

Processor clock:
Bus clock: 8 Mhz

SPECIFICATIONS

Table A-l. Specifications

80386 32-bit microprocessor

8-, 16-, 32-bits
22 0 bytes in Real mode,

224 bytes in Protected mode

2^6 bytes

16 MHz

up to 128 KB

Dimensions

RAM on board: 512 KB
Extended RAM: 0 to 15 MB on 32-bit memory board
Expanded RAM: on option card

Length and width:

Height (max. with

mounted components):

Thickness

12.0 by 13.8 inches

(304.8 by 350.5 mm)

0.5 inches (12.7 mm) without option

cards and cables

0.0625 inches nominal

(continued)

iSBC® 386AT

A-l

Specifications

Table A-l. Specifications (continued)

Weight

Environment
Required

18 ounces (510 grams)

Operating Temperature 10°to 40°C

Airflow
Storage Temperature
Humidity
Altitude

50 linear feet per minute across 80386

-40° to 70°C
0 to 90%, noncondensing
0 to 10,000 feet

A-2

iSBC® 386AT

APPENDIX B

intel®

Stake Pin
Numbers

E1-E2
E2-E3 *

E4-E5
E5-E6

JUMPERS

Table B-l contains a complete list of the jumper options available with the

iSBC 386AT board. The options indicated with an asterisk (*) are the default
settings when the board is shipped from Intel.

Table B-l. Jumper Descriptions

Function

Connects Reset line to keyboard

Disables keyboard reset

Pins do not exist
Pins do not exist

E7-E8 *
E8-E9

E10-E11
E11-E12 *

E13-E14 *
E14-E15
E16-E17
E17-E18 *

* default setting

Uses trailing edge of Acknowledge signal

from printer for interrupt

Uses leading edge of Acknowledge signal

from printer for interrupt

Selects monochrome monitor
Selects color monitor

Selects ROM size for 27256 and 27512 ROMs
Selects ROM size for 27128 ROMs
Selects ROM size for 27512 ROMs
Selects ROM size for 27128 and 27256 ROMs

iSBC® 386AT

B-l

Jumpers

Stake Pin
Numbers

Table B-l. Jumper Descriptions (continued)

Function

E19-E20
E20-E21 *

E22-E23
E24-E25 *
E26-E27

Disables serial communications port
Enables serial communications port

Selects printer port 1 (LPT1)
Selects printer port 2 (LPT2)
Disables parallel printer port

E28 thru E36 RAM size selection; please see Chapter 3 for

information.

E37-E38 *
E38-E39

E40-E41
E41-E42 *

E43-E44 *

Connects serial channel 1 interrupt to IRQ4
Connects serial channel 2 interrupt to IRQ3

Selects serial channel 2 (COM2)
Selects serial channel 1 (COM1)

Connects parallel channel 2 interrupt to

IRQ5

E44-E45

Connects parallel channel 1 interrupt to

IRQ7

E46-E47

E48-E49 *

* default setting

B-2

A math coprocessor is installed

No math coprocessor installed

iSBC® 386AT

APPENDIX C

intel'

This appendix contains a list of the software and hardware products that
have been verified to work with the iSBC 386AT board. This list in no way
constitutes all of the programs that run on the iSBC 386AT board. Rather, it
represents the products tested by Intel Corporation at the time this manual
went to print.

The software and hardware listed may have specific hardware and software
requirements, such as MS-DOS Version 3.x. Where possible, latest versions
of applications and system software are used for testing.

CA U T IO N Ensure that all peripheral cards you install on the 386AT system

BUSINESS MANAGEMENT

TESTED SOFTWARE AND HARDWARE

board can run at 8 MHZ.

VisiSchedule vl.OlA / Visicorp
Project v2.04 / Microsoft
Total Project Manager vl.l / Harvard Software

COMMUNICATIONS

Smartmodem 1200B Internal Modem / Hayes
Smartcom II v2.1 / Hayes

Access vl.O / Microsoft

3278/79 Emulator vl.O / IBM

Multimodem 224E / Multitech Systems

Forte v2.02 / Forte Data Systems

iSBC® 386AT

C-l

Tested Software

DATABASE AND FILE MANAGEMENT

dBASE III Plus vl.l / Aston Tate

Reflex vl.l / Borland

DISK AND TAPE SYSTEMS

WD 1002-WA2 Disk Controller / Western Digital
WD 1003-WA2 Disk Controller / Western Digital
Hard Disk and Diskette Adapter / IBM
OMTI 8620 Disk and Diskette Adapter / SMS

Intelligent SCSI Host Adapter RCP / Racet Computes

Q540 Hard Disk 40MB / Quantum

MKM0353E Hard Disk 86MB / Toshiba
ST4038 Hard Disk 33MB / Seagate
ST225 Hard Disk 20 MB / Seagate

203E Hard Disk 90MB / Rodine

XT-1140 Hard Disk 140MB / Maxtor
MKF3FB Hard Disk 86.5 MB / Fujitsu
B03B-4695 Hard Disk 20 MB / Fujitsu
M223SAS Hard Disk 20 MB / Fujitsu
B042A Hard Disk / Fujitsu
40MB Hard Disk / Atasi
5412 Hard Disk / CMI
5619 Hard Disk / CMI
20MB Hard Disk / Microscience

40MB Hard Disk / Rodine
440-TD 40MB Tape / ADIC

EDUCATIONAL, RECREATIONAL, AND TRAINING

Flight Simulator v2.12 / Microsoft
Jet / Sublogic

Sargon III / Hayden Software
Rogue / Epyx
Many Public Domain Games & Utilities

C-2

iSBC® 386AT