Compaq Deskpro 4000N - Desktop PC Use and care manual

Technical
Reference
Guide
for
Compaq Deskpro 4000N and 4000S Personal Computers

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Deskpro 4000N and 4000S Personal Computers
TRG

Technical Reference Guide
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition – September 1997
i
NOTICE
The information in this document is subject to change without notice.
COMPAQ COMPUTER CORPORATION SHALL NOT BE LIABLE FOR TECHNICAL OR
EDITORIAL ERRORS OR OMISSIONS HEREIN; NOR FOR INCIDENTAL OR
CONSEQUENTIAL DAMAGES RESULTING FROM THE FURNISHING, PERFORMANCE,
OR USE OF THIS MATERIAL. IT IS THE RESPONSIBILITY OF MANUFACTURERS TO
ENSURE THAT DEVICES DESIGNED TO BE USED WITH COMPAQ PRODUCTS
COMPLY WITH FCC CLASS B EMISSIONS REQUIREMENTS.
This guide contains information protected by copyright. No part of this document may be
photocopied or reproduced in any form without prior written consent from Compaq Computer
Corporation.
1997 Compaq Computer Corporation
All rights reserved. Printed in the USA
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Registered U.S. Patent and Trademark Office
Product names mentioned in this document may be trademarks and/or registered trademarks of other companies.
For more information regarding specifications and Compaq-specific parts please contact Compaq
Computer Corporation, Industry Relations Department.
Technical Reference Guide for
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September 1997
Document Number DSK-109A/0907

Technical Reference Guide
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition – September 1997
ii

Technical Reference Guide
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition – September 1997
iii
TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION.............................................................................................................
1.1 ABOUT THIS GUIDE ...........................................................................................................1-1
1.1.1 USING THIS GUIDE.....................................................................................................1-1
1.1.2 ADDITIONAL INFORMATION SOURCES..................................................................1-1
1.2 NOTATIONAL CONVENTIONS..........................................................................................1-2
1.2.1 VALUES........................................................................................................................1-2
1.2.2 RANGES........................................................................................................................1-2
1.2.3 SIGNAL LABELS..........................................................................................................1-2
1.2.4 REGISTER NOTATION AND USAGE .........................................................................1-2
1.2.5 BIT NOTATION............................................................................................................ 1-2
1.3 COMMON ACRONYMS AND ABBREVIATIONS..............................................................1-3
CHAPTER 2 SYSTEM OVERVIEW.....................................................................................................
2.1 INTRODUCTION..................................................................................................................2-1
2.2 FEATURES...........................................................................................................................2-2
2.2.1 STANDARD FEATURES.............................................................................................. 2-2
2.2.2 MODEL DIFFERENCES...............................................................................................2-3
2.2.3 OPTIONS.......................................................................................................................2-3
2.3 MECHANICAL DESIGN......................................................................................................2-4
2.3.1 CABINET LAYOUT......................................................................................................2-4
2.3.2 CHASSIS LAYOUT.......................................................................................................2-6
2.3.3 SYSTEM BOARD LAYOUT......................................................................................... 2-7
2.4 SYSTEM ARCHITECTURE..................................................................................................2-8
2.4.1 MICROPROCESSOR...................................................................................................2-10
2.4.2 MEMORY....................................................................................................................2-10
2.4.3 SUPPORT CHIPSET....................................................................................................2-11
2.4.4 MASS STORAGE........................................................................................................ 2-11
2.4.5 SERIAL AND PARALLEL INTERFACES.................................................................. 2-11
2.4.6 UNIVERSAL SERIAL BUS INTERFACE................................................................... 2-12
2.4.7 GRAPHICS SUBSYSTEM........................................................................................... 2-12
2.5 SPECIFICATIONS.............................................................................................................. 2-13
CHAPTER 3 PROCESSOR/MEMORY SUBSYSTEM........................................................................
3.1 INTRODUCTION..................................................................................................................3-1
3.2 PENTIUM MMX-BASED PROCESSOR/MEMORY SUBSYSTEM.....................................3-2
3.2.1 PENTIUM MMX MICROPROCESSOR.........................................................................3-3
3.2.2 BUS/PROCESSING SPEED SELECT............................................................................3-4
3.2.3 SECONDARY (L2) CACHE MEMORY........................................................................3-4
3.2.4 SYSTEM MEMORY...................................................................................................... 3-5
3.2.5 SUBSYSTEM CONFIGURATION.................................................................................3-8

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Compaq Deskpro 4000N and 4000S Personal Computers
First Edition – September 1997
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CHAPTER 4 SYSTEM SUPPORT.........................................................................................................
4.1 INTRODUCTION..................................................................................................................4-1
4.2 PCI BUS OVERVIEW...........................................................................................................4-2
4.2.1 PCI CONNECTOR.........................................................................................................4-3
4.2.2 PCI BUS MASTER ARBITRATION..............................................................................4-4
4.2.3 PCI BUS TRANSACTIONS...........................................................................................4-5
4.2.4 OPTION ROM MAPPING .............................................................................................4-8
4.2.5 PCI INTERRUPT MAPPING.........................................................................................4-9
4.2.6 PCI CONFIGURATION............................................................................................... 4-10
4.3 ISA BUS OVERVIEW.........................................................................................................4-11
4.3.1 ISA CONNECTOR ......................................................................................................4-12
4.3.2 ISA BUS TRANSACTIONS......................................................................................... 4-13
4.3.3 DIRECT MEMORY ACCESS......................................................................................4-15
4.3.4 INTERRUPTS.............................................................................................................. 4-18
4.3.5 INTERVAL TIMER.....................................................................................................4-22
4.3.6 ISA CONFIGURATION...............................................................................................4-22
4.4 SYSTEM CLOCK DISTRIBUTION....................................................................................4-23
4.5 REAL-TIME CLOCK AND CONFIGURATION MEMORY............................................... 4-24
4.5.1 CONFIGURATION MEMORY BYTE DEFINITIONS................................................ 4-25
4.6 I/O MAP AND REGISTER ACCESSING............................................................................ 4-41
4.6.1 SYSTEM I/O MAP ......................................................................................................4-41
4.6.2 87307 I/O CONTROLLER CONFIGURATION........................................................... 4-42
4.7 SYSTEM MANAGEMENT SUPPORT ............................................................................... 4-44
4.7.1 FLASH ROM WRITE PROTECT ................................................................................ 4-44
4.7.2 PASSWORD PROTECTION........................................................................................4-45
4.7.3 I/O SECURITY............................................................................................................ 4-46
4.7.4 USER SECURITY........................................................................................................ 4-46
4.7.5 TEMPERATURE SENSING........................................................................................ 4-47
4.7.6 POWER MANAGEMENT........................................................................................... 4-48
CHAPTER 5 INPUT/OUTPUT INTERFACES.....................................................................................
5.1 INTRODUCTION..................................................................................................................5-1
5.2 ENHANCED IDE INTERFACE............................................................................................ 5-1
5.2.1 IDE PROGRAMMING...................................................................................................5-1
5.2.2 IDE CONNECTORS...................................................................................................... 5-8
5.3 DISKETTE DRIVE INTERFACE........................................................................................5-10
5.3.1 DISKETTE DRIVE PROGRAMMING ........................................................................ 5-11
5.3.2 DISKETTE DRIVE CONNECTOR.............................................................................. 5-14
5.4 SERIAL INTERFACES.......................................................................................................5-15
5.4.1 RS-232 INTERFACE ................................................................................................... 5-15
5.4.2 SERIAL INTERFACE PROGRAMMING.................................................................... 5-16
5.5 PARALLEL INTERFACE................................................................................................... 5-21
5.5.1 STANDARD PARALLEL PORT MODE ..................................................................... 5-21
5.5.2 ENHANCED PARALLEL PORT MODE..................................................................... 5-22
5.5.3 EXTENDED CAPABILITIES PORT MODE............................................................... 5-22
5.5.4 PARALLEL INTERFACE PROGRAMMING.............................................................. 5-23
5.5.5 PARALLEL INTERFACE CONNECTOR ................................................................... 5-27

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First Edition – September 1997
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5.6 KEYBOARD/POINTING DEVICE INTERFACE ............................................................... 5-28
5.6.1 KEYBOARD INTERFACE OPERATION ...................................................................5-28
5.6.2 POINTING DEVICE INTERFACE OPERATION .......................................................5-30
5.6.3 KEYBOARD/POINTING DEVICE INTERFACE PROGRAMMING ......................... 5-30
5.6.4 KEYBOARD/POINTING DEVICE INTERFACE CONNECTOR................................ 5-34
5.7 ETHERNET INTERFACE...................................................................................................5-35
5.7.1 NIC CONFIGURATION/CONTROL ........................................................................... 5-36
5.7.2 NIC CONNECTORS.................................................................................................... 5-36
5.8 UNIVERSAL SERIAL BUS INTERFACE........................................................................... 5-37
5.8.1 USB CONFIGURATION.............................................................................................. 5-37
5.8.2 USB CONTROL........................................................................................................... 5-38
5.8.3 USB CONNECTOR .....................................................................................................5-38
CHAPTER 6 GRAPHICS SUBSYSTEM...............................................................................................
6.1 INTRODUCTION..................................................................................................................6-1
6.2 SUBSYSTEM DESCRIPTION ..............................................................................................6-2
6.2.1 S3 TRIO64V2/GX GRAPHICS CONTROLLER ...........................................................6-2
6.2.2 S3 TRIO64V2/GX GRAPHICS CONFIGURATIONS ...................................................6-3
6.2.3 S3 TRIO64V2/GX GRAPHICS SUBSYSTEM PROGRAMMING.................................6-4
6.2.4 MONITOR POWER CONTROL....................................................................................6-5
6.2.5 CONNECTORS .............................................................................................................6-6
CHAPTER 7 POWER SUPPLY AND DISTRIBUTION.......................................................................
7.1 INTRODUCTION..................................................................................................................7-1
7.2 POWER SUPPLY ASSEMBLY/CONTROL.......................................................................... 7-1
7.2.1 POWER SUPPLY ASSEMBLY......................................................................................7-2
7.2.2 POWER CONTROL....................................................................................................... 7-3
7.3 POWER DISTRIBUTION......................................................................................................7-4
7.3.1 3.5/5/12 VDC DISTRIBUTION......................................................................................7-4
7.3.2 LOW VOLTAGE DISTRIBUTION................................................................................7-5
7.4 SIGNAL DISTRIBUTION.....................................................................................................7-6
CHAPTER 8 BIOS ROM .......................................................................................................................
8.1 INTRODUCTION..................................................................................................................8-1
8.2 BOOT FUNCTIONS..............................................................................................................8-2
8.2.1 BOOT BLOCK...............................................................................................................8-2
8.2.2 QUICKBOOT.................................................................................................................8-2
8.2.3 SILENTBOOT ...............................................................................................................8-2
8.3 ACCESSING CONFIGURATION MEMORY.......................................................................8-3
8.3.1 ACCESSING CMOS......................................................................................................8-3
8.3.2 SETTING DEFAULT PARAMETERS.......................................................................... 8-3
8.3.3 ACCESSING CMOS FEATURE BITS...........................................................................8-4

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First Edition – September 1997
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8.4 CLIENT MANAGEMENT SUPPORT...................................................................................8-5
8.4.1 SYSTEM ID................................................................................................................... 8-7
8.4.2 SYSTEM INFORMATION TABLE...............................................................................8-7
8.4.3 TEMPERATURE SENSOR.......................................................................................... 8-12
8.4.4 DRIVE FAULT PREDICTION..................................................................................... 8-12
8.4.5 DIMM SUPPORT......................................................................................................... 8-13
8.4.6 SECURITY FUNCTIONS............................................................................................8-15
8.4.7 ACCESSING CMOS FEATURE BITS......................................................................... 8-16
8.5 PNP SUPPORT.................................................................................................................... 8-17
8.6 POWER MANAGEMENT SUPPORT ................................................................................. 8-18
APPENDIX A ERROR MESSAGES AND CODES.............................................................................A
A.1 INTRODUCTION.................................................................................................................A-1
A.2 POWER-ON MESSAGES..................................................................................................... A-1
A.3 BEEP CODE MESSAGES.................................................................................................... A-1
A.4 POWER-ON SELF TEST (POST) MESSAGES.................................................................... A-2
A.5 PROCESSOR ERROR MESSAGES (1XX-XX) ...................................................................... A-3
A.6 MEMORY ERROR MESSAGES (2XX-XX)........................................................................... A-4
A.7 KEYBOARD ERROR MESSAGES (30X-XX)....................................................................... A-4
A.8 PRINTER ERROR MESSAGES (4XX-XX)............................................................................ A-5
A.9 VIDEO (GRAPHICS) ERROR MESSAGES (5XX-XX).......................................................... A-5
A.10 DISKETTE DRIVE ERROR MESSAGES (6XX-XX) ......................................................... A-6
A.11 SERIAL INTERFACE ERROR MESSAGES (11XX-XX)................................................... A-6
A.12 MODEM COMMUNICATIONS ERROR MESSAGES (12XX-XX).................................... A-7
A.13 HARD DRIVE ERROR MESSAGES (17XX-XX)............................................................... A-8
A.14 HARD DRIVE ERROR MESSAGES (19XX-XX)............................................................... A-9
A.15 VIDEO (GRAPHICS) ERROR MESSAGES (24XX-XX) .................................................... A-9
A.16 AUDIO ERROR MESSAGES (3206-XX)......................................................................... A-10
A.17 NETWORK INTERFACE ERROR MESSAGES (60XX-XX) ........................................... A-10
A.18 SCSI INTERFACE ERROR MESSAGES (65XX-XX, 66XX-XX, 67XX-XX) ....................... A-11
A.19 POINTING DEVICE INTERFACE ERROR MESSAGES (8601-XX).............................. A-11
A.20 CEMM PRIVILEDGED OPS ERROR MESSAGES........................................................ A-12
A.21 CEMM EXCEPTION ERROR MESSAGES ................................................................... A-12
APPENDIX B ASCII CHARACTER SET.............................................................................................
B.1 INTRODUCTION..................................................................................................................B-1
APPENDIX C KEYBOARD...................................................................................................................
C.1 INTRODUCTION..................................................................................................................C-1
C.2 KEYSTROKE PROCESSING................................................................................................C-2
C.2.1 TRANSMISSIONS TO THE SYSTEM ..........................................................................C-3
C.2.2 KEYBOARD LAYOUTS ...............................................................................................C-4
C.2.3 KEYS.............................................................................................................................C-7
C.2.4 KEYBOARD COMMANDS.........................................................................................C-10
C.2.5 SCAN CODES.............................................................................................................C-10

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First Edition – September 1997
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C.3 SCANNER DESCRIPTION.................................................................................................C-14
C.3.1 SCANNER OPERATION.............................................................................................C-15
C.3.2 SCANNER INTERFACE .............................................................................................C-18
C.3.3 SCANNER SPECIFICATIONS/REQUIREMENTS......................................................C-20

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Compaq Deskpro 4000N and 4000S Personal Computers
First Edition – September 1997
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LIST OF FIGURES
FIGURE 2–1. COMPAQ DESKPRO 4000S PERSONAL COMPUTER WITH MONITOR....................................... 2-1
FIGURE 2–2. CABINET LAYOUT, FRONT VIEW .......................................................................................2-4
FIGURE 2–3. CABINET LAYOUT, REAR VIEW .........................................................................................2-5
FIGURE 2–4. CHASSIS LAYOUT, TOP VIEW ............................................................................................2-6
FIGURE 2–5. SYSTEM BOARD LAYOUT, COMPONENT SIDE .....................................................................2-7
FIGURE 2–6. COMPAQ DESKPRO 4000N AND 4000S SYSTEM ARCHITECTURE, BLOCK DIAGRAM..............2-9
FIGURE 2–7. MICROPROCESSOR ARCHITECTURAL DIAGRAM ................................................................ 2-10
FIGURE 3–1. PROCESSOR/MEMORY SUBSYSTEM ARCHITECTURE............................................................3-2
FIGURE 3–2. PENTIUM MMX MICROPROCESSOR INTERNAL ARCHITECTURE...........................................3-3
FIGURE 3–3. SYSTEM MEMORY MAP.......................................................................................................3-7
FIGURE 4–1. PCI BUS DEVICES AND FUNCTIONS.....................................................................................4-2
FIGURE 4–2. 32-BIT PCI BUS CONNECTOR (32-BIT TYPE) .....................................................................4-3
FIGURE 4–3. TYPE 0 CONFIGURATION CYCLE........................................................................................4-6
FIGURE 4–4. PCI CONFIGURATION SPACE MAP......................................................................................4-7
FIGURE 4–5. ISA BUS BLOCK DIAGRAM................................................................................................ 4-11
FIGURE 4–6. ISA EXPANSION CONNECTOR.......................................................................................... 4-12
FIGURE 4–7. MASKABLE INTERRUPT PROCESSING, BLOCK DIAGRAM.................................................... 4-18
FIGURE 4–8. CONFIGURATION MEMORY MAP...................................................................................... 4-24
FIGURE 5–1. 40-PIN IDE CONNECTOR. .................................................................................................5-8
FIGURE 5–1. 50-PIN IDE CONNECTOR. .................................................................................................5-9
FIGURE 5–2. 34-PIN DISKETTE DRIVE CONNECTOR.............................................................................. 5-14
FIGURE 5–3. SERIAL INTERFACES BLOCK DIAGRAM ............................................................................. 5-15
FIGURE 5–4. SERIAL INTERFACE CONNECTOR (MALE DB-9 AS VIEWED FROM REAR OF CHASSIS)........... 5-15
FIGURE 5–5. PARALLEL INTERFACE CONNECTOR (FEMALE DB-25 AS VIEWED FROM REAR OF CHASSIS).. 5-27
FIGURE 5–6. 8042-TO-KEYBOARD TRANSMISSION OF CODE EDH, TIMING DIAGRAM............................ 5-28
FIGURE 5–7. KEYBOARD OR POINTING DEVICE INTERFACE CONNECTOR............................................... 5-34
FIGURE 5–8. ETHERNET INTERFACE BLOCK DIAGRAM ......................................................................... 5-35
FIGURE 5–9. ETHERNET AUI CONNECTOR (DB-15, VIEWED FROM REAR)............................................. 5-36
FIGURE 5–10. ETHERNET RJ-45 CONNECTOR...................................................................................... 5-36
FIGURE 5–11. UNIVERSAL SERIAL BUS CONNECTOR (ONE OF TWO AS VIEWED FROM REAR OF CHASSIS)... 5-38
FIGURE 6–1. S3 TRIO64V2/GX-BASED GRAPHICS SUBSYSTEM, BLOCK DIAGRAM...................................6-2
FIGURE 6–2. VGA MONITOR CONNECTOR, (FEMALE DB-15, AS VIEWED FROM THE REAR OF CHASSIS). ... 6-6
FIGURE 7–1. POWER SUPPLY ASSEMBLY, BLOCK DIAGRAM.................................................................... 7-1
FIGURE 7–2. POWER CABLE DIAGRAM .................................................................................................. 7-4
FIGURE 7–3. LOW VOLTAGE SUPPLY, BLOCK DIAGRAM.........................................................................7-5
FIGURE 7–4. SIGNAL DISTRIBUTION DIAGRAM.......................................................................................7-6
FIGURE C–1. KEYSTROKE PROCESSING ELEMENTS, BLOCK DIAGRAM ....................................................C-2
FIGURE C–2. KEYBOARD-TO-SYSTEM TRANSMISSION OF CODE 58H, TIMING DIAGRAM..........................C-3
FIGURE C–3. U.S. ENGLISH (101-KEY) KEYBOARD KEY POSITIONS.......................................................C-4
FIGURE C–4. NATIONAL (102-KEY) KEYBOARD KEY POSITIONS............................................................C-4
FIGURE C–5. U.S. ENGLISH WINDOWS (101W-KEY) KEYBOARD KEY POSITIONS...................................C-5
FIGURE C–6. NATIONAL WINDOWS (102W-KEY) KEYBOARD KEY POSITIONS ........................................C-5
FIGURE C–7. U.S. ENGLISH WINDOWS (101WE-KEY) KEYBOARD KEY POSITIONS.................................C-6
FIGURE C–8. NATIONAL WINDOWS (102WE-KEY) KEYBOARD KEY POSITIONS......................................C-6
FIGURE C–9. SCANNER ELEMENTS, BLOCK DIAGRAM..........................................................................C-14
FIGURE C–10. SCANNER OPERATION FLOW CHART ..............................................................................C-16

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Compaq Deskpro 4000N and 4000S Personal Computers
First Edition – September 1997
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LIST OF TABLES
TABLE 1–1. ACRONYMS AND ABBREVIATIONS.......................................................................................1-3
TABLE 2–1. ARCHITECTURAL COMPARISON.............................................................................................2-8
TABLE 2–2. SUPPORT CHIPSETS .......................................................................................................... 2-11
TABLE 2–3. GRAPHICS SUBSYSTEM OVERVIEW....................................................................................2-12
TABLE 2–4. ENVIRONMENTAL SPECIFICATIONS....................................................................................2-13
TABLE 2–5. ELECTRICAL SPECIFICATIONS ...........................................................................................2-13
TABLE 2–6. PHYSICAL SPECIFICATIONS............................................................................................... 2-13
TABLE 2–7. DISKETTE DRIVE SPECIFICATIONS.....................................................................................2-14
TABLE 2–8. 8X CD-ROM DRIVE SPECIFICATIONS................................................................................ 2-14
TABLE 2–9. HARD DRIVE SPECIFICATIONS...........................................................................................2-15
TABLE 3–1. PROCESSOR/MEMORY ARCHITECTURAL HIGHLIGHTS ............................................................ 3-1
TABLE 3–2. PENTIUM MMX MICROPROCESSOR BUS/CORE SPEED SWITCH SETTINGS .............................3-4
TABLE 3–3. SW1 BUS/CORE SPEED POSITIONS TO GPIO ASSIGNMENTS...................................................3-4
TABLE 3–4. SDRAM PERFORMANCE TIMES............................................................................................3-5
TABLE 3–5. SPD ADDRESS MAP (SDRAM DIMM).................................................................................3-6
TABLE 3–6. HOST/PCI BRIDGE CONFIGURATION REGISTERS (VT82C595) ..............................................3-8
TABLE 4–1. 32-BIT PCI BUS CONNECTOR PINOUT.................................................................................4-3
TABLE 4–2. PCI BUS MASTERING DEVICES...........................................................................................4-4
TABLE 4–3. PCI DEVICE CONFIGURATION ACCESS................................................................................ 4-6
TABLE 4–4. PCI FUNCTION CONFIGURATION ACCES..............................................................................4-7
TABLE 4–5. PCI DEVICE IDENTIFICATION .............................................................................................4-8
TABLE 4–6. PCI/ISA BRIDGE CONFIGURATION REGISTERS FOR THE VT82C586 (P55C-BASED SYSTEMS)4-10
TABLE 4–7. ISA EXPANSION CONNECTOR PINOUT............................................................................... 4-12
TABLE 4–8. DEFAULT DMA CHANNEL ASSIGNMENTS ......................................................................... 4-15
TABLE 4–9. DMA PAGE REGISTER ADDRESSES................................................................................... 4-16
TABLE 4–10. DMA CONTROLLER REGISTERS......................................................................................4-17
TABLE 4–11. MASKABLE INTERRUPT PRIORITIES AND ASSIGNMENTS.................................................... 4-19
TABLE 4–12. MASKABLE INTERRUPT CONTROL REGISTERS.................................................................. 4-19
TABLE 4–13. INTERVAL TIMER FUNCTIONS .........................................................................................4-22
TABLE 4–14. INTERVAL TIMER CONTROL REGISTERS........................................................................... 4-22
TABLE 4–15. CLOCK GENERATION AND DISTRIBUTION (PENTIUM-BASED SYSTEM)............................... 4-23
TABLE 4–16. CONFIGURATION MEMORY (CMOS) MAP....................................................................... 4-25
TABLE 4–17. SYSTEM I/O MAP........................................................................................................... 4-41
TABLE 4–18. 87307 I/O CONTROLLER PNP STANDARD CONTROL REGISTERS ........................................ 4-42
TABLE 4–19. SYSTEM MANAGEMENT CONTROL REGISTERS................................................................... 4-44
TABLE 5–1. IDE PCI CONFIGURATION REGISTERS ................................................................................ 5-2
TABLE 5–2. IDE BUS MASTER CONTROL REGISTERS.............................................................................5-2
TABLE 5–3. IDE ATA CONTROL REGISTERS.........................................................................................5-3
TABLE 5–4. IDE CONTROLLER COMMANDS ..........................................................................................5-6
TABLE 5–5. 40-PIN IDE CONNECTOR PINOUT .......................................................................................5-8
TABLE 5–6. 40-PIN IDE CONNECTOR PINOUT .......................................................................................5-9
TABLE 5–7. DISKETTE DRIVE CONTROLLER CONFIGURATION REGISTERS ............................................. 5-11
TABLE 5–8. DISKETTE DRIVE CONTROLLER REGISTERS ....................................................................... 5-12
TABLE 5–9. 34-PIN DISKETTE DRIVE CONNECTOR PINOUT................................................................... 5-14
TABLE 5–10. DB-9 SERIAL CONNECTOR PINOUT................................................................................. 5-15
TABLE 5–11. SERIAL INTERFACE CONFIGURATION REGISTERS.............................................................. 5-16

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First Edition – September 1997
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TABLE 5–12. SERIAL INTERFACE CONTROL REGISTERS........................................................................ 5-17
TABLE 5–13. PARALLEL INTERFACE CONFIGURATION REGISTERS......................................................... 5-23
TABLE 5–14. PARALLEL INTERFACE CONTROL REGISTERS ................................................................... 5-24
TABLE 5–15. DB-25 PARALLEL CONNECTOR PINOUT .......................................................................... 5-27
TABLE 5–16. 8042-TO-KEYBOARD COMMANDS .................................................................................. 5-29
TABLE 5–17. KEYBOARD/MOUSE INTERFACE CONFIGURATION REGISTERS ........................................... 5-30
TABLE 5–18. CPU COMMANDS TO THE 8042......................................................................................5-32
TABLE 5–19. KEYBOARD/POINTING DEVICE CONNECTOR PINOUT........................................................ 5-34
TABLE 5–20. USB INTERFACE CONFIGURATION REGISTERS................................................................. 5-37
TABLE 5–21. USB CONTROL REGISTERS............................................................................................. 5-38
TABLE 5–22. USB CONNECTOR PINOUT.............................................................................................. 5-38
TABLE 6–1. GRAPHICS SUBSYSTEM COMPARISON ..................................................................................6-1
TABLE 6–2. S3 TRIO64V2/GX-BASED SUBSYSTEM EXTENDED VGA MODES.........................................6-3
TABLE 6–3. GD5436 PCI CONFIGURATION SPACE REGISTERS ...............................................................6-4
TABLE 6–4. STANDARD VGA MODE I/O MAPPING................................................................................6-4
TABLE 6–5. S3-SPECIFIC CONTROL REGISTER MAPPING.........................................................................6-5
TABLE 6–6. MONITOR POWER MANAGEMENT CONDITIONS....................................................................6-5
TABLE 6–7. DB-15 MONITOR CONNECTOR PINOUT............................................................................... 6-6
TABLE 7–1. POWER SUPPLY SPECIFICATIONS.........................................................................................7-2
TABLE 8–1. PNP CLIENT MANAGEMENT FUNCTIONS (INT15)................................................................ 8-5
TABLE 8–1. PNP BIOS FUNCTIONS..................................................................................................... 8-17
TABLE 8–2. APM BIOS FUNCTIONS (INT15) .....................................................................................8-19
TABLE A–1. POWER-ON MESSAGES ..................................................................................................... A-1
TABLE A–2. BEEP CODE MESSAGES..................................................................................................... A-1
TABLE A–3. POWER-ON SELF TEST (POST) MESSAGES........................................................................ A-2
TABLE A–4. PROCESSOR ERROR MESSAGES ......................................................................................... A-3
TABLE A–5. MEMORY ERROR MESSAGES............................................................................................. A-4
TABLE A–6. KEYBOARD ERROR MESSAGES.......................................................................................... A-4
TABLE A–7. PRINTER ERROR MESSAGES.............................................................................................. A-5
TABLE A–8. VIDEO (GRAPHICS) ERROR MESSAGES .............................................................................. A-5
TABLE A–9. DISKETTE DRIVE ERROR MESSAGES.................................................................................. A-6
TABLE A–10. SERIAL INTERFACE ERROR MESSAGES............................................................................. A-6
TABLE A–11. SERIAL INTERFACE ERROR MESSAGES............................................................................. A-7
TABLE A–12. HARD DRIVE ERROR MESSAGES...................................................................................... A-8
TABLE A–13. HARD DRIVE ERROR MESSAGES...................................................................................... A-9
TABLE A–14. HARD DRIVE MESSAGES................................................................................................. A-9
TABLE A–15. AUDIO ERROR MESSAGES............................................................................................. A-10
TABLE A–16. NETWORK INTERFACE ERROR MESSAGES ...................................................................... A-10
TABLE A–17. SCSI INTERFACE ERROR MESSAGES ............................................................................. A-11
TABLE A–18. POINTING DEVICE INTERFACE ERROR MESSAGES........................................................... A-11
TABLE A–19. CEMM PRIVILEGED OPS ERROR MESSAGES.................................................................. A-12
TABLE A–20. CEMM EXCEPTION ERROR MESSAGES ......................................................................... A-12
TABLE B–1. ASCII CHARACTER SET ....................................................................................................B-1
TABLE C–1. KEYBOARD-TO-SYSTEM COMMANDS ...............................................................................C-10
TABLE C–2. KEYBOARD SCAN CODES.................................................................................................C-11
TABLE C–3. SCANNER PERFORMANCE CHART .....................................................................................C-17
TABLE C–4. SCANNER I/F SIGNALS.....................................................................................................C-18
TABLE C–5. SCANNER SPECIFICATIONS...............................................................................................C-20

Technical Reference Guide
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September 1997
1-1
Chapter 1
INTRODUCTION
1. Chapter 1 INTRODUCTION
1.1 ABOUT THIS GUIDE
This guide provides technical information about the Compaq Deskpro 4000N and 4000S
Personal Computers. This document includes information regarding system design, function, and
features that can be used by programmers, engineers, technicians, and system administrators.
1.1.1 USING THIS GUIDE
This guide consists of chapters and appendices. The chapters primarily describe the hardware
and firmware elements contained within the chassis and specifically deal with the system board
and the power supply assembly. The appendices contain general information about standard
peripheral devices such as the keyboard as well as separate audio or other interface cards, as well
as other general information in tabular format.
1.1.2 ADDITIONAL INFORMATION SOURCES
This guide does not describe in detail other manufacturer’s components used in the product
covered. For more information on individual commercial-off-the-shelf (COTS) components refer
to the indicated manufacturers’ documentation. The products covered by this guide use
architecture based on industry-standard specifications that can be referenced for detailed
information.
Hardcopy documentation sources:
♦The Lotus/Intel/Microsoft Expanded Memory Specification, Ver. 4.0
♦PCI Local Bus Specification Revision 2.1
♦Extended Industry Standard Architecture Expansion Bus Technical Reference Guide,
p/n 130584, Second Edition, Compaq Computer Corporation
♦Compaq Basic Input/Out System (BIOS) Technical Reference Guide
Doc.# 074A/0693, Fourth Edition, Compaq Computer Corporation
Online information sources:
♦Compaq Computer Corporation: http://www.compaq.com
♦Intel Corporation: http://www.intel.com
♦VIA Technologies Incorporated: http://www.via.com
♦National Semiconductor: http://www.national.com
♦S3 Incorporated: http://www.S3.com

Chapter 1 Introduction
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September 1997
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1.2 NOTATIONAL CONVENTIONS
1.2.1 VALUES
Hexadecimal values are indicated by the letter “h” following an alpha-numerical value. Binary
values are indicated by the letter “b” following a value of ones and zeros. Memory addresses
expressed as “SSSS:OOOO” (SSSS = 16-bit segment, OOOO = 16-bit offset) can be assumed as
a hexadecimal value. Values that have no succeeding letter can be assumed to be decimal.
1.2.2 RANGES
Ranges or limits for a parameter are shown as a pair of values separated by two dots:
Example: Bits <7..4> = bits 7, 6, 5, and 4.
1.2.3 SIGNAL LABELS
Signal names are indicated using abbreviations, acronyms, or, if possible, the full signal name in
all capital letters. Signals that are meant to be active low are indicated with a dash immediately
following the name.
1.2.4 REGISTER NOTATION AND USAGE
This guide uses standard Intel naming conventions in discussing the microprocessor’s (CPU)
internal registers. Registers that are accessed through programmable I/O using an indexing
scheme are indicated using the following format:
03C5.17h
Index port
Data port
In the example above, register 03C5.17h is accessed by writing the index port value 17h to the
index address (03C4h), followed by a write to or a read from port 03C5h.
1.2.5 BIT NOTATION
Bit values are labeled with bit <0> representing the least-significant bit (LSb) and bit <7>
representing the most-significant bit (MSb) of a byte. Bytes, words, double words, and quad
words are typically shown with most-significant portions on the left or top and the least-
significant portions on the right or bottom respectively.

Technical Reference Guide
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September 1997
1-3
1.3 COMMON ACRONYMS AND ABBREVIATIONS
Table 1-1 lists the acronyms and abbreviations used in this guide.
Table 1–1. Acronyms and Abbreviations
Table 1-1.
Acronyms and Abbreviations
Acronym/Abbreviation Description
A ampere
AC alternating current
ACPI Advanced Configuration and Power Interface
A/D analog-to-digital
AGP advanced graphics port
API application programming interface
APM advanced power management
ASIC application-specific integrated circuit
AT 1. attention (commands) 2. 286-based PC architecture
ATA AT attachment (mode)
AVI audio-video interleaved
AVGA Advanced VGA
BCD binary-coded decimal
BIOS basic input/output system
bis second/new revision
BitBLT bit block transfer
BNC Bayonet Neill-Concelman (connector)
bps or b/s bits per second
BSP Bootstrap processor
CAS column address strobe
CD compact disk
CD-ROM compact disk read-only memory
CDS compct disk system
CF carry flag
CGA color graphics adapter
Ch channel
CLUT color look-up table (pallete)
cm centimeter
CMC cache/memory controller
CMOS complimentary metal-oxide semiconductor (configuration memory)
Cntlr controller
codec compressor/decompressor
CPQ Compaq
CPU central processing unit
CRT cathode ray tube
CSM Compaq system management / Compaq server management
DAA direct access arrangement
DAC digital-to-analog converter
db decibel
DC direct current
DCH DOS compatibility hole
DDC Display Data Channel
DF direction flag
Continued

Chapter 1 Introduction
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September 1997
1-4
Table 1-1. Acronyms and Abbreviations
Continued
Acronym/Abbreviation Description
DIMM dual inline memory module
DIN Deutche IndustriNorm (connector standard)
DIP dual inline package
DMA direct memory access
dpi dots per inch
DRAM dynamic random access memory
DRQ data request
EDID extended display identification data
EDO extended data out (RAM type)
EEPROM electrically eraseable PROM
EGA enhanced graphics adapter
EIA Electronic Industry Association
EISA extended ISA
EPP enhanced parallel port
EIDE enhanced IDE
ESCD Extended System Configuration Data (format)
EV Environmental Variable (data)
ExCA Exchangeable Card Architecture
FIFO first in / first out
FL flag (register)
FM frequency modulation
FPM fast page mode (RAM type)
FPU Floating point unit (numeric or math coprocessor)
ft foot
GB gigabyte
GND ground
GPIO general purpose I/O
GPOC general purpose open-collector
GUI graphics user interface
h hexadecimal
HW hardware
hex hexadecimal
Hz hertz
IDE integrated drive element
IEEE Institute of Electrical and Electronic Engineers
IF interrupt flag
I/F interface
in inch
INT interrupt
I/O input/output
IPL initial program loader
IrDA InfraRed Data Association
IRQ interrupt request
ISA industry standard architecture
JEDEC Joint Electron Device Engineering Council
Kb / KB kilobits / kilobytes (x 1024 bits / x 1024 bytes)
Kb/s kilobits per second
kg kilogram
KHz kilohertz
kv kilovolt
Continued

Technical Reference Guide
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September 1997
1-5
Table 1-1. Acronyms and Abbreviations
Continued
Acronym/Abbreviation Description
lb pound
LCD liquid crystal display
LED light-emitting diode
LIF low insertion force (socket)
LSI large scale integration
LSb / LSB least significant bit / least significant byte
LUN logical unit (SCSI)
MMX multimedia extensions
MPEG Motion Picture Experts Group
MOSFET Metal oxide silicon field effect transistor
ms millisecond
MSb / MSB most significant bit / most significant byte
mux multiplex
MVA motion video acceleration
MVW motion video window
n variable parameter/value
NIC network interface card/controller
NiCad nickel cadmium
NiMH nickel-metal hydride
NMI non-maskable interrupt
ns nanosecond
NT nested task flag
NTSC National Television Standards Committee
NVRAM non-volatile random access memory
OEM original equipment manufacturer
OS operating system
PAL 1. programmable array logic 2. phase altering line
PC personal computer
PCI peripheral component interconnect
PCM pulse code modulation
PCMCIA Personal Computer Memory Card International Association
PF parity flag
PIN personal identification number
POST power-on self test
PROM programmable read-only memory
PTR pointer
RAM random access memory
RAS row address strobe
rcvr receiver
RF resume flag
RGB red/green/blue
RH Relative humidity
RMS root mean square
ROM read-only memory
RPM revolutions per minute
RTC real time clock
R/W read/write
Continued

Chapter 1 Introduction
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September 1997
1-6
Table 1-1. Acronyms and Abbreviations
Continued
Acronym/Abbreviation Description
SCSI small computer system interface
SDRAM Synchronous Dynamic RAM
SEC Single Edge-Connector
SECAM sequential colour avec memoire (sequential color with memory)
SF sign flag
SGRAM Synchronous Graphics RAM
SIMM single in-line memory module
SIT system information table
SMI system management interrupt
SMM system management mode
SMRAM system management RAM
SPD serial presence detect
SPP standard parallel port
SRAM static RAM
STN super twist pneumatic
SVGA super VGA
SW software
TAD telephone answering device
TAM telephone answering machine
TCP tape carrier package
TF trap flag
TFT thin-film transistor
TIA Telecommunications Information Administration
TPE twisted pair ethernet
TPI track per inch
TTl transistor-transistor logic
TV television
TX transmit
UART universal asynchronous receiver/transmitter
us / µs microsecond
USB Universal Serial Bus
UTP unshielded twisted pair
Vvolt
VESA Video Electronic Standards Association
VGA video graphics adapter
vib vibrato
VLSI very large scale integration
VRAM Video RAM
Wwatt
WRAM Windows RAM
ZF zero flag
ZIF zero insertion force (socket)

Technical Reference Guide
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition -September
2-1
Chapter 2
SYSTEM OVERVIEW
2. Chapter 2 SYSTEM OVERVIEW
2.1 INTRODUCTION
The Compaq Deskpro 4000N and 4000S Personal Computers are based on Pentium
microprocessors featuring MMX technology and designed with an emphasis on speed, storage
capacity, and multimedia compatibility to meet the requirements of the business environment.
These models feature architectures incorporating the PCI and ISA buses. All models are easily
upgradeable and expandable to keep pace with the needs of the office or home.
Figure 2–1. Compaq Deskpro 4000S Personal Computer with Monitor

Chapter 2 System Overview
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September 1997
2-2
2.2 FEATURES
This section describes the standard and distinguishing features.
2.2.1 STANDARD FEATURES
The following standard features are included on all models:
♦Pentium microprocessor with MMX technology
♦256-KB second-level cache
♦16 or 32 megabytes of SDRAM, with support for ECC and SDP memory
♦Integrated S3 Trio64V2/GX graphics controller with 2-MB frame
♦Enhanced IDE controller supporting Ultra ATA (UDMA) modes 0-2
♦Hard drive fault prediction
♦PCI connector
♦Two serial interfaces
♦Parallel interface
♦Two universal serial bus ports
♦Integrated network interface controller (RJ-45/AUI ports)
♦Compaq Space Saver keyboard w/Windows support
♦Compaq PS/2-type mouse
♦APM 1.2 power management support
♦Plug ’n Play compatible (with ESCD support)
♦Energy Star compliant
♦76-watt, surge-tolerant power supply
The Deskpro 4000N and 4000S support the Intelligent Manageability features listed below:
Configuration
Management Asset Management Fault Management Security Management
Remote ROM Flash RAM Type Data ECC RAM Fault Prediction Memory Change Alert
Remote Security DMI BIOS SMART II Hard Drive Ownership Tag
Remote Wakeup Asset Tag Monitor Fault Diag. Config. Cntrl. Hardware
Remote Shutdown Sys. Serial # UDMA Integrity Log. Setup Password
Replicated Setup Sys. Manuf./Model Proactive Backup Power-On Password
ACPI-Ready Sys. Board Rev. Level Thermal Sensor QuickLock/QuickBlank
Dual-State Power Sw. ROM rev. Diskette Boot Cntrl.
Failsafe Boot Block ROM Hard Drive Type Data Diskette Write Cntrl.
Monitor Type Data I/O Port En/Dis. Cntrl.
Compaq Insight Edition Cable Lock Provision
The Intelligent Manageability features provide support for DMI 2.0, Compaq Insight Manager,
and Management Solutions Partners.