Compaq EN Series Use and care manual

Technical
Reference
Guide
For the
Compaq Deskpro EN Series of Personal Computers
Net PC and Small Form Factor Models

This hardcopy is designed to be placed into a standard 3-ring binder. Provided below is a title block that
can be copied and cut out and placed into the slip or taped onto the edge of the binder.
Deskpro EN Series of Personal Computers
Net PC and Small Form Factor Models
TRG

Technical Reference Guide
Compaq Deskpro EN Series of Personal Computers
Net PC and Small Form Factor Models
First Edition - June 1998
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.
1998 Compaq Computer Corporation
All rights reserved. Printed in the USA
Compaq, Deskpro, LTE, Contura, Presario, ProLinea
Registered U.S. Patent and Trademark Office
Product names mentioned in this document may be trademarks and/or registered trademarks of other companies.
“Pentium, ” “Celeron,” and “MMX” are trademarks ofIntel Corporation.
“Windows” is a trademark of Microsoft Corporation.
For more information regarding specifications and Compaq-specific parts please contact Compaq
Computer Corporation, Industry Relations Department.
Technical Reference Guide
for
Compaq Deskpro EN Series of Personal Computers, Net PC and Small Form Factor Models
First Edition – June 1998
Document Number DSK-008A/0698

Technical Reference Guide
Compaq Deskpro EN Series of Personal Computers
Net PC and Small Form Factor Models
First Edition - June 1998
ii

Technical Reference Guide
Compaq Deskpro EN Series of Personal Computers
Net PC and Small Form Factor Models
First Edition - June 1998
iii
TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION........................................................................................................1-1
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
2.1 INTRODUCTION.................................................................................................................. 2-1
2.2 FEATURES AND OPTIONS.................................................................................................2-2
2.2.1 STANDARD FEATURES..............................................................................................2-2
2.2.2 OPTIONS.......................................................................................................................2-3
2.3 MECHANICAL DESIGN...................................................................................................... 2-4
2.3.1 CABINET LAYOUTS....................................................................................................2-4
2.3.2 CHASSIS LAYOUT.......................................................................................................2-6
2.3.3 BOARD LAYOUTS.......................................................................................................2-7
2.4 SYSTEM ARCHITECTURE.................................................................................................. 2-8
2.4.1 PENTIUM II PROCESSOR.......................................................................................... 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.................................................................. 2-12
2.4.6 UNIVERSAL SERIAL BUS INTERFACE................................................................... 2-12
2.4.7 GRAPHICS SUBSYSTEM........................................................................................... 2-12
2.4.8 AUDIO SUBSYSTEM .................................................................................................2-12
2.5 SPECIFICATIONS..............................................................................................................2-13
CHAPTER 3 PROCESSOR/MEMORY SUBSYSTEM...................................................................3-1
3.1 INTRODUCTION.................................................................................................................. 3-1
3.2 PROCESSOR/MEMORY SUBSYSTEM ..............................................................................3-2
3.2.1 INTEL PENTIUM II PROCESSOR................................................................................3-3
3.2.2 SYSTEM MEMORY...................................................................................................... 3-6
3.2.3 SUBSYSTEM CONFIGURATION.................................................................................3-9

Technical Reference Guide
Compaq Deskpro EN Series of Personal Computers
Net PC and Small Form Factor Models
First Edition - June 1998
iv
CHAPTER 4 SYSTEM SUPPORT....................................................................................................4-1
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 POWER MANAGEMENT SUPPORT.....................................................................4-9
4.2.7 PCI CONFIGURATION............................................................................................... 4-10
4.3 AGP BUS OVERVIEW .......................................................................................................4-11
4.3.1 BUS TRANSACTIONS................................................................................................4-11
4.3.2 AGP CONFIGURATION............................................................................................. 4-14
4.4 ISA BUS OVERVIEW......................................................................................................... 4-15
4.4.1 ISA CONNECTOR ......................................................................................................4-16
4.4.2 ISA BUS TRANSACTIONS......................................................................................... 4-17
4.4.3 DIRECT MEMORY ACCESS......................................................................................4-19
4.4.4 INTERRUPTS.............................................................................................................. 4-22
4.4.5 INTERVAL TIMER..................................................................................................... 4-26
4.4.6 ISA CONFIGURATION...............................................................................................4-26
4.5 SYSTEM CLOCK DISTRIBUTION.................................................................................... 4-27
4.6 REAL-TIME CLOCK AND CONFIGURATION MEMORY............................................... 4-28
4.7 I/O MAP AND REGISTER ACCESSING............................................................................ 4-45
4.7.1 SYSTEM I/O MAP ......................................................................................................4-45
4.7.2 GPIO UTILIZATION................................................................................................... 4-46
4.8 SYSTEM MANAGEMENT SUPPORT ............................................................................... 4-50
4.8.1 FLASH ROM WRITE PROTECT ................................................................................4-51
4.8.2 PASSWORD PROTECTION........................................................................................ 4-51
4.8.3 I/O SECURITY............................................................................................................ 4-52
4.8.4 USER SECURITY........................................................................................................4-52
4.8.5 TEMPERATURE SENSING........................................................................................4-53
4.8.6 SMART COVER LOCK...............................................................................................4-54
4.8.7 BACKPLANE DETECT ..............................................................................................4-54
4.8.8 POWER MANAGEMENT........................................................................................... 4-55
CHAPTER 5 INPUT/OUTPUT INTERFACES................................................................................5-1
5.1 INTRODUCTION.................................................................................................................. 5-1
5.2 ENHANCED IDE INTERFACE............................................................................................ 5-1
5.2.1 IDE PROGRAMMING...................................................................................................5-1
5.2.2 IDE CONNECTOR........................................................................................................5-8
5.3 DISKETTE DRIVE INTERFACE..........................................................................................5-9
5.3.1 DISKETTE DRIVE PROGRAMMING ........................................................................ 5-10
5.3.2 DISKETTE DRIVE CONNECTOR.............................................................................. 5-13
5.4 SERIAL INTERFACES....................................................................................................... 5-14
5.4.1 RS-232 INTERFACE ................................................................................................... 5-14
5.4.2 SERIAL INTERFACE PROGRAMMING.................................................................... 5-15

Technical Reference Guide
Compaq Deskpro EN Series of Personal Computers
Net PC and Small Form Factor Models
First Edition - June 1998
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5.5 PARALLEL INTERFACE................................................................................................... 5-20
5.5.1 STANDARD PARALLEL PORT MODE ..................................................................... 5-20
5.5.2 ENHANCED PARALLEL PORT MODE..................................................................... 5-21
5.5.3 EXTENDED CAPABILITIES PORT MODE............................................................... 5-21
5.5.4 PARALLEL INTERFACE PROGRAMMING.............................................................. 5-22
5.5.5 PARALLEL INTERFACE CONNECTOR ................................................................... 5-26
5.6 KEYBOARD/POINTING DEVICE INTERFACE ............................................................... 5-27
5.6.1 KEYBOARD INTERFACE OPERATION ...................................................................5-27
5.6.2 POINTING DEVICE INTERFACE OPERATION .......................................................5-29
5.6.3 KEYBOARD/POINTING DEVICE INTERFACE PROGRAMMING ......................... 5-29
5.6.4 KEYBOARD/POINTING DEVICE INTERFACE CONNECTOR................................ 5-33
5.7 UNIVERSAL SERIAL BUS INTERFACE...........................................................................5-34
5.7.1 USB KEYBOARD CONSIDERATIONS...................................................................... 5-34
5.7.2 USB CONFIGURATION.............................................................................................. 5-34
5.7.3 USB CONTROL........................................................................................................... 5-35
5.7.4 USB CONNECTOR .....................................................................................................5-35
5.8 AUDIO SUBSYSTEM.........................................................................................................5-36
5.8.1 PCM AUDIO PROCESSING........................................................................................ 5-38
5.8.2 FM SYNTHESIS AUDIO PROCESSING..................................................................... 5-40
5.8.3 PROGRAMMING........................................................................................................ 5-41
5.8.3 SPECIFICATIONS.......................................................................................................5-44
5.9 NETWORK INTERFACE CONTROLLER..........................................................................5-45
5.10.1 FUNCTIONAL DESCRIPTION................................................................................... 5-45
5.10.2 POWER MANAGEMENT SUPPORT.......................................................................... 5-46
5.10.3 CONFIGURATION/CONTROL................................................................................... 5-47
5.10.4 RJ-45 CONNECTOR....................................................................................................5-47
5.10.5 SPECIFICATIONS.......................................................................................................5-47
CHAPTER 6 GRAPHICS SUBSYSTEM..........................................................................................6-1
6.1 INTRODUCTION.................................................................................................................. 6-1
6.2 FUNCTIONAL DESCRIPTION.............................................................................................6-2
6.2.1 ATI RAGE PRO TURBO AGP GRAPHICS CONTROLLER.........................................6-3
6.3 DISPLAY MODES................................................................................................................ 6-4
6.4 PROGRAMMING..................................................................................................................6-5
6.4.1 CONFIGURATION........................................................................................................6-5
6.4.2 CONTROL..................................................................................................................... 6-5
6.5 MONITOR POWER MANAGEMENT CONTROL...............................................................6-6
6.6 CONNECTORS.....................................................................................................................6-6
6.6.1 MEMORY EXPANSION CONNECTOR....................................................................... 6-6
6.6.2 MONITOR CONNECTOR.............................................................................................6-7

Technical Reference Guide
Compaq Deskpro EN Series of Personal Computers
Net PC and Small Form Factor Models
First Edition - June 1998
vi
CHAPTER 7 POWER SUPPLY AND DISTRIBUTION..................................................................7-1
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......................................................................................................7-5
7.3.1 3.3/5/12 VDC DISTRIBUTION......................................................................................7-5
7.3.2 LOW VOLTAGE DISTRIBUTION................................................................................7-6
7.4 SIGNAL DISTRIBUTION.....................................................................................................7-7
CHAPTER 8 BIOS ROM ..................................................................................................................8-1
8.1 INTRODUCTION.................................................................................................................. 8-1
8.2 BOOT/RESET FUNCTIONS.................................................................................................8-2
8.2.1 BOOT BLOCK...............................................................................................................8-2
8.2.2 QUICKBOOT.................................................................................................................8-2
8.2.3 SILENTBOOT ............................................................................................................... 8-2
8.2.4 RESET...........................................................................................................................8-2
8.3 MEMORY DETECTION AND CONFIGURATION..............................................................8-3
8.4 DESKTOP MANAGEMENT SUPPORT ...............................................................................8-4
8.4.1 SYSTEM ID................................................................................................................... 8-6
8.4.2 SYSTEM INFORMATION TABLE...............................................................................8-6
8.4.3 EDID RETRIEVE ........................................................................................................ 8-13
8.4.4 DRIVE FAULT PREDICTION.....................................................................................8-13
8.4.5 SYSTEM MAP RETRIEVAL....................................................................................... 8-14
8.4.6 FLASH ROM FUNCTIONS......................................................................................... 8-15
8.4.7 POWER BUTTON FUNCTIONS................................................................................. 8-15
8.4.8 ACCESSING CMOS.................................................................................................... 8-16
8.4.9 ACCESSING CMOS FEATURE BITS......................................................................... 8-16
8.4.10 SECURITY FUNCTIONS............................................................................................ 8-18
8.5 PNP SUPPORT.................................................................................................................... 8-19
8.5.1 SMBIOS....................................................................................................................... 8-20
8.6 POWER MANAGEMENT FUNCTIONS ............................................................................ 8-21
8.6.1 INDEPENDENT PM SUPPORT .................................................................................. 8-21
8.6.2 ACPI SUPPORT...........................................................................................................8-21
8.6.3 APM SUPPORT........................................................................................................... 8-22
8.7 USB LEGACY SUPPORT ...................................................................................................8-24
8.8 BIOS UPGRADING............................................................................................................. 8-24
APPENDIX A ERROR MESSAGES AND CODES......................................................................... A-1
A.1 INTRODUCTION.................................................................................................................A-1
A.2 POWER-ON MESSAGES..................................................................................................... A-1
A.3 BEEP/KEYBOARD LED CODES........................................................................................ 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

Technical Reference Guide
Compaq Deskpro EN Series of Personal Computers
Net PC and Small Form Factor Models
First Edition - June 1998
vii
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
B.1 INTRODUCTION..................................................................................................................B-1
APPENDIX C KEYBOARD............................................................................................................. C-1
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-6
C.2.4 KEYBOARD COMMANDS...........................................................................................C-9
C.2.5 SCAN CODES...............................................................................................................C-9

Technical Reference Guide
Compaq Deskpro EN Series of Personal Computers
Net PC and Small Form Factor Models
First Edition - June 1998
viii
LIST OF FIGURES
FIGURE 2–1. COMPAQ DESKPRO EN SERIES SMALL FORM FACTOR PERSONAL COMPUTER WITH MONITOR2-1
FIGURE 2–2. CABINET LAYOUT, FRONT VIEW .......................................................................................2-4
FIGURE 2–3. CABINET LAYOUT, REAR VIEW .........................................................................................2-5
FIGURE 2–4. DESKTOP CHASSIS LAYOUT, TOP VIEW..............................................................................2-6
FIGURE 2–5. BOARD CONNECTOR AND SWITCH LOCATIONS...................................................................2-7
FIGURE 2–6. SYSTEM ARCHITECTURE, BLOCK DIAGRAM........................................................................2-9
FIGURE 2–7. PENTIUM II SEC CARTRIDGE AND HEAT SINK.................................................................. 2-10
FIGURE 3–1. PROCESSOR/MEMORY SUBSYSTEM ARCHITECTURE............................................................ 3-2
FIGURE 3–2. PENTIUM II PROCESSOR INTERNAL ARCHITECTURE............................................................3-3
FIGURE 3–3. SYSTEM MEMORY MAP..................................................................................................... 3-8
FIGURE 4–1. PCI BUS DEVICES AND FUNCTIONS.....................................................................................4-2
FIGURE 4–2. PCI BUS CONNECTOR (32-BIT 5-VOLT TYPE).................................................................... 4-3
FIGURE 4–3. TYPE 0 CONFIGURATION CYCLE........................................................................................ 4-6
FIGURE 4–4. PCI CONFIGURATION SPACE MAP...................................................................................... 4-7
FIGURE 4–5. AGP 1X DATA TRANSFER (PEAK TRANSFER RATE: 266 MB/S)........................................ 4-12
FIGURE 4–6. AGP 2X DATA TRANSFER (PEAK TRANSFER RATE: 532 MB/S)........................................ 4-13
FIGURE 4–7. ISA BUS BLOCK DIAGRAM................................................................................................ 4-15
FIGURE 4–8. ISA EXPANSION CONNECTOR..........................................................................................4-16
FIGURE 4–9. MASKABLE INTERRUPT PROCESSING, BLOCK DIAGRAM.................................................... 4-22
FIGURE 4–10. CONFIGURATION MEMORY MAP.................................................................................... 4-28
FIGURE 5–1. 40-PIN IDE CONNECTOR. .................................................................................................5-8
FIGURE 5–2. 34-PIN DISKETTE DRIVE CONNECTOR.............................................................................. 5-13
FIGURE 5–3. SERIAL INTERFACES BLOCK DIAGRAM ............................................................................. 5-14
FIGURE 5–4. SERIAL INTERFACE CONNECTOR (MALE DB-9 AS VIEWED FROM REAR OF CHASSIS)........... 5-14
FIGURE 5–5. PARALLEL INTERFACE CONNECTOR (FEMALE DB-25 AS VIEWED FROM REAR OF CHASSIS).. 5-26
FIGURE 5–6. 8042-TO-KEYBOARD TRANSMISSION OF CODE EDH, TIMING DIAGRAM............................ 5-27
FIGURE 5–7. KEYBOARD OR POINTING DEVICE INTERFACE CONNECTOR............................................... 5-33
FIGURE 5–8. UNIVERSAL SERIAL BUS CONNECTOR (ONE OF TWO AS VIEWED FROM REAR OF CHASSIS)..... 5-35
FIGURE 5–9. AUDIO SUBSYSTEM BLOCK DIAGRAM .............................................................................. 5-37
FIGURE 5–10. ANALOG SIGNAL SAMPLING/QUANTIZING ...................................................................... 5-38
FIGURE 5–11. DAC OPERATION ......................................................................................................... 5-38
FIGURE 5–12. AUDIO SUBSYSTEM-TO-ISA BUS PCM AUDIO DATA FORMATS / BYTE ORDERING .......... 5-39
FIGURE 5–13. FM SYNTHESIS PATCH.................................................................................................. 5-40
FIGURE 5–14. AUDIO CONTROLLER-TO-ISA BUS FM AUDIO DATA FORMAT ........................................ 5-40
FIGURE 5–15. 10/100 TX NETWORK INTERFACE CONTROLLER BLOCK DIAGRAM ................................. 5-45
FIGURE 5–16. ETHERNET TPE CONNECTOR (RJ-45, VIEWED FROM CARD EDGE) ................................... 5-47
FIGURE 6-1. GRAPHICS SUBSYSTEM BLOCK DIAGRAM ............................................................................6-2
FIGURE 6-2. ATI 3D RAGE PRO TURBO AGP 2X GRAPHICS CONTROLLER ............................................6-3
FIGURE 6-3. VGA MONITOR CONNECTOR............................................................................................. 6-7
FIGURE 7–1. POWER DISTRIBUTION AND CONTROL, BLOCK DIAGRAM....................................................7-1
FIGURE 7–2. POWER CABLE DIAGRAM ..................................................................................................7-5
FIGURE 7–3. LOW VOLTAGE SUPPLY, BLOCK DIAGRAM.........................................................................7-6
FIGURE 7–4. SIGNAL DISTRIBUTION DIAGRAM.......................................................................................7-7
FIGURE 7–5. HEADER PINOUTS .............................................................................................................7-8