Viper 60s Installation guide

Models 608, 1258, and 150S
1/4-lnch Streaming Cartridge Tape Drive
.
, Theory of Operation and
Maintenance Manual
~J!YE' ____________ ---1

Viper® SCSI
Models 60S, 125S, and 150S
1/4-lncl1 Streaming Cartridge Tape Drive
Theory of Operation and
Maintenance Manual

I DATE
July, 1989
Dec., 1989
REVISION RECORD
REV REVISED PAGES
A
B
New
Page 3-5
ii
Manual Part Number 21981-001
Copyright © 1989 by Archive Corporation. All rights
reserved.
No part of this publication may be repro-
duced, stored in a retrieval system, or transmitted, in
any form
or by any means, electronic, mechanical,
photocopying, recording
or otherwise, without the
prior written permission of the publisher.
Archive
and Viper are registered trademarks of Ar-
chive Corporation.
Product features
and specifications described in this
manual are subject to change without notice.

VIPER SCSI 60, 125 & 150 THEORY OF OPERATION AND MAINTENANCE
PREFACE
Archive Viper tape drives are manufactured to ensure high performance in a 1/ 4-inch
streaming tapedrive. Viperenhanced mechanics
and performancefeatures include an embed-
ded controller in a half-high 5-1/4 inch form factor drive.
The
manual contains detailed technical information about Viper SCSI (Small Computer
Systems Interface) tape drives. SCSI technology provides a flexible environment by allowing
up to eight devices to be daisy chained. Archive Viperdrives conform to ANSI Specification
X3.31 and QIC tape format standards.
Archive's commitment to high quality
and advanced technology mean Viper tape drives are
efficient
and reliable for data backup in varied installations and environments.
iii

VIPER SCSI 60, 125 & 150 THEORY OF OPERATION AND MAINTENANCE
CONTENTS
Chapter 1
Introduction ...............................................................................................................................
1-1
1.1 Overview............................................................................................................................... 1-1
1.2 Viper Capacities ................................................................................................................... 1-1
1.3 PhYSical Description ........................................................................................................... 1-1
1.4 System Configurations....................................................................................................... 1-2
1.5 Viper Drive Models ............................................................................................................
1-3
1.6 About This Manual.............................................................................................................. 1-4
Chapter 2
Specifications...........................................................................................................................
2-1
2.1 Overview....................................... .... .................................................................................. 2-1
2.2 Physical Specifications ...................................................................................................... 2-1
2.3 Power Requirements ......................................................................................................... 2-2
2.3.1 Power Connector.......................................................................................................2-2
2.4 Drive Performance Specifications ................................................................................... 2-3
2.5 Environmental Specifications ............... .... ....................................................................... 2-4
2.6 Data Cartridge Specifications .......................................................................................... 2-4
2.6.1 Model 60S ..................................... .... ...... ................................................................... 2-4
2.6.2 Model
125S ................................................................................................................ 2-5
2.6.3 Model 150S ................................................................................................................ 2-5
2.7 Regulatory Compliance .................................................................................................... 2-5
2.8 ANSI X3.131 Conformance Statement............................................................................ 2-6
Chapter 3
Installation .................................................................................................................................
3-1
3.1 Introduction .......................................................................................................................... 3-1
3.2 Guidelines and Cautions .................................................................................................. 3-1
3.3 Unpacking and Inspection............................................................................................... 3-1
3.4 Installation .......................................................................................................................... 3-2
3.5 Internal Viper Drives...........................................................................................................3-2
3.5.1 Mounting Screws...................................................................................................... 3-2
3.5.2 Connectors................................................................................................................. 3-3
3.5.3 Jumper Configuration
........ ............................. .... ................. ..... .............................. 3-4
3.5.4 Operational Mode .................................................................................................... 3-4
3.5.5 Parity Enable ............................................................................................................. 3-4
3.5.6 Drive Identification .................................................................................................. 3-5
3.5.7 Selectable Buffer Disconnect....................................................................................3-5
3.6 Connecting External Vipers ...............................................................................................3-6
3.6.1 SCSI Drive Identification Switch .............................................................................3-7
v

VIPER SCSI 60, 125 & 150 THEORY OF OPERATION AND MAINTENANCE
Chapter 4
Interface .................................................................................................................................... 4-1
4.1 Overview..................................... ........ ................................................................................ 4-1
4.1.1 ANSI SCSI Bus Standards....................................................................................... 4-1
4.1.2 Signal Notation Conventions ................................................................................. 4-1
4.2
SCSI Bus Connector Signals ............................................................................................. 4-2
4.3 Signal Descriptions
.. .... ........................ .... ................................................ ..... ................. .... 4-3
4.4
Command Set Description............................................................................................... 4-4
4.5
SCSI Bus Protocol....................... ... ............................................. ... ..................................... 4-5
4.6 Waiting
and Control Phases............................................................................................. 4-6
4.6.1 Nonarbitrating Systems........................................................................................... 4-6
4.6.2 Arbitrating Systems ................................................................................................. 4-6
4.7 Selection
and Reselection Phases .................................................................................... 4-9
4.8 Information Transfer Phases ........................................................................................... 4-10
4.8.1 Asynchronous Data Transfer ................................................................................ 4-10
4.8.1.1 Transfer from Target to Initiator ................................................................. 4-11
4.8.1.2 Transfer from Initiator to Target ................................................................. 4-12
4.9
Command Phase ............................................................................................................... 4-13
4.10 Data Phase........................................................................................................................ 4-13
4.10.1 Data-In Phase ......................................................................................................... 4-13
4.10.2 Data-Out Phase...................................................................................................... 4-13
4.11 Status Phase ..................................................................................................................... 4-13
4.12 Message Phase................................................................................................................. 4-13
4.12.1 Message-In Phase .................................................................................................. 4-13
4.12.2 Message-Out Phase............................................................................................... 4-14
4.13 Con1mand Descriptor Block.......................................................................................... 4-14
4.14
SCSI Message Descriptions and Definitions............................................................... 4-16
4.15
SCSI Status Code Descriptions and Definitions......................................................... 4-19
4.16 Attention Condition ....................................................................................................... 4-21
4.17 Reset Condition............................................................................................................... 4-21
4.18 Unit Attention Condition .............................................................................................. 4-21
4.19 Buffered Mode................................................................................................................. 4-22
4.20 Imn1ediate Function ....................................................................................................... 4-22
4.21 Residual Length Function ............................................................................................. 4-22
4.22 Disconnect/Reconnect Function .................................................................................. 4-24
4.23 SCSI Memory Address Pointers ................................................................................... 4-25
4.23.1 Current Data Pointers........................................................................................... 4-25
4.23.2 Saved Data Pointers .............................................................................................. 4-25
4.24 Early Warning Function ................................................................................................ 4-25
4.25 Error Reporting ............................................................................................................... 4-26
4.25.1 Soft Errors............................................................................................................... 4-26
4.25.2
Hard Errors ............................................................................................................ 4-26
4.26
SCSI Bus Phase Timing .................................................................................................. 4-26
vi

VIPER SCSI 60. 125& 150 THEORY OF OPERATlON AND MAINTENANCE
Chapter 5
Viper SCSI Commands............................................................................................................ 5-1
5.1 Introduction ......................................................................................................................... 5-1
5.2 Descriptor Block .................................................................................................................. 5-2
5.2.1
Command Descriptor Block Format ...................................................................... 5-2
5.2.2
Command Descriptor Block Field Descriptions................................................... 5-2
5.2.3 Flag
and Link Bit Descriptions................................................................................ 5-3
5.3 TEST
LTNIT READY (OOh) .................................................................................................. 5-4
5.3.1 TEST
UNIT READ Command Descriptor Block .................................................. 5-4
5.3.2
Completion Status ..................................................................................................... 5-4
5.4 REWIND (Olh) .................................................................................................................... 5-5
5.4.1 REWIND
command Descriptor Block ................................................................... 5-5
5.4.2
Command Descriptor Block Field DescriAtion .................................................... 5-5
5.4.3
Completion Status ..................................................................................................... 5-5
5.5 REQUEST BLOCK ADDRESS (02h) ................................................................................ 5-6
5.5.1 REQUEST BLOCK ADDRESS
Command Descriptor Block .............................. 5-6
5.5.2
Command Descriptor Block Field .......................................................................... 5-6
5.5.3 REQUEST BLOCK ADDRESS Data
Format ......................................................... 5-6
5.5.4 REQUEST BLOCK ADDRESS Data Field Description........................................ 5-7
5.5.5
Completion Status..................................................................................................... 5-7
5.6 REQUEST SENSE ( 03h ) ...................................................................................................
5-S
5.6.1 REQUEST SENSE Command Descriptor Block ................................................... 5-S
5.6.2 Command Descriptor Block Field Description .................................................... 5-S
5.6.3 Extended Sense Data Format .................................................................................. 5-9
5.6.4
Extended Sense Data Field Descriptions ............................................................. 5-10
5.6.4 Extended Sense Data Field Descriptions Continued .......................................... 5-11
5.6.5 Priority and Definition of Sense Keys ...................................................................5-12
5.6.6
Completion Status ....................................................................................................5-13
5.7 READ BLOCK LIMITS (05h) ...........................................................................................5-14
5.7.1 READ BLOCK LIMITS
Command DeSCriptor Block .........................................5-14
5.7.2
Command Descriptor Block Field Descriptions ..................................................5-14
5.7.3 READ BLOCK LIMITS Data Format.....................................................................5-14
5.7.4
Completion Status....................................................................................................5-15
5.8 READ (aSh) .........................................................................................................................5-16
5.8.1 READ
Command Descriptor Block.......................................................................5-16
5.8.2
Command Descriptor Block Field Descriptions..................................................5-16
5.S.3 READ
Command Description................................................................................5-16
5.8.3.1
End of Data ......................................................................................................5-17
5.S.3.2 Filen·lark., .......................................................................................................5-17
5.8.3.3 Transfer Length Satisfied ..............................................................................5-17
5.8.3.4
End of Tape (EOT) ..........................................................................................5-17
5.8.3.5 Unrecoverable
Data Error .............................................................................5-17
5.8.4
Completion Status....................................................................................................5-18
5.9 WRITE (OAh) ......................................................................................................................5-19
5.9.1 WRITE
Command Descriptor Block .....................................................................5-19
vii

VIPER SCSI 60, 125 & 150 THEORY OF OPERATlON AND MAINTENANCE
5.9.2 Command Descriptor Block Field Descriptions ..................................................5-20
5.9.3 Completion Status....................................................................................................5-20
5.9.3 Completion Status Continued ............................................................................... 5-21
5.10 SEEK BLOCK (OCh) .........................................................................................................5-22
5.10.1 SEEK BLOCK Command Descriptor Block .......................................................5-22
5.10.2 Command Descriptor Block Field Descriptions................................................5-22
5.10.3 Completion Status..................................................................................................5-23
5.11 WRITE FILEMARKS (10h) .............................................................................................5-24
5.11.1 Write Filemark
Command Descriptor Block .....................................................5-24
5.11.2
Command Descriptor Block Field Descriptions................................................5-24
5.11.3 Completion Status..................................................................................................5-25
5.12 SPACE (11h) .....................................................................................................................5-26
5.12.1 SPACE Command Descriptor Block ...................................................................5-26
5.12.2 Command DeSCriptor Block Field Descriptions................................................5-27
5.12.3 Space-by-Count Functions ....................................................................................5-27
5.12.4 Space
by Position Functions .................................................................................5-28
5.12.5 Completion Status .................................................................................................. 5-28
5.13 INQUIRY (12h) .................................................................................................................5-30
5.13.1 INQUIRY command Descriptor Block................................................................5-30
5.13.2 Command Descriptor Block Field Description..................................................5-30
5.13.3 INQUIRY Command Data Format ...................................................................... 5-31
5.13.4 INQUIRY Command Data Field Descriptions .................................................. 5-31
5.13.5 Completion Status ..................................................................................................5-32
5.14 VERIFY (13h) .........................................................................................
.., .........................5-33
5.14.1 VERIFY Command Descriptor Block ..................................................................5-33
5.14.2
Command Descriptor Block Field .......................................................................5-33
5.14.3 Con1pletion Status.................................................................................................. 5-34
5.15 RECOVER BUFFERED DATA 04h) .............................................................................5-35
5.15.1 RECOVER BUFFERED DATA Command Descriptor Block ..........................5-35
5.15.2 Command Descriptor Block Field Descriptions ................................................5-35
5.15.3 Completion Status ..................................................................................................5-36
5.16 MODE SELECT (ISh) ....................................................................................:................. 5-37
5.16.1 MODE SELECT Command Descriptor Block.................................................... 5-37
5.16.2
Command Descriptor Block Field Description..................................................5-37
5.16.3 Parameter List
Header Format.............................................................................5-37
5.16.4 Parameter List Header Field Descriptions .........................................................5-38
5.16.5 Parameter List-Block DeSCriptor .......................................................................5-38
5.16.6 Parameter List-Block Descriptor Field Descriptions......................................5-39
5.16.7 Paranleter
List-Block Descriptor Field Descriptions......................................5-40
5.16.8 COlnpletion Status .................................................................................................. 5-41
5.17 RESERVE UNIT (16h) .....................................................................................................5-42
5.17.1 RESERVE UNIT Command Descriptor Block ...................................................5-42
5.17.2
Command Descriptor Block Field Descriptions................................................5-43
5.17.3 Completion Status..................................................................................................5-43
viii

VIPER SCSI 60, 125 & 150 THEORY OF OPERATION AND MAINTENANCE
5.18 RELEASE UNIT (17h) .....................................................................................................5-44
5.18.1 RELEASE UNIT Command Descriptor Block ...................................................5-44
5.18.2 Command Descriptor Block Field Descriptions................................................ 5-44
5.18.3 Completion Status..................................................................................................5-45
5.19 COpy (18h) .......................................................................................................................5-46
5.19.1 Command Descriptor Block ................................................................................. 5-46
5.19.2 Command Descriptor Block Field Description ................................................. 5-46
5.19.3 COpy Command Description ..............................................................................5-46
5.19.4 COPY Parameter List Header Block ...................................................................5-47
5.19.5 Parameter List Header Block Field Descriptions .............................................. 5-48
5.19.6 D/ A to SEQ Segment Descriptor.........................................................................5-48
5.19.6.1 D/ A to SEQ Segment Descriptor Block ....................................................5-49
5.19.6.2
D/ A to SEQ Segment Descriptor Field Descriptions..............................5-49
5.19.7 SEQ to
D/ A Segment Descriptor......................................................................... 5-50
5.19.7.1 SEQ to D/ A Segment Descriptor Block ....................................................5-50
5.19.7.2 SEQ to D/ A Segment Descriptor Field ~escriptions .............................. 5-51
5.19.8 SEQ to SEQ Segment Descriptor.......................................................................... 5-51
5.19.8.1 SEQ to SEQ Segment Descriptor Block .....................................................5-52
5.19.8.2 SEQ to SEQ Segment Descriptor Field Descriptions...............................5-53
5.19.9 Completion Status..................................................................................................5-54
5.20 ERASE (19h) .....................................................................................................................5-56
5.20.1 ERASE Command Descriptor Block ...................................................................5-56
5.20.2
Command Descriptor Block Field Descriptions................................................ 5-56
5.20.3 Completion Status..................................................................................................5-57
5.21 MODE SENSE (IAh) .......................................................................................................5-58
5.21.1 MODE SENSE Command Descriptor Block ......................................................5-58
5.21.2
Command Descriptor Block Field Description .................................................5-58
5.21.3 MODE SENSE Header Data Format ...................................................................5-58
5.21.4 MODE SENSE
Header Data Field Descriptions................................................5-59
5.21.5 Block Length DeSCriptor Field Descriptions ......................................................5-60
5.21.5.1Density Code, Byte 0 ....................................................................................5-60
5.21.5.2 Implicit Mode -Default Density Code Mode...........................................5-60
5.21.5.3 Explict Mode.................................................................................................. 5-61
5.21.5.4 Number of Blocks, Bytes 1 to 3................................................................... 5-61
5.21.5.5 Block Length, Bytes 5 to 7............................................................................ 5-61
5.21.6 Completion Status.................................................................................................. 5-62
5.22 LOAD/UNLOAD (IBh) ................................................................................................5-63
5.22.1 LOAD/UNLOAD Command Descriptor Block................................................5-63
5.22.2 Command Descriptor Block Field Descriptions................................................5-63
5.22.3 Completion Status ..................................................................................................
·5-64
5.23 SEND DIAGNOSTIC (1Dh) ...........................................................................................5-65
5.23.1 SEND DIAGNOSTIC Command Descriptor Block ..........................................5-65
5.23.2
Command Descriptor Block Field .......................................................................5-65
5.23.3 COlnpletion Status..................................................................................................5-66
ix

VIPER SCSI 60, 125 & 150 THEORY OF OPERATION AND MAINTENANCE
5.24 PREVENT/ ALLOW Media Removal (1Eh) .....,..........,....,..........................................5-67
5.24.1 PREVENT/ALLOW MEDIA REMOVAL
Command Descriptor Block .......5-67
5.24.2
Command Descriptor Block Field Description .................................................5-67
5.24.3 Completion Status..................................................................................................5-68
5.25 WRITE DATA BUFFER (3Bh) ........................................................................................5-69
5.25.1 WRITE DATA BUFFER
Command Descriptor Block ......................................5-69
5.25.2
Command Descriptor Block Field .......................................................................5-70
5.25.3 WRITE DATA BUFFER Data Header .................................................................5-70
5.25.4 Completion Status.................................................................................................. 5-71
5.26 READ DATA BUFFER (3Ch) .........................................................................................5-72
5.26.1 READ DATA BUFFER
Command Descriptor Block........................................5-72
5.26.2
Command Descriptor Block Field ....................................................................... 5-72
5.26.3 READ DATA BUFFER
Header ............................................................................5-73
5.26.4 READ DATA BUFFER
Header Field ..................................................................5-73
5.26.5 Completion Status..................................................................................................5-73
Chapter 6
Theory of Operations .............................................................................................................. 6-1
6.1 Overview .............................................................................................................................. 6-1
6.2 Printed Circuit Board ......................................................................................................... 6-1
6.2.1 Basic VLSI Controller................................................................................................ 6-3
6.2.2 Write and Erase Circuits .......................................................................................... 6-5
6.2.3 Read Circuits.............................................................................................................. 6-6
6.2.4 Tape Hole Sensor....................................................................................................... 6-7
6.2.5 Phase Lock Loop........................................................................................................ 6-7
6.2.6 Reset Circuits ............................................................................................................. 6-7
6.3 Data Transfer ....................................................................................................................... 6-8
6.3.1 Erase Operation ......................................................................................................... 6-8
6.3.2 Write Data (Backup) Operation .............................................................................. 6-9
6.3.3 Read Data (Restore) Operation ..............................................................................6-10
6.4 Drive Mechanics ................................................................................................................6-10
6.4.1 Loading Mechanism ................................................................................................6-10
6.4.2 Cartridge Loading....................................................................................................6-10
6.4.3 Cartridge Removal ................................................................................................... 6-11
6.4.4 Tape Motion .............................................................................................................. 6-11
6.5 Sensors/Interlocks............................................................................................................. 6-11
6.5.1 Cartridge Switch Assembly .................................................................................... 6-11
6.5.2 Write Protect .............................................................................................................6-12
6.5.3
Tape Hole Sensors....................................................................................................6-12
6.6 Motor Driver Printed Circuit Board ...............................................................................6-12
6.6.1 Interface .....................................................................................................................6-13
6.6.2 Motor Controller
LSI ................................................................................................6-14
6.6.3 EPROM Interface......................................................................................................6-16
6.7
Head Assembly ..................................................................................................................6-16
6.7.1 Read/Write Head Operation .................................................................................6-16
6.7.2 Serpentine Recording ..............................................................................................6-18
x

VIPER SCSI 60, 125& 150 THEORY OF OPERATION AND MAINTENANCE
6.8 Firmware ............................................................................................................................. 6-21
6.8.1 Write Error Recovery............................................................................................... 6-21
6.8.2 Write Buffer Underrun ............................................................................................6-23
6.8.3 Read Buffer
Underrun ............................................................................................. 6- 23
6.8.4 Read Data Errors ......................................................................................................6-24
6.8.5 Streaming Termination............................................................................................6-24
6.9 Data Cartridge ....................................................................................................................6-26
6.9.1 Tape Operation .........................................................................................................6-28
6.9.2 Recording...................................................................................................................
6-28
6.9.2.1 Preamble .......................................................................................................... 6-29
6.9.2.2 Data Block Marker.......................................................................................... 6-29
6.9.2.3 Data Block ........................................................................................................6-29
6.9.2.4 Block
Address ..................................................................................................6-30
6.9.2.5 Cyclical Redundancy Check ......................................................................... 6-31
6.9.2.6 Postamble......................................................................................................... 6-31
6.9.2.7 Format Differences .........................................................................................6-32
Chapter 7
Maintenance and Relaibility .................................................................................................. 7-1
7.1 Maintenance ........................................................................................................................ 7-1
7.2 Tape Drive Cleaning .......................................................................................................... 7-1
7.2.1 Cleaning Supplies ..................................................................................................... 7-2
7.2.2 Cleaning the Tape Drive Heads .............................................................................. 7-2
7.3 Reliability .............................................................................................................................
7-3
7.4 Reporting a Problem ...........................................................................................................7-4
Glossary ..................................................................................................................................... G-1
Index .......................................................................................................................................... I-1
xi

VIPER SCSI 60, 125 & 150 THEORY OF OPERA TlON AND MAINTENANCE
FIGURES
Figure 1-1. SCSI Bus Support Configurations ........................................................................1-2
Figure
1-2. Top View of Viper Drive.........................................................................................1-3
Figure
1-3. Front View of Viper External Drive ...................................................................... 1-3
Figure 3-1. Internal Installation..................................................................................................3-2
Figure
3-2. Mounting Hole Locations .......................................................................................3-3
Figure 3-3. Viper Rear View .......................................................................................................3-3
Figure 3-4. Configuration
Jumper Block ..................................................................................3-4
Figure 3-5. External Installation.................................................................................................3-6
Figure 3-6. Viper External Interface Connectors
and ID Switch........................................... 3-6
Figure 3-7. Viper SCSI Daisy-Chain Diagram .........................................................................3-7
Figure
4-1. Phase Sequencing with Nonarbitration................................................................4-6
Figure
4-2. Phase Sequencing with Arbitration.......................................................................4-7
Figure
4-3. Arbitration and Selection Phase Signal Timing ..................................................4-7
Figure
4-4. Signals Used in Transfer from Target to Initiator ............................................. 4-11
Figure 4-5. Signals Used in Transfer from Initiator to Target .............................................4-12
Figure
6-1. Viper Drive Functional Block Diagram ................................................................ 6-2
Figure 6-2. Cartridge Loading................................................................................................. 6-11
Figure 6-3. Motor Driver PCB Block Diagram....................................................................... 6-13
Figure
6-4. Motor Controller LSI Functional Block Diagram..............................................6-14
Figure
6-5. Read/Write/Erase Magnetic Head Configuration...........................................6-16
Figure
6-6. Typical Serpentine Recording .............................................................................. 6-18
Figure
6-7. Track Positioning ...................................................................................................6-19
Figure
6-8. Serpentine Recording: 9- Track.............................................................................6-19
Figure
6-9. Serpentine Recording: IS-Track' ..........................................................................6-20
Figure 6-10. Serpentine Recording: 18- Track .......................................................................... 6- 20
Figure 6-11. Read After Write Error Sequence ....................................................................... 6- 21
Figure 6-12. Data Cartridge, Exploded View..........................................................................6-27
Figure
6-13. Recorded Block Format ........................................................................................ 6-28
Figure 6-14. Block Address Definition ..................................................................................... 6-30
Figure 7-1. Head and Sensor Cleaning ...................................................................................... 7-3
xii

VIPER SCSI 60, 125 & 150 THEORY OF OPERATION AND MAINTENANCE
TABLES
Table 1-1. Viper Streaming Tape Drive Storage Capacities.................................................... 1-1
Table 3-1. SCSI ID Selection.........................................................................................................3-5
Table 3-2. Buffer Disconnect Size Selection...............................................................................3-5
Table 4-1. SCSI Signal Locations on Drive Connector.............................................................4-2
Table
4-2. SCSI Interface Signals................................................................................................. 4-3
Table 4-3. Group 0 Commands for SCSI Bus Sequential Access Devices ............................ 4-4
Table 4-4. Operational Phases ..................................................................................................... 4-5
Table 4-5. Arbitration Phase Protocal ........................................................................................4-8
Table 4-6. Informtion Transfer Phases .....................................................................................
4-10
Table 4-7. Command Descriptor Block Format ......................................................................4-14
Table
4-8. CDB Fields Common to group 0 and 1 Commands ............................................4-15
Table
4-9. SCSI Message Codes.................................................................................................4-16
Table 4-10. SCSI Message Definitions.............................................................................4-17, 4-18
Table 4-11. Status
Code Definitions ........................................................................................ 4-19
Table 4-12. Status Code Block Format ....................................................................................
4-20
Table 4-13. SCSI Status Code Descriptions .............................................................................4-20
Table 4-14. SCSI Bus Sequence Timing...................................................................................4-27
Table
5-1. SCSI Commands for Bus Sequential Access Devices ........................................... .5-1
Table 6-1. VLSI Features ....................................................................................................... 6-3, 6-4
Table 6-2. Motor Controller LSI Functions ....................................................................6-14, 6-15
Table 6-4. Streaming Termination Description .............................................................6-24, 6-25
xiii

VIPER SCSI 60, 125 & 150 THEORY OF OPERATION AND MAINTENANCE
TABLES
Table 1-1. Viper Streaming Tape Drive Storage Capacities.................................................... 1-1
Table 3-1. SCSI ID Selection......................................................................................................... 3-5
Table 3-2. Buffer Disconnect Size Selection............................................................................... 3-5
Table 4-1. SCSI Signal Locations on Drive Connector.............................................................4-2
Table
4-2. SCSI Interface Signals................................................................................................. 4-3
Table 4-3. Group a Commands for SCSI Bus Sequential Access Devices ............................ 4-4
Table 4-4. Operational Phases ..................................................................................................... 4-5
Table 4-5. Arbitration Phase Protocal ........................................................................................ 4-8
Table 4-6. Informtion Transfer Phases ..................................................................................... 4-10
Table 4-7. Command Descriptor Block Format ...................................................................... 4-14
Table 4-8. CDB Fields Common to group a and 1 Commands ............................................4-15
Table
4-9. SCSI Message Codes................................................................................................. 4-16
Table 4-10. SCSI Message Definitions.............................................................................4-17, 4-18
Table 4-11. Status Code Definitions ........................................................................................ 4-19
Table 4-12. Status Code Block Format .................................................................................... 4-20
Table 4-13. SCSI Status Code Descriptions ............................................................................. 4-20
Table 4-14. SCSI Bus Sequence Timing................................................................................... 4-27
Table 5-1. SCSI Commands for Bus Sequential Access Devices ...........................................
Table
6-1. VLSI Features ....................................................................................................... 6-3, 6-4
Table 6-2. Motor Controller LSI Functions ....................................................................6-14, 6-15
Table 6-4. Streaming Termination Description ............................................................. 6-24, 6-25
xiii

1.1 Overview
CHAPTER 1
INTRODUCTION
INTRODUCTION
Archive's Vipe~ SCSI models 60S, 125S, and 150S are 1/4-inch streaming tape drives that
provide reliable and cost-efficient backup for high-capacity Winchester disk drives. Other
applications include software distribution, transaction logging, data collection, data ex-
change, and program loading. Viper SCSI drives, featuring LSI circuitry and surface-mount
technology, conform
to ANSI X3.131 and QIC format standards. Backward read compatibility
with previous Archive drives is standard with all Viper models.
1.2 Viper Capacities
Viper drives are available in internal and external models. Storage capacity varies from 45
megabytes to 150 megabytes. Table 1-1 shows the capacity for each model.
Table 1-1. Viper Streaming Tape Drive Storage CapaCities
VIPER MODEL STORAGE CAPACITY
60S1
* 45 or 60 megabytes
125S1
125 megabytes
150S1 * 125 or 150 megabytes
Viper60E
60 megabytes
Viper 150E 150 megabytes
I
*Formatted capacity is determined by type of data cartridge used. Refer to
Chapter 2 for data cartridge specifications.
1.3 Physical Description
The Viper drive consists of multiple mechanical subassemblies, two electrical assemblies
(PCB's),
and a front bezel. All are assembled in a half-height, 5 1/4-inch drive chassis
configured
to fit inside a standard half-height floppy disk slot.
1-1

VIPER SCSI 60, 125 & 150 THEORY OF OPERATION AND MAINTENANCE
1.4 System Configurations
TheSCSI standard supports up to eight IDs. These IDs can refer to host adapters or peripheral
devices
such as printers, magnetic disks, optical disks, or tape drives. Figure 1-1 shows
examples of SCSI systems.
•
-
SCSI Bus -Viper
Computer Host
System Adapter
.......
,. Drive
•
SINGLE INITIATOR· SINGLE TARGET
Computer Host
1-
SCSI Bus .....
Viper
System Adapter
......
,..
Drive
•
SINGLE INITIATOR -MULTI TARGET Magnetic
....
Disk,
,. Printer,
or
Optical
Disks
Computer Host
.,
SCSI Bus"
Viper
System Adapter
-. ...
Drive
Magnetic
-Disk,
,.
Printer, or
Optical
Disks
Magnetic
..... Disk•
,.
Printer, or
Optical
Disks
1-
Magnetic
Computer Host -Disk,
System Adapter
......
,..
Printer, or
Optical
Disks
MULTI INITIATOR -MULTI TARGET
Figure 1-1. SCSI Bus Support Configurations
1-2

INTRODUCTION
1.5 Viper Drive Models
Figure 1-2 shows a top view of a Viper Internaldrive and its subassemblies. Figure 1-3 shows
a front view of a Viper external drive.
BELT DRIVE SYSTEM CAPSTAN DRIVE MOTOR
HEAD ACTUATOR MECHANISM
MOTOR DRIVER BOARD
CAPSTAN ASSEMBLY
--CHASSIS
BEZEL
Figure 1·2. Top View of Viper Drive
Figure 1-3. Front View of Viper External Drive
1-3

VIPER SCSI 60, 125& 150 THEORY OF OPERATION AND MAIfv1ENANCE
1.6 About This Manual
The remaining chapters in this manual are described briefly in the table below.
Table 1-2. Chapter Descriptions
CHAPTER CHAPTER
NUMBER
TITLE DESCRIPTION
2
Specifications
Contains the physical, performance, environmental,
power, data and tape handling, tape cartridge
I
specification tables, and SCSI conformance statement.
I 3
Installation
I
Contains guidelines, cautions, unpacking tips, and
I
inspection information.
4 I
Interface
I
Describes the Viper SCSI interface including signals, pin
assignments, and timing.
5
Viper SCSI
I
Individually describes the SCSI sequential access device
Commands commands used in the Viper drive.
6
Theory of
Details the functional operation of each assembly of the
Operation Viper drive with descriptions of the tape drive cartridge
and media formats.
I 7
Maintenance and Gives preventive maintenance schedule and procedures.
Reliability Also included in this chapter is information about reporting
I
IJfUUltllIll:!.
I
1-4

2.1 Overview
CHAPTER 2
SPECIFICATIONS
SPECIFICATlONS
Archive Viper SCSI drives provide reliable backup for microcomputer data. This chapter
includes technical specifications for all Viper models. Information included describes the
following specifications
and requirements.
• Physical Specifications
• Power Requirements
• Drive Performance Specifications
• Environmental Requirements
• Data Cartridge Specifications
• Regulatory Compliance
• SCSI Conformance Statement
2.2 Physical Specifications
DIMENSION
CONFIGURATION
SPECIFICATION
US
METRIC
Internal
Height
1.625 in
41.27 mm
Width
5.750 in
146.00 mm
Depth
8.000 in 203.20 mm
Weight
3.0001b 1.36 kg
External Height
3.500 in 89.00 mm
Width
6.600 in 168.00 mm
Depth
11.400 in
290.00 mm
Weight 8.0001b 3.65 kg
2-1

VIPER SCSI60, 125& 150 THEORY OF OPERATION AND MAINTENANCE
2.3 Power Requirements
I
POWER SUPPL Y VOLTAGE
SPECIFICATION +12 VOLTS
+5 VOLTS
I
Tolerance (inc!. max. ±10% ±5%
I
ripple of 100 mV)
Standby Current 0.2 Amps nominal 1.1 Amps nominal
Operational Current 0.8 Amps nominal 1.1 Amps nominal
I
1.7 Amps maximum
1.5 Amps maximum
I
Tape Start Surge 2.5 Amps maximum
i
(up to 300 msec)
Power Dissipation 9.6 Watts typical 5.5 Watts typical
(operational) 22.4 Watts maximum
7.8 Watts maximum
i
33 Watts maximum
i
(tape start surge)
2.3.1 Power Connector
FEATURE
SPECIFICATION
Input Connector AMP 641737-1
Mating Connector
AMP 1-480424-0
Pins
AMP 60617-1
PIN
I
ASSIGNMENT
i
1
+12 VDC
2
+12 Retum
3
+5 Retum
4
+5 VDC
2-2