Seagate STT20000A User manual

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STT20000A
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ATAPI Minicartridge Drive
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Product Manual
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© 1998 Seagate Technology, Inc. All rights reserved
No part of this publication may be reproduced in any form without written permission from Seagate
Technology, Inc.
Publication Number
10005136-001
, March 1998
Seagate, Seagate Technology, the Seagate logo and Sidewinder are trademarks or registered trademarks of
Seagate Technology, Inc. Other product names are trademarks or registered trademarks of their owners.
Seagate reserves the right to change, without notice, product offerings or specifications. Seagate Technology
provides this manual "as is," without warranty of any kind, either expressed or implied, including, but not limited to,
the implied warranties of merchantability and fitness for a particular purpose. Seagate Technology assumes no
responsibility for the accuracy, completeness, sufficiency, or usefulness of this manual, nor for any problem that
might arise from the use of the information in this manual.

FCC Notice
This equipment generates and uses radio frequency energy and, if not installed and used properly—that is, in strict
accordance with the manufacturer's instructions—may cause interference to radio communications or radio and
television reception. It has been tested and found to comply with the limits for a Class B computing device in
accordance with the specifications in Part 15 of FCC Rules, which are designed to provide reasonable protection
against such interference in a residential installation. However, there is no guarantee that interference will not occur
in a particular installation. If this equipment does cause interference to radio or television reception, which can be
determined by turning the equipment on and off, you are encouraged to try to correct the interference by one or
more of the following measures:
• Reorient the receiving antenna.
• Relocate the computer with respect to the receiver.
• Move the computer into a different outlet so that the computer and receiver are on different branch
circuits.
If necessary, you should consult the dealer or an experienced radio/television technician for additional suggestions.
You may find the following booklet prepared by the Federal Communications Commission helpful:
How to Identify
and Resolve Radio-TV Interference Problems
This booklet (Stock No. 004-000-00345-4) is available from the U.S. Government Printing Office, Washington, DC
20402.
Caution. Changes or modifications made to this equipment which have not been expressly approved
by Seagate Technology may cause radio and television interference problems that could void
the user's authority to operate the equipment.
Further, this equipment complies with the limits for a Class B digital apparatus in accordance with Canadian Radio
Interference Regulations.
Cet appareil numérique de la classe B est conforme au Règlement sur brouillage radioélectrique, C. R. C., ch.
1374.
Additional warnings:
• To prevent fire or electrical shock hazard, do not expose the unit to rain or moisture.
• To avoid electrical shock, do not open the cabinet. Refer servicing to qualified personnel.

Important Information About This Manual
All information contained in or disclosed by this document is considered proprietary by Seagate Technology. By
accepting this material, the recipient agrees that this material and the information contained therein are held in
confidence and in trust and will not be used, reproduced in whole or in part, nor its contents revealed to others,
except to meet the purpose for which it was delivered. It is understood that no right is conveyed to reproduce or
translate any item herein disclosed without express written permission from Seagate Technology.
Seagate Technology provides this manual "as is," without warranty of any kind, either expressed or implied,
including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. Seagate
Technology reserves the right to change, without notification, the specifications contained in this manual.
Seagate Technology assumes no responsibility for the accuracy, completeness, sufficiency, or usefulness of this
manual, nor for any problem that might arise from the use of the information in this manual.

Table of Contents
STT20000A Product Manual Page v
Table of Contents
Introduction 1
Drive overview........................................................................................................ 1
Features................................................................................................................. 3
Typical system configurations................................................................................. 4
Minicartridge technology overview........................................................................... 4
Flash EEPROM...................................................................................................... 5
Software................................................................................................................. 5
References............................................................................................................. 5
About this manual................................................................................................... 6
Specifications 7
Overview ................................................................................................................ 7
Physical specifications............................................................................................ 7
Power specifications............................................................................................... 9
Performance specifications................................................................................... 10
Environmental requirements ................................................................................. 11
Reliability.............................................................................................................. 12
Mean-Time-Between Failures......................................................................... 12
Mean-Time-To-Repair .................................................................................... 12
Recommended tapes............................................................................................ 13
Regulatory compliance.......................................................................................... 13
Installation 15
Introduction........................................................................................................... 15
Before you begin................................................................................................... 15
Handling guidelines......................................................................................... 15
Setting jumpers..................................................................................................... 16
Installing the drive................................................................................................. 17
Mounting dimensions............................................................................................ 18
ATA-2 Interface pin assignments.......................................................................... 20
Drive operation and maintenance 23
Introduction........................................................................................................... 23
Front panel LED.................................................................................................... 23
Using Travan cartridges........................................................................................ 24
Loading and unloading cartridges ................................................................... 24

Table of Contents
Page vi STT20000A Product Manual
Setting the write–protect switch ...................................................................... 25
Loading revised firmware via Seagate firmware cartridge...................................... 26
Drive maintenance................................................................................................ 27
Caring for tape cartridges ............................................................................... 27
Cleaning the drive read/write head.................................................................. 27
Troubleshooting.................................................................................................... 28
ATAPI interface 31
Introduction........................................................................................................... 31
ATA-2 Interface .................................................................................................... 31
ATA-2 Signals ................................................................................................ 31
DASP-...................................................................................................... 31
PDIAG-.................................................................................................... 31
ATA registers ................................................................................................. 32
Status Register......................................................................................... 32
Error Register........................................................................................... 33
Feature Register ...................................................................................... 33
Supported ATA Commands............................................................................ 34
Execute Drive Diags (90h)........................................................................ 34
Idle Immediate (E1h)................................................................................ 34
Standby Immediate (E0h)......................................................................... 34
Check Power Mode (E5h)......................................................................... 34
Sleep (E6h).............................................................................................. 34
Set Features (EFh)................................................................................... 35
ATAPI Identify Device (A1h)..................................................................... 36
ATAPI Packet Command (A0h)................................................................ 37
ATAPI Soft Reset (08h)............................................................................ 37
ATAPI interface .................................................................................................... 38
Reserved Fields.............................................................................................. 39
Erase command.................................................................................................... 40
Inquiry command.................................................................................................. 41
Load/Unload command......................................................................................... 42
Locate command.................................................................................................. 43
Log Select command............................................................................................ 44
Log Sense command............................................................................................ 45
Error Counter Page (Read)............................................................................. 46
Tape Capacity Page Code.............................................................................. 47
Mode Select command ......................................................................................... 49
Mode Sense command......................................................................................... 50
Mode Parameter Header ................................................................................ 50

Table of Contents
STT20000A Product Manual Page vii
Mode Block Descriptor.................................................................................... 51
Mode Medium Partition Page.......................................................................... 52
Mode Capabilities and Mechanical Status Page.............................................. 52
Mode Tape Parameters Page......................................................................... 53
Read command .................................................................................................... 54
Read Position command....................................................................................... 55
Request Sense command..................................................................................... 57
Rewind command................................................................................................. 59
Space command................................................................................................... 60
Test Unit Ready command.................................................................................... 61
Write command .................................................................................................... 62
Write Filemark command...................................................................................... 63
Write Buffer (download microcode) command....................................................... 64
Tape format 65
Introduction........................................................................................................... 65
Tape partitioning................................................................................................... 65
Track positions ..................................................................................................... 65
Track numbering................................................................................................... 66
Track format......................................................................................................... 66
Frames........................................................................................................... 66
Blocks ............................................................................................................ 68
Tape reference servo pattern................................................................................ 68
Write equalization ................................................................................................. 69
Randomization...................................................................................................... 69
Theory of operations 71
Overview .............................................................................................................. 71
Block diagram....................................................................................................... 71
Drive mechanisms ................................................................................................ 72
Mechanics...................................................................................................... 72
Cartridge-load mechanism.............................................................................. 72
Capstan/drive-motor assembly ....................................................................... 72
Chassis .......................................................................................................... 72
Control circuits...................................................................................................... 72
Head design ......................................................................................................... 73
Flash EEPROM.................................................................................................... 73
Sensors and switches........................................................................................... 73
Drive media (Travan minicartridges)...................................................................... 74

Table of Contents
Page viii STT20000A Product Manual
Glossary 75
Acronyms and measurements 78
Acronyms and abbreviations................................................................................. 78
Units of measurement........................................................................................... 80

Introduction Chapter 1
STT20000A Product Manual Page 1
Introduction
Drive overview
The Seagate STT20000A extends the Seagate family of one-inch high, DC2000
drives that feature high performance, high reliability, and quiet operation. The drive
transfers data at up to 60 megabytes per minute (Mbytes/min) without compression.
With optimal system resources and compressible data structures, nominal transfer
rates of up to 120 Mbytes/min can be observed using software data compression
(assumes 2:1 compression ratio).
System optimizations include but are not limited to allocating the maximum amount
of the base 640 Kbytes of memory available
Data compression is available within the Seagate Backup software package for
DOS and Windows and typically provides for up to a 2:1 compression ratio. The
compression ratio is dependent on the specific system and the nature of the files
being compressed.
This drive optimizes throughput through the Seagate feature FastSenseTM. This
feature enables the drive to automatically sense the fastest supportable data
transfer rate of the host system and choose a transfer speed of either 1,000, 733, or
489 kilobytes/second (Kbyte/sec). This process maximizes system throughput by
eliminating tape repositioning, which is typically required when the tape drive
operates faster than the host computer.
The product is available as an internal device in either a 3.5-inch or half-high 5.25-
inch configuration. The drive form factors are tailored for easy installation in today's
computers.
The drive supports the QIC-3220-MC format standard and will provide 10 gigabytes
uncompressed storage capacity, 20 gigabytes compressed, with a Travan TR-5
cartridge.
The drive will also read tapes conforming to the QIC-3095 standard.
A precision burst intelligent positioning system is used to achieve high track
densities.
1

Chapter 1 Introduction
Page 2 STT20000A Product Manual
The STT20000A conforms to the QIC-3220-MC development standard adopted by
Quarter-Inch Cartridge Drive Standards Inc. (QIC). The drive records in a serpentine
fashion utilizing a 1,7 RLL (Run Length Limited) data encoding method, and
provides for 108 data tracks and one (1) directory track on Travan TR-5 media.
The drive offers electronically erasable, programmable, read-only memory (flash
EEPROM), which enables qualified Seagate OEMs to download revised firmware to
the drive.
With the availability of greater capacity disk drives and the growth of small networks,
the need for cost-effective, high-capacity storage has grown. The STT20000A is
ideal for high-end standalone computers, workstations, and small networks.
Built using long-wearing materials and custom Large Scale Integration (LSI)
components, the ATAPI drive was engineered for heavy-duty computer applications.
Providing carefully controlled tape handling and rapid, smooth operation, the design
promotes long life for key components such as the motors, drive heads, and the
media itself. One major benefit of this new, computer grade engineering is low
power consumption.
Figure 1-1 illustrates the STT20000A ATAPI minicartridge internal drive. Figure 1-2
illustrates the internal drive equipped with mounting brackets.
Figure 1-1
STT20000A internal drive without mounting brackets

Introduction Chapter 1
STT20000A Product Manual Page 3
Figure 1-2
Internal STT20000A with mounting brackets
Features
The STT20000A embodies Seagate 's commitment to engineer reliable and durable
tape drive products. Key features of the drive are as follows:
• Internal form factor for installation in a 5.25-inch half-high or 3.5-inch by one-
inch space
• Capability to write and read Travan TR-5 (QIC-3220-MC) media, as well as read
TR-4 media conforming to the QIC-3095 standard
• QIC-3220-MC tape format compliance for compatibility and information
interchange
• Typical uncompressed capacities of 10 gigabytes on 740 foot TR-5 media
• Typical compressed capacities of 20 gigabytes on 740 foot TR-5 media
• Transfer rate optimized with
FastSense
—automatic selection of fastest
supportable data transfer rate (1,000, 733, or 489 Kbyte/sec)
• ATAPI interface that supports DMA and PIO modes 0, 1, or 2 with 512 Kbytes
on-drive data buffer to facilitate the most efficient use of the host computer and
tape drive.
• Uncorrectable error rate of less than 1 in 1015 bits
• Flash EEPROM to enable electrically upgradeable drive firmware
• Custom Seagate -designed LSI circuitry to reduce component count and boost
drive reliability
• Low power consumption—less than 15.0 Watts (typical) for internal drives

Chapter 1 Introduction
Page 4 STT20000A Product Manual
Typical system configurations
The Enhanced IDE standard supports up to four ATAPI peripherals: two devices on
the primary port and two devices on the secondary port. Of the two devices, one
must be slave to the other, which is the master. Figure 1-3 shows sample
configurations for two ATAPI systems.
Figure 1-3
Sample ATAPI configurations
Minicartridge technology overview
Having evolved from the original mass-storage medium—reel-to-reel, 1/2-inch tape
storage—the minicartridge technology of today offers fast, efficient, high-capacity
storage in a compact, easy-removable hard-shell package. In little more than a
decade, storage capacities have increased from some 60 megabytes (Mbytes) on 9
tracks (QIC-24, 1982) to the to the 20 Gbyte capacity achievable with the
STT20000A minicartridge drive on a single Travan TR-5 cartridge.
The streaming-tape intelligence in the STT20000A provides a continuous tape
motion with an uninterrupted, precisely coordinated flow of data to and from the
minicartridge. This "streaming" motion combined with the "serpentine" recording
method is one element that contributes to the increased storage capacities,
efficiency, and speed of today's minicartridge technology.
Use of the "serpentine" recording method exploits the bi-directional capabilities of
the cartridge. With this method, the tape is not rewound at the end of a track.
Computer
system Enhanced IDE
controller
Primary
IDE bus
Secondary
IDE bus
Hard
disc CD-ROM
(master)
STT20000A
(slave)
Computer
system Enhanced
IDE
controller
Primary
IDE bus
Secondary
IDE bus
Hard
disc
Acculogic
IDE
controller
STT20000A

Introduction Chapter 1
STT20000A Product Manual Page 5
Instead, the write-read heads are logically or mechanically switched to a different
position on the tape and another track is written or read in the reverse direction.
That is, the drive first records track 1 in one direction and when the end of the tape
is reached, the head is moved and the direction of tape motion is reversed to record
track 2. This serpentine process continues until the entire tape is recorded. The
individual tracks are sequential to minimize the amount of head motion as the heads
change position for each track.
Flash EEPROM
The STT20000A incorporates leading-edge technology in the flash EEPROM, which
is useful should the drive's firmware need to be upgraded at some point. With the
permanently installed, electrically upgradeable, flash EEPROM memory, revised
firmware for the drive can be loaded via any one of two methods:
• Seagate OEM firmware cartridge (See chapter 4)
• Host IDE bus
This feature enables qualified OEMs needing to revise the drive firmware to do so
rapidly and at a reduced cost. Flash EEPROM should also prolong the life cycle of a
drive because many new techniques—such as increasing the capacity of the drive
through support for longer tapes—may require only a firmware upgrade.
Software
The STT20000A is a cost-effective means of backing up fixed disks. The drive is
compatible with DOSTM version 5.0 or later, Microsoft WindowsTM 3.1 or later,
Microsoft Windows 95, or Windows NT and will operate with many of the popular
backup software applications such as Seagate 's Backup for DOS and Windows,
Windows 95, NetWare, or Windows NT.
References
The following standards documents describe some of the technology incorporated in
the drives referenced in this manual.
• QIC-170—Preformatted magnetic minicartridge
• QIC-157—ATAPI command set for streaming tape
• QIC-3095-MC—Serial recorded magnetic tape minicartridge (TR-4)
• QIC-3220-MC—Serial recorded magnetic tape minicartridge (TR-5)
For more information about a particular QIC standard, contact Quarter-Inch
Cartridge Standards, Inc., c/o Freeman Associates, 311 East Carrillo Street, Santa
Barbara, California 93101.

Chapter 1 Introduction
Page 6 STT20000A Product Manual
About this manual
The remaining chapters and the appendices in this manual are briefly described in
the following table. A glossary of terms is also included.
Chapter Title Description
2Specifications Contains physical, performance, environmental,
reliability, power, and minicartridge specification
tables.
3Installation Provides cautions, unpacking tips, inspection
information, and installation/connection steps
including cabling requirements and connector
pinouts.
4Drive operation and
maintenance Explains the simple operation of the drive.
5ATAPI Interface Lists general information about the interface.
6Tape format Provides an overview of the QIC-3220 tape
format.
7Theory of operation Details the functional operation of various
assemblies of the ATAPI drive.
Appendix A Glossary Defines key terms.
Appendix B Acronyms and
measurements Lists the acronyms and measurements used in the manual.

Specifications Chapter 2
STT20000A Product Manual Page 7
Specifications
Overview
The STT20000A provides exceptional reliability in storing large amounts of
computer data. This chapter includes the following specifications and requirements:
• Physical specifications
• Power requirements
• Drive performance specifications
• Environmental requirements
• Recommended tapes
• Tape capacities and formats
• Regulatory compliance
Physical specifications
The physical specifications of the STT20000A are listed in the following table.
Specification Drive for 3.5-Inch Mount Drive for 5.25- Inch Mount
Height 1.0 in/ 25 mm 1.7 in/ 43 mm
Width 4.0 in/102 mm 5.87 in/149.1 mm
Length 6.36 in/161.5 mm 6.51 in/165.5 mm
Weight 1.0 lbs/0.5 kg 1.5 lbs/0.7 kg
Figures 2-1 and 2-2 show the general dimensions of the STT20000A in 3.5-inch
configuration (without mounting brackets) and in the 5.25-inch configuration (with
mounting brackets).
2

Chapter 2 Specifications
Page 8 STT20000A Product Manual
Figure 2-1
STT20000A (3.5-Inch mount) general dimensions
4.00 in (101.6 mm)
6.36 in (161.5 mm)
0.157 in
(4 mm)
4.00 in (101.6 mm)
1.00 in
(25.4 mm)
Figure 2-2
STT20000A (5.25-Inch mount) general dimensions
1.685"
(42.8mm)
5.87"
(149.0mm)
0.20" (5.0mm)
0.86" (21.8mm)
5.76" (146.4mm)5.49" (139.4mm)
DRIVE ACTIVE
(GREEN)

Specifications Chapter 2
STT20000A Product Manual Page 9
Power specifications
The following table lists the power specifications for the STT20000A. (Power
specifications are measured at the tape drive power connector and are nominal
values.)
Specification Measurement
DC Voltage +12 VDC +5 VDC
Voltage Tolerance ± 10% ± 5%
Operational Current 2.0 amps 1.0 amp
Standby Current 0.2 amp 0.6 amp
Peak 2.2 amps max. —
Power Sequence None None
Ripple (peak to peak) ≤100 mV ≤100 mV
Power use
(nominal) < 15 Watts
(excluding surge) < 15 Watts (excluding surge)
The following table lists pin assignments for the power connector for the drive.
Pin Assignment
1+12 VDC
2+12 return
3+5 return
4+5 VDC

Chapter 2 Specifications
Page 10 STT20000A Product Manual
Performance specifications
The following table lists the performance specifications for the STT20000A.
Feature Specification
Capacity 10.0 gigabytes—1650 Oe 740' Travan cartridge
(uncompressed)
20.0 gigabytes—1650 Oe 740’ Travan cartridge
(compressed)
Effective backup rate up to 60 Mbytes/min native; up to 120 Mbytes
/min compressed
Data transfer rate 489 / 733 / 1,000 Kbytes per second
FastSense
Tape speed
Read/Write
Search/Rewind 46, 70, or 94 ips
90 ips maximum
Recording method Serpentine
Recording format QIC-3220-MC
Recording code 1,7 RLL
Error recovery Reed Solomon ECC
Recording unrecoverable
errors Less than 1 in 1015 data bits
Head configuration Wide write/narrow read
Recording media 1650-Oe 740' Travan TR-5
Cartridge size 3.2 in. x 2.4 in. x 0.4 in. (81 mm x 61 mm)
Data density 100,400 bits per inch
Tracks 107 data tracks, one (1) directory track

Specifications Chapter 2
STT20000A Product Manual Page 11
Environmental requirements
The following table lists the environmental specifications for the STT20000A. The
drive may be mounted either vertically or horizontally.
Specification Operational Non-operational
Temperature +41° to +113° F1
(+ 5° to + 45° C) –40° to +149oF2
(–40° to + 65oC)
Thermal gradient 1° C per minute
(no condensation) 20° C per hour
Relative humidity 20% to 80%
non-condensing15% to 95%
non-condensing2
Maximum wet bulb temperature 78.8° F (26° C) No condensation
Altitude –1000 to +15,000 feet –1000 to +50,000 feet
Vibration
Peak to Peak
Displacement 0.005 in. max.
(5 to 44.3 Hz) 0.1 in. max. (5 to 17 Hz)
Peak Acceleration 0.50 g max.
(44.3 to 500 Hz) 1.5 g max. (17 to 500 Hz)
Acoustic level operational
(A-wt sum) 55 dBA maximum
(measured in suitable
enclosure at 3-ft distance
and operator height)
—
Shock (1/2 sine wave) 2.5 g’s peak, 11 msec 100 g's peak, 11 msec
1Specification applies to drive mechanism and media
2Specification applies to drive mechanism only

Chapter 2 Specifications
Page 12 STT20000A Product Manual
Reliability
The STT20000A is designed for maximum reliability and data integrity. The following
table summarizes the reliability specifications.
Feature Specification
Non-recoverable error rate < 1 in 1015 bits
Error recovery and control Reed-Solomon Error Correction Code techniques
Error monitoring and reporting (Error Log)
Media pre-written
Retry on read
Data randomization
Mean-Time-Between-Failures
(MTBF) More than 250,000 hours
Mean-Time-To-Repair (MTTR) Less than 0.33 hour
Mean-Time-Between Failures
The Mean-Time-Between Failures (MTBF) is greater than 200,000 hours. This
specification includes all power-on and operational time but excludes maintenance
periods. Operational time is assumed to be 20% of the power-on time. Operational
time is the time the tape is loaded.
Note:
Seagate does not warrant the stated MTBF as representative of any
particular unit installed for customer use. The failure rate quoted here is
derived from a large database of test samples. Actual rates may vary from
unit to unit.
Mean-Time-To-Repair
The Mean-Time-To-Repair (MTTR) is the average time required by as qualified
service technician to diagnose a defective drive and install a replacement drive. The
MTTR for the drive is less than 0.33 hour (20 minutes).
The STT20000A is a field replaceable unit. If a problem occurs with a subassembly
or component in the drive, the entire unit should be replaced. The faulty drive should
be returned to the factory in its original packaging. Contact your distributor, dealer,
your computer system company, or your Seagate sales representative to arrange
the return.