Quantum 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
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.
, March 1998
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:
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.
How to Identify
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
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
STT20000A Product Manual Page v
Table of Contents
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
Page vi STT20000A Product Manual
Table of Contents
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
STT20000A Product Manual Page vii
Table of Contents
Glossary 75
Acronyms and measurements 78
Acronyms and abbreviations................................................................................. 78
Units of measurement........................................................................................... 80
Page viii STT20000A Product Manual
Introduction Chapter 1
Introduction
1
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 FastSense 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 5.25­inch 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.
TM
. This
STT20000A Product Manual Page 1
Chapter 1 Introduction
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
Page 2 STT20000A Product Manual
Introduction Chapter 1
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
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 10
Flash EEPROM to enable electrically upgradeable drive firmware
Custom Seagate -designed LSI circuitry to reduce component count and boost
drive reliability
FastSense
—automatic selection of fastest
15
bits
Low power consumption—less than 15.0 Watts (typical) for internal drives
STT20000A Product Manual Page 3
Chapter 1 Introduction
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
Computer
system
Computer
system
Enhanced
IDE
controller
Enhanced
IDE
controller
Acculogic
IDE
controller
Primary IDE bus
Secondary
IDE bus
Primary
IDE bus
Secondary
IDE bus
Hard
disc
CD-ROM
(master)
STT20000A
(slave)
Hard
disc
STT20000A
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.
Page 4 STT20000A Product Manual
Introduction Chapter 1
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
References
The STT20000A is a cost-effective means of backing up fixed disks. The drive is compatible with DOS 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.
The following standards documents describe some of the technology incorporated in the drives referenced in this manual.
QIC-170
QIC-157
QIC-3095-MC
QIC-3220-MC
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.
—Preformatted magnetic minicartridge —ATAPI command set for streaming tape
TM
version 5.0 or later, Microsoft WindowsTM 3.1 or later,
—Serial recorded magnetic tape minicartridge (TR-4) —Serial recorded magnetic tape minicartridge (TR-5)
STT20000A Product Manual Page 5
Chapter 1 Introduction
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
2
3
4
5
6
7
Appendix A
Appendix B
Specifications Contains physical, performance, environmental,
reliability, power, and minicartridge specification tables.
Installation Provides cautions, unpacking tips, inspection
information, and installation/connection steps including cabling requirements and connector pinouts.
Drive operation and maintenance
ATAPI Interface Lists general information about the interface.
Tape format Provides an overview of the QIC-3220 tape
Theory of operation Details the functional operation of various
Glossary Defines key terms.
Acronyms and measurements
Explains the simple operation of the drive.
format.
assemblies of the ATAPI drive.
Lists the acronyms and measurements used in the manual.
Page 6 STT20000A Product Manual
Specifications Chapter 2
Specifications
2
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
Height
Width
Length
Weight
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).
Drive for 3.5-Inch
Mount
1.0 in/ 25 mm 1.7 in/ 43 mm
4.0 in/102 mm 5.87 in/149.1 mm
6.36 in/161.5 mm 6.51 in/165.5 mm
1.0 lbs/0.5 kg 1.5 lbs/0.7 kg
Drive for 5.25-
Inch Mount
STT20000A Product Manual Page 7
Chapter 2 Specifications
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
0.86" (21.8mm)
5.76" (146.4mm)5.49" (139.4mm)
0.20" (5.0mm)
5.87"
(149.0mm)
DRIVE ACTIVE
(GREEN)
1.685"
(42.8mm)
Page 8 STT20000A Product Manual
Specifications Chapter 2
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
Voltage Tolerance
Operational Current
Standby Current
Peak
Power Sequence
Ripple (peak to peak)
Power use (nominal)
+12 VDC +5 VDC
± 10% ± 5%
2.0 amps 1.0 amp
0.2 amp 0.6 amp
2.2 amps max.
None None
100 mV
< 15 Watts (excluding surge)
100 mV
< 15 Watts (excluding surge)
The following table lists pin assignments for the power connector for the drive.
Pin Assignment
1
+12 VDC
2
3
4
STT20000A Product Manual Page 9
+12 return
+5 return
+5 VDC
Chapter 2 Specifications
Performance specifications
The following table lists the performance specifications for the STT20000A.
Feature Specification
Capacity
Effective backup rate
Data transfer rate
Tape speed
Read/Write Search/Rewind
Recording method
Recording format
Recording code
Error recovery
Recording unrecoverable errors
10.0 gigabytes—1650 Oe 740' Travan cartridge (uncompressed)
20.0 gigabytes—1650 Oe 740’ Travan cartridge (compressed)
up to 60 Mbytes/min native; up to 120 Mbytes /min compressed
489 / 733 / 1,000 Kbytes per second
46, 70, or 94 ips 90 ips maximum
Serpentine
QIC-3220-MC
1,7 RLL
Reed Solomon ECC
15
Less than 1 in 10
data bits
FastSense
Head configuration
Recording media
Cartridge size
Data density
Tracks
Page 10 STT20000A Product Manual
Wide write/narrow read
1650-Oe 740' Travan TR-5
3.2 in. x 2.4 in. x 0.4 in. (81 mm x 61 mm)
100,400 bits per inch
107 data tracks, one (1) directory track
Specifications Chapter 2
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
Thermal gradient
Relative humidity
Maximum wet bulb temperature
Altitude
Vibration
Peak to Peak Displacement
Peak Acceleration
Acoustic level operational (A-wt sum)
1° t
o +113° F
+4 (+ 5° to + 45° C)
1° C per minute
1
–40° to +149 (–40° to + 65oC)
20° C per hour
oF2
(no condensation)
20% to 80% non-condensing
1
5% to 95% non-condensing
2
78.8° F (26° C) No condensation
–1000 to +15,000 feet –1000 to +50,000 feet
0.005 in. max. (5 to 44.3 Hz)
0.50 g max. (44.3 to 500 Hz)
55 dBA maximum
0.1 in. max. (5 to 17 Hz)
1.5 g max. (17 to 500 Hz)
— (measured in suitable enclosure at 3-ft distance and operator height)
Shock (1/2 sine wave)
1
Specification applies to drive mechanism and media
2
Specification applies to drive mechanism only
2.5 g’s peak, 11 msec 100 g's peak, 11 msec
STT20000A Product Manual Page 11
Chapter 2 Specifications
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)
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).
More than 250,000 hours
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.
Page 12 STT20000A Product Manual
Specifications Chapter 2
Recommended tapes
The STT20000A uses pre-formatted minicartridges. The following cartridges are recommended:
Description Seagate 3M/Imation
Travan—740 ft (QIC-3220-MC)
10.0 GB capacity (20.0 GB capacity with data compression)
Note. The STT20000A reads and writes the QIC-3220-MC format.
The STT20000A reads (but does not write) the QIC-3095-MC format.
Regulatory compliance
The STT20000A complies with the regulations listed in the following table.
Agency Regulation
CSA
TUV & IEC-RHEINLAND
UL
Canadian Dept. of Communications
EN55022 (CISPR-22)
with additional CE-Mark test requirements
20000TT TR-5
C22.2, No. 950-M89
EN 60 950/IEC 950
1950
Class B
Class B
FCC
Class B, Part 15
Use the STT20000A only in equipment where the combination has been determined to be suitable by an appropriate certification organization (for example, Underwriters Laboratories Inc. or the Canadian Standards Association in North America). You should also consider the following safety points.
Install the drive in an enclosure that limits the user's access to live parts, gives adequate system stability, and provides the necessary grounding for the drive.
Provide the correct voltages (+5 VDC and +12 VDC) based on the regulation applied—Extra Low Voltage (SEC) for UL and CSA and Safety Extra Low Voltage for BSI and VDE (if applicable).
STT20000A Product Manual Page 13
Chapter 2 Specifications
Notes
Page 14 STT20000A Product Manual
Installation Chapter 3
Installation
3
Introduction
This chapter explains how to install the STT20000A. The following paragraphs briefly outline the organization of this chapter.
Before you begin
Handling guidelines
The following section, should read before you begin the installation.
Setting jumpers
Installing the drive
Because the drive unit can be damaged by electrostatic discharge, an electrostatic grounding strap is recommended. This strap prevents an electrostatic discharge from damaging the electronic components on or in the drive unit
If you do not have an electrostatic grounding strap, perform the installation at a static-safe workstation. If one is not available, follow these guidelines as you install the drive unit:
Work in an uncarpeted area.
To protect the
anti-static bag until you are ready to install it.
drive from static electricity, DO NOT remove the drive from its
Before you begin
shows the master/slave jumpers and describes their uses.
explains how to mount the internal drive unit.
contains general information that you
Before you remove the drive from the anti-static bag, touch a metal or grounded surface to discharge any static electricity buildup from your body.
Caution:
Hold the drive by the edges only. Avoid direct contact with any printed circuit
Lay the drive only on top of its anti-static bag or return the drive to its bag when
Caution:
STT20000A Product Manual Page 15
If you touch static-sensitive parts of the drive (such as the printed circuit
board) electronic components may be damaged.
board.
you need to lay the drive down.
If you substitute an ATAPI adapter card or longer cables, or if you chain the tape drive to an existing ATAPI adapter or peripheral, the compatibility and/or operation of the tape subsystem may be seriously affected.
Chapter 3 Installation
Setting jumpers
Review the jumper settings to ensure that the jumpers are properly configured for your system. Figure 3-1 shows the location of the jumper block. Figure 3-2 shows the jumper block.
Note:
Record your jumper settings prior to installation. They are not visible after
the drive has been installed. The default setting is Slave mode with a jumper over pin 3 and pin 4. Your system setting may vary, so be sure to check your computer or ATAPI
controller manual to determine the proper configuration choice for your system.
Figure 3-1 Location of jumper block and connectors
NOTE:
Bottom of drive shown.
JUMPER
BLOCK
PIN 1
IDE
CONNECTOR
POWER
CONNECTOR
IDE PIN 1
Figure 3-2 Jumper block and jumper settings
(TOP OF TAPE DRIVE)
1
CABLE SELECT
6432
SLAVE
75
8
NOT USED
MASTER
JUMPER ON
JUMPER OFF
Page 16 STT20000A Product Manual
Installation Chapter 3
Installing the drive
The internal drive can be installed in a one-half-inch high by 3.5-inch form factor drive bay or in an inch-high by 5.25-inch form factor (with mounting brackets). The drive can be installed in three different orientations: horizontally (LED to the left) and vertically (on either side).
The following section provides directions for mounting the drive in either a 3.5-inch enclosure or in a 5.25-inch enclosure.
1. Before you install the drive, write down the serial number and model number shown on the drive and put this information in a safe place. You need this information if you ever call for service.
2. With the computer cover removed, remove the face plate from the drive bay in which you plan to install the drive. Refer to the manual that you received with your computer for instructions about removing the face plate if necessary.
Note:
3. Attach any special mounting hardware to the drive that your system might
4. Locate the mounting screw holes in the drive brackets. Each side contains two
5. Slide the tape drive into the computer so that the drive bezel and the computer
If devices are installed in any drive bays adjacent to the one you are using for the internal drive, partially removing those devices might give you more working space.
require. Refer to the manual that you received with your computer for requirements.
sets of holes. Use the set that aligns the drive properly within the drive bay.
face plate are flush. Then, align the mounting holes as shown in Figure 3-3.
Figure 3-3 Aligning the drive in the computer
STT20000A Product Manual Page 17
Chapter 3 Installation
6. Secure the drive using the mounting screws. The threaded mounting brackets are designed for M3.0 metric screws. If you are mounting the drive in a 3.5-inch bay, use the screw supplied with the drive. Do not substitute other screws. Using longer screws may damage the drive. If slide rails are needed, use the plastic slide rails (supplied with the drive in some configurations).
7. Connect an available power cable to the power connector on the drive. Figure
3-1 shows the location of the power connector. The recommended power mating connector requires an AMP 1-48024-0 housing with AMP 60617-1 pins or equivalent.
Note:
8. Connect the interface cable with the connector on the rear of the unit. When
you make the connection, be sure pin 1 of the connector aligns with pin 1 on the cable connector. See Figure 3-1 for the location of the connector and the Pin 1 location.
Note:
9. Replace the computer cover. Be sure to reconnect any peripherals that you
disconnected during the installation.
10. Plug the computer and any peripherals into an AC power outlet.
11. Start the computer and install your tape backup software.
Mounting dimensions
Turn off all power before inserting connectors.
Pin 1 on the connector on the rear of the drive is to your right as you look at the back of the drive (right side up). (See Figure 3-1.) Your cable should have Pin 1 highlighted by a color or dark strip. Be sure to mate Pin 1 on the cable to Pin 1 on the drive. Failure to do so could make the drive inoperative. Also, the cable is keyed to prevent incorrect installation. Make sure that the blocked pin in the cable connector coincides with the missing pin on the connector on the rear of the drive. (See Figure 3-1.)
Figures 3-4 and 3-5, respectively, show the location of the mounting holes for the internal drive without and with mounting brackets.
Page 18 STT20000A Product Manual
Installation Chapter 3
Figure 3-4 Mounting holes on internal drive (without mounting brackets)
3.7 in (94 mm)
2.758 in (70 mm)
6.36 in (161.5 mm)
1.220 in (31 mm)
1.0 in
4.0 in (102.6 mm)
0.157 in
(25.4 mm)
(4 mm)
Figure 3-5 Mounting holes on internal drive (with mounting brackets)
0.2 in (5 mm)
0.315 in (8 mm)
3.543 in (90 mm)
2.382 in (60 mm)
0.984 in (25 mm)
5.76 in (146.4mm)
5.87 in (149.0mm)
.075 in (1.9mm)
2 PLACES
3.12 in
(79,2mm)
1.81 in
(45.9mm)
0.197 in (5mm)
1.7 in
(43mm)
2.36 in
(60mm)
0.4 in
(10.2mm)
0.62 in
(15.7mm)
0.86 in
(21.8mm)
3.12 in
(79mm)
2.08 in
(53mm)
0.51 in
(13.0mm)
5.49 in
(139mm)
STT20000A Product Manual Page 19
Chapter 3 Installation
ATA-2 Interface pin assignments
The STT20000A provides a standard ATA-2 connector. The pin assignments for this connector are listed in the following table for your reference.
Pin Assignment Description Source
10
11
12
13
1
2
3
4
5
6
7
8
9
RESET Reset Host
Gnd Ground N/A
DD7 Data Bus bit 7 Host/Device
DD8 Data Bus bit 8 Host/Device
DD6 Data Bus bit 66 Host/Device
DD9 Data Bus bit 9 Host/Device
DD5 Data Bus bit 6 Host/Device
DD10 Data Bus bit 10 Host/Device
DD4 Data Bus bit 4 Host/Device
DD11 Data Bus bit 11 Host/Device
DD3 Data Bus bit 3 Host/Device
DD12 Data Bus bit 12 Host/Device
DD2 Data Bus bit 2 Host/Device
14
15
16
17
18
19
20
21
22
23
Page 20 STT20000A Product Manual
DD13 Data Bus bit 13 Host/Device
DD1 Data Bus bit 1 Host/Device
DD14 Data Bus bit 14 Baby sitting
DD0 Data Bus bit 0 Baby sitting
DD15 Data Bus bit 15 Host/Device
GND Ground N/A
--- Key pin N/A
DMARQ DMA Request Device
GND Ground N/A
DIOW- I/O Write Host
Installation Chapter 3
Pin Assignment Description Source
24
25
26
27
28
29
30
31
32
33
34
35
36
–REQ Ground N/A
–I/O I/O Read Host
GND Ground N/A
IORDY I/O Ready Device
CSEL Cable Select Device
DMACK DMA Acknowledge Host
GND Ground N/A
INTRQ Interrupt Request Device
10CS16- 16-Bit I/O Device
DA1 Device Address Bit 1 Host
PDIAG Passed Diagnostics Device
DA0 Device Address Bit 0 Host
DA2 Device Address Bit 2 Host
37
38
39
40
CS0- Chip Select 0 Host
CD1- Chip Select 1 Host
DASP- Device Active or Slave
Present
Ground Ground N/A
Device
STT20000A Product Manual Page 21
Chapter 3 Installation
Notes
Page 22 STT20000A Product Manual
Drive operation and maintenance Chapter 4
4
Drive operation and maintenance
Introduction
This chapter describes important operational procedures for the STT20000A. It covers the following topics:
Use of the front panel LED
Using cartridges
Loading revised firmware (updating flash EEPROM)
Drive maintenance and troubleshooting instructions.
Front panel LED
The front panel of the Travan drive (see Figure 4-1) contains the cartridge opening and one amber light-emitting diode (LED). This LED is lit any time that the tape is NOT at the beginning of the tape. Thus, the LED indicates tape movement.
Figure 4-1 Front panel—internal drive
DRIVE ACTIVE
(AMBER)
STT20000A Product Manual Page 23
Chapter 4 Drive operation and maintenance
Using Travan cartridges
The minicartridges recommended for use with the STT20000A are listed in chapter
2. This section describes some operations using the cartridges.
Loading and unloading cartridges
Your tape drive has a flip-up door that covers the cartridge opening when a tape cartridge is not installed in the drive. Once a cartridge is inserted, it is held firmly in place by the drive's positive locking mechanism.
Caution: DO NOT
any tape operations and wait until the amber LED is OFF before removing the cartridge.
To load
door facing into the drive. Figure 4-2 illustrates the loading of a cartridge.
Figure 4-2 Loading a Travan cartridge
To unload
cartridge straight out. Figure 4-3 illustrates the unloading of a cartridge.
a cartridge, insert it with the metal base plate down and the tape access
a cartridge, wait until the drive activity LED is OFF and then pull the
remove a tape cartridge while the drive is active. Complete
Figure 4-3 Unloading a Tape cartridge
Page 24 STT20000A Product Manual
Drive operation and maintenance Chapter 4
Setting the write–protect switch
Travan minicartridges feature a sliding write protect tab located in the upper left corner of the cartridge. You can set the tab to keep data from being written on the tape. Use this switch when you want to make sure that important data on the tape will not be overwritten.
Figure 4-4 shows the cartridge with the switch in the non-protected (read/write) or unlocked position.
Figure 4-4 Travan cartridge write-protect switch—unlocked position
Figure 4-5 shows the tab in the protected (read only) or locked position.
Figure 4-5 Travan cartridge write-protect switch—locked position
To return a cartridge to the "writeable" state, push the switch toward the end of the cartridge or to the unlocked position.
STT20000A Product Manual Page 25
Chapter 4 Drive operation and maintenance
Loading revised firmware via Seagate firmware cartridge
The STT20000A uses flash EEPROM. Flash EEPROM enables you to download new firmware when revisions to firmware are released. Firmware revisions are released on specially encoded cartridges that are automatically recognized by these drives. These firmware revisions are available for qualified OEMs only from Seagate Peripherals, Inc.
To load a firmware upgrade tape, follow these steps.
1. Power on the host system and the STT20000A drive. Allow the system boot up process to reach the point where there is no ATAPI bus activity.
2. Place the firmware upgrade cartridge record switch to the non-record position. Insert the firmware upgrade cartridge in the drive and observe the amber LED light on the front of the drive.
3. Once the upgrade cartridge is inserted, tape motion begins. The drive LED
flashes on and off. Approximately 15 seconds later, tape motion stops, and the LED continues to flash.
4. The LED flashes on and off at a steady rate as the firmware upgrade continues.
Approximately 45 seconds later, the drive resets internally, and the tape moves back and forth, then stops.
5. The LED light will go off and remain off. Double check that the LED remains off .
Make sure that there is not further tape motion. Remove the upgrade cartridge.
6. The firmware is now upgraded to the new revision. The drive is operational and
the new firmware is active. Turning power off at this time does not affect the firmware revision level.
Note:
If a problem occurs during the firmware loading process, the LED on the front panel goes out. In that case, the firmware upgrade cartridge may be defective, or the drive may not be operating correctly.
If after a repeat loading of the firmware cartridge, the same condition is observed, contact your Seagate sales representative.
Firmware upgrade cartridges are available to qualified Seagate OEM customers. Contact your Seagate sales representative for information.
Once the firmware upgrade cartridge is inserted in the drive, it is important that no power interruption occurs while the firmware is loading. DO NOT POWER OFF THE DRIVE AT THIS TIME. If a power interruption occurs, the firmware may not be loaded correctly, and the drive may not operate properly.
Page 26 STT20000A Product Manual
Drive operation and maintenance Chapter 4
Drive maintenance
Minimal maintenance is needed to ensure that your STT20000 SCSI minicartridge drive operates at peak condition. This section explains how to care for tape cartridges and how to clean the drive head.
Caring for tape cartridges
Although minicartridge tape cartridges are ruggedly built, they must be handled with care to preserve the data that they contain. The following points are guidelines for storing and using minicartridges.
Do not open the tape access door of the cartridge or touch the tape itself. One fingerprint can prevent the drive from reading the tape.
Keep the cartridge away from sources of electromagnetic fields, such as telephones, dictation equipment, mechanical or printing calculators, motors, and bulk erasers. Do not lay cartridges on the computer monitor or on the base unit of the computer.
Keep the cartridge away from direct sunlight and heat sources, such as radiators or warm air ducts.
Keep the cartridge free of moisture. Do not wet or submerge a cartridge in any liquid.
Do not expose the cartridge to temperature extremes. Allow the cartridge to assume room temperature slowly.
Retensioning the tape cartridge is always recommended for optimal performance, particularly after exposure of the cartridge to temperature changes or shock. Retensioning restores the proper tape tension to the media.
Cleaning the drive read/write head
Caution.
To properly maintain the tape drive, you should periodically clean the read/write head. No other periodic maintenance is required.
Follow these guidelines to help ensure that your drive provides long, reliable service:
Operate the drive in a clean, dust-free environment.
Never apply a lubricant to the drive.
Never clean the read/write head of the drive with anything other than a
lint-free swab or an approved cleaning cartridge. Do not touch the head with anything other than a lint-free swab.
Generally Travan drives are highly reliable and require little user maintenance. For normal operations cleaning once per month is quite adequate.
For new cartridges, clean the head after two hours of tape movement. Thereafter the drive can be cleaned as per normal operations.
STT20000A Product Manual Page 27
Chapter 4 Drive operation and maintenance
You can clean the drive head by one of two methods: you can use the Seagate approved 3M DC2000 cleaning cartridge DC051111 (12947), P/N CKDC2000, which is available through Seagate Express 1-800-531-0968, or you can manually clean the drive head. To manually clean the drive head, follow these steps.
1. Moisten a clean, lint-free swab in 90% isopropyl alcohol so that it is wet but not dripping. (Never use a dry swab.)
2. Hold the drive access door open and wipe the head gently using a side-to-side motion. The upright rectangle with the stripe in Figure 4-6 is the head.
Figure 4-6 Cleaning the drive head and capstan
Capstan Tape Head
Troubleshooting
3. Use a new swab saturated with 90% isopropyl alcohol to wipe the capstan. The capstan is the flat, roller to the left of the head as shown in Figure 4-6. Rotate the capstan until its entire surface is clean.
4. Allow the drive to dry for 3 minutes before using.
If you experience problems after you install the drive, take the following actions to try to solve the problems.
Check that all connections are secure.
Check the drive to be sure that the jumper settings are correct.
If a power interruption occurs during a backup or restore operation, start over when the power is restored. If the drive appears to fail during a backup or restore operation, try the following steps:
1. Remove and replace the cartridge and try again. Make sure you are using the correct type of tape cartridge.
2. Turn off all power to the computer and drive. Wait for the computer to power down and then start over.
Page 28 STT20000A Product Manual
Drive operation and maintenance Chapter 4
3. Try a different tape—preferably one that has never been used.
4. Check all cable connections for proper contact.
5. Clean the tape drive head as previously instructed. Then try the operation again.
If problems persist, contact your tape drive supplier or Seagate technical support at
US and Canada 1-800-SEAGATE (1-800-732-4283) Outside US and Canada 1-405-936-1234 Seagate Web Site http://www.seagate.com Seagate BBS 1-405-936-1630
Before you call technical support, be sure that you have the documentation for your computer and for all installed peripheral devices.
STT20000A Product Manual Page 29
Chapter 4 Drive operation and maintenance
Notes
Page 30 STT20000A Product Manual
ATAPI Interface Chapter 5
5
ATAPI interface
Introduction
The STT20000A provides an ATA Packet Interface (ATAPI) controller for communications between the host computer and the drive. The drive supports the QIC-157 standard interface.
The STT20000A provides a connection between the driver/card and the component of the PC. Refer to chapter 3 for specific cabling and connector information.
ATA-2 Interface
ATA-2 Signals
DASP-
Note:
This chapter clarifies the use of several ATA-2 signals and ATAPI commands that are either vague or optional in the QIC-157 specification.
The information about the ATA-2 interface is presented in the following topics: ATA­2 Signals, ATA Registers, and ATA Commands.
Only the DASP and PDIAG- signals are described in the following paragraphs.
This signal is used during power-up handshake sequences for master/slave identification per ATA-2 specifications.
Because the device has its own front-panel activity LED, this signal is not driven by this device (to indicate activity) after power-up is complete.
Refer to the interface.
QIC-157 Standard
for detailed information about the this
PDIAG-
This signal is used during power-up handshake sequences for master/slave identification per ATA-2 specifications.
STT20000A Product Manual Page 31
Chapter 5 ATAPI Interface
ATA registers
The following table lists the values for the registers during register initialization.
Register POR RESET–
(Hard Reset)
STATUS
00h 00h 00h 10h 41h
ATA Reset (SRST Bit)
ATAPI Soft Reset
Read/Identify Device Cmds
(DRDY+ERR)
ERROR
01h (No
01h 01h 01h 04h
(ABRT)
Error)
Sector Count (ATAPI Intr. Reason)
Sector Number (ATAPI Reserved)
Cylinder Low (ATAPI Byte Count High)
Cylinder High (ATAPI Byte Count High)
Drive/Head
01h 01h 01h 01h
01h 01h 01h 01h
14h 14h 14h 14h 14h
EBh EBh EBh EBh EBh
00 00 00
During an ATA soft reset or aborted ATA command, the host view of the DSC bit (Status register) will be cleared, along with the DRDY bit. Any ATAPI command including ATAPI Identify) can be used to set DRDY true and to re-enable host view of DSC bit.
Status Register
The following layout represents the Status Register. The CORR and IDX bits are not used by the drive.
76543 2 1 0
BSY DRDY -
Bit Mnemonic Description
7 BSY Busy—set when only drive has access to ATA registers. 6 DRDY Drive Ready—set when DSC is valid. 4 DSC Drive Seek Complete—set when drive ready for command. 3 DRQ Data Request—set when data ready to be transferred. 0 CHECK Check—set when an error has occurred.
(0)
DSC DRQ CORR
(0)
IDX
(0)
CHECK
Page 32 STT20000A Product Manual
ATAPI Interface Chapter 5
Error Register
The following layout represents the Error Register.
76543 2 1 0
Sense Key [3..0] MCR ABRT EOM ILI
Bit(s) Mnemonic Description
7-4 Sense Key Set to indicate the reason for the CHECK bit being set in
the Status Register. 3 MCR Media Change Request—Always 0. 2 ABRT Aborted Command—Set when an ATA or ATAPI
command is aborted. 1 EOM End Of Media—The end of the current partition was
0 ILI Illegal Length Indication—This bit is set when an illegal
Feature Register
The following layout represents the Feature Register.
7654 3 2 1 0
.... . . .
Bit Mnemonic Description
0 DMA DMA Data Transfer—When this bit is a 1, the data transfer
detected. On a WRITE command, unrecoverable data
might be left in the buffer.
length block is read. Sense Status also indicates ILI.
DMA
is in DMA mode. If the bit is 0, PIO data transfer is used. All ATAPI packet commands are transferred in PIO mode.
The value in this register must be set before
ATAPI command that transfers
every
data (including log/mode set/sense) to determine the transfer method. This register is overwritten by the drive after every command completion to present Error
STT20000A Product Manual Page 33
Chapter 5 ATAPI Interface
information. If you do not program this register correctly, the drive "hangs" in the BSY state. To correct this problem, reset operations.
Supported ATA Commands
The ATA commands are briefly described in the following paragraphs.
Execute Drive Diags (90h)
This command is executed regardless of the state of the DRV bit. The command causes an actual microprocessor reset (drive loses all logical position information). Power-up diagnostics are performed, and the PDIAG/DASP handshake is performed per ATA-2 specification. The master device will generate an interrupt.
Idle Immediate (E1h)
This command causes the device to set its Power Mode state to Idle and to generate an interrupt. Although the drive has no actual power saving features, this command is emulated for software compatibility.
Standby Immediate (E0h)
This command causes the device to set its Power Mode state to Standby and to generate an interrupt. Although the drive has no actual power saving features, this command is emulated for software compatibility.
Check Power Mode (E5h)
This command causes the device to return its Power Mode state in the Int Reason register, and generate an interrupt. If the drive is in Standby mode, this command returns 00h in the Int Reason register, otherwise this command returns FFh in the Int Reason register (indicating IDLE mode).
Previous Cmd Int Reason
Reset/Power-up FFh (Idle) Standby Immed. 00h (Standby) Idle Immediate FFh (Idle) Any Other Cmd FFh (Idle)
Sleep (E6h)
This command is treated as an Idle command and does NOT prevent the drive from responding to further commands.
Page 34 STT20000A Product Manual
ATAPI Interface Chapter 5
Set Features (EFh)
If an unsupported feature is selected, the command is aborted. Otherwise, the indicated parameter is set. The following list indicates the supported features:
Feature Number Set Feature Commands
03h Set Transfer Mode from Sector Count register 66h Disable reverting to power-on defaults (no-op) CCh Enable reverting to power-on defaults (no-op)
Set Transfer Mode Feature
If the Set Transfer Mode feature (03h) is received, the Sector Count (ATAPI Interrupt Reason) register is used to set the transfer mode based on the following table. Any transfer modes not listed in the table cause the command to be aborted.
Sector Transfer Mode
00h PIO Transfer Mode 4 (default) 01h PIO Transfer Mode 2 (explicit IORDY disable) 08h PIO Transfer Mode 0 09h PIO Transfer Mode 1 0Ah PIO Transfer Mode 2 0Bh PIO Transfer Mode 3 0Ch PIO Transfer Mode4 10h Single Word DMA Mode 0 11h Single Word DMA Mode 1 12h Single Word DMA Mode 2 20h Multi-word DMA Mode 0 21h Multi-word DMA Mode 1 22h Multi-word DMA Mode 2
STT20000A Product Manual Page 35
Chapter 5 ATAPI Interface
Issuing PIO and DMA transfer modes does not actually select these operations; however, issuing these modes selects the rate of either type of transfer, as selected by the DMA bit (bit 0) of the ATAPI Features register.
ATAPI Identify Device (A1h)
The protocol and timing of this command conforms to a standard ATA type command as defined in ATA-2.
This command is similar to the ATA Identify Device command except it uses
Note:
a different op-code. The ATA Identify Device command is aborted.
This command is generally intended to be used by a low-level ATAPI driver to determine the number and type of ATA/ATAPI devices attached to the interface. This driver might be able to program transfer rates and other parameters in the host ATA (IDE) interface.
The following table defines the values returned by the drive.
Word Description Value Meaning
0 General Configuration 81C0h ATAPI Streaming Tape, Removable
Accelerated DRQ, 12 byte packets
1-3 Disk info: cylinders, heads 0000h Unsupported
4-6 Disk info: track, sector sizes 0000h Unsupported
7-9 Reserved 0000h
10-19 Serial Number (20 ASCII characters) "N...N" Serial Number
20 Buffer Type 4002h Cap & Mech Sts bytes 6 and 7
21 Buffer Size 02D8h 14 frames of 52 data blocks=728
22 ECC Bytes Available 0000h Unsupported
23-26 Firmware Revision (8 ASCII
characters)
27-46 Model Number (40 ASCII characters) Model Number. "Seagate STT20000A"
47,48 Disk info: mult-xfer, double word I/O 0000h Unsupported
49 Capabilities 0F00h IORDY supported. Logical Blocks
"N.NN" Firmware Revision
Addressing and DMA supported
50 Reserved 0000h
51 PIO Data Transfer Cycle Timing 0200h Mode 2
52 DMA Data Transfer Cycle Timing 0200h Mode 2
Page 36 STT20000A Product Manual
ATAPI Interface Chapter 5
Word Description Value Meaning
53 Field Validity 0002h Fields 54-58 not valid. Fields 64-70
54-56 Current Cylinder/Heads/Sectors 0000h Unsupported
57-58 Current Capacity 0000h Unsupported
59 Reserved 0000h
60-61 User Addressable Sectors 0000h Unsupported
62 Single Word DMA Mode 0407h Selected DMA mode 2 (Upper Byte),
63 Multi Word DMA Mode 0407h Selected DMA mode 2 (Upper Byte)
64 Enhanced PIO Mode 0003h PIO Mode 3 and 4 Supported
65 Minimum Multi Word DMA Cycle Time 0078h Mode 2 (120 nanoseconds)
66 Recommended Multi Word DMA Cycle
Time
67 Minimum PIO Cycle Time w/o IORDY 0078h Mode 4 (120 nanoseconds)
0078h Mode 2 (120 nanoseconds)
valid
DMA modes 2,1,0 Supported.
DMA modes 2, 1, 0 supported.
68 Minimum PIO Cycle Time with IORDY 0078h Mode 4 (120 nanoseconds)
69-255 Reserved/Vendor Unique 0000h
ATAPI Packet Command (A0h)
Before issuing the ATAPI Packet command, the host writes to the Byte Count register (high and low) the maximum/preferred number of bytes to be transferred in a single PIO DRQ. For Data Transfer commands (READ and WRITE), this value is assumed to be greater than or equal to 512 and is ignored.
ATAPI Soft Reset (08h)
The ATAPI Soft Reset command performs a complete microprocessor reset. Current physical and logical position is lost, and if a tape is present, a LOAD sequence is performed, resulting in a Ready at BOP0 condition (with Unit Attn).
The DSC is set to 1 before the BSY bit is cleared.
STT20000A Product Manual Page 37
Chapter 5 ATAPI Interface
ATAPI interface
The following table lists the ATAPI interface commands for the drive. In this table, DSC restrictive means that the host should wait for DSC to be set before issuing the command for minimum IDE bus overhead. Note that all ATAPI commands are 12 bytes in length. The command descriptions show only the first 6 or 10 bytes of these commands, even though the commands are actually 12 bytes long.
Code DSC
Restrictive
00h
01h
03h
08h
0Ah
10h
11h
12h
15h
Y TEST UNIT
Y REWIND
N REQUEST
buffer READ Delay occurs if first READ is not READ 0 blocks.
buffer WRITE Write 0 not required to initialize DSC.
Y WRITE
Y SPACE Space forward/reverse Filemarks and space to
N INQUIRY DSC not affected.
MODE
Command Comments
Not DSC restrictive on some other drives.
READY
Null status if DSC not set.
SENSE
Flush always. WFM 0 to flush.
FILEMARK
EOD only.
Select speed, FDP, page 2B updates only.
SELECT
19h
1Ah
1Bh
2Bh
34h
3Bh
Page 38 STT20000A Product Manual
Y ERASE Constitutes a logical erase; accepted at BOP0/1
or EOD only.
MODE
SENSE
Y LOAD/UNL
OAD
Y LOCATE Locates logically only; can also select partition.
Y READ
POSITION
WRITE
BUFFER
UNLOAD to make not ready; LOAD to return to Ready. LOAD w/Retension any time. (All LOADS imply REWIND and select partition 0.)
Also used to wait for previous command done.
Use for download only. Drive must be "unloaded".
ATAPI Interface Chapter 5
4Ch
4Dh
Reserved Fields
Unless otherwise stated, all reserved and unsupported fields are not verified when the drive accepts a command. These fields are filled with 00s for future compatibility.
LOG
SELECT
LOG
SENSE
Resets Error Counts.
Contains Error Counts (WRITE and READ) and tape capacity.
STT20000A Product Manual Page 39
Chapter 5 ATAPI Interface
Erase command
Bit=>
Byte
0 Operation code (19h)
1 Reserved 1 (Long)
2 Reserved
3 Reserved
4 Reserved
5 Reserved
76543210
The Erase command is only accepted when the drive is ready and located at either BOP 0/1 or EOD. Erase at BOP causes the drive to write a Control/Filler Frame at the beginning of the current partition, followed by an EOD pattern. (The Use Count field of the Control Frame is incremented from its previous value). This action results in a logical erasure of the current partition. If partition 0 is erased, partition 1 becomes logically erased because of the use count field. Erase at EOD is accepted, but no operation is performed except a write flush if following a WRITE command. This result is because all data following EOD is already logically erased.
The DSC bit is reset (0) after this command is accepted and is set (1) when the command is complete. REQUEST SENSE can then be used to verify successful command completion.
Page 40 STT20000A Product Manual
ATAPI Interface Chapter 5
Inquiry command
Bit
Byte
0 Operation code (12h)
1 Reserved
2 Reserved
3 Reserved
4-7 Allocation Length
8-15 Vendor ID (8 ASCII characters) ASCII “Seagate “
16-31 Product ID (16 ASCII characters ASCII “STT20000A “
76543210
The INQUIRY command is always accepted, regardless of the state of the DSC bit. The command does not modify the status of DSC. The INQUIRY command returns the lesser of 36 bytes or the Allocation Length parameter of information. The following table defines the returned values.
Much of the information returned by this command is redundant with the
Note:
ATAPI Identify Device command response.
Byte Description Value Meaning
0
1
2
3
4
5-7
8-15
16-31
32-35
Peripheral Device Type 01h Streaming Tape Drive (QIC-
121 Architectural Model)
Removable Media Bit (RMB) 80h Removable
ISO/ECMA/ANSI Version 02h ANSI=02
Response Data Format 02h This Format
Additional Length 32. 36 total bytes
Reserved 00h
Vendor ID (8 ASCII characters) ASCII "Seagate "
Product ID (16 ASCII characters) ASCII "STT20000A "
Product Revision (4 ASCII characters) ASCII "N.NN"
The INQUIRY command is not to be used by the low-level driver; rather, it is intended to be used by applications, which usually have access to the drive only through the ATAPI protocol.
STT20000A Product Manual Page 41
Chapter 5 ATAPI Interface
Load/Unload command
Bit
Byte
0 Operation code (1Bh)
1 Reserved
2 Reserved
3 Reserved
4 Reserved Re-Ten Load
5 Reserved
76543210
LOAD (with or without Re-tension) is accepted any time a tape is present in the drive, (even if status indicates it is already loaded). This command includes implicit rewind and select partition 0 operations. The DSC bit is reset (0) after this command is accepted and is set (1) when the drive has initialized and is ready. REQUEST SENSE can then be used to verify successful command completion.
The UNLOAD option(s) re-tensions the tape (if selected) and moves the tape to the logical BOT or EOT end (as selected), then causes the drive to report not ready to any subsequent media access commands. Either a manual load operation or LOAD command is required for the drive to return to ready.
Page 42 STT20000A Product Manual
ATAPI Interface Chapter 5
Locate command
Bit
Byte
0 Operation code (2Bh)
1 Reserved CP Reserved
2 Reserved
3 (MSB)
4 Logical Block Address
5
6 (LSB)
7 Reserved
8 Partition
9 Reserved
76543210
If the Change Partition (CP) bit is set, the drive first changes to the specified partition, then attempts to locate before the specified logical block. (All addresses are interpreted as logical.) A locate to Block 0 (in any partition) is treated like a rewind (to BOP)and does not start a read-ahead. Depending on the exact sequence of commands, LOCATE to Block 0 might or might not report a Blank Check error.
The DSC bit is reset (0) after this command is accepted and is set (1) when completed. REQUEST SENSE can then be used to verify successful command completion.
STT20000A Product Manual Page 43
Chapter 5 ATAPI Interface
Log Select command
Bit
Byte
0 Operation code (4Ch)
1 Reserved PCR Reserved
2 01(PC) Reserved
3 Reserved
4 Reserved
5 Reserved
6 Reserved
7 (MSB) Parameter List Length
8 (LSB)
9 Reserved
76543210
The PC (Page Control) field is 01, for current values. The Parameter List Length field specifies the number of data bytes to transfer. If the PCR bit is 1 and the Parameter List Length is 0, the error counters are all reset (0).
All of the counters defined in the Log Sense command are reset by the Log Select command and are otherwise only cleared by a power-on (hard) or ATAPI reset.
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ATAPI Interface Chapter 5
Log Sense command
Bit
76543210
Byte
0 Operation code (4Dh)
1 Reserved
2 01(PC) Page Code
3 Reserved
4 Reserved
5 (MSB) Parameter Pointer
6 (LSB)
7 (MSB) Allocation Length
8 (LSB)
9 Reserved
The PC (Page Control) field is 01, for current values. The Page Code field identifies which page of data is being requested. The Parameter Pointer field allows requested parameter data to begin from a specific parameter code. The Allocation Length field specifies the number of data bytes to transfer.
The following table presents the supported log pages.
Byte Description Value Meaning
0
1
2,3
4
5
6
7
Page Code 00h Supported Log Pages Page
Reserved 00h -
Page Length 00,04h 4 Supported Pages
First Supported Page 00h Supported Log Pages Page Code
03h Error Counter (Read) Page Code
31h Tape Capacity Page Code
Last Supported Page 00h Filler
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Chapter 5 ATAPI Interface
Error Counter Page (Read)
The following table presents the Error Counter Page layout.
Byte Description Value Meaning
0 Page Code 03h Error Counter (Read) Page
1 Reserved 00h -
2,3 Page Length 0030h 48 Bytes Following
4,5 Parameter Code 0000h ECC Corrections Code
6 Parameter Bits 40h Device Controlled Counter
7 Parameter Length 04h 4-byte Counter
8-11 Number of ECC Corrections N,N,N,N Counter Value
12,13 Parameter Code 0001h Read Retries Code
14 Parameter Bits 40h Device Controlled Counter
15 Parameter Length 04h 4-byte Counter
16-19 Number of Retries N,N,N,N Counter Value
20,21 Parameter Code 8020h Even Tracks ECC Corrections
22 Parameter Bits 40h Device Controlled Counter
23 Parameter Length 04h 4-byte Counter
24-27 Even Tracks(reverse) ECC Corrections N,N,N,N Counter Value
28,29 Parameter Code 8021h Odd Tracks ECC Corrections
30 Parameter Bits 40h Device Controlled Counter
31 Parameter Length 04h 4-byte Counter
32-35 Odd Tracks (forward) ECC Corrections N,N,N,N Counter Value
36,37 Parameter Code 8022h Even Tracks Read Retries Code
38 Parameter Bits 40h Device Controlled Counter
Code
Code
39 Parameter Length 04h 4-byte Counter
40-43 Even Tracks (reverse) Read Retries N,N,N,N Counter Value
44,45 Parameter Code 8023h Odd Tracks Read Retries Code
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ATAPI Interface Chapter 5
Byte Description Value Meaning
46 Parameter Bits 40h Device Controlled Counter
47 Parameter Length 04h 4-byte Counter
48-51 Odd Tracks (Forward) Read Retries N,N,N,N Counter Value
Tape Capacity Page Code
The following table presents the Tape Capacity Page layout.
Byte Description Value Meaning
0
1
2,3
4,5
6
7
8-11
12-15
16-19
20-23
24-27
Page Code 31h Tape Capacity Page
Reserved 00h -
Page Length 00,20h 32 Bytes Following
Parameter Code 0001h Remaining Capacity, Part 0 Code
Parameter Bits 40h Device Controlled Counter
Parameter Length 04h 4-byte Counter
Remaining Capacity, Partition 0 Value N,N,N,N
Parameter: Code, Bits, Length 0002h,
40h,04h
Remaining Capacity, Partition 1 Value N,N,N,N
Parameter: Code, Bits, Length 0003h,
40h,04h
Maximum Capacity, Partition 0 Value N,N,N,N
Remaining Capacity, Part 1 Code
Maximum Capacity, Part 0 Code
28-31
32-35
Parameter: Code, Bits, Length 0004h,
40h,04h
Maximum Capacity, Partition 1 Value N,N,N,N
Maximum Capacity, Part 1 Code
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Chapter 5 ATAPI Interface
The Remaining Capacity for non-current partitions shall be the same as the Maximum Capacity for that partition. Capacities are multiplied by 1024 to determine the number of bytes. These values are conservative estimates.
The Parameter bit, TSD (not shown), is zero implying that the drive can save parameters across resets, etc. Parameters are not saved but are re-computed correctly from any logical position, regardless of the previous states of the tape drive.
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ATAPI Interface Chapter 5
Mode Select command
Bit
Byte
0 Operation code (15h)
1 Reserved 1 (PF) Reserved
2 Reserved
3 (MSB) Parameter List Length
4 (LSB)
5 Reserved
76543210
The Mode Select command provides a means to change device parameters. The PF (Page Format) bit is 1, since the Mode Pages are in SCSI-2 format. The only changeable parameters are Speed Selection (in the Mode Parameter Header), and certain fields in Mode Page 2Bh (MFM mode). The Parameter List Length field specifies the length in bytes of the Mode Select parameter list that are transferred to the device as data. A Parameter List Length of zero indicates that no data is transferred.
Mode Sense should be issued prior to Mode Select to determine the supported pages, page lengths, and other parameters.
The device terminates the Mode Select command with a Check Condition status, sets the Sense Key to Illegal Request, and sets the Additional Sense Code to Invalid Field in Parameter List for the following conditions:
If an attempt is made to change an unchangeable value in the Mode Select header, block descriptor, or any page.
If an attempt is made to send a page with a length not equal to the parameter length reported for that page by the Mode Sense command.
If an attempt is made to send a value for a parameter that is outside the range supported by the device.
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Chapter 5 ATAPI Interface
Mode Sense command
Bit
Byte
0 Operation code (1Ah)
1 Reserved DBD Reserved
2 00(PC) Page Code
3 (MSB) Allocation Length
4 (LSB)
5 Reserved
76543210
The PC (Page Control) field is 00, since only current values are reported. If DBD (Disable Block Descriptor) is set (1), then the Mode Block Descriptor is not included in the data returned to the host. The Allocation Length field specifies the number of data bytes to transfer
The following pages are supported for Mode Select and Mode Sense commands.
Page Code Description
11h Medium Partition Page 2Ah Capabilities and Mechanical Status Page 2Bh Tape Parameters Page (MFM mode) 3Fh Return All Pages
Mode Parameter Header
The following table describes the Mode Parameter header.
Byte Description Value Meaning
0
1
2
Mode Data Length NN Select: Reserved
Medium Type NN Tape type
Device Specific Parameters WP,001,Speed Bit 7 = Write Protect, Bits 6-4 = 001, Bits 3-
Sense: Length of Available Following Data
0 = Speed Selection
3
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Block Descriptor Length 00/08h If 8, Block Descriptor follows
ATAPI Interface Chapter 5
The only supported Buffered Mode (bits 6-4 of byte 2) is 001, indicating that write operations
buffered. Only the Speed Selection field can be changed.
are
The following table defines the tape speeds supported with QIC-3095 tapes.
Speed Tape Speed Transfer Rate
0000b Automatic Automatic 0001b 46 ips 489 Kbytes/sec 0010b 69 ips 733 Kbytes/sec 0011b 92 ips 1,000 Kbytes/sec
Mode Block Descriptor
The Block Descriptor is returned to the MODE SENSE command unless the DBD bit in the command packet is set to one. If the Block Descriptor is not sent, the Block Descriptor Length field (in the Mode Parameter Header) is 0.
Byte Description Value Meaning
4
5-7
8
9-11
Density Code NN Current Density
Number of Blocks 000000h Zero
Reserved 00h
Block Length 000200h Always 512 byte blocks
The Number of Blocks is 0, indicating that all blocks in the media match this descriptor, (the blocks are fixed 512 byte blocks).
None of the Block Descriptor parameters may be changed (Block Length is fixed).
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Chapter 5 ATAPI Interface
Mode Medium Partition Page
The following table describes the Mode Medium Partition Page layout.
Byte Description Value Meaning
0 Page Code 11h Medium Partition Page
1 Page Length 06h 6 Bytes of Information
2,3 Maximum Additional Partitions,
Additional Partitions Defined
4 FDP (bit 7), reserved 80h Fixed Data Partitions
5 Medium Format Recognition 03h Format and Partition Recognition
6,7 Reserved 00h,00h
00h,00h Not Supported
None of the Medium Partition Page (11h) parameters can be changed.
Mode Capabilities and Mechanical Status Page
The following table describes the Mode Capabilities and Mechanical Status Pages
Byte Description Value Meaning
.
0
1
2,3
Page Code 2Ah Capabilities and Mechanical Status Page
Page Length 12h 18 Bytes of Information
Reserved 00h,00h
4
5
6
7
8,9
10,11
12,13
14,15
16,17
SPREV (bit 5), RO (bit 0) 20h Space Reverse supported, bit 0 = Write
QFA (bit 5) 20h QFA supported
ECC (bit 6) 40h ECC supported
BLK1024 (bit 1), BLK512 (bit 0) 03h 512 byte blocks (1024 if floppy tape)
Maximum Speed Supported (Kbytes per second)
Maximum Stored Defect List Entries
Continuous Transfer Limit (blocks) 0034h 52 blocks per Read/Write command
Current Speed Selected (Kbytes per second)
Buffer Size (in 512 bytes) 02D8h 14 frames of 52 blocks = 728
600. 1,000 Kbytes/sec Maximum
0000h
NNNN Current transfer rate
Protect status
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ATAPI Interface Chapter 5
Byte Description Value Meaning
.
18-19
Reserved 00h
None of the Mode Capabilities and Mechanical Status Page (2Ah) parameters can be changed.
Mode Tape Parameters Page
Byte Description Value Meaning
0
1
2
3
4
5
6,7
8,9
Page Code 2Bh Tape Parameters Page
Page Length 0Eh 14 Bytes of Information
Density in Kilo bits per inch NN Density can imply tape format
Reserved 00h
Reserved (Format Fill Byte) 00h Not used, MFM mode is read only
BSEG 20h Number of Blocks per Segment (32)
SEGTRK NNNN Number of Segments per Track
TRKS NN Number of Tracks (per Tape)
10
11
12
13,14
15
MAXSECT 80h Max MFM Sector Value (128)
MAXCYL NN Max MFM Cylinder Value
MAXHD NN Max MFM Head Value
Reserved 0000h
WDAM,RM,FW (bits 7-5) 00h Not Used, MFM mode is read only
This page is used for MFM (Modified Frequency Modulation), or floppy interface tape formats, such as 2080, 2120, TR1, TR2, TR3, etc. This feature is not available in the STT20000A.
The following fields are changeable: SEGTRK, TRKS, MAXCYL, and MAXHD.
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Chapter 5 ATAPI Interface
Read command
Bit
Byte
0 Operation code (08h)
1 Reserved 1 (Fixed)
2 (MSB)
3 Transfer Length
4 (LSB)
5 Reserved
76543210
The Transfer Length specifies the number of fixed 512 byte blocks to be transferred. A transfer length of 0 indicates that no data is to be transferred but will initiate a read-ahead.
The DSC bit is reset (0) after this command is accepted and is set (1) when at least 52 blocks in the buffer are available for the next READ command. Issuing a READ command when the DSC bit is reset (0) will keep the ATA bus busy (BSY = 1) while the drive is reading the required data into the buffer. This delay could be more than a minute if exhaustive retries are required to read the data.
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ATAPI Interface Chapter 5
Read Position command
Bit
76543210
Byte
0 Operation code (34h)
1 Reserved
2 Reserved
3 Reserved
4 Reserved
5 Reserved
6 Reserved
7 Reserved
8 Reserved
9 Reserved
The following table describes the Read Position layout.
Byte Description Value Meaning
0
1
2,3
4-8
8-11
12
13-15
BOP, EOP, BPU nn 80h = Beginning of Partition
40h = End of Partition
04h = Block Position Unknown
Partition Number 00/01h Current Partition (bit 0)
Reserved 00h -
First Block Location
(Host Block Location)
Last Block Location
(Medium Block Location)
Reserved 00h
Blocks in Buffer 000000
NNNNNNNN Logical Number of next block to transfer
NNNNNNNN
*
between host and buffer
Not Supported
*
Not Supported
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Chapter 5 ATAPI Interface
Byte Description Value Meaning
16-19
These fields might appear to report the number of bytes/blocks in the buffer.
*
Bytes in Buffer 00000000
*
Not Supported
However, this information is not guaranteed to be accurate. You should not rely on this information.
The only position that is guaranteed is the host logical block position. The First and Last Block Locations both return the same host location, and Blocks and Bytes in Buffer are reported as 0.
Because Read Position is DSC restrictive on all ATAPI tape drives, it can be used to “wait” for any previous command to complete. This can be useful for applications with ATAPI only access to determine the actual completion of a command. Note, this will keep the ATA bus busy during the “wait”. DSC polling (to wait for DSC set) is preferred when possible.
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ATAPI Interface Chapter 5
Request Sense command
Bit
Byte
0 Operation code (03h)
1 Reserved
2 Reserved
3 Reserved
4 Allocation Length
5 Reserved
76543210
An Allocation Length value of 20 will return all Request Sense data. The Request Sense command is always accepted, regardless of the state of the
DSC bit, but the status is valid only when DSC or CHK (error) is set (1). If DSC and CHK are both reset (0), a non-error “null” status is returned. Normally, if CHK is set, DSC is set. The only time CHK is set and DSC is reset, is during writes at logical end of media; DSC remains a buffer indicator, and CHK is set to indicate EOM, which is a warning, not an error.
If a command completes with a check (error) condition, the next command issued, if not Request Sense or Inquiry, will be aborted, and a deferred error will be reported. If the command is Request Sense, a non-deferred error is reported. The Inquiry command does not affect status reporting.
The following table describes the REQUEST SENSE layout.
Byte Description Value Meaning
0
1
2
Valid, Error Code 70h,71h 80h = Information Field Valid
+ 70h = Current Errors
or 71h = Deferred Errors
Reserved (Segment Number) 00
Filemark, EOM, ILI, Sense Key NN 80h = Filemark
+ 40h = EOM
+ 20h = ILI
+ Sense Key
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Chapter 5 ATAPI Interface
3-6
7
8-11
12
13
14
15
16,17
18,19
Information NNNNNNNN Transfer Residue or
Unwritten Blocks + Filemarks
Additional Sense Length 0Ah 10 bytes following
Command Specific Information 00h Not Supported
Additional Sense Code (ASC) NN
Additional Sense Code Qualifier (ASCQ)
Field Replaceable Unit Code 00h Not Supported
SKSV + Sense Key Specific 00h Not Supported
Sense Key Specific 0000h Not Supported
Pad 0000h Pad to 4-byte boundary
NN
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ATAPI Interface Chapter 5
Rewind command
Bit
Byte
0 Operation code (01h)
1 Reserved
2 Reserved
3 Reserved
4 Reserved
5 Reserved
76543210
The Rewind command first ensures that all buffered write data has been transferred to the medium, then causes the device to position to BOP of the current partition.
The DSC bit is reset (0) after this command is accepted and is set (1) when the drive is ready to write at BOP0 (or encountered a hardware error). REQUEST SENSE can then be used to verify successful command completion.
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Chapter 5 ATAPI Interface
Space command
Bit
Byte
0 Operation code (11h)
1 Reserved Space Code
2 (MSB)
3 Count
4 (LSB)
5 Reserved
76543210
The only Space codes that are supported are 001b (Filemarks) and 011b (End of Data on Current Partition). For Space Filemarks, negative count (2s compliment) indicates Space Filemarks Reverse.
The DSC bit is reset (0) after this command is accepted and is set (1) when the command is completed and the drive is ready. REQUEST SENSE can then be used to verify successful command completion.
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ATAPI Interface Chapter 5
Test Unit Ready command
Bit
Byte
0 Operation code (00h)
1 Reserved
2 Reserved
3 Reserved
4 Reserved
5 Reserved
76543210
This command can be used to determine the readiness of the device to accept a media access command. It’s purpose is to indicate the cartridge state: no cartridge (or drive fault), cartridge becoming ready, or cartridge/drive ready.
If the drive is busy with a previous command (DSC reset), the drive will wait for the previous operation to complete before releasing the ATA bus. On some other ATAPI tape drives, Test Unit Ready does not wait for DSC set before completing, and if an application needs to “wait” for an command done via the ATAPI interface, Read Position should be used instead.
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Chapter 5 ATAPI Interface
Write command
Bit
Byte
0 Operation code (0Ah)
1 Reserved 1 (Fixed)
1 Reserved
2 (MSB)
3 Transfer Length
4 (LSB)
5 Reserved
76543210
The Transfer Length specifies the number of fixed 512 byte blocks to be transferred. A transfer length of 0 indicates that no data is to be transferred but is used on some drives to put DSC into write buffer mode.
The DSC bit is reset (0) after this command is accepted and all data has been transferred. This bit is set (1) when there are at least 52 empty blocks in the buffer available for the next WRITE command. Issuing a WRITE command when the DSC bit is reset (0) will keep the ATA bus busy (BSY=1) until buffer
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ATAPI Interface Chapter 5
Write Filemark command
Bit
Byte
0 Operation code (10h)
1 Reserved
2 Reserved
3 Reserved
4 Reserved Count
5 Reserved
76543210
After receiving this command, the device sets DSC (0) and returns completion status. Any data remaining in the buffer is then written to tape (flush/ synchronize), and if the count is 1, a Filemark is written. In any case, an EOD is then written.
The Immed bit in the command packet is ignored, and the DSC bit is reset (0) after this command is accepted. The DSC bit is set (1) after the EOD has been successfully written. REQUEST SENSE can then be used to verify successful command completion.
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Chapter 5 ATAPI Interface
Write Buffer (download microcode) command
Bit
Byte
0 Operation code (3Bh)
1 Reserved 101 (Mode)
2 Reserved
3 Reserved
4 Reserved
5 Reserved
6 (MSB)
7 Transfer Length
8 (LSB)
9 Reserved
76543210
The Write Buffer command is intended only to provide a method for downloading new drive microcode (firmware) into Flash EPROM, so the only valid MODE is 101 (download microcode and save). The drive must be Not Ready (unloaded) for this command to be accepted, and the transfer length is set to the download file size, which is currently 0x026800. All data is transferred in one command.
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Tape Format Chapter 6
6
Tape format
Introduction
The STT20000A conforms to the QIC-3220-MC recording format standard. This format is for streaming magnetic tape in a minicartridge that is to be used for information interchange among information processing systems, communication systems, and associated equipment.
This chapter provides an overview of the tape format used by the STT20000A.
Tape partitioning
The drive uses factory pre-written Travan TR-5 media. The tape is always divided into two partitions:
Track positions
Partition 1 is the directory partition and is recorded on the Directory track only.
Partition 0 contains the data (tracks 0 through 107) and is recorded on all tracks
except the Directory track.
Recording data at 100,400 bits per inch (BPI), the drive can store 10.0 GB on the data partition of one 740-foot long, 0.315-inch (8.0 mm) wide Travan TR-5 tape. Using software data compression, these capabilities are typically doubled.
The recording format and partitioning support Quick File Access (QFA).
The centermost track is called the Directory Track and has larger guard bands on both sides of it to allow it to be written without interfering with its adjacent tracks.
Track zero is the track immediately below the Directory Track. The even numbered tracks are positioned sequentially below track 0. Thus, track 2 is below track 0, and track 4 is below track 2, and so on down to track 70, which is the closest to the reference edge of the tape. (The reference edge is the edge of the tape that is nearest to the baseplate of the cartridge.)
Track 1 is the track immediately below the Directory Track. The odd numbered tracks are positioned sequentially up from track 1. Thus, track 3 is above track 1, and track 5 is above track 3, and so up to track 71, which is the closest to the upper edge of the tape.
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Chapter 6 Tape Format
Track numbering
All even numbered tracks, and the Directory Track, are recorded in the forward direction (the direction from the BOT marker to the EOT marker). All odd numbered tracks are recorded in the reverse direction (the direction from the EOT marker to the BOT marker). All even numbered tracks are located below the Directory Track; all odd numbered tracks are above it.
Track format
Tracks are recorded sequentially beginning with track 0, then track 1, and so on. Before recording, data are grouped into blocks, and blocks are grouped into frames with 128 blocks per frame.
Two numbering methods are used for blocks: physical numbering and logical numbering. Both numbers start from 0 at the beginning of each partition.
Physical numbering is related directly to the recorded block on the tape. Each new block is given a unique physical number, regardless of its contents.
Logical numbering does not relate to the blocks physically recorded on the tape; rather, this type of numbering is the block numbering system used by the host computer. Often the host system operates with logical blocks that are a different size from the 512-byte blocks that are physically recorded on the tape.
Frames
The host blocks can be larger or smaller than 512-bytes and can also be fixed or variable. Fixed host blocks contain the same number of data bytes in each block. Variable host blocks may contain a different number of data bytes in each block.
The format provides both a physical block number for each block recorded on the tape and a logical block number that can span more than one physical block. These two numbers are recorded in the control field of every block.
Every track on the tape is recorded in blocks that contain 512 data bytes. The data bytes are 8-bit bytes, which are numbered b0 to b7 with b7 being the most significant bit.
A frame is made up of 128 blocks—108 data blocks plus 20 error-correction code (ECC) blocks. Figure 6-1 illustrates the general track layout of sequentially recorded frames.
Figure 6-1 General track layout
Frame N Frame N+1 Frame N+2 Frame N+3 Frame N+4
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Tape Format Chapter 6
Frames are numbered indirectly using the 26 most significant bits of the Physical Block Address. Frame operation is controlled by the drive and generally invisible to the host. Frames are used primarily as a means to control the error correction operations.
Frames can be overwritten with new data frames or an end-of-data (EOD) frame. Append operations can only begin at EOD.
An underrun is not allowed in the middle of a frame, regardless of the frame type. Filler blocks can be used to complete a frame as long as they are not used interior to a logical block.
A frame that cannot be completed on one track is rewritten in its entirety at the beginning of the following track. Frames are not split around corner turns.
The general frame layout—108 data blocks and 20 ECC blocks—is illustrated in Figure 6-2.
Figure 6-2 General frame layout
Data Block 0
Data Block 1
Data Block 2
... Data
Block 107
ECC Block 0
ECC Block 1
The four types of frames are as follows:
Data frames
The
Media Header frame
contain data and information blocks in addition to ECC blocks.
contains only Media Header blocks and ECC blocks.
This frame is recorded as the first frame on the Directory Track.
Track ID frames
are recorded as part of the pre-formatting process of the cartridge. These frames are easily distinguished from other frame types because they reside entirely outside of the data region of the tape.
An
frame is an absolute indicator of the end of the recorded data. It is
EOD
recorded after the last frame containing host data upon terminating a Write process.
... ECC
Block 19
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Chapter 6 Tape Format
Blocks
Information in the Block Control byte determines the type of block being recorded except for ECC blocks which are recognized by their block numbers. Also, information about the number of user data bytes available in each data block is recorded in the Block Control byte of the block.
The Data Field of the blocks always contain 512 bytes. However, the number of valid data bytes in the block may be less than 512.
The seven different types of blocks are as follows:
Data blocks
data block can contain from 1 through 511 valid data bytes depending on the selected logical block size of the host.
Media Header blocks
well as the Volume Directory. The first frame on the Directory Track is the Media Header Frame. This frame contains 108 Media Header blocks (plus the normal 20 ECC blocks).
Information blocks
blocks—contain specific types of information. Filemark blocks are physical blocks written to tape in response to a host WRITE FILEMARKS command. Setmark blocks are physical blocks written to tape in response to a host WRITE SETMARKS command. Cancelmark blocks are physical blocks written to tape under firmware control.
Filler blocks
used to fill incomplete frames.
EOD blocks
ECC blocks
integrity during read operations.
Track ID
cartridge.
contain user data. A full Data block contains 512 bytes; however,
contain specific host., drive, and vendor information as
—Filemark blocks, Setmark blocks, and Cancelmark
contain no valid information in the data area. These blocks are
are absolute indicators of the end of recorded data.
contain error correction parity bytes that are used to ensure data
blocks are recorded as part of the pre-formatting process of the
Tape reference servo pattern
To increase track density, a track servo reference pattern is prerecorded on the tape at the factory. The pattern is recorded referenced to servo patterns in the region between the beginning-of-tape (BOT) hole and the load point market (LP) hole. The same pattern is recorded between the end-of-tape (EOT) hole and the early warning (EW) hole. The servo pattern is written across the entire width of the tape.
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Tape Format Chapter 6
Write equalization
The drive uses the technique of write equalization. Write equalization inserts short pulses in the write current to break up the long spacing intervals. These pulses are too short to be detected in the read process but result in significant improvement in read-back resolution.
On 1650-Oersted media, write equalization provides the benefit of compatibility with Magneto-Resistive (MR) heads. MR heads are prone to saturation by low frequency flux with high energy content. Equalization redistributes this energy to higher frequencies and eliminates the problem.
Randomization
To reduce problems resulting from long strings of repetitive data with a bad peak shift or amplitude characteristics, a data randomizer algorithm is used on all bytes in the data and control area of each block. This randomizing takes place prior to the encoding of the data.
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Chapter 6 Tape Format
Notes
Page 70 STT20000A Product Manual
Theory of operations Chapter 7
7
Theory of operations
Overview
The STT20000A is a low-cost, high-performance TR-5 minicartridge tape drive that is ideal for stand-alone users or small network computer systems. With capacities of
10.0 Gbytes to 20.0 Gbytes dependent upon media and data compression, this drive offers quick, efficient backup and restore operations. Its unique
FastSense
feature automatically selects the appropriate transfer rate—1,000, 733, or 489 Kbytes/sec—based on the speed of the operating system.
The STT20000A is based on proven Seagate designs, Seagate firmware, and the latest technology. This drive uses second generation, custom LSIs for efficient circuit layout and increased reliability with low power consumption. The drive also uses flash EEPROM devices for easy firmware upgrades.
TM
Block diagram
This chapter describes the drive in more detail and explains implementation specific information.
The electronics of the STT20000A are laid out on one main printed circuit board (PCB). Figure 7-1 shows a simplified block diagram of the drive.
Figure 7-1 Simplified block diagram for STT20000A
256KB
EEPROM
(5 volt)
Control Logic Module
IDE
Interface
V20 uP
(10 MHz)
Digital ASIC
buffer mgr.
ECC
RWW
40 MHz Crystal
Read Channel
Write Driver
Stepper
Motor
Motor
Control
Head,
Non RWW
Capstan
Motor
IDE ONLY
512KB DRAM
STT20000A Product Manual Page 71
Sensors:
-cartridge present
-write protect
-tape hole
-top stop
Chapter 7 Theory of operations
Drive mechanisms
This section generally describes the hardware design features of the STT20000A. You may want to refer to the block diagrams referenced previously as you read this information.
Mechanics
The mechanical package for the STT20000A was designed to provide you with all the advantages of easy cartridge loading and unloading while maintaining the positioning accuracy necessary for high-density data recording. The orientation of the cartridge is the same as the majority of QIC minicartridge drives in the field.
Cartridge-load mechanism
The cartridge is inserted in the drive by sliding it through the aperture in the bezel and into a tray mechanism. When fully inserted the back portion of the cartridge protrudes about 3/4-inch from the aperture. A switch is actuated at this point that causes a microprocessor to complete the loading operation.
When the tape is in motion, the amber LED on the front panel flashes. The LED is not lit when the tape is positioned at BOT.
Capstan/drive-motor assembly
Chassis
Control circuits
In the STT20000A, the cartridge is driven by the capstan/belt motor assembly, which is on a linear slide. The cartridge is loaded against the cartridge drive roller which exerts a net radial dynamic force of 18 to 26 ounces. The motor is a brushless DC drive motor with integral capstan which is designed to provide maximum reliability.
The motor operates from the 12V nominal supply and moves the tape at speeds from 35 to 100 inches per second (IPS).
The drive mechanism is mounted in a molded frame that provides the mounting holes for the industry standard 3.5-inch by one inch form factor. A 5.25-inch mounting kit is an available option. The bezel is a simple snap-on design that is available in several standard and custom colors. The front-panel LED is amber and indicates tape activity.
The control logic module shown in Figure 7-1 includes a buffer manager to handle data movement between the controller, the buffer, and the tape formatter. This module also includes logic to perform ECC and CRC generation and testing, WRITE/READ data formatting, head stepper control, and drive motor control.
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Theory of operations Chapter 7
The microprocessor directs all functions performed by the control logic. The instructions are read from a flash EEPROM, which can be updated with new firmware through a specially written tape cartridge.
The 512-Kbyte DRAM data buffer allows the drive to maintain streaming when the host cannot provide data continuously at the tape streaming rate.
The write driver receives data from the write formatter and generates write current, causing data to be written on tape by the tape head.
The read channel amplifies and conditions the signal from the tape head and passes it back to the read formatter.
The head stepper and drive motor both receive current from the control logic to control the stepping of the head from track to track and to move the tape forward and back across the tape head.
Head design
The recording/playback head is a state-of-the art, thin-film design—a thin-film inductive write head paired with an advanced magneto-resistive read head. This head design provides the drive with exceptional performance and reliability. The material composition of the head also results in exceptional wear characteristics, resulting in stable performance throughout the life of the drive.
Flash EEPROM
Because the drive uses flash EEPROM (electronically erasable, programmable read-only memory), the drive firmware can be easily upgraded when new revisions of the firmware are released. The circuitry includes 128 Kbyte of flash EEPROM.
You can load new firmware by using a specially encoded firmware upgrade cartridge. Refer to chapter 4 for information about loading new firmware using a Seagate firmware upgrade cartridge.
Sensors and switches
A number of mechanical and optical sensors and switches are integrated in the drive design. The Cartridge In switch detects when a cartridge is fully loaded and positioned against the A-plane datum of the cartridge. The Unsafe switch senses the position of the SAFE indicator on the cartridge and disables writing of write­protected (SAFE) cartridges.
The Head-Position Sensor is an electro-optical assembly (LED and photo-transistor) to determine the approximate head position.
The drive has an electro-optical sensor assembly comprised of a solid-state light source (LED) and a photo-sensor (photo-transistor) that sense the beginning-of-tape (BOT), end-of-tape (EOT), load point, and early warning holes of the cartridge.
STT20000A Product Manual Page 73
Chapter 7 Theory of operations
Drive media (Travan minicartridges)
The drive is designed to use Travan TR-5 cartridges. These small (approximately 2 inches by 3 inches by 0.4 inch) cartridges house 1650-Oersted Gamma Ferric Oxide magnetic tape. Figure 7-2 shows a Travan minicartridge.
Figure 7-2 Travan minicartridge
The cartridge also provides for write protection so that existing data on the cartridge is not overwritten. A write-protected cartridge allows the existing data to be read but does not allow new data to be written to the tape. The position of the sliding write­protect tab on the cartridge determines whether or not data can be written to the tape. See chapter 4 for illustrations of the write-protect position.
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Glossary Appendix A
Glossary
A
ATA Packet Interface—
(standard QIC-157).
Azimuth—
reference edge.
Backup—
Beginning of Media (BOM)—
Beginning of Tape (BOT)—
Bezel—
Bit—
Bit Error Rate—
Block—
BOP—
BOT marker—
Byte—
The angular deviation, in minutes of arc, of the mean flux transition line from the line normal to the tape
Copy of a file or collection of files on fixed disk, diskette, or tape. Ensures against data loss.
Front panel of a drive.
A single digit in the binary numbering system.
The number of errors divided by the total number of bits written or read.
A group of 512 consecutive data bytes plus additional control bytes recorded as a unit.
Beginning of Partition. The position at the beginning of the permissible recording region of a partition.
The beginning of tape (BOT) marker is a set of two holes punched side by side in the tape.
A group of 8 binary bits operated on as a unit.
The interface providing for communications between the host computer and the drive
Equal to the physical beginning of the tape.
Equal to the logical beginning of the tape.
Cancelmark—
Filemark or Setmark, the drive when reading the tape will logically ignore the Cancelmark and the Filemark or Setmark it cancels.
Cartridge—
Control field—
address, track address, and block type.
Cyclic Redundancy Check (CRC)—
error detection.
Data block—
Data Compression—
Compressed data requires less storage space than uncompressed data.
Data Density—
(bpi).
Decompression—
Dew—
Collection of moisture in a tape drive.
A "negative" Filemark or Setmark. When a Cancelmark follows as the first block in the next frame after a
An enclosure containing magnetic tape wound on two coplanar hubs.
A group of 8 bytes recorded before the data area in each block, containing information about clock
A group of 2 bytes recorded at the end of each block of data for the purpose of
A block containing user valid data in its data field
The process of removing redundant data from a data stream before recording the data to tape.
The number of single-byte characters stored per unit length of track. Usually expressed as bits-per-inch
The process of restoring compressed data to its original state.
STT20000A Product Manual Page 75
Appendix A Glossary
Directory track
Disc Drive—
by a program.
ECC
—(Error Correction Code) Special drive generated information that can be used to correct bad blocks.
ECC block—
Encoding—
End-of-Data (EOD)—
End-of-Media (EOM)—
End-of-Partition (EOP)
End of Tape (EOT)—
Error Correction Codes (ECC)-
reconstruct errors during the data reading operation.
Early Warning (EW)—
of the usable recording area in the forward direction.
File—
A logical unit of information.
—The track at the centerline of the tape, identified as track 254 by its Track ID frame.
A peripheral storage device that rotates the disk, writes data onto it, and reads data from it as instructed
A block containing drive-generated ECC data in its data field and part of control field.
A method whereby a group of data bits is translated into a group of recording bits.
Indicates the point where the host stopped writing data to the tape.
Equal to the physical end of tape.
—The position at the end of the permissible recording area of a partition.
Equal to the logical end of the tape.
Information written on tape during the recording operation that can later be used to
The early warning marker is a single hole punched in the tape to indicate the approaching end
Filler block—
Fixed Disk—
Frame—
Full-high (or full-height)—
Half-high (or half-height)—
Head Clog—
obstruct the reading or writing of data.
Interleaving—
are not recorded physically adjacent.
Magnetic Tape—
information processing.
Media Header block
Noise—
radiated sources.
Randomizing—
RF envelope level.
A block containing no valid information in its data field.
A non-removable hard disk. All data must be transferred to and from the disk via the computer.
A group of 128 blocks forming a complete logical group.
Usually refers to a tape drive fitting in a vertical space of 3-1/2 inches.
Refers to the size of tape drive occupying a vertical space of about 1-1/2 inches.
Particles from the tape or from outside the drive adhere to the head gap on a read or write head and
The process of shuffling the order of data blocks before writing them to tape so the consecutive bytes
A tape that accepts and retains magnetic signals intended for input, output, and storage of data for
—A unique block identifying the type of format being recorded.
A disturbance of the signal caused by the read channel, write channel, head/tape interaction, or conducted or
A re-coding of data symbols before they are written to tape in order to provide a consistently uniform
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Glossary Appendix A
RLL (Run Length Limited)—
with regard to the maximum and minimum distances between flux transitions.
Serpentine—
a track. This recording method exploits the bi-directional capabilities of the cartridge.
Streaming
start and stop within an inter-block gap.
Tape Drive—
drive. (See also Disk Drive.)
Track
—A longitudinal area on the tape along which magnetic signals can be serially recorded.
Track ID block
Uncorrected Bit Error Rate—
Underrun
for streaming operation.
A recording method in which tracks are laid down sequentially, and the tape is not rewound at the end of
—A method of recording on magnetic tape that maintains continuous tape motion without the requirement to
A peripheral storage device that records data onto removable tape cartridges. Used to back up a disk
—A block recorded in the Load Point and Early Warning regions to designate the track number.
—A condition developed when the host transmits or receives data at a rate less than required by the device
A data encoding method where data bits are encoded so that certain constraints are met
The probability of a bit being in error, without using any error correction techniques.
STT20000A Product Manual Page 77
Appendix B Acronyms and Measurements
B
Acronyms and measurements
Acronyms and abbreviations
Acronym Meaning
ANSI American National Standards Institute
BIOS Basic Input Output System
BOM Beginning of Media
BOT Beginning Of Tape
BPI Bits Per Inch
CD Compact Disc
CMOS Complementary Metal-Oxide Semiconductor
CSA Canadian Standard Association
DMA Direct Memory Access
ECC Error Correction Code
ECMA European Computer Manufacturers Association
EEPROM Electronically Erasable, Programmable Read-Only Memory
EOD End of Data
EOM End of Media
EOT End Of Tape
FCC Federal Communications Commission
FTPI Flux Transitions Per Inch
IEC International Electrotechnical Commission
IPS Inches Per Second
LED Light Emitting Diode
LSI Large Scale Integration
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Acronyms and Measurements Appendix B
Acronym Meaning
MTBF Mean Times Between Failures
MTTR Mean Time To Repair
OEM Original Equipment Manufacturer
PCB Printed Circuit Board
QIC Quarter Inch Cartridge Drive Standards, Incorporated
RAM Random Access Memory
RLL Run Length Limited
SCSI Small Computer System Interface
UL Underwriters' Laboratories, Inc.
VDC Volts Direct Current
VDE Verband Deutscher Electrotechniker
STT20000A Product Manual Page 79
Appendix B Acronyms and Measurements
Units of measurement
Measure Meaning
A Amp C Celsius or Centigrade cm centimeter dBa decibels, A-weighted sound power reference one picowatt F Fahrenheit ft foot or feet g acceleration of a free-falling body; equal to 32.17 feet per second Gbyte gigabyte Hz Hertz in. inch k kilo
2
Kbyte kilobyte kg kilogram KHz kilohertz lb(s) pound(s) m meter M mega Mbits megabits Mbyte megabyte MHz megaHertz min minute mm millimeter ms millisecond RPM revolutions per minute V Volt W Watt
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