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.

10005136-001

, 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.

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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

STT20000A Product Manual Page 45

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

STT20000A Product Manual Page 47

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.

Page 48 STT20000A Product Manual

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

Page 50 STT20000A Product Manual

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.

STT20000A Product Manual Page 53

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

Page 66 STT20000A Product Manual

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.

Page 68 STT20000A Product Manual

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.

STT20000A Product Manual Page 69

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.

Page 72 STT20000A Product Manual

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.

Page 74 STT20000A Product Manual

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

Page 76 STT20000A Product Manual

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

Page 78 STT20000A Product Manual

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

Page 80 STT20000A Product Manual