Seagate 2HP, ST12450W-WD User Manual

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BARRACUDA 2, 2HP

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Disc Drive

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ST12450W/WD

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Installation Guide

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Contents

Preface .................................................................. 1

Electrostatic discharge protection........................... 1

Important safety information and precautions ......... 2

Wichtige Sicherheitshinweise ............................... 5

Technical support services ..................................... 10

General description ................................................ 12

Initial setup information........................................... 17

Kühlung des Systems .......................................... 28

© 1995 Seagate Technology, Inc. All rights reserved
Publication Number: 83328890, Rev. B
March 1995

Seagate®, Seagate Technology®, and the Seagate logo
are registered trademarks of Seagate Technology, Inc.
Barracuda™, SeaFAX™, SeaFONE™, SeaTDD™,
and SeaBOARD™ are trademarks of Seagate Tech­nology, Inc. Other product names are registered trade­marks or trademarks of their owners.

No part of this publication may be reproduced in a n y
form without written permission from Seagate Tech­nology, Inc.

ST12450W/WD Installation Guide, Rev. B 1

Preface

This manual contains information for users of the
Seagate® ST12450W/WD Barracuda™ SCSI disc
drives. It provides support services, performance speci­fications, and initial setup information. Additional infor­mation is available in the

Manual

sales representative if you need to order this publication.

Electrostatic discharge protection
Caution. Removal of circuit boards by personnel not

All drive electronic assemblies are sensitive to static
electricity, due to the electrostatically sensitive devices
used within the drive circuitry. Although some devices
such as metal-oxide semiconductors are extremely sen­sitive, all semiconductors, as well as some resistors and
capacitors, may be damaged or degraded by exposure
to static electricity.

Electrostatic damage to electronic devices may be
caused by the direct discharge of a charged conductor
or by exposure to the static fields surrounding charged
objects. To avoid damaging drive electronic assemblies,
observe the following precautions when installing or
servicing the drive:

(part number 83328900). Contact your Seagate

performing depot repair will damage com­ponents and may void the warranty.

Barracuda 2, 2HP Product

2 ST12450W/WD Installation Guide, Rev. B

• Ground yourself to the drive whenever the drive elec-

tronics are or will be exposed. Connect yourself to

ground with a wrist strap (Seagate part number

12263496). Connection may be made to any grounded

metal assembly. As a general rule, remember that you

and the drive electronics must all be grounded to avoid

potentially damaging static discharges.

• Turn off the power before removing or installing the DC

power cable.

• Do not remove any circuit boards from the drive.

• Never use an ohmmeter on any circuit boards.

Important safety information and precautions
Caution. Use forced-air ventilation when bench-testing

the drive to ensure proper cooling of drive
components.

Use proper safety and repair techniques for safe, reliable
operation of this unit. Service should be done only by
qualified persons. We recommend the procedures in this
manual as effective ways of servicing the unit. Some
procedures require the use of special tools. For proper
maintenance and safety, you must use these tools as
recommended.

The procedures in this manual and labels on the unit
contain warnings and cautions that must be carefully

ST12450W/WD Installation Guide, Rev. B 3
read and followed to minimize or eliminate the risk of

personal injury. The warnings point out conditions or
practices that may endanger you or others. The cautions
point out conditions or practices that may damage the
unit, possibly making it unsafe for use.

These warnings and cautions are not exhaustive. We
cannot possibly know, evaluate, and advise you of all the
ways in which maintenance might be performed or the
possible risk of each technique. Consequently, we have
not completed any such broad evaluation. If you use a
non-approved procedure or tool, first ensure that the
method you choose will not risk either your safety or unit
performance.

Always observe the following warnings and precautions:

• Perform all maintenance by following the procedures in
this manual.

• Follow all cautions and warnings in the procedures.

• Use sound safety practices when operating or repair­ing the unit.

• Use caution when troubleshooting a unit that has
voltages present. Turn off power to the unit before
servicing it.

• Wear safety shoes when removing or replacing heavy
parts.

4 ST12450W/WD Installation Guide, Rev. B

• Ensure that the internal temperature of the rack or
cabinet does not exceed the limits defined for the drive
when the drive is mounted in an equipment rack or
cabinet. When units are stacked vertically, pay special
attention to the top where temperatures are usually
highest.

• Follow the precautions listed above in “Electrostatic
discharge protection.”

• Do not remove any circuit boards from the drive chas­sis. Return the entire drive for depot repair if any circuit
board is defective. Removal of circuit boards by per­sonnel not performing depot repair will damage com­ponents and may void the warranty.

• Do not remove the head and disc assembly (HDA) from
the drive chassis. Return the entire drive for depot
repair if the HDA is defective.

• Do not attempt to disassemble the HDA. It is not field
repairable. If the sealed HDA is opened by personnel
not performing depot repair, this will damage compo­nents and void the warranty.

As a component, this drive is designed to be installed
and operated in accordance with UL1950, IEC950,
EN60950, CSA C22.2 950, and VDE0805.

Seagate takes all reasonable steps to ensure that its
products are certifiable to currently accepted stan-

ST12450W/WD Installation Guide, Rev. B 5
dards. Typical applications of these disc drives include

customer packaging and subsystem design. Safety
agencies conditionally certify component assemblies,
such as the Barracuda disc drive, based on their final
acceptability in the end-use product. The subsystem
designers are responsible for meeting these conditions
of acceptability in obtaining safety/regulatory agency
compliance in their end-use products and for certifying
where required by law. A necessary part of meeting
safety requirements is the provision for overcurrent
protection on drive SELV supply voltages.

This unit is a component part and as such is not meant
to comply with FCC or similar national requirements as
a stand-alone unit. Engineering radiated emissions test
results are available through the Seagate Safety Depart­ment to assist the subsystem designer.

Wichtige Sicherheitshinweise
Vorsicht. Beim Testen des Laufwerks auf dem

Prüftisch ist Fremdbelüftung vorzusehen, um eine
ausreichende Kühlung der Laufwerkkomponenten
sicherzustellen.

Verwenden Sie geeignete Sicherheits- und
Reparaturverfahren, um den sicheren, zuverlässigen
Betrieb dieser Einheit zu gewährleisten. Reparaturen
dürfen nur von qualifiziertem Fachpersonal

6 ST12450W/WD Installation Guide, Rev. B
vorgenommen werden. Wir empfehlen die Verfahren in

diesem Handbuch als effektive Methoden zur
Wartung und Reparatur der Einheit. Einige Verfahren
erfordern Spezialwerkzeuge; diese müssen zur
sachgemäßen Ausführung der Wartungsarbeiten und
aus Sicherheitsgründen den Empfehlungen
entsprechend verwendet werden.

Die Verfahren in diesem Handbuch und die Aufkleber
auf dem Gerät enthalten Warn- und Vorsichtshinweise.
Diese Hinweise sind sorgfältig durchzulesen und zu
beachten, um das Risiko von Verletzungen auf ein
Mindestmaß zu beschränken oder ganz zu vermeiden.
Die Warnhinweise machen auf Situationen oder Praktiken
aufmerksam, die Sie oder andere gefährden könnten.
Die Vorsichtshinweise machen auf Situationen oder
Praktiken aufmerksam, die die Einheit beschädigen
können, so daß deren Gebrauch mit Risiko behaftet ist.

Die Warn- und Vorsichtshinweise sind nicht
allumfassend! Es ist uns einfach nicht möglich, alle
Wartungsmethoden oder die eventuellen Risiken jeder
Methode zu kennen, zu beurteilen und Sie
entsprechend zu beraten. Aus diesem Grund haben
wir auf eine derartige umfassende Beurteilung
verzichtet. Falls Sie ein hier nicht beschriebenes
Verfahren oder Werkzeug verwenden, stellen Sie
zuerst sicher, daß das gewählte Verfahren weder Ihre

ST12450W/WD Installation Guide, Rev. B 7
persönliche Sicherheit noch die Leistung der Einheit

gefährdet.
Beachten Sie in jedem Fall die folgenden Warn-und

Vorsichtshinweise:

• Führen Sie alle Wartungsarbeiten entsprechend den
Anweisungen in diesem Handbuch aus.

• Beachten Sie alle Warn- und Vorsichtshinweise in
diesem Handbuch.

• Treffen Sie beim Betrieb oder bei der Reparatur der
Einheit angemessene Sicherheitsvorkehrungen.

• Wenn eine Einheit unter Spannung steht, gehen Sie
bei der Fehlerdiagnose besonders vorsichtig vor.
Schalten Sie die Einheit aus, bevor Sie mit den
Reparaturarbeiten beginnen.

• Tragen Sie Sicherheitsschuhe, wenn Sie schwere
Teile aus- bzw. einbauen.

• Wenn das Laufwerk in einem Einbaugestell oder
Gehäuse montiert ist, sorgen Sie dafür, daß die
Temperatur im Inneren des Gestells oder Gehäuses
die für das Laufwerk vorgegebenen Grenzwerte nicht
übersteigt. Wenn Einheiten vertikal übereinander
betestigt werden, achten Sie besonders auf den oberen
Stapelbereich, da dort die Temperatur gewöhnlich am
höchsten ist.

8 ST12450W/WD Installation Guide, Rev. B

• Befolgen Sie die oben unter “Electrostatic Discharge
Protection” angegebenen Sicherheitsmaßnahmen.

• Nehmen Sie keine Platinen aus dem Laufwerkgehäuse.
Wenn eine Platine defekt ist, muß das gesamte
Laufwerk zur Reparatur eingeschickt werden. Die
Herausnahme von Platinen durch anderePersonen als
die für die werkseitige Reparatur zuständigen kann zu
einer Beschädigung der Komponenten und Erlöschen
des Garantieanspruchs führen.

• Die vormontierte Kopf- und Festplatteneinheit (HDA)
nicht aus dem Laufwerkgehäuse nehmen! Falls die
HDA beschädigt ist, schicken Sie das gesamte
Laufwerk zur Reparatur ein.

• Die HDA ist nicht vor Ort reparierbar und darf nicht
auseinandergenommen werden! Öffnen der
versiegelten HDA durch andere Personen als die für
die werkseitige Reparatur zuständigen hat eine
Beschädigung der Komponenten und Erlöschen des
Garantieanspruchs zur Folge.

Als Teilkomponente ist dieses Laufwerk für die Installa­tion und den Betrieb in Übereinstimmung mit UL 1950,
IEC950, EN60950, CSA C22.2 950 und VDE0805
vorgesehen.

Seagate ist ständig bemüht, die Zulassungsfähigkeit
von Seagate-Produkten im Rahmen der gegenwärtig

ST12450W/WD Installation Guide, Rev. B 9
geltenden Standards zu gewährleisten. Zu den typischen

Anwendungen dieser Festplattenwerke zählen
Systemeinbau durch den Kunden und die Konstruktion
von Untersystemen. Sicherheitsbehörden gewähren eine
bedingte Zulassung für Komponenten wie das Barra­cuda-Festplattenlaufwerk vorbehaltlich der endgültigen
Zulasssung im Endprodukt. Designer von Untersystemen
sind dafür verantwortlich, die Voraussetzungen für die
Einhaltung sicherheits- oder aufsichtsbehördlicher
Vorschriften in ihren Endprodukten und - falls gesetzlich
vorgeschrieben - für die Zulassung zu schaffen.
Eine Grundvoraussetzung zur Einhaltung der
Sicherheitsanforderungen ist die Bereitstellung
eines Überlastschutzes für die SELV­Versorgungsspannungen des Laufwerks.

Dieses Gerät ist eine Baugruppe und unterliegt als
solche nicht den Anforderungen der FCC oder ähnlicher
nationaler Behörden für eigenständige Geräte.
Technische Testergebnisse zu elektromagnetische
Strahlung sind für Designer von Untersystemen auf
Anfrage von der Seagate-Sicherheitsabteilung
erhältlich.

10 ST12450W/WD Installation Guide, Rev. B

Technical support services

Seagate Technology provides technical support litera­ture and diagnostic utilities to authorized distributors.
Please contact your dealer for technical support and
installation troubleshooting. Product technical support
is available for all Seagate products by calling the
SeaFAX™, SeaFONE™, SeaTDD™, or SeaBOARD™
services. These are toll calls if you dial from outside of
the number’s local dialing area.

SeaFAX:
USA [phone]; England 44-62-847-7080

You can use a touch-tone telephone to access Seagate’s
automated FAX delivery system and select technical
support information by return FAX. This service is avail­able 24 hours a day, 7 days a week.

CompuServe Forum

Online support for Seagate products is available on
CompuServe. Type "Go Seagate" to access the Seagate
forum. This service is available 24 hours a day, 7 days
a week.

SeaFONE: [phone]

Technical support specialists are available to answer
questions from 8:00 A.M. to 5:00 P .M. PST, Monday
through Friday. Recordings are accessible 24 hours a
day, 7 days a week.

ST12450W/WD Installation Guide, Rev. B 11

SeaTDD: [phone]

TDD is a telecommunication device for the deaf where
two people can communicate using a keyboard that is
connected to the phone line. A TDD device is required to
access this service, which is available from 8:00 A.M. to
5:00 P.M. PST, Monday through Friday.

SeaBOARD:

The Seagate Technical Support Bulletin Board System
(BBS) is available 24 hours a day, 7 days a week. A
modem is required to access this service. The commu­nications software must be set for eight data bits, no
parity, and one stop bit (8N1), 9600 baud max.

With this service you can access:

• Specifications and jumper configurations

• Reprints of Seagate documentation

• Utilities that you can download to your own computer

Location Modem number

USA, Mexico, Latin America [phone]
England 44-62-847-8011
Germany 49-89-140-9331
Singapore 65-292-6973
Australia 61-2-756-2359
Canada [phone]
France 33-1-40 67 10 34
Korea 82-2-556-7294

12 ST12450W/WD Installation Guide, Rev. B

General description

Barracuda 2, 2HP SCSI disc drives are high-speed,
random-access data storage devices. Two-head par­allel technology effectively doubles the internal data
transfer rate when compared to non-parallel head
technologies.

ST12450W/WD drives are illustrated in Figure 1. Speci­fications and DC power requirements for the drives are
listed in tables following the figure.

The drive is a component for installation in an enclosure
designed for the drive. This is often a rack within the
system or an external enclosure designed to house one
or more disc drives or other peripheral units. In either
case, the disc drive must receive adequate cooling (refer
to “Providing adequate cooling”) and it must be suffi­ciently grounded and shielded from emissions. The

Barracuda 2, 2HP Product Manual

83328900) contains guidelines for a properly designed

enclosure.

(part number

ST12450W/WD Installation Guide, Rev. B 13

SCSI I/O

Connector

J5

J4

DC Power
Connector

Figure 1. Barracuda 2, 2HP disc drive

J01

14 ST12450W/WD Installation Guide, Rev. B

Characteristics ST12450W/WD

Interface Fast & Wide SCSI-2
Cache type

Multi-segmented 1,024 Kbytes

Capacity

Unformatted 2,437 Mbytes
Formatted

2

1,849 Mbytes

Recording

Cylinders (user accessible) 2,710
Heads (physical) 18
Heads (logical) 9
Modulation RLL 1,7 code

SCSI rate

Max burst transfer 20 Mbytes/sec

Seek time

3

Average read 8.0 msec
Average write 9.0 msec

Disc rotation

RPM 7,200
Average latency 4.17 msec

1

Can also be operated according to SCSI-1 protocol.

2

Standard factory units are formatted as follows:

512 data bytes per sector
9 spare sectors per cylinder
1 cylinder at the inner track reserved for spares

3

Not including on-board controller overhead.

1

ST12450W/WD Installation Guide, Rev. B 15

DC power requirements

Single-ended Differential

++

++

+5V

+12V

++

Voltage regulation

5

±±

± 5%

±±

++
±±

± 5%

±±

Maximum operating current11.32 0.91 1.65 0.91
Maximum starting current

Peak DC

Peak AC
Delayed motor start (max)
Peak operating current

Typ DC

Max DC

3, 6
3

1,10

1

1.3 2.18 1.43 2.18
– 3.1 – 3.1

4

1.25 1.5 1.31 1.5

1.3 0.84 1.6 0.84

1.32 0.91 1.65 0.91

Max (peak) 1.4 1.85 2.4 1.85
Track following (DC)

Read track

at OD

1

at ID

OD DC

1

1, 13

1.3 0.78 1.4 1.85

1.3 0.82 1.4 0.78

1.4 0.81 1.9 0.81

AC 1.5 1.16 2.5 1.16

Seeking

Typical DC

Maximum DC

1, 12

1

1.3 1.06 1.4 1.06

1.3 1.14 1.44 1.14

Maximum (peak) AC 1.3 1.85 2.2 1.85

2

Amps

++

+5V

++
±±

± 5%

±±

++

+12V

++
±±

± 5%

±±

2

1

Measured with an average reading DC ammeter. Instanta­neous +12V current peaks will exceed these values.

16 ST12450W/WD Installation Guide, Rev. B

2

A –10% tolerance is permissible during initial start of the
spindle but must return to ±5% before reaching 7,200 RPM.
The ±5% must be maintained after the drive signifies that its
power-up sequence has been completed and that the drive
is able to accept selection by the host initiator.

3

See the +12V current profile in the

Product Manual

4

This condition occurs when the Motor Start option is en-

(publication number 83328900).

abled and the drive has not yet received a Start Motor
command.

5

See “Conducted noise immunity” in the

Product Manual.

The specified voltage tolerance is inclu-

sive of ripple, noise, and transient response.

6

At power-up, the motor current regulator limits the +12V
current to an average value of less than 2.0A, although
instantaneous peaks may exceed this value. These peaks
should measure 5 msec duration or less.

7

Minimum current loading for each supply voltage is not less
than 3% of the maximum operating current shown.

8

Use separate ground returns for +5 and +12V supplies.

9

Where power is provided to multiple drives from a common
supply, carefully consider individual-drive power require­ments. Where multiple units are powered on simultaneously,
be sure the peak starting current is available to each device.

10

Operating condition is a third-stroke seek at OD and Read
One Track. The command is issued every 0.07 seconds for
ST12450WD models and every 0.075 seconds for
ST12450W models.

Barracuda 2, 2HP

Barracuda 2, 2HP

ST12450W/WD Installation Guide, Rev. B 17

11

No terminator power. See Section 11.7.3.4 in the

cuda 2, 2HP Product Manual.

12

Seeking is defined as a third-stroke seek at OD. The
command is issued every 20 msec.

13

Read track is defined as repeat reads of track 15 with a
60% duty cycle.

Barra-

Initial setup information

The following topics are presented to guide you through
the installation process. These topics are presented in
the order you should follow to properly install the drive.

• Setting the SCSI ID jumpers

• Terminating the drive

• Changing other applicable jumper options

• Synchronizing spindles in multiple-drive configurations
(optional)

• Providing adequate cooling

• Mounting the drive and connecting cables

• Formatting the drive

Several illustrations are provided to make the installation
process easy.

Write down the original jumper settings before you make
any changes. This makes it easy to revert to the original
configuration if necessary.

18 ST12450W/WD Installation Guide, Rev. B

Setting the SCSI ID jumpers

Each device on the SCSI chain must have a unique SCSI
ID. The host system’s SCSI controller usually uses the
highest-numbered ID available (ID15 in wide systems);
therefore the lower-numbered SCSI IDs are normally
used for the other SCSI devices such as this Barracuda
disc drive.

Note. Most SCSI controllers (host adapters) allow you to

skip a SCSI ID. For example, you can have ID0,
ID1, and ID3 (skipping ID2). Other controllers do
not allow this so be sure to refer to your system or
controller user’s manual for details about its re­quirements for proper SCSI device installation.

Use connector J5 to set the SCSI ID (Figure 2). Most
Barracuda disc drives are factory set with the SCSI ID
set at 0. To change the SCSI ID, install jumpers on the
appropriate pins as shown in the illustration.

If, after completing the installation process, the drive’s
LED does not show on/off activity when the host is trying
to communicate with the drive, a duplicate SCSI ID may
be the problem. If this is the case, change the ID so that
each device on the SCSI chain has its own unique ID.
Also check your system or controller user’s manual to
ensure that you have not violated its SCSI ID numbering
recommendations.

ST12450W/WD Installation Guide, Rev. B 19

SCSI I/O

Connector

Pin 1

J5

ID3

ID2

J5

SCSI ID = 0 (default)
SCSI ID = 1

SCSI ID = 2
SCSI ID = 3
SCSI ID = 4
SCSI ID = 5
SCSI ID = 6
SCSI ID = 7
SCSI ID = 8
SCSI ID = 9
SCSI ID = 10
SCSI ID = 11
SCSI ID = 12
SCSI ID = 13
SCSI ID = 14
SCSI ID = 15

Figure 2. Setting the SCSI ID

Pin 1

4P 3P 2P 1P

ID1

ID0

DC Power
Connector

20 ST12450W/WD Installation Guide, Rev. B

Terminating the drive

If you are installing a Barracuda 2, 2HP drive in a system
that has other SCSI devices installed, terminate only the
end devices on the SCSI chain. A SCSI “device” is any
disc drive, scanner, tape-backup unit, or other piece of
hardware connected to your system using the SCSI bus.

The top example in Figure 3 shows an internal hard disc
at one end of the SCSI bus with the SCSI controller at the
other end (both are terminated). The bottom example
shows two additional SCSI devices connected exter­nally—this means the SCSI controller is no longer on the
end of the SCSI chain and should not be terminated.

Internal SCSI cable

Internal

SCSI device

Internal

SCSI device

Internal SCSI cable

Internal

SCSI device

Internal

SCSI device

Terminate

Controller

Terminate

Figure 3. SCSI bus termination

Controller

External

SCSI
cable

External

SCSI device

External

SCSI device

ST12450W/WD Installation Guide, Rev. B 21
ST12450W (single-ended) drives are terminated with

permanently mounted active IC terminators. If you install
an ST12450W drive and it is not on the end of the
SCSI bus, remove the jumper from pins 11 and 12 of
connector J4 (see Figure 4). This disables the termina­tors on the drive. If you install an ST12450W drive on the
end of the SCSI bus, ensure that a jumper is installed on
pins 11 and 12 of connector J4.

Note. Use active t erminators when terminating the bus.
ST12450WD (differential) drives do not have internal

terminators or any other way of adding internal termina­tion to the drive. You must provide external termination
to these drives when termination is required.

Pin 1

Power

Connector

Drive Termination Options
Disable drive terminators.

Enable drive terminators.*

* Valid for single-ended drives only.

J4

J4

Figure 4. Terminating ST12450W drives

J01

Pin 1

22 ST12450W/WD Installation Guide, Rev. B

Terminator power

ST12450W drives may be conf igured in four d iffere nt
ways (see F igure 5); however , yo u usually will not need
to change this option and should normally leave the
drive configured as it was shipped from the factory.
ST1 2450WD drives should be configured with a jumper
connecting J01 pins 1 and 3 (and no jumper on J01 pins
2 and 4 ) as illus t ra ted in Figure 5.

Power

Connector

*

Term. power from drive.
Term. power from SCSI bus.

*

Term. power to SCSI bus.

*

Term. power to SCSI bus and drive.
* Valid for single-ended drives only.

J4

J01

Pin 3

J01

Figure 5. Setting terminator power jumpers

Pin 1

Pin 1
Pin 2

ST12450W/WD Installation Guide, Rev. B 23

Changing other applicable jumper options

Barracuda 2, 2HP drives are designed for use in a variety
of systems. Unique installations may require you to
change one or more of the other jumpers to meet specific
system requirements; however, in most cases, you will
not need to change any of these jumpers for normal drive
operation. Figures 6a and 6b provide the information
necessary to configure all jumpers not discussed else­where in this manual.

Pin 1

J5

Remote LED Connector*
Pin 9 (top pin) is negative (cathode),

Pin 10 (bottom pin) is positive (anode).

*Note to subsystem designers: In Europe, a red LED indicates 
an error or warning condition. For this reason, you may want to 
use a color other than red with this connection.

J5

Figure 6a. Additional jumper options

24 ST12450W/WD Installation Guide, Rev. B

J4

Pin 1

J01

Reserved (RES)
Reserved for future use.

Parity Check option (PAR)
Enable parity check of SCSI bus data.

Disable parity check of SCSI bus data (default).
Motor Start option (MTR)

Enable motor start. This makes the drive wait for 
the Start Unit command from the host before starting 
the spindle motor.

Disable motor start. This causes the drive to start 
according to the Delay Motor Start option setting 
as described below (default).

Delay Motor Start option (DMS)
(valid only if the Motor Start option is disabled)

Motor start delay equal to the SCSI ID multiplied 
by 10 seconds , plus 3 additional seconds max. 
For example, if the SCSI ID = 2, the drive will delay 
for 23 seconds before starting.

Disable the delay motor start option (default).
Write Protect option (WP)

Write Protect = On (disables writing).
Write Protect = Off (enables writing – default).

EDT

PAR

RES

RES

RES

MTR

DMS

WP

J4

Figure 6b. Additional jumper options

ST12450W/WD Installation Guide, Rev. B 25

Synchronizing spindles
in multiple drive configurations

If you are installing two or more Barracuda drives, you
may (optionally) want to synchronize their spindles to
reduce the latency associated with switching from one
drive to another.

Spindle sync cables are used to connect the drives.
Use pins 11 and 12 on the J5 connector to attach the

spindle sync cable. Pin 11 provides the reference index
signal (REFSIG+) and pin 12 provides ground (GND).
See Figure 7.

SCSI I/O

Connector

Spindle Sync Cable Connector (SSC)
These pins are used to connect a
spindle sync cable.

Spindle sync reference index signal 
(REFSIG+).

Ground (GND).

Pin 1

J5

DC Power

Connector

SSC

J5

Figure 7. Spindle sync jumpers and connectors

26 ST12450W/WD Installation Guide, Rev. B
Figure 8 illustrates a typical synchronized spindle

configuration.
After connecting each drive with spindle sync cables,

you must designate a master spindle sync reference
source. This master source is normally a disc drive
located on the same SCSI bus as the other drives you
want to synchronize with. To designate a drive as the
master, use SCSI interface commands. Refer to the
product manual for information about using these
commands.

Sync Interface

Master Sync

Source

Host

(or other drive)

System

Interface

Spindle
Control

+5V

Drive 1

Spindle
Control

+5V

Drive 2

Spindle
Control

+5V

Drive n

Figure 8. Spindle sync diagram

J5

11
12

R

T

J5

11
12

R

T

J5

11
12

R

T

ST12450W/WD Installation Guide, Rev. B 27

Providing adequate cooling

The encl osure d es ig n must ensure ad equate c o oli ng
for the dr ive. The maximu m ambient temp erature is
50oC.

The dr ive’s produc t manual (83328900) describes how
to ev aluate the air -flo w de sign. T he e va lua tion c onsi sts
of ensuring that the case temperatures of certain critical
components remain within acceptable limits during
drive op eratio n.

We r ecommend orienting the drive or di recting the air
flow in a way that creates the least amount of air-flow
resistance while providing air flow above the circuit
boards and around the head and disc assembly (HDA ).
Also, choose the shortest possible path between the air
inlet and exit. This mi nimizes the d istan ce traveled by
air that is heated by the drive and by other nearby heat
sources.

Figure 9 sh ows two design ap proaches with one or
more fans used to generate air flow. The air-flow pat­terns can be created by the fans either pushing or
drawing air. The overall flow pattern can be directed
from front to back, back to front, or side to side.

28 ST12450W/WD Installation Guide, Rev. B

Kühlung des Systems

Die Gehäusekonstruktion muß eine ausreichende
Kühlung des Laufwerkes gewährleisten. Die
Umgebungstemperatur darf maximal 50oC betragen.

Die Produkthandbuch Barracuda 2, 2HP (Dokument

83328900) enthalten Anweisungen zur Beurteilung der
Luftstromkonstruktion. Die Beurteilung muß sicherstellen,
daß sich die Gehäusetemperatur bestimmter kritischer
Komponenten bei Laufwerkbetrieb innerhalb
zugelassener Grenzen hält.

Wir empfehlen, das Laufwerk so zu orientieren oder den
Luftstrom so zu lenken, daß der geringste
Luftstromwiderstand erzeugt wird und gleichzeitig ein
Luftstrom über den Platinen und um die Kopf- und
Festplatteneinheit (HDA) gegeben ist. Wählen Sie einen
möglichst kurzen Weg zwischen Lufteinlaß und -auslaß.
Dadurch wird die Strecke, die die vom Laufwerk und
anderen nahegelegenen Hitzequellen aufgewärmte Luft
zurücklegt, auf ein Minimum beschränkt.

Abbildung 9 zeigt zwei Konstruktionsmöglichkeiten, bei
denen ein oder mehrere Lüfter den Luftstrom erzeugen.
Der Luftstromverlauf wird durch die Lüfter gesteuert, die
entweder Luft einblasen oder abziehen. Generell kann
der Luftstrom entweder von vorne nach hinten oder von
hinten nach vorne verlaufen.

ST12450W/WD Installation Guide, Rev. B 29

Above unit
Über der Einheit

Note. Air flows in the direction shown (back to front)
or in reverse direction (front to back)

Hinweis. Luftstrom in der angezeigten Richtung
(von vorne nach hinten) oder in umgekehrter
Richtung (von hinten nach vorne)

Note. Air flows in the direction shown or
in reverse direction (side to side)

Hinweis. Luftstrom in der angezeigten Richtung oder in
umgekehrter Richtung (von Seite zu Seite)

Figure 9. Suggested air flow
Abbildung 9. Empfohlener Luftstromverlauf

Under unit
Unter der Einheit

Above unit
Über der Einheit

Under unit
Unter der Einheit

30 ST12450W/WD Installation Guide, Rev. B

Mounting the drive and connecting cables

Do not touch the connector pins or any components on
the control board without observing static-discharge
precautions. Always handle the drive by the frame only.

The drive may be mounted in any orientation (horizon­tally, vertically, and any combination thereof); however,
you must ensure that the drive receives adequate air
flow for cooling.

1. Mount the drive to the host system’s chassis using
four 6-32 UNC screws. Two mounting holes are in
each side of the drive and there are four mounting
holes in the bottom of the drive.

The maximum length that the screws should ex­tend into the chassis mounting holes is 0.15 inch
(3.81 mm), measured from the outer surface of the
chassis. Tighten the screws down evenly. Do not
over-tighten or force the screw if it does not seem to
screw in easily, because this means the threads are
not properly aligned. In this case, back the screw out
and try again.

ST12450W/WD Installation Guide, Rev. B 31

Installation des Laufwerkes
und Anschluß der Kabel

Beachten Sie beim Handhaben und Anfassen der
Anschlußstifte und Komponenten die
Vorsichtsmaßnahmen zur Verhinderung statischer
Aufladung. Fassen Sie das Laufwerk nur am Rahmen an.

Das Laufwerk kann in beliebiger Orientierung (horizon­tal, vertikal oder schräg) installiert werden; jedoch muß
dafür gesorgt werden, daß ein ausreichender Luftstrom
zur Kühlung des Laufwerkes vorhanden ist.

1. Befestigen Sie das Laufwerk mit vier 6-32-UNC­Schrauben am Gehäuse des Host-Systems. Die
beiden Seiten des Laufwerkes sind mit jeweils zwei
Befestigungslöchern versehen, die Unterseite des
Laufwerkes weist vier weitere Befestigungslöcher
auf.

Gemessen von der Außenfläche des Gehäuses dürfen
die Schrauben maximal 3,81 mm in die
Befestigungslöcher des Gehüuses hineinragen. Die
Schrauben müssen gleichmäßig, jedoch nicht zu
fest, angezogen werden. Wenn sich eine Schraube
nicht ohne Widerstand einschrauben läßt, sind die
Gewinde nicht korrekt aneinander ausgerichtet. In
diesem Fall die Schraube nicht in das Gewindeloch
forcieren, sondern die Schraube herausnehmen und
erneut in das Gewindeloch einführen.

32 ST12450W/WD Installation Guide, Rev. B

2. Verify that all connections between the drive and the
host system are correctly installed.

2. Prüfen Sie, ob alle Verbindungen zwischen dem
Laufwerk und dem Host-System korrekt hergestellt
sind.

3. Verify that you have correctly installed jumpers (see
Figures 2, 4, 5, and 6).

3. Stellen Sie sicher, daß die Kennungsbrücken installiert
sind. Siehe Abbildung 2, 4, 5, und 6.

4. Connect the 50-pin SCSI cable into the drive’s SCSI
connector (shown earlier in Figure 1). Take care not
to stretch or crimp this cable, and do not block the
system’s cooling air flow with the cable.

The drive receives DC power through a 4-pin connec­tor mounted next to the SCSI connector. The output
of a power supply must meet SELV (safety extra low
voltage) as defined in IEC 950. Figure 10 provides the
pin information for the DC power connector. To con­nect the DC power cable to the drive, insert the cable
end into the drive’s DC power connector.

4. Schließen Sie das 50-polige SCSI-Kabel an den
SCSI-Steckverbinder des Laufwerkes an (wie bereits
in Abbildung 1 gezeigt). Das Kabel darf nicht gedehnt

ST12450W/WD Installation Guide, Rev. B 33

oder gedrückt werden und es darf den Luftstrom zur
Kühlung des Systems nicht behindern.

Das Laufwerk wird über einen 4-poligen, neben dem
SCSI-Anschluß befestigten Steckverbinder mit
Gleichstrom versorgt. Der Ausgang eines Netzteils
muß SELV (safety extra low voltage) nach IEC 950
entsprechen. Abbildung 10 zeigt die Steckerbelegung
für den Gleichstromanschluß. Zum Anschluß des
Gleichstromkabels an das Laufwerk das Kabelende
in den Gleichstromanschluß des Laufwerkes stecken.

Pin

Pin

Power

1

+12V

2

+12V return

3

+ 5V return

4

+ 5V

4321

Figure 10. DC power connector
Abbildung 10. Gleichstromanschluß

Gleichstrom

1

+12 V

2

+12 V Rückleitung

3

+ 5 V Rückleitung

4

+ 5 V

34 ST12450W/WD Installation Guide, Rev. B
Note. Signal ground on the power control board (PCB)

and the head and disc assembly (HDA) are con­nected together in this drive and you cannot sepa­rate them. The equipment in which you have
mounted the drive is connected directly to the HDA
and PCB without electrically isolating shock mounts.
Maximizing the conductive contact area between
HDA ground and system ground may reduce radi­ated emissions. If you do not want the system
chassis to be connected to the HDA/PCB ground,
you must provide a nonconductive (electrically
isolating) method of mounting the drive in the host
system. This may increase radiated emissions and
is the system designer’s responsibility.

Hinweis:

Die Signalerde auf der Stromregelungskarte (PCB)
und der Kopf- und Festplatteneinheit (HDA) sind in
diesem Laufwerk miteinander verbunden und
können nicht getrennt werden. Das Gerät, in das
Sie das Laufwerk eingebaut haben, ist ohne
elektrisch isolierende Stoßdämpfer direkt an die
HDA und PCB angeschlossen. Die
elektromagnetische Strahlung kann reduziert
werden, indem Sie eine möglichst große leitende
Kontakfläche zwischen der HDA-Erdung und der
Systemerdung vorsehen. Wenn Sie das

ST12450W/WD Installation Guide, Rev. B 35

Systemgehäuse nicht an die HDA/PCB-Erdung
anschließen wollen, müssen Sie das Laufwerk
auf nichtleitende Weise (galvanisch isoliert) im
Host-System einbauen. Die daraus u.U.
resultierende verstärkte elektromagnetische
Strahlung fällt in den Zuständigkeitsbereich des
Systemdesigners.

5. Replace the host system’s cover.

5. Setzen Sie das Gehäuseoberteil des Host-Systems
wieder auf.

36 ST12450W/WD Installation Guide, Rev. B

Formatting the drive
Warning. Formatting a drive erases all user data. Be

sure that you understand this principle before
formatting any hard disc drive.

It is not necessary to format a drive which has
previously been used to store data, unless
your intention is to erase all user data.

1. Turn on DC power.

2. Boot the system from a system floppy disc or from a
previously installed hard disc drive if there is one.

3. Format the disc drive. The Barracuda 2, 2HP disc
dri ve i s des ign ed to oper ate with a variety of opera ting
systems; therefore, please refer to your system or
SCSI controller manuals for information about for­matting and setting up the drive.

Seagate Technology, Inc.
920 Disc Drive, Scotts Valley, CA 95066-4544, USA

Publication Number: 83328890, Rev. B, Printed in USA