Seagate ST34571N-W-WC-WD-DC, ST34371N-W-WC-WD-DC, ST32171N-W-WC-WD-DC, ST32271N-W-WC-WD-DC User Manual

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Barracuda 4LP

••••••••••••••••••••••••••

Disc Drive

••••••••••••••••••••••••••

ST34371N/W/WC/WD/DC

••••••••••••••••••••••••••

ST32171N/W/WC/WD/DC

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ST34571N/W/WC/WD/DC

••••••••••••••••••••••••••

ST32271N/W/WC/WD/DC

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Installation Guide

Contents

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

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

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

Wichtige Sicherheitshinweise ......................................................4

European Union Compliance....................................................... 7

Technical support services...........................................................8

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

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

Kühlung des Systems................................................................27

Installation des Laufwerkes

und Anschluß der Kabel.......................................................... 29

N drives section......................................................................... 36

W/WD drives section ................................................................. 40

WC/DC drives section................................................................45

©1997 Seagate Technology, Inc. All rights reserved
Publication Number: 77767492, Rev. B
January 1997

Seagate, S eagate Technology, and the Seagate logo are regis-

tered trademarks of Seagate Technology, Inc. Barracuda,
SeaFAX, SeaFONE, SeaNET, SeaTDD, and SeaBOARD are
either trademarks or register ed trademarks of Seagate Technol­ogy, Inc. or one of its subsidiaries. All other trademarks or regis­tered trademarks are the property of their respective owners.

No part of this publication may be re pro duced in any form without
written permission from Seagate Technology, Inc.

Barracuda 4LP Installation Guide, Rev. B 1

Preface

This manual contains information for users of the Seagate®
Barracuda 4LP SCSI disc drives. It provides support services,
performance specifications, and initial setup information. Addi­tional information is available in the

Manual

(part number 77767491). Contact your Seagate sales

representative if you need to order this publication.

Electrostatic discharge p rotecti on

Caution. Removal of circuit boards by personnel not perform-

ing depot repair will damage components and may

void the warranty.
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:

• Ground yourself to the drive whenever the drive electronics

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.

Barracuda 4LP Product

2 Barracuda 4LP Installation Guide, Rev. B

• 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.

• When installing the drive on a carrier or tray, discharge the

carrier or tray prior to inserting it into the system.

Important safety inform ati on and precau tions

Caution. Use forced-air ventilation when bench-testing the

drive to ensure proper cooling of drive components.
Use proper safety techniques for safe, reliable operation of this

unit.
The procedures in this manual and labels on the unit contain

warnings and cautions that must be carefully 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.

Always observe the following warnings and precautions:

• Follow all cautions and warnings in the procedures.

• Use sound safety practices when operating, installing, or

removing the unit.

• Use caution when troubleshooting a unit that has voltages

present. Turn off power to the unit before removing it.

• 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

Barracuda 4LP Installation Guide, Rev. B 3

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. 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. Return the entire drive for depot repair if the HDA is
defective.

• Do not attempt to disassemble the HDA. It is not field repair-

able. 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 d esigned to be installe d and op er­ated in accordance with UL1950, EN60950, CSA C22.2 950­M89, and VDE0805.

Seagate takes all reasonable steps to ensure that its products
are certifiable to currently accepted standards. 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
accepta b il ity 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 protect ion on drive SELV supply voltages.

4 Barracuda 4LP Installation Guide, Rev. B
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 Sich erh eitsh in wei se

Vorsicht. Beim Testen des Laufwerks auf dem Prüftisch ist

Fremdbelüftung vorzusehen, um eine ausreichende Kühlung der
Laufwerkkomponenten sicherzustellen.

Verwenden Sie geeignete Sicherheits- um den sicheren, zuver­lässigen Betrieb dieser Einheit zu gewährlei sten.

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 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
persönliche Sicherheit noch die Leistung der Einheit gefährdet.

Barracuda 4LP Installation Guide, Rev. B 5
Beachten Sie in jedem Fall die folgenden Warn-und Vorsicht-

shinweise:

• Beachten Sie alle Warn- und Vorsichtshinweise in diesem

Handbuch.

• Treffen Sie beim Betrieb, bei der Installation oder bei der

Entfernung 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 Installations-und Entfernung­sarbeiten beginnen.

• 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.

• Befolgen Sie die oben unter “Electrostatic Discharge Protec-

tion” angegebenen Sicherheitsmaßnahmen.

• Nehmen Sie keine Platinen aus dem Laufwerk. Wenn eine

Platine defekt ist, muß das gesamte Laufwerk zur Reparatur
eingeschickt werden. Die Herausnahme von Platinen durch
andere Personen als die für die werkseitige Reparatur zustän­digen kann zu einer Beschädigung der Komponenten und
Erlöschen des Garantieanspruchs führen.

6 Barracuda 4LP Installation Guide, Rev. B

• Die vormontierte Kopf- und Festplatteneinheit (HDA) nicht aus

dem Laufwerk nehmen! Falls die HDA beschä dig t ist, schicken
Sie das gesamte Laufwerk zur Reparatur ein.

• Die HDA ist nicht vor Ort reparierbar und darf nicht auseinan-

dergenommen 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 Teilkom ponente ist dieses Laufwerk für die Installation und
den Betrieb in Übereinstimmung mit UL 1950, EN60950, CSA
C22.2 950-M89 und VDE0805 vorgesehen.

Seagate ist ständig b emüht, die Zulassungsf ähigkeit von
Seagate -Produk ten im Rah men der ge genw ärtig gelten den
Standards zu gewährleisten. Zu den typischen Anwendungen
dieser Festplattenwerke zählen Systemeinbau durch den
Kunden un d die Ko nstruk tion von Unt ersystemen. Sicherheits­behörden gewähren eine bedingte Zulassung für Komponenten
wie das Barracuda-Festplattenlaufwerk vorbeha ltlich der
endgültigen Zulasssung im Endprodukt. Designer von Untersys­temen sind dafür verantwortlich, die Voraussetzungen für die
Einhaltung sicherhe its- oder aufsichtsbehö rdl ich er Vorschri ften
in ihren Endprodukten und - falls gesetzlich vorgeschrieben - für
die Zulassung zu schaffen. Eine Grundvoraussetzung zur Ein­haltung der Sicherhei tsanforde rungen ist d ie Bereitst ellung
eines Überlastschutzes für die SELV-Versorgungsspannungen
des Laufwerks.

Dieses Gerät ist ei ne Baugruppe und unt erliegt als solche nicht
den Anforderungen der FCC oder ähnlicher nationaler Behörden
für eigenständige Geräte. Technische Testergebnisse zu elektro-

Barracuda 4LP Installation Guide, Rev. B 7
magnetische Strahlung sind für Designer von Untersystemen auf

Anfrage von der Seagate-Sicherheitsabteilung erhältlich.

European Uni on Compl iance

If this model has the CE Marking, it complies with the European
Union requirements of the Electromagnetic Compatibility Di rec­tive 89/336/EEC of 03 May 1989 as amended by Directive 92/
31/EEC of 28 April 1992 and Directive 93/68/EEC of 22 July

1993.
Seagate uses an independent laboratory to confirm compliance

to the above directives. The drive was tested in a representative
system for typical applications. The sele cted system represents
the most popular characteristics for test platforms. The system
configurations include:

• 486, Pentium, and PowerPC Microprocessors

• 3.5-inch Floppy Disc Drive

• Keyboard

• Monitor/Display

• Mouse

• Printer
Although the test system with this Seagate model complies to

the directives, we cannot guarantee that all systems will comply.
The computer manufacturer or system integrator shall confirm
EMC compliance and provide CE Marking for their product.

8 Barracuda 4LP Installation Guide, Rev. B

Technical support services

If you need assistance installing your drive, consult your dealer.
Dealers are familiar with their unique system configurations and
can help you with system conflicts and other technical issues. If
you need additional assistance with your Seagate
other Seagate products, use one of the Seagate technical sup­port services listed below.

SeaFONE® at 1-800-SEAGATE (1-800-732-4283)

Seagate’s 800 number allows toll-free access to automated self­help services, providing answers to commonly asked questions,
troubleshooting tips, and specifications for disc drives and ta pe
drives. This service is available 24 hours daily and requires a
touch-tone phone. If you need to speak to a technical support
engineer, dial this number and listen to the options for technical
support. (International callers can also reach this automated
self-help service by dialing 408-4 56-4496).

Seagate Technology online services

Using a modem, you can obtain troubleshooting tips, free utility
programs, drive specifications and jumper settings for Seagate’s
entire product line. You can also download software for installing
and analyzing your drive.

SeaNET

You can obtain technical information on Seagate drives, Seagate
software, and mu ch more ove r the Internet fro m Seagate’s
World Wide Web hom e page (http ://www.seagate.co m) or
Seagate’s ftp server (ftp://ftp.seagate.com).

™

®

drive or

Barracuda 4LP Installation Guide, Rev. B 9

SeaBOARD

SeaBOARD is a computer bulletin board system (BBS) that con­tains information about Seagate’s disc and tape drive products
and is available 24 hours daily. Set your communications soft­ware to eight data bits, no pari ty, and one stop bit (8-N-1). Sea­BOARD phone numbers are listed in the following table.

BBS Location Modem number

United States Disc: 408-434-1080;
England 44-1628-478011

France 33 1-48 25 35 95
Germany 49-89-140-9331
Singapore 65-292-6973
Thailand 662-531-8111
Australia 61-2-9756-2359
Taiwan 886-2-719-6075

®

Tape: 408-456-4415

Seagate Compu S erve Fo ru m

Online technical support for Seagate products is available on
CompuServe. To access our technical support forum, type

seagate

SeaBOARD. In addition, you can type questions or browse
through previous questions and answers on the forum mes­sages.

. This forum provides information similar to that found on

go

10 Barracuda 4LP Installation Guide, Rev. B

Seagate Technology FAX services
SeaFAX

You can use a touch-tone telephone to access Seagate’s auto­mated FAX system to receive technical support information by
return FAX. This service is available 24 hours daily.

Location Telephone number

United States 1-800-SEAGATE or 408-456-4496
England 44-1628-894084
Australia 61-2-9756-5170

®

Seagate techn ical suppo rt FAX

You can FAX questions or comments to technical support spe­cialists 24 hours daily. Responses are sent during business
hours.

Location FAX number

United States 408-944-9120
England 44-1628-890660
France 33 1-46 04 42 50
Germany 49-89-1430-5100
Australia 61-2-9725-4052
Singapore 65-293-4722
Hong Kong 852-2368 7173
Taiwa n 886-2-715-2923
Korea 82-2-556-7294/4251

Seagate techn ical suppo r t

You can talk to a technical support specialist during business
hours Monday through Friday for one-on-one technical help.

Barracuda 4LP Installation Guide, Rev. B 11
Before calling, note your system configuration and dri ve model

number (ST

xxxx

). There are several technical support phone

numbers available for various Seagate products.

Location Telephone number

United States Please dial 1-800-SEAGATE for the specific

product telephone number. (6:00
1 1:15

A.M., 12:30 P.M. to 5:00 P.M., M–F)

England 44-1628-894083 (10:00

2:00

P.M. to 5:00 P.M., M–F)

France 33 1-41 86 10 86 (9:30

2:00

P.M. to 5:00 P.M., M–F)

A.M. to 1:00 P.M.,

A.M. to 12:30 P.M.,

A.M. to

Germany Disc: 49-89-140-9332; Tape: 49-89-140-9333

(9:30

A.M. to 12:30 P.M., 2:00 P.M. to 4:00 P.M.,

M–F)
Australia 61-2-9725-3366
Singapore 65-290-3998 or 65-485-3998 (9:00

12:00

P.M., 2:00 P.M. to 5:00 P.M., M–F)

A.M. to

Hong Kong 852-2368 9918
Taiwan 886-2-514-2237
Korea 82-2-556-8241

SeaTDD™ 408-944-9121

Using a telecommunications device for the deaf (TDD), you can
send questions or comments 24 hours daily and exchange mes­sages with a technical support specialist between 6:00
11:15

A.M. and 12:30 P.M. to 5:00 P.M. (Pacific time) Monday

through Friday.

A.M. to

12 Barracuda 4LP Installation Guide, Rev. B

General description

Barracuda 4LP SCSI disc drives are high-speed, random-access
digital-data storage devices.

The drive i s a componen t for installation in an enclos ure
designed for the drive. This is often a rack within the system or
an external enclosure designed to house one or more disc d rives
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

77767491) contains guidelines for a properly designed
enclosure.

Barracuda 4LP Pr oduct Manual

(part num ber

*

*Model “N” versio n with 50-pin SCSI I/O connector

Figure 1. Barracuda 4LP family drive

Barracuda 4LP Installation Guide, Rev. B 13

Table 1. Drive characteristics

Interface UltraSCSI [1]
Capacity Formatted [2] Unformatted

ST34371 4.35 Gbyte [2] 5.31 Gbyte
ST32171 2.16 Gbyte [2] 2.65 Gbyte
ST34571 4.55 Gbyte [2] 5.54 Gbyte
ST32271 2.26 Gbyte [2] 2.77 Gbyte

Recording

Cylinders (user) 5,178
Read/write data heads

ST32171/ST32271 5
ST34371/ST34571 10

Access time [3]

Average read 9.4 msec
Average write 10.4 msec

Disk rotation

RPM 7,200 r/min
Average latency 4.17 msec

Internal transfer rate (vari abl e with z one)

ST32171/ST34371 80–122 Mbits/sec
ST32271/ST34571 80–126 Mbits/sec

Maximum synchronous SCSI transfer rate

N model 20 Mbytes/sec
W/WD/WC/DC models 40 Mbytes/sec

Multi-segmented cache 442 Kbytes

[1] Can also be operated according to SCS I-1 and SCSI-2 pro tocols.

Referred to also as “SCSI Fast-20.”

14 Barracuda 4LP Installation Guide, Rev. B

[2] Standard facto ry unit s are fo rmatted 512 da ta byte s per secto r wit h

sparing equi valent to eight y spare sect ors per eight cylinder reg ion.
Spares are located at the end of each sparing regio n.

[3] Includes controller overhead.

Table 2a. DC power requirements (Amps)

ST34371/ST34571
N/W/WC
Single-ended

WD/DC
Differential

Voltage +5V +12V +5V +12V
Regulation [5] ±5% ±5%[2] ±5% ±5% [ 2]
Max. operating current

DC3σ [1] 0.81 0.95 1.21 0.95

Avg. idle current DCX

[1] 0.46 0.54 0.70 0.54

Max. starting current

(peak DC) DC3σ [3]
(peak AC) AC3σ [3]

0.78 2.44

3.1

1.1 2.44

3.1

Delayed motor start (max)

DC3σ [1] [ 4] 0.48 0.20 0.90 0.20

Peak operating current

Typical DCX
Maximum DC3σ [1]
Maximum (peak) 3σ

[1][6]

0.75

0.81

1.5

0.76

0.95

2.5

1.05

1.21

2.0

0.76

0.95

2.5

Notes for this table follows Table 2b.

Barracuda 4LP Installation Guide, Rev. B 15

Table 2b. DC power requirements (Amps)

ST32171/ST32271
N/W/WC
Single-ended

Voltage +5V +12V +5V +12V
Regulation [5] ±5% ±5%[2] ±5% ±5% [ 2]
Max. operating current

DC3σ [1] 0.81 0.85 1.21 0.85
Avg. idle current DCX
Max. starting current

(peak DC) DC3σ [3]

(peak AC) AC3σ [3]
Delayed motor start (max)

DC3σ [1] [ 4] 0.50 0.20 0.90 0.20
Peak operating current

Typical DCX

Maximum DC3σ [1]

Maximum (peak) 3σ
[1] Measured with an average reading DC ammeter. Instanta-

neous +12V current peaks will exceed these values.

[2] A –10% droop is permissible during initial star t 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 s election by the host initiator.

[3] See the +12V current profile in the

Manual

[4] This condition occurs when the Motor Start option is enabled

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

(publication number 77767491).

[1] 0.46 0.52 0.70 0.52

0.78 2.00

3.1

[1][6]

0.72

0.81

1.5

0.73

0.85

2.3

Barracuda 4LP Product

WD/DC
Differe ntial

1.1 2.00

3.1

0.91

1.21

2.0

0.73

0.85

2.3

16 Barracuda 4LP Installation Guide, Rev. B
[5] See “Conducted noise immunity” in the

uct Manual.

The specified voltage tolerance is inclusive of

Barracuda 4LP Prod-

ripple, noise, and transient response.

[6] Operating condition is defined as random seek read opera-

tions with a block count of 64.

General Notes from Tables 2a and 2b.

1. Minimum current loading for each supply voltage is not less

than 4% of the maximum operating current shown.

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

3. Where power is provided to multiple driv es 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.

Table 3. Dimensions of the drive

inches mm

Height 1.00 25.4
Width 4.00 101.6
Depth 5.74 145.8
Weight 1.5 pounds (0.68 kilograms)

Barracuda 4LP Installation Guide, Rev. B 17

Initial setup information

The general information beginning on this page applies to all of
the Barracuda 4LP drive models. After reading the general infor­mation topics, refer to the appropriate drive-specific section
listed below for additional information about configuring and
installing your particular model.

Drive models Page

ST32171N ST32271N
ST34371N ST34571N 36

ST32171W/WD ST32271W/WD
ST34371W/WD ST34571W/WD 40

ST32171WC/DC ST32271WC/DC
ST34371WC/DC ST34571WC/DC 45

General information

The following general information topics are discussed:

• SCSI ID jumpers

• Drive termination

• Terminator power

• Interface drivers and data path width notes

• Other applicable jumper options

• Providing adequate cooling

• Mounting the drive and connecting cables

• Formatting the drive

1

This mounting procedure does not apply to “WC” or “DC” model

drives. To mount a “WC” or “DC” drive, plug the drive into the
system’s single connector attachment (SCA) position on the
system’s back panel.

1

18 Barracuda 4LP Installation Guide, Rev. B

SCSI ID jumpers

Each device on the SCSI chain must have a unique SCSI I D.
The host system’s SCSI controller usually uses the ID that has
the highest priority interrupt in the SCSI I/O system. This is
always ID7. ID0 is lowest priority i n an 8-bit I/O system. ID8 is
lowest priority in a 16-bit I/O system. The lower priority SCSI IDs
are normally used for 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 controll ers 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
installati on.

Note. This drive is a SCAM (SCSI Configured Auto Magically)

compliant drive. If the system into which you are installing
this drive requires SCAM compliant drives, you do not
need to be concerned about the drive ID jumper settings,
as the system automatically assigns your new drive the
ID it wants it to have. The system may or may not use the
existing drive ID jumper settings. Setting the drive ID
doesn’t hurt anything, but is not necessary in a SCAM
compliant system.

Most Barracuda disc drives are factory set with the SCSI ID set
at 0. To change the SCSI ID, refer to the appropriate drive sec­tion for your model.

If, after completing the installation process, the drive’s LED does
not show on/off activity when the host is t rying to communicate
with the drive, a duplicate SCSI ID may be the problem. If this is

Barracuda 4LP Installation Guide, Rev. B 19
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.

Drive terminati on

If you are installing a Barracuda 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 co nnected to your sys­tem using the SCSI bus.

The top example in Figure 2 shows an internal hard disc at one
end of the SCSI bus with the SCSI controller at th e 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.

Note. Some controllers prefer to remain terminated even if they

are in the middle of the chain. Also, some controllers treat
the internal and external chains as separate logical
buses. This means you may need to terminate both the
first and last devices on both logical buses to achieve
proper termination. If necessary, refer to your system or
controller documentation to see how this is handled in
your particular system.

20 Barracuda 4LP Installation Guide, Rev. B
For information about how to terminate your drive, refer to the

appropriate drive-specific section.

Internal SCSI cable

Internal

SCSI device

Internal

SCSI device

Internal SCSI cable

Internal

SCSI device

Internal

SCSI device

Terminate

Controller

Terminate

Controller

External

SCSI
cable

External

SCSI device

External

SCSI device

Figure 2. SCSI bus termination

Terminator po wer

You usually will not need to change this option and can normally
leave the drive configured as it was shipped from the factory. For
information about how to change the terminator power option on
your drive, refer to the appropriate drive-specific section.

I/O circuits and data path widths

• “WD” and “DC” models use differential I/O circuits. You cannot

mix these models with single-ended models (“N,” “W,” “WC”)

on the same SCSI bus. The circuits are incompatible with

each other.

• “W,” “WD,” and “WC” models have a “wide” (16-bit) SCSI data

bus rather than the standard (non-wide) 8-bit SCSI data bus;

however, you can use these wide drives on a standard (non-

wide) 8-bit data bus.

Barracuda 4LP Installation Guide, Rev. B 21
Figures 3a, 3b, 3c, and 3d show typical drive connections. The

following table lists the maximum cable lengths and number of
devices with single-ended I/O circuits allowed on a daisy-chain
cable for <

10 and <20 M transfers/sec I/O data transfer rates.

Table 4. Cable chara cteristics for single-ended circuits

I/O transfer rate

Maximum number of
devices on line

Maximum cable
length allowed

<10 M transfers/s 8 (reg. SCSI bus) 6 meters (19.7 ft.)

10 M transfers/s 16 (wide SCSI bus) 6 meters (19.7 ft.)

<

20 M transfers/s 4 (reg./wide SCSI bus) 3 meters (9.8 ft.)

<

20 M transfers/s 8 (re g./wide SCSI bus) 1.5 meters (4.9 ft.)

<

For devices having differential I/O circuits, a maximum cable
length of 25 meters (82 feet) is allowed. A maximum of 8 devices
can be connected on an 8-bit wide data bus, and a maximum of
16 devices can be connected on a 16-bit wide data bus.

22 Barracuda 4LP Installation Guide, Rev. B

HDA

Pin 1

Figure 3a. Fifty pin I/O connection to drive

HDA

Pin 1

Figure 3b. Sixty-eight pin connection to drive

Barracuda 4LP Installation Guide, Rev. B 23

“N” Model

Drive

SCSI ID X

(or last drive)

[1]

SCSI ID 1

SCSI ID 0

Additional
SCSI devices

Pin 1

(check your

adapter for Pin 1 location)

SCSI ID 7

Host

Adapter

PCB

[1] “X” means up to 6 or the maximum allowable number of devices on

the SCSI bus. See Table 4 and system documentation.

Figure 3c. Multiple drive connection to host adapter

24 Barracuda 4LP Installation Guide, Rev. B

“W” Model

Drive [1]

SCSI ID X

(or last drive)

[2]

SCSI ID 1

SCSI ID 0

“WD” Model

Drive [1]

Additional
SCSI devices

Pin 1

(check your

adapter for Pin 1 location)

SCSI ID 7

Host

Adapter

PCB

[3]

[1] Do not mix “W” and “WD” mode l drives on the daisy chai n.
[2] “X” means up to 15 or the maximum allowable number of devices on

the SCSI bus. See Table 4 and system documentation.

[3] External terminator.

Figure 3d. Multiple-dr ive connection to host adapter

Barracuda 4LP Installation Guide, Rev. B 25

Note. This drive model plugs directly into a backplane connec-

tor and therefore uses no cables.

Figure 3e. Drive model “WC” or “DC” with single 80-pin I/O

and power connector

26 Barracuda 4LP Installation Guide, Rev. B

Providin g adequ ate cool ing

The enclosure design must ensure adequate cooling for the
drive. The maximum ambient temperatur e is 50°C.

The drive’s product manual (77767491) describes how to evalu­ate the air-flow design. The evaluation consists of ensurin g that
the case temperature of certain critical components remains
within acceptable limits during drive operation.

We recommend orienting the drive or directing the air flow in a
way that creates the l east 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 minimizes the distance
traveled by air that is heated by the drive and by other n earby
heat sources.

Figure 4 shows two design approaches 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.

Barracuda 4LP Installation Guide, Rev. B 27

Kühlung des System s

Die Gehäusekonstruktion m uß eine ausr eichende Kühlung d es
Laufwerk es gewährl eisten . Die Umge bungste mperatur darf
maximal 50°C betragen.

Die Produkthandbuch Barracuda 4LP (Dokument 77767491)
enthalten Anwei sungen zur Beur teilung der Luftst romkonstruk­tion. Die Beurteilu ng muß sicherst ellen, daß sich die Ge häuse­temperatur bestimmter kritischer Komponenten bei
Laufwerkbetrieb innerhalb zugelassener Grenzen hält.

Wir empfehlen, das Laufwerk so zu orientieren oder den Luft­strom so zu lenke n, daß der gering ste Luftstrom widerstand
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 4 zeigt zwei Konstruktionsmöglichkeiten, bei denen
ein oder mehrere Lüfter den Luftstrom erzeugen. Der Luftstro m ­verlauf 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.

28 Barracuda 4LP Installation Guide, Rev. B

H

.

Above unit
Über der Einheit

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

inweis. 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)

Under unit
Unter der Einheit

Above unit
Über der Einheit

Under unit
Unter der Einheit

Figure 4. Suggested air flow
Abbildung 4. Empfohlener Luftstromverlauf

Barracuda 4LP Installation Guide, Rev. B 29

Mounting the drive and co nne ctin g cable s

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 (horizontall y, 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 m m), 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.

Installatio n des Laufwer kes
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 w erden; jedoch muß dafür gesorgt
werden, daß ein ausreichender Luftstrom zur Kühlung des Lauf­werkes vorhanden ist.

30 Barracuda 4LP Installation Guide, Rev. B

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

Gemessen von der Außenfläch e des Gehäuses dürfen die
Schrauben maximal 3,81 mm in die Befestigungslöcher des
Gehüus es hinei nragen. D ie Sch rauben m üssen gleich­mäßig, jedoch nicht zu fest, angezogen werden. Wenn sich
eine Schraube nicht ohne Widerstand einschrauben läßt,
sind die Gewinde ni cht korrekt aneinander ausger ichtet. In
diesem Fall die Schraube nicht in das Gewindeloch
forcieren, sondern die Schraube herausnehmen und erneut
in das Gewindeloch einführen.

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.

3. Stellen Sie sicher, daß die Kennungsbrücken installiert sind.

4. Connect the SCSI cable into the drive’s SCSI connector.
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

Barracuda 4LP Installation Guide, Rev. B 31

Power

Cable

DC Power
Connector

4321

Pin

1
2
3
4

Power

+12V
+12V ret
+ 5V ret
+ 5V

Pin

1
2
3
4

Gleichstrom

+12V
+12V Rückleitung
+ 5V Rückleitung
+ 5V

defined in IEC 950. Figure 5 provides the pin information for
the DC power connector. To connect the DC power cable to
the drive, simply insert the cable end into the drive’s DC
power connector.

4. Schließen Sie das SCSI-Kabel an den SCSI-Steckverbinder
des Laufw erkes an. Das Kabel d arf nicht gedehnt ode r
gedrückt werden und es darf den Luftstrom zur Kühlung des
Systems nicht behindern.

Das Laufwerk wird über einen 4-poligen, neben dem SCSI­Anschluß befestigten Steckverbinder mit Gleichs trom ver­sorgt. Der Ausgang eines Netzteils muß SELV (safety extra
low voltage) na ch IEC 950 entspr echen. Abbildung 5 zeigt
die Steckerbelegung für den Gleichstromanschluß. Zum
Anschluß des Gleichstromkabels an das Laufwerk das
Kabelende in den Gleichstromanschluß des Laufwerkes
stecken.

Figure 5. DC power connector
Abbildung 5. Gleichstromanschluß

32 Barracuda 4LP 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 angeschlos sen.
Die elektromagnetische Strahlung kann reduziert wer­den, indem Sie eine möglichst große leitende Kontak­fläche zwischen der HDA-Erdung und der Systemerdung
vorsehen.

Wenn Sie das Systemgehäuse nicht an die HDA/PCB­Erdung anschließen wollen, müssen S ie das Laufwerk
auf nichtleitende Weise (galvanisch isoliert) im Host-Sys-

Barracuda 4LP Installation Guide, Rev. B 33

tem 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.

34 Barracuda 4LP Installation Guide, Rev. B

[4]

[3]

C

G

L

[1]

B

J

[2]

H

K

N

[4]

M

D

F

A

E

Notes:

[1] Mounting holes three on each side, 6-32 UNC. 
Max screw length into side of drive 0.15 in. 
(3.81 mm). Screw tightening torque 6.0 in-lb 
(.675 NM) max with minimum thread 
engagement of 0.12 in. (3.05 mm).



[2] Mounting holes four on bottom, 6-32 UNC. 
Max screw length into bottom of drive 0.20 in. 
(5.08 mm). Screw tightening torque 6.0 in-lb 
(.675 NM) max with minimum thread 
engagement of 0.12 in. (3.05 mm).



[3] Power and interface connectors can extend 
past the "A" dimension by 0.040 in. (1.02 mm).



[4] Decorative front panel (optional).



[5] Although the illustration shows the 50 pin I/O 

connector drive model, mounting hole locations 
are the same for all Barracuda 4LP models.

Inches

5.74 

A

4.00 

B

1.00 

C



2.362

D

.620

E

4.000

F

.250

G



1.750

H

P

3.750

J

2.370

K

1.00 

L

4.000

M

0.19 

N

0.015

P

± .010
± .010

+ .021



– .009

± .010
± .020
± .010

+ .010



– .005

± .010
± .010
± .020
± .010
± .010
± .010

max

Millimeters

145.80 

101.60 

25.40 

60.00 

15.75 

101.60 

6.35 

44.45 

95.25 

60.20 

25.4 

101.6 

4.83 

0.381

Figure 6. Mounting configuration dimensions

± .25
± .25

+ .53



– .22

± .25
± .50
± .25

+ .25


– .12

± .25
± .25
± .50
± .25
± .25
± .25

max

Barracuda 4LP Installation Guide, Rev. B 35

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
that previously has been used to store data, unless
your intention is to erase all user data.

Note. Seagate is not responsible for lost 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. Barracuda 4LP disc drives are
designed to operate with a variety of operating systems.
Please refer to your system or SCSI controller manual for
information about formatting a nd setting up the drive. Some
quick desktop system notes are provided below.

Quick reference desktop system notes
Note. Refer to your system or util ity manual for detailed instruc-

tions)

• DOS. Set the drive type in CMOS to “

hard drive installed

tems that have operating system Windows 95 release 950B or
later do not need to partition the drive.

• Macintosh. Use a third-party drive utility (Apple’s HD Setup

utility only works with drives having special Apple firmware).

.” Use FDISK.EXE and FORMA T.EXE. Sys-

Zero,” “None,”

or “

No

36 Barracuda 4LP Installation Guide, Rev. B

N drives

N/ND drives sectionSetting the SCSI ID jumpe rs

Use the J6 connector to set the SCSI ID (see Figure 7). To
change the SCSI ID, i nstall jumpers on the appropriate pins as
shown in the illustration.

Drive
Front

Jumper Plug

(enlarged to
show detail)

SCSI ID = 0

SCSI ID = 1
SCSI ID = 2
SCSI ID = 3

SCSI ID = 4
SCSI ID = 5

SCSI ID = 6
SCSI ID = 7

Reserved

J6

L

R

R

E

E

E

A2A1A

D

S

S

Pin 1

0

(default)

Figure 7. Setting the SCSI ID on model N drives

Barracuda 4LP Installation Guide, Rev. B 37

N drives

Termina tin g the drive

“N” model drives are terminated with permanently mounted IC
active terminators. If you install one of these drives and it is not
on the end of the SCSI bus, disable the terminators by removing
the jumper “TE” from pins 15 and 16 of connector J2 (see Fig­ure 8). If you install the drive on the end of the SCSI bus, enable
termination by installing a jumper on pins 15 and 16 of connector
J2.

J2









T

D

M

W

P

E

S

E

P

D

Enable SCSI terminator (default)
Disable SCSI terminator

Pin 1



R





E

T

T

S

P

P

J6

Drive

J2 Jumper Type

(enlarged to
show detail)

Front

Figure 8. Terminating the drive

J2

SCSI I/O

Connector

DC Power
Connector

J1

38 Barracuda 4LP Installation Guide, Rev. B

N drives

Terminator po wer

There are three possible terminator power (TP ) configurations
for “N” model drives (see Figure 9). You will not normally need to
change this option and can leave the drive configured as it was
shipped from the factory.

J2









T

D

M

W

P

E

S

E

P

“N” model drives

D

Term. Power from Drive (default)
Term. Power to SCSI Bus
Term. Power from SCSI Bus

Position A

Pin 1



R





E

T

T

S

P

P

J2

SCSI I/O

Connector

DC Power
Connector

J2 Jumper Type

(enlarged to
show detail)

J6

Drive
Front

Figure 9. Setting terminator power jumpers

J1

Barracuda 4LP Installation Guide, Rev. B 39

N drives

Other appli cab le jumper options

Several other jumper opti ons are available as illustrated.

Drive with
HDA up, PCB
down, viewed

from front

Reserved

Reserved
Remote

LED

Shipped with cover installed.

Do not remove.

Do not install jumpers

on these four positions.

Drive Front

DC Power
Connector

SCSI I/O

Connector

Pin 1

HDA

L

R

R

E

E

E

A2A1A

D

S

S

11

12

J6

J2

J1

J2 Jumper Type

(enlarged to
show detail)

J6

0

CATH

Jumper Type

(enlarged to
show detail)

Pin 1

End

Pin 1

J6

Reserved
Delay Motor Start option 

(valid only if the Enable 
Motor Start jumper is 
not connected)

Disable the Delay Motor 
Start option.

Motor start delay equal 
to the SCSI ID multiplied 
by 12 seconds. For 
example, if the SCSI 
ID = 2, the drive starts 
in 24 seconds.

Motor Start option
Disable motor start. 

The drive starts 
according to the 
Delay Motor Start option.

Enable motor start. The 
drive waits for the Start 
Unit command from the 
host before starting the 
spindle motor.

Write Protect option
Write protect = Off 

(enables writing).
Write protect = On 

(disables writing).
Parity Check option

Enable parity check of 
SCSI bus.

Disable parity check.

Figure 10. Additional jumper options

J2

Pin 1

(default)

(default)

(default)

(default)

40 Barracuda 4LP Installation Guide, Rev. B

W/WD drives

W/WD drives sectionSetting the SCSI ID jumpe rs

Use the J6 jumper block to set the SCSI ID (Figure 11). To
change the SCSI ID, install jumpers on the appropriate pins as
shown in the illustration. Optional connections to switching cir­cuits in host equipment are provided on J1 auxiliar y to set the
SCSI ID (see Figure 12).

Drive
Front

Jumper Plug

(enlarged to
show detail)

L

R

Reserved

E

E

D

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

S

J6

A2A3A1A

Pin 1

0

Figure 11. Set ting the SCSI ID on model W/WD drives

Barracuda 4LP Installation Guide, Rev. B 41

W/WD drives

68 Pin SCSI I/O

Connector

J1
SCSI ID = 0
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

not used

Host Alternate
Usage Plug

+5V

Dashed area is optional host circuitry (external to the 
drive) connected to host supplied optional usage plug.

Pin 1

+5V

N.C.

Ground

Drive Activity LED

+5V

Ground

A

3A2A1

1197531

12 10 8 6 4 2

J1-Auxiliary

Pin 1A

4P 3P2P 1P

(default)

For ID selection use
jumpers as shown or
connect a cable for
remote switching as
shown below.

A

0

A0A1A2A

3

Drive

PCB

HDA
Rear

J1-DC Power

Pins 1, 3, 5, and 7 are 
optional connections to 
switching circuits in host 
equipment to establish 
drive ID.

Remote Switches

Pins 2, 4, 6, and 8 are normally 
not grounded. They are driven low 
(ground) for 250 ms after a Reset or 
PWR ON to allow drive to read 
SCSI ID selected. Pin 8 may
also be used to drive the cathode
of an external Activity LED.

Figure 12. Usi ng J1-Auxillary connector for model “W”

and “WD” drive alternate ID select and LED
connection

42 Barracuda 4LP Installation Guide, Rev. B

W/WD drives

Termina tin g the drive

“W” model drives are terminated with permanently mounted IC
active terminators. If you install one of these drives and it is not
on the end of the SCSI bus, disable the terminators by removing
the jumper “TE” from pins 15 and 16 of connector J2. If you
install the drive on the end of the SCSI bus, enable termination
by installing a jumper on pins 15 and 16 of connector J2 (see
Figure 13).

Note. Use active (ANSI SCSI-2 Alternative 2) terminators when

terminating the bus.

“WD” model drives do not have internal terminators or any other
way of adding internal termination to the drive. You must provide
external differential termination to these drives when termination
is required.

J2









T

D

M

W

E

S

E

P

*Enable SCSI terminator (default)

*Disable SCSI terminator

*“W” model only

Pin 1



R





P

E

T

T

D

S

P

P

J2

SCSI I/O

Connector

DC Power
Connector

J1

J2 Jumper Type

(enlarged to
show detail)

J6

Drive
Front

Figure 13. Terminating the drive (“W” model shown)

Barracuda 4LP Installation Guide, Rev. B 43

W/WD drives

Terminator po wer

There are three possible terminator power (TP ) configurations
for “W” model drives (see Figure 14). You will not norm ally n e ed
to change this option and can leave the drive configured as it
was shipped from the factory.

There are two possible terminator power (TP) configurations for
“WD” model drives (see Figure 14).

J2









T

D

M

W

P

E

S

E

P

“W” model drives

D

Term. Power from Drive (default)
Term. Power to SCSI Bus
Term. Power from SCSI Bus

“WD” model drives

Position A

Term. Power to SCSI Bus (default)
Host adapter or other device provides 

term. power to external terminator.

Pin 1



R





E

T

T

S

P

P

J2

SCSI I/O

Connector

DC Power
Connector

J2 Jumper Type

(enlarged to
show detail)

J6

Drive
Front

Figure 14. Setting terminator power jumpers

J1

44 Barracuda 4LP Installation Guide, Rev. B

W/WD drives

Other appli cab le jumper options

Other option jumpers are available as illustrated below.

Drive with
HDA up, PCB
down, viewed

from front

Reserved

Reserved
Remote

LED

Shipped with cover installed.

Do not remove.

Do not install jumpers

on these four positions.

Drive Front

DC Power
Connector

SCSI I/O

Connector

Pin 1

HDA

L

R

E

E

A2A3A1A

D

S

11

12

J6

J2

J1

J2 Jumper Type

(enlarged to
show detail)

J6

0

CATH

Jumper Type

(enlarged to
show detail)

Pin 1

End

Pin 1

J6

Reserved
Delay Motor Start option 

(valid only if the Enable 
Motor Start jumper is 
not connected)

Disable the Delay Motor 
Start option.

Motor start delay equal 
to the SCSI ID multiplied 
by 12 seconds. For 
example, if the SCSI 
ID = 2, the drive starts 
in 24 seconds.

Motor Start option
Disable motor start 

(default). The drive 
starts according to the 
Delay Motor Start option.

Enable motor start. The 
drive waits for the Start 
Unit command from the 
host before starting the 
spindle motor.

Write Protect option
Write protect = Off 

(enables writing.
Write protect = On 

(disables writing).
Parity Check option

Enable parity check of 
SCSI bus.

Disable parity check.

Figure 15. Additional jumper options

J2

Pin 1



(default)

(default)

(default)

(default)

Barracuda 4LP Installation Guide, Rev. B 45

WC/DC drives

WC/DC drive s sectio nSetting the SCSI ID jumpe rs

The SCSI ID for “WC” and “DC” model drives is normally set
over the SCSI bus by the host system using connector contacts
39 (ID0), 40 (ID2), 79 (ID1), and 80 (ID3). Users need not install
jumpers to select SCSI ID.

Termina tin g the drive

“WC” and “DC” model dr ives do not have internal terminator s or
any other way of adding internal term ination to the dri ve. Exter­nal termination f or these dr ives is normally supplied by the host
equipment when termination is required.

46 Barracuda 4LP Installation Guide, Rev. B

WC/DC drives

Applica bl e jump er op tio n s

Option jumpers are available as i llustrated below.

J2

Delay Motor Start option
The host system has complete 

control over motor start functions. Do 
not install a jumper on these pins.

Enable Motor Start option
The host system has complete 

control over motor start functions. Do 
not install a jumper on these pins.

Write Protect option
Write protect = Off 

(enables writing)
Write protect = On 

(disables writing)
Parity Check option

Enable parity check of SCSI bus.
Disable parity check.









T

D

M

W

E

S

E

P

Pin 1



R





P

E

T

T

D

S

P

P

(default)

(default)

J6

Drive

J2 Jumper Type

(enlarged to
show detail)

Front

Figure 16. Jumper options

J2

SCSI I/O

Connector

DC Power
Connector

J1

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

Publication Number: 77767492, Rev. B, Printed in USA