Seagate ST373455LC - Cheetah 73.4 GB Hard, Barracuda 18LP Drive Installation Manual

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Barracuda 18LP

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Disc Drive

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ST39175LW/LC

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ST318275LW/LC

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Installation Guide

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Contents

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

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

Important safety information and precautio ns...... ............. ...........2

Wich tige Sic h er h e its h in w ei se ..... ....... ....... ........ ....... ....... ... ....... ...4

Regulatory agency complian ce....... .. ....... .. ...... ....... .. ...................7

Seag a te Technol o gy su ppo rt s ervic e s.... ....... ........ ....... ....... ... .....9

General description....................................................................15

Init ia l se t up in form a t io n....... ... ....... ....... ........ .. ........ ....... ....... ......1 9

Kühl u ng de s Sy s te ms ..... ....... ....... ....... ........ ....... ... ....... ....... ......30

Inst allation des Laufwerk es

und Anschluß der Kabel..........................................................32

LW dr ives se c tion.... ... .. ....... ........ ....... ....... ... ....... ....... ........ ....... .40

LC drives section .......................................................................45

©1997-1999 Seagate Technology, Inc. All rights reserved
Publication Number: 77767527, Rev. B
May 1999

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

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

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

Barracuda 18LP Installation Guide, Rev. B 1

Preface

This manual contains information for users of the Seagate®
Barracuda 18LP SCSI disc drives. It provides support services,
performance specifications, and initial setup information. Addi­tional information is available in the

Manual

(part number 77767526). Contact your Seagate sales

Barracuda 18LP Product

representative if you need to order this publication.

Note.

If any differences exist between specification values in
this guide and the product manual, the product manual
values are the auth oritative values.

Electrostatic discharge protection

Caution.

All drive electronic assemblies are sensitive to static electricity,
due to the electrostatically sensitive devices used within the
drive circuitry. Alt hough some d evices such as metal-oxide semi-

Removal of circuit boards by personnel not perform­ing depot repair will damage components and may
void the warr anty.

conductors are extremely sensitive, all semiconductors, as well
as some resisto rs and capacitors, may be damaged or degraded
by exposure to static electricity.

Electr ost atic damage t o electr onic de vices may be caus ed 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,

2 Barracuda 18LP Installation Guide, Rev . B

remember that you and the drive electronics must all be
grounded to avoid potentially damaging static discharges.

• Tur n off the power before removing or installing the DC power
cable.

• Do not remove any circuit boards from the driv e.

• Never use an ohmmeter on any circuit boards.

• When inst alli ng the drive on a carrier or t ra y, disch arge the car -

rie r o r tray pr io r to ins e rti n g it into th e sy st e m .

Importan t safety information and precautions

Caution.

Use forced-air ventilation when bench-testing the
drive to ensure prop er cooling of driv e com ponents.

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 minim ize or eliminat e the risk of pers onal injury. The warnings
point out conditions or practices that may endanger you or oth­ers. The cautions point out conditions or pr actices that may dam­age the uni t, possibly making it unsafe for use .

Always obs erve the foll owing warnin gs 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 18LP 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
repai r 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 repair­abl e. If the sealed HDA is opened b y personnel not per forming
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, EN60950, CAN/CSA C22.2
950-95, 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
acceptabilit y in obtaining saf ety-re gulatory agency com pliance in
their end-use products and for certifying where required by law.
A necessary part of meeting saf ety requirements is the provision
for overcurre nt pr otection on driv e SELV supply vo lt ages.

4 Barracuda 18LP Installation Guide, Rev . B
This unit is a component part and as such is not meant to com-

ply 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 sicherzustel len.

Verwenden Sie geeignete Sicherheits- um den sicheren, zuver­lässigen Betri eb dieser Einheit zu gewährleisten.

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 Risi ko behaft et 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 beurt eilen 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 Ver fahren weder Ihre
persönliche Sicherheit noch die Leistung der Einheit gefährdet.

Barracuda 18LP 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 Si e mit den Ins tal lations-und Entfernungsar­beiten beginnen.

• Wenn das Laufwerk in einem Einbaugestell oder Gehäuse

montier t ist, sorgen Sie dafür, d a ß 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 i st.

• Befolgen Sie die oben unter “Electrostatic Discharge Protec-

tion” angegebenen Sicherh eit sm aßnahmen.

• 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 zustän-
digen kann zu einer Beschädigung der Komponenten und
Erlöschen des Garantieanspruchs führen.

• Die vormontierte Kopf- und Festplatteneinheit (H DA) nicht aus

dem Laufwerk nehmen! Fa ll s die HDA beschädi gt i st, schicken
Sie das ges am te Lauf werk zur Reparatur ein.

6 Barracuda 18LP Installation Guide, Rev . B

• 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 zustän-
digen hat eine Beschädigung der Komponenten und
Erlöschen des Garantieanspruchs zur Folge .

Als Teil komponente i st diese s Laufwer k für die I nstallati on und
den Betr ieb in Übe reinstimmun g mit UL 19 50, EN6 0950, C AN/
CSA C22.2 950-95 und VDE0805 v orgesehen.

Seagate ist ständig bemüht, die Zulassungsfähigkeit von
Seaga te-Produ kten im R ahmen de r gegenwär tig gel tenden
Stan da rds z u gewährleisten. Zu den typischen Anwendungen
dieser Festplattenwerke zählen Systemeinbau durch den
Ku nden und di e Kon strukti on von Unter systemen. Sicherh eitsbe ­hörden gewähren eine bedi ngte Zul assung für Komponenten wi e
das Barracud a-Festplattenl aufwerk v orbehaltli ch der endgültigen
Zulass sun g im E ndprod ukt. De sign er von Un tersyste men s ind
dafür verantwor tlich, die Voraussetzungen für die Einhaltung
sicherheits- oder aufsichtsbehördlicher Vo rschriften in ihren
Endprodukten und - falls gesetzlich vorgeschrieben - für die
Zula ss ung zu sc ha ffen. Eine Gr un dvorau sset zu ng zu r E inha l­tung der Sicherheitsanforderungen ist die Bereitstellung eines
Über lastschutzes für die SELV-Versorgungsspannungen des
Laufwerks.

Dieses Gerät ist eine Baugruppe und unterl iegt als solche ni cht
den Anforderungen der FCC oder ähnlicher nationaler Behörden
für eigenständige G eräte. Technische Testergebn isse zu elektro-
magneti sche Str ahlung si nd für Designer v on Untersy stemen auf
Anfr age von der Seagat e-Sicherheitsabteilung erhältlich.

Barracuda 18LP Installation Guide, Rev. B 7

Regulatory agency compliance

Elect romagneti c susceptibility

As a component assembly, the dr ive is not required to meet any
susceptibili ty performance requirement s. I t is t he responsibilit y of
those integrating the drive within their systems to perform those
tests required and design their system to ensure that equipment
operating in the same system as the drive or external to the sys­tem does not adversely affect the performance of the drive. See
Table 2, DC power requirements.

Elect romagneti c com pliance

Seagate uses an independent laboratory to confirm compliance
to the directives/standard(s) for CE Marking and C-Tick Marking.
The drive was tested in a representative system for typical appli­cations. The selected system represents the most popular char­acteristics for test platforms. The system con figurations include:

• 486, Pent ium, and PowerPC microprocessors

• 3.5-inch floppy disc drive

• Keyboard

• Monitor/display

• Printer

• External modem

• Mouse

Although the test system with this Seagate model complies to
the directives/standard(s), we cannot guarantee that all systems
will comply. The computer manufacturer or system integrator
shall confirm EMC compliance and provide CE Marking and C­Tic k M arki ng for their product.

8 Barracuda 18LP Installation Guide, Rev . B

Elect romagnetic compliance for the Europ ean Union

If this model has the CE Marking it complies with the European
Union requirements of the Electromagnetic Compatibility Direc­tive 89/336/EEC of 03 M ay 1989 as amended by Directive 92/31 /
EEC of 28 April 1992 and Directive 93/68/EEC of 22 July 1993.

Australian C-Tick

If this model has the C-Tick Marking it complies with the Austra­lia/New Zealand Standard AS/NZS3548 1995 and meets the
Electromagnetic Compatibility (EMC) Framework requirements
of Austr alia’s Spectrum Management Agency (SMA).

Barracuda 18LP Installation Guide, Rev. B 9

Seagate Technology support serv ices

Onli n e Servic es

Internet

For online information about Seagate products, visit
www.seagate.com or e-mail your disc or tape questions to:

Presales Support:

Disc: http://www.seagate.com/support /email/

email_presales.shtml

Tape: http://www.seagate.com/support/email/

email_tape_presales.shtml
[e-mail]

Technical Support

Disc: http://www.seagate.com/support /email/

email_disc_support.shtml

Tape: http://www.seagate.com/support/email/

email_tape_support.shtml

SeaBOARD®

information about Seagate disc and tape drive products and is
available 24 hours daily. Set your communications software to
eight data bits, no parity and one stop bit (8-N-1). This service is

:

is a computer bulletin board system that contains

or

[e-mail]

or

or

DiscSuppo [e-mail]

or

TapeSuppor [e-mail]

avail a bl e worl d wide.

Automated Serv i ces

SeaFONE

800-732-4283) to access our automated self-help services.
Using a touch-tone phone, you can find answers to service
phone numbers, commonly asked questions, troubleshooting

1-800-SEAGATE)

® (

is Seagate's toll-free number (1-

10 Barra cuda 18LP Installat ion Guide, Rev . B
tips and specifications for disc drives and tape drives 24 hours

daily. International callers can reach this service by dialing +1­405-936-1234.

SeaFAX

®

is Seagate's automated FAX deliver y system. Using a
touch-tone phone, you can obtain technical support information
by retu rn FAX 24 hours daily. This service is availab le worldwide.

Presales Support

Our Presales Support staff can help you determine which
Seagate products are best suited for your specific application or
computer system.

Seagate Express

You can purchase select tape products and tape accessories
through Seagate Express 24 hours daily by calling 1-800-531­0968 or by fa xing your order to: [phone].

Te c hnical Support

If you need help 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 help, y ou can talk to a Se agate techn ical suppo rt
specialist. Before calling, note your system configuration and
drive m odel number (ST

SeaTDD™([phone])

for the deaf (TDD). You can send questions or comments 24
hours daily and exchange messages with a technical support
specialist from 8:00 A.M. to 12:15 P.M. and 1:30 P.M. to 6:00
P. M. (central ti m e) Monday thr ough Fri day.

####).

is a telecommunications device

Barracuda 18LP Installation Guide, Rev. B 11

Custo mer Ser vice (CSO)

Warranty Re pair

Seagate offers worldwide customer support for Seagate drives.
Seagate direct OEM, Distribut ion and System I ntegrat or custom­ers should contact their Seagate service center representative
for warranty information. Other customers should contact their
place of purchase.

Authorized Service Centers

If you live outsi de the US, you can contact an Authorized Servi ce
Ce nter fo r se rvice or re pa ir.

USA/Canada/Latin America Support Services

Presales Supp ort

Disc:

Tape:

Technica l Su pport (Se aFONE)

1-800-SEAGATE or [phone] (for specific product
phone number)

FAX:

SeaFAX
SeaTDD

1-877-271-3285 or FAX: [phone]
[phone]

1-800-626-6637 or FAX: [phone]
[phone]

Disc: +

1-405-936-1685;

1-800-SEAGATE
[phone]

Tape:

[phone]

SeaBOARD

Disc: +

1-405-936-1600;

Tape:

[phone]

12 Barra cuda 18LP Installat ion Guide, Rev . B

Warranty Re pair

USA 1-800-468-3472 FAX: [phone]
Mexi co and
Latin Ame ric a [phone] FAX: [phone]

Authorized Service Centers

Brazil

MA Informatica

[phone] FAX: [phone]

Canada

Memofix
Adtech

1

1

[phone] FAX: [phone]
[phone] or FAX: [phone]
1-800-624-9857

European Support Services

For European customer support, dial the toll-free number for
your specific country for presales support, technical support,
SeaFAX and warranty repair.

If your countr y is not listed here, dial our European call center at
[phone] from 8:30
time) Monday through Friday. The European call center is

A.M

. to 5:00 P.M. (European central

located in Amsterdam, The Netherlands.

Call Center

Austria 0 800-20 12 90
Belgium 0 800-74 876
Denmark 80 88 12 66
France 0 800-90 90 52
Germany 0 800-182 6831
Ire land 1 800-55 21 22

1

Authorized Service Centers

Barracuda 18LP Installation Guide, Rev. B 13
Ita ly 1 677 90 695

Netherlands 0 800-732 4283
Norway 800-113 91
Poland 00 800-311 12 38
Spain 900-98 31 24
Sweden 0 207 90 073
Switzerland 0 800-83 84 11
Turkey 00 800-31 92 91 40
United Kingdom 0 800-783 5177

SeaBOARD

Germany [phone]

Fax Services—All Euro pean Countries

Presales/Technical Support/W arrant y Repair [phone]

Africa/Middle East Support Services

For presales, technical support, warranty repair and FAX ser­vice s in Africa and the Middle East, dial our Euro pean call center
at [phone] from 8:30 a.m. to 5:00 p.m. (European cen­tral time) Monday through Friday, or send a FAX to +31-20-653-

3513. The European call center is located in Amsterdam, The
Netherlands.

Asia/Pacific East Support Services

Technic al Su pport

Austra li a [phone] FAX: [phone]
Hong Kong [phone] FAX: [phone]
Japan — FAX: [phone]
Singap ore [phone] FAX: [phone]
Taiwan [phone] FAX: [phone]

14 Barra cuda 18LP Installat ion Guide, Rev . B

SeaFAX

Australia [phone]

Warranty Re pair

Japan [phone] FAX: [phone]
Asia/Pacific and [phone] FAX: [phone]

Australia

Barracuda 18LP Installation Guide, Rev. B 15

General description

Barracuda 18LP SCSI disc drives are high-speed, random­access digital-data stor age devices.

The drive is a component for installation in an enclosure
designed for the drive. This is often a rack within the system or
an ex ternal encl osure desi gned to house one or more disc driv es
or other peripher al units. In either case, the disc dri ve must
receive adequate cooling (refer to “Providing adequate cooling”)
and it must be sufficiently grounded and shielded from emis­sions. The

Barracuda 18LP Product Manual

(part number

77767526) contains guidelines for a properly designed
enclosure.

*

*Model “LW” version with 68-pin SCSI I/O conne ctor

Figur e 1. Barrac uda 18LP family drive

16 Barra cuda 18LP Installat ion Guide, Rev . B

Table 1. Drive ch arac ter is tic s

Interface UltraSCSI [1]
Capacity Formatted [2] Max. data blocks [2]

ST39175 9.1 Gbyte [2] 10F59C7h [2]
ST318275 18.2 Gbyte [2] 21EB38Fh [2]

Recording

Cylinders (user) 11,721
Read/write dat a heads

ST39175 5
ST318275 10

Acce s s ti m e [3]

Average read 6.9 msec
Average write 7.7 msec

Dis k rotation

RPM 7,200 r/min
Average latency 4.17 msec

Int ernal transf er rate (vari able with zone)

ST39175 137–240 M bits / sec
ST318275 137–24 0 M b i ts/se c

Maximum synchronous SCSI transfer rate

LW/LC 80 Mbytes/sec

[1] Operated according to SCSI-2 and SCSI-3 protocols. Referred to

also as “SCSI Fast-20” and “Fast-40.”

[2] Read data capacity. Add one for total capacity. Standard factory

units are formatted 512 data bytes per sector with spare tracks
reserved for reallocating bad sectors.

[3] Includes cont roller overhead.

Barracuda 18LP Installation Guide, Rev. B 17

Table 2. DC power requirements (Amps), m ult imode

(SE/LVD)

ST39175LW/LC ST318275LW/LC

Voltage +5V +12V +5V +12V
Regulation [5] ±5% ±5%[2] ±5% ±5%[2]
Avg . id le cu rr e nt

DCX

[1] 0.75 0.35 0.75 0.5

Max. starting current

(peak DC) [3]
(pe a k AC) [3]

1.0

—

1.3

2.4

1.05

—

1.6

2.4

Delayed motor
start (max) [1] [4] 0.65 0.05 0.65 0.05

Peak operating current

Typical DCX

[1][ 6 ]
Maximum DC [1]
Maximum (peak)

1.0

1.3

1.7

0.7

1.4

2.1

1.05

1.4

1.7

0.8

1.5

2.4

[1] Measured with an average reading DC ammeter. Instanta-

neous +12V current peaks wil l exceed these va lues.

[2] A –10% droop 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
powe r-up sequen ce has been compl eted and that the driv e is
able to accept selection by the host initiator.

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

Manual

(publication number 77767526).

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

and the drive has not ye t received a Start Motor com mand.

Barracuda 18LP Product

18 Barra cuda 18LP Installat ion Guide, Rev . B
[5] See “Conducted noise immunity” in the

Product M anual.

The specified voltage tolerance is inclusive

Barracuda 18LP

of 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 Table 2.

1. Minimum current loading for each supply voltage is not less
than 4% of th e max imum operati ng current sho wn.

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

3. 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 starti ng current is available to ea ch device.

Table 3 shows the nominal (no tolerance specified) dimensions
and weight of the drive.

Table 3. Dimensi ons of the drive

inches mm

Height 1.00 25.4
Width 4.00 101.6
Depth 5.75 146.05
Weight 1.5 pounds (0. 589 kilogr am s)

Barracuda 18LP Installation Guide, Rev. B 19

Initial setup information

The general infor mation beginning on this page applies to all of
the Barracuda 18LP 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 Pa ge

ST39175LW ST318275LW 40
ST39175LC ST318275LC 45

Gener a l in format io n

The followi ng general information topics are discussed:

• SCSI ID jumpers

• Drive termi nation

• Ter m inator power

• Int erface driv ers and data pat h widt h notes

• Other appli cable j um per options

• Providing adequate cooling

• Mounting the drive and connecting cables

1

• Formatting the drive

1

This mounting procedure does not apply to “LC” model drives.

To mou n t a n “LC” drive, plug the drive into the system’s single
connector attachment (SCA) position on the system’s back
panel.

20 Barra cuda 18LP Installat ion Guide, Rev . B

SC SI ID ju mpers

Each device on the SCSI chain must have a unique SCSI ID.
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 in 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.

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.

This drive is a SCAM (SCSI Configured Auto Magically)
compli ant drive. If the system int o which y ou are installi ng
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 sys tem m ay or m ay not use t he
existing drive ID jumper settings. Setting the drive ID
doesn’t hurt anything, but is not necessary in a SCAM
compli ant 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 trying to communicate
with the drive, a duplicate SCSI ID may be the problem. If this is

Barracuda 18LP Installation Guide, Rev. B 21
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
numberi ng recommendations.

Drive termination

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 connected 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 the other end
(bot h 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 e ven if they
are in the middl e of the chain. Als o, some cont rollers 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.

22 Barra cuda 18LP Installat ion 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

Te rminator power

You usually will not need to change this option and can normally
lea ve the dri ve confi gured 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

Note. Make sure your system I/O controller circuit board has

the proper I/O circuits to communicate with this drive. You
may have to replace your old controller with a newer one
having the proper I/O circuits. The following paragraphs
and tables will help you to know whether you want to
operate the drive I/O circuits in single-ended (SE) mode
or low volt age differential ( LVD) mode. If your old I/O con­troller operated the I/O circuits in differential mode,
chances are it was high voltage differential mode (HVD).

Barracuda 18LP Installation Guide, Rev. B 23

This drive must not be operated with that kind of control­ler. This drive can operate with older SE controllers, how­ever.

•“LW” and “LC” models use SCSI multimode I/O circuits. Multi-

mode circuits operate either in single-ended mode or low volt­age differential mode. No high voltage differential devices
should be connected in the I/O daisy chain with “LW” or “LC”
model drives. The state of the I/O “DIFFSNS” line determines
whether the devices on the SCSI bus operate their I/O circuits
in single-ended or low voltage differential mode. The host
device on the SCSI bus operates the “DIFFSNS” line. How­ever, the SE jumper on J2 forces “DIFFSNS” to nominal
ground (see Figure 12). The host device cannot override the
SE jum pe r. If “DIFFSNS” is at nominal ground (0V to .6V), all
of the bus receivers/drivers operate in single-ended mode. If
“DIFFSNS” is between .7V and 1.9V, all bus receiver/drivers
operate in low voltage differential (LVD) mode.

•“LC” and “LW” 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. However, the unused lines must be terminated
the same as the used lines.

Figures 3a, 3b, and 3c show typical drive connections. The fol­lowing tables list the maximum cable lengths and number of
devices allowed on a daisy-chain cable for I/O data transf er rat es
shown.

Note. For LVD operation, twisted pair cables are recom-

mended. For LVD Fast-40 operation, twisted pair cables
are

strongly

twisted pair cables are

recommended. For Fast-80 operation,

required

.

24 Barra cuda 18LP Installat ion Guide, Rev . B

Table 4a. Cable characteristics for single-ended I/O

circuits

Ma ximum dis tan ce betwee n

Number of attached SCSI
devices

terminators (meters) [1] [3]
Fast-5 Fast-10 Fast-20 Fast-40

1 to 4 maximum capacitance
(25 pF) SCSI dev ices 6 3 3 N/A

5 to 8 maximum capacitance
(25 pF) SCSI dev ices 6 3 1.5 N/A

9 to 16 maximum capacitanc e
(25 pF) SCSI devices 6 3 [2] N/A

[1] F or envir o nm ents wh ere a ll eleme nt s of the b u s ( cab le s, de vi ce i nt er-

faces, environmental noise and other parameters) are controlled to
be better than minimally required, it may be possible to extend the
path length and device count.

[2] E xten ding the device coun t beyond eight r equ ire s speci fic atio n con -

trol beyond the minimum specified in the ANSI T10/1142D docu­ment. It is recommended that the devices be uniformly spaced
between terminators with the end devices loc ated as close as possi­ble to the terminators.

[3] Values specified by data rate shall apply even if a slower data rate is

negotiated.

Barracuda 18LP Installation Guide, Rev. B 25

Table 4b. Cable characteristics for differential I/O circuits

Ma ximum dis tan ce betwee n
terminators (meters) [1] [3]

Interconnect

Fast-5 Fast-10 Fast-20 Fast-40

Point-to-point interconnect
(2 devices) 25 25 25 25 [ 2]

Daisy- chain interconnect
(up to 16 de vices) [4] 15 15 15 12

[1] F or envir o nm ents wh ere a ll eleme nt s of the b u s ( cab le s, de vi ce i nt er-

faces, environmental noise and other parameters) are controlled to
be better than minimally required, it may be possible to extend the
path length and device count.

[2] SCSI devices shall be within a stub length of the termination (.1

meter).

[3] Values specified by data rate shall apply even if a slower data rate is

negotiated.

[4] Loads spaced at least 8 inches (20.3 cm) apart (refer to SCSI EPI

T10/1143D specifica tion).

26 Barra cuda 18LP Installat ion Guide, Rev . B

Power

Cable

Figure 3a. Sixty-eight pin connection to “LW” model drive

Barracuda 18LP Installation Guide, Rev. B 27

“LW” Model

Drive

[6]

SCSI ID 1

Note. Do not mix drives operating
single-ended with drives
operating differential on the
daisy chain.

Terminator

[1]

2 through X

SCSI devices [4]

Pin 1

(check your

adapter for Pin 1 location)

[2]

SCSI ID 0

[2]

SCSI ID 7 [5]

[1]

Host Adapter

PCB

[3]

[1] Cl osed end type 68 pin connector used. Termina tor r equired.
[2] Open end type (in-line application) connector used. No terminator.
[3] H os t need no t be on the en d of the dai sy c h ain. A no th er devi ce c an

be on the end with the terminator, the ho st having no terminato r.

[4] Total inter face cable lengt h must not exce ed th at spe cified in AN SI

Standard X3T10/1142D (including host adapter/initiator). The cable
length restriction limits the total number of devices allowed.

[5] S CS I ID 7 h as highes t a r bi tr at io n priority. For “LW” models , prior i ty is

ID7 to ID0, then ID15 to ID8 (ID 8 very lowest).

[6] Last drive on the daisy chain.

Figure 3b. Multiple-drive “LW” model connection to host

adapter

28 Barra cuda 18LP Installat ion Guide, Rev . B

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

tor and therefore uses no cables.

Figure 3c. Drive model “LC” with single 80-pin I/ O and

power connector

Barracuda 18LP Installation Guide, Rev. B 29

Providing a dequate co ol in g

The enclosure design must ensure adequate cooling for the
drive. The maximum ambient air temperature around the drive
should not exceed 50°C. However, to achieve maximum reliabil­ity, the ambient temperature should be about 15°C below this
value most of the tim e.

The drive’s product manual (77767526) describes how to evalu-
ate the air-flow design. The evaluation consists of ensuring 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 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 minimizes the distance
traveled by air that is heated by the drive and by other nearby
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 t he fans either pushing or drawin g air. The o veral l flow pattern
can be directed from front to back, back to front, or side to side.

30 Barra cuda 18LP Installat ion Guide, Rev . B

Kühlung des Syst ems

Die Gehäusekonstruktion muß eine ausreichende Kühlung des
Laufw erkes ge währlei sten. Die Umgeb ungstemperat ur darf m ax­imal 50°C betragen.

Die P rod ukt hand buch Ba rracu da 18 LP (Doku men t 77 7675 26)
enthalten An weisunge n zur Beur teilun g der Luftstr omkonstruk­tion. Die Beur teilung muß si cherstellen, daß sich die Gehäuse-
temperatur bestimmter kritischer Komponenten bei
Laufwerkbetrieb innerhalb zugelassener Grenzen hält.

Wir empfehlen, das Laufwerk so zu orientieren oder den Luft­strom so zu len ken, daß der ger ingste L uftstromwiders tand
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 aufgewär mte Luft
zurück legt, auf ein Mini mum beschränkt.

Abbil dung 4 zeig t zwei Konstr ukti onsm öglic hkeite n, b ei dene n
ein oder mehrere Lüfter den Luftstrom erzeugen. Der Luftstrom­verlauf wird durch die Lüfter gesteuert, die entweder Luft einbla­sen ode r abzie hen. Genere ll kann d er Luf tstrom entweder von
vorne nach hinten oder von hinten nach vorne verlaufen.

Barracuda 18LP Installation Guide, Rev. B 31

.

Above unit

Under unit

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

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

Figure 4. Suggested air flow
Abbildung 4. Empfohlener Luftstrom verlauf

Above unit

Under unit

32 Barra cuda 18LP Installat ion 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 hand le t he drive by the fr ame only.

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

1. Mount the drive to the host system’s chas sis 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 s eem to screw in e asily, because this means the threads
are not properly aligned. In this case, back the screw out
and tr y again.

Installation des Laufwerkes
und A nschluß der Ka b el

Beacht en Sie beim Handhaben und Anf assen der Anschl ußstifte
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 vor handen ist.

Barracuda 18LP Installation Guide, Rev. B 33

1. Befestigen Sie das Laufwerk mit vier 6-32-UNC-Schrauben
am G ehäu se des Host-System s. Die beiden Sei ten des
Laufwerkes sind mit jeweils zwei Befestigungslöchern
versehen, die Unterseite des Laufwerkes weist vier weitere
Befestigungslöcher auf.

Gemess en von der Außenfläch e des Gehäuses dürfen die
Schrauben maximal 3,81 mm in die Befestigungslöcher des
Gehüus es hinei nragen. Die Schra uben müsse n gleic h-
mäßig, jedoch nicht zu fest, angezogen werden. Wenn sich
eine Schraube nicht ohne Widerstand einschrauben läßt,
sind die Gewinde nicht korrekt aneinander ausgeri chtet. In
dies em 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 correctl y installed.

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

3. Verify that you have cor rectly installed jumpers.

3. Stellen Sie sicher, daß die Kennungsbrücken inst all iert sind.

4. Connect the SCSI cable into the drive’s SCSI connector.
Take care not to stretch or crimp this cab le, and do not bl ock
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 5 provides the pin information for

34 Barra cuda 18LP Installat ion Guide, Rev . B

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 Lau fwerkes a n. Das Kabe l darf n icht gedehnt o der
gedrückt werden und es dar f den Luft str om zur Kühlung des
Systems nicht behindern.

Das Laufwerk wird über einen 4-poligen, neben dem SCSI­Anschluß befestigten Steckverbinder mit Gleichstrom ver­sorgt. Der Ausgang eines Netzteils muß SELV (safety extra
low voltage) nach IEC 950 en tsprechen . Abbildung 5 zeig t
die Steckerbelegung für den Gleichstromanschluß. Zum
Ansc hlu ß des Gleic hstrom kabels an da s Laufwe rk d as
Kabelende in den Gleichstromanschluß des Laufwerkes
stecken.

Barracuda 18LP Installation Guide, Rev. B 35

J1

Pin 1

J1-Auxiliary

Pin 1A

J1-DC Power

Pin

1
2
3
4

1P2P3P4P

PCB

Pin

Power

1

+12V

2

+12V ret

3

+ 5V ret

4

+ 5V

Gleichstrom

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

Power

Cable

Figur e 5. DC power connector
Abbildung 5. Gle ichstrom anschluß

Note. Signal ground on the power control board (PCB) and the

head and disc as sem bly (HDA) are connec ted togeth er i n
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

36 Barra cuda 18LP Installat ion Guide, Rev . B

(el ectrically isolating) method of mounting the dri ve in the
host system. This may increase radiated emissions and
is the system designer’s responsibility.

Hinweis:

Die Sign alerde au f der Strom regelung skar te (P CB) und
der Kopf - und Fes tplat tene inh eit (HDA ) s ind in di esem
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 a ngeschlossen.
Die elektromagnetische Strahlung kann reduziert wer­den, indem Sie eine möglichst große leitende Kontak­fläche zwischen der HDA-Erdung und der Systemerdung
vorsehen.

Wenn Sie da s Syst emgeh äus e nic ht an d ie HDA/P CB­Erdung anschließe n wollen, müssen Sie das Laufwerk
auf nichtleitende Weise (galvanisch isoliert ) im Host-Sys­tem ein ba uen. D ie da raus u. U. resultie ren de verst ärkte
elektromagnetische Strahlung fällt in den Zus tändigkeits-
berei ch des Systemdesi gners.

5. Replace the host system’s cover.

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

Barracuda 18LP Installation Guide, Rev. B 37

K

H

C

[2]

M [6]

[6] N

[3]

J2

[1]
E

G

D

F

A

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 0.15 in. (3.81 mm). Screw tightening torque 6.0 in-lb

B

(.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]

J

[4] L

Centerline of pad for Pin 1 of power connector.

[5]

Centerline of pad for Pin 1 of J6.

[6]

Centerline of pad for Pin 1 of J2. Dimensions indicated are for
reference only.

[7]

Dimensions to Pin 1 of each connector are nominal values.

[8]

To pin ends on J6. Pin ends on J6 are nominally
flush with end of drive.

[9]

Nominal values cannot be added to any toleranced dimension to
achieve a valid toleranced dimension.

Dimension Table

Millimeters

146.05

101.60

25.45

60.00

28.45

101.60

6.35

44.45

95.25

41.28

3.63

19.13

4.19

10.29

52.53

59.69

S [8]

J6 LED

P [5]

R

Inches

A
B

C
D

E
F

G
H

J
K
L

M
N

P

R

S

5.75

4.00

1.002

2.362

1.120

4.000
.250

1.750

3.750

1.625
.143
.753
.165
.405

2.265

2.350

± .025
± .015

+ .027

– .21

± .010
± .020
± .010

+ .010
– .005

± .010
± .010
± .020

[7] [7]

Figure 6. Mounting configuration dimensions

± .64
± .25

+ .69

– .53

± .25
± .51
± .25

+ .25
– .12

± .25
± .25
± .51

38 Barra cuda 18LP Installat ion Guide, Rev . B

Formatting the drive

The drive has been low level formatted at the factory. You do not
need to perform another low level format on this drive unless y ou
deci de to perfo rm certain diagnostics through the host adapter.

If you do decide to perform a low level format, do not abort the
format as this is likely to make the dr ive inoperable. Also, it is a
good idea to protect against power failure or other power inter­ruptions during the format. Keep in mind that it may take up to
one hour per gigabyt e to lo w level format the dri ve. Do not reboot
or othe rwise disrupt the process.

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 intenti on is to erase all user dat a.

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 18LP 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 and setting up the drive. Some
quic k desktop system notes are pr ovided bel ow.

Quick refer ence desktop system notes
Note.

Refer to your system or utility manual for detailed instruc­tions)

Barracuda 18LP Installation Guide, Rev. B 39

• DOS. Set the drive type in CMOS to “

hard driv e instal led

.” Use FDISK.EXE and FORMAT.EXE. Sys-

Zero,” “None,”

or “

No

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).

40 Barra cuda 18LP Installat ion Guide, Rev . B

LW dr ives

Setting the SCSI ID jumper s

Use the J6 jum per bl ock to set the SCSI ID (Figure 7). 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 auxiliary to set the SCSI ID (see
Figure 8).

Ter minating th e drive

“LW” m odel drives do not have internal term inators or any other
way of adding internal termination to the drive. External termina­tion for these drives must be supplied by the host equipment.

Barracuda 18LP Installation Guide, Rev. B 41

LW dr ives

Drive
Front

Jumper Plug

(enlarged to
show detail)

Pin 1

[1]

J6

R

Reserved

SCSI ID = 0 (default)
SCSI ID = 1

L

E

E

A2A1A

A

3

S

D

0

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 7. Setting the SCSI ID on model LW drives

42 Barra cuda 18LP Installat ion Guide, Rev . B

LW dr ives

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

Pin 1

+5V

Ground

J5

Pin 1

4P 3P2P 1P

(default)

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

J1-DC Power

Drive

HDA

Rear

PCB

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

+5V

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

N.C.

Ground

Drive Activity LED

A

3A2A1

1197531

12 10 8 6 4 2

A

0

A0A1A2A

3

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.

Figur e 8. Using J5 connector for model “LW” drive

alt ernate ID select and LED connecti on

Barracuda 18LP Installation Guide, Rev. B 43

LW dr ives

Other applicable jumper options

Other option jumpers are a vail able as i llustrated in Figures 9 and

10.

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

HDA

L

R

E

E

D

S

11

12

3

J6

J2

[1]

Pin 1

J6

A2A

A1A

0

CATH

J6

Jumper Type

(enlarged to
show detail)

Pin 1

End

Reserved
Delay Motor Start option

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

Disable the Delay Motor
Sta r t 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.

Pin 1

(default)

(default)

J2

DC Power
Connector

J1

SCSI I/O

Connector

J2 Jumper Type

(enlarged to
show detail)

[1] See Figure 10 for this jumper position option for “LW” drives.

Figure 9. Additional jumper options for “LW” drives

Pin 1

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.

(default)

(default)

44 Barra cuda 18LP Installat ion Guide, Rev . B

LW dr ives

Pin 1

[3]

Jumper

Positions

A jumper here forces single-ended
I/O operation. [2]

J2

SEDSMEWPP

D

R
E
S

R
EST

P

No jumper allows host to select either

(default)

single-ended or LVD operation.

Term. Power to SCSI Bus (default)

Host adapter or other device provides

term. power to external terminator.

J2

J6

Drive

J2 Jumper Plug

(enlarged to
show detail)

Front

[1]

[1] TP not used on “LC” drive
[2] Jumper not t o be installed for “LW” operation
[3] Jumper position names shown here are not marked on the PCB.

They are shown here for refe rence only.

Figure 10. Additional jumper option for “LW” drives

Barracuda 18LP Installation Guide, Rev. B 45

LC dr ives

WC/DC drives sectionSetting the SCSI ID jumper s

The SCSI ID for “LC” 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 .

Ter minating th e drive

“LC” model drives do not have internal terminators or any other
way of adding internal termination to the drive. External termina­tion for these drives must be supplied by the host equipment.

46 Barra cuda 18LP Installat ion Guide, Rev . B

LC dr ives

Pin 1

J2

Delay Motor Start option

Jumper

Positions

[1]

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

SEDSMEWPP

D

R
E
S

R
E
S

R
E
S

(default)

(default)

Write protect = Off (enables writing)
Write protect = On (disables writing)

Parity Check option
Enable parity check of SCSI bus.

Disable parity check.

J6

Drive

J2 Jumper Plug

(enlarged to
show detail)

Front

(default)

(default)

J2

[1] Jumper position names shown here are not marked on the PCB.

They are shown here for refe rence only.

Figure 11. Jumper options for “LC” drives

Barracuda 18LP Installation Guide, Rev. B 47

LC dr ives

Single-ended/low-voltage-differential selection

The

SE

jumper, when insta ll ed on J2, forc es the drive I/O ci rcuits
and all other devices on the SCSI bus to operate in the single­ended (SE) mode. When the

SE

jumper is not on, the SCSI I/O
can operate in either single-ended or low-voltage differential
(LVD) mode, depending on which mode the host device has
selected using the “DIFFSNS” I/O line. The

SE

jumper should
not be installed unless the system documentation specifically
stat es that it should be installe d. The I/O b us can transf er data at
a much higher data rate in the LVD mode, but the system must
be desi gned to accommodate a higher data rate.

48 Barra cuda 18LP Installat ion Guide, Rev . B

LC dr ives

Pin 1

Single-Ended I/O

Jumper

Positions

[1]

A SE jumper here forces single-ended
I/O operation.

J2

SEDSMEWPP

D

R
E
S

R
E
S

R
E
S

No jumper allows host to select either

(default)

single-ended or LVD operation.

J2

J6

Drive

J2 Jumper Plug

(enlarged to
show detail)

Front

[1] Jumper position names shown here are not marked on the PCB.

They are shown here for refe rence only.

Figure 12. Additional jumper options for “LC” drives

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

Publicati on Number: 77767527, Rev. B, Printe d in USA