seagate ST39175LW, ST39175LC, ST318275LW, ST318275LC Installation Guide

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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 precautions......... .. .......... .........2

Wichti g e Sic h er h e i ts h in w ei se ....... ... ......... .......... .......... .. .......... ...4

Regulatory agency compl iance......... .. .......... .......... .......... ...........7

Seagate Technology supp o rt ser v ic e s .... .. .......... .......... .......... .. ...9

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

Initial se t up in form a t io n....... ... .. .......... .......... .......... .. .......... ........19

Kühlung de s Sy s te ms ......... ... .. .......... .......... .......... ......... .......... .30

Installa ti on des Laufwerkes

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

LW drives section......... .......... .. .......... .......... .......... ......... .......... .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 their 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

representative if you need to order this publ ication.

Note.

If any differences exist between specification values in
this guide and the product manual , the product manual
values are t he authoritative values.

Electrostatic discharge protection

Caution.

All drive electronic assembli es are sensit ive to static electricity,
due to the electrostatically sensitive devices used within the
drive circuitry. Although some de vices such as metal-oxide semi­conductors are extremely sensitive, all semiconductors, as well
as some resistors and capacitors, may be damaged or deg raded
by ex posure to static electricity.

Electrost atic damage t o electroni c 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 yourse lf to ground with a wrist
strap (Seagate part number 12263496). Connection may be
made to any grounded metal assembly. As a general rule,

Removal of circuit boards by personnel not perfor m­ing depot repair will damage components and may
void the war ranty.

Barracuda 18LP Product

2 Barra cuda 18LP Installation Guide, Rev. B

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

• Turn off the power before removing or installing the DC power
cable.

• Do not remove any circuit boards from the drive.

• Never use an ohm meter on any cir cuit boards.

• When installing th e drive on a carrier or t ra y, discharge the car-

rier or tray pr io r to ins e rtin g it into th e sy st e m.

Important safety information and precautions

Caution.

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 elimi nate the risk of personal injury. The warnings
point out conditions or practices that may endanger you or oth­ers. The cautions point out conditions or pr actices that may dam ­age the unit, poss ibly making it unsafe f or use.

Always observe the following warnings and precautions:

• Follow all cautions and war nings 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 re mo ving 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

Use forced-air ventilation when bench-testing the
drive to ensur e proper cooling of drive components.

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 “Electrost atic discharge
protection.”

• Do not remove any circuit boards from the drive. Retur n the
entire drive for depot repair if any circuit board is defective.
Removal of circuit boar ds 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 atte mpt to disassemble the HDA. It is not field repair­able. I f the sealed HDA is opened by personnel not performing
depot repair, this will damage components and void the
warranty.

As a component, this drive is designed to be installed and oper­ated in accordance with UL1950, 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
acceptabil ity in obtaining safety-regulato ry agency compliance in
their end-use products and for certifying where required by law.
A necessary part of meeting safety requirements is the provi sion
for overcurrent protection on drive SELV supply vo lt ages.

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

ply with FCC or simil ar national r equirements 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.

Fremdbelüftung vorzusehen, um eine ausreichende Kühlung der
Laufwerkkom ponenten sicherzustellen.

Verwenden Sie geeignete Sicherheits- um den sicheren, zuver­lässigen Betrieb 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 War nhinweise machen auf Situationen
oder Praktiken aufmerksam, die Sie oder andere gefährden
könnten. Die Vorsichtshinweise machen auf Situationen oder
Praktiken aufmerksam, die Einhei t 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.

Beim Testen des Laufwerks auf dem Prüftisch ist

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 au s, bevor Sie m it den Installations-und Entfernungsar­beiten beginne n.

• Wenn das Laufwerk in einem Einbaugestell oder Gehäuse
montiert ist, sorgen Sie dafür, d aß 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 Si e 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 zustän-
digen kann zu einer Beschädigung der Komponenten und
Erlöschen des Garantieanspruchs führen.

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

6 Barra cuda 18LP Installation Guide, Rev. B

• Die HDA ist nicht vor Or t reparierbar und darf nicht auseinan­dergenommen 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 is t diese s Laufwerk für die I nstallati on und
den Betrieb in Übe reinstim mung mit UL 19 50, EN6 0950, C AN/
CSA C22.2 950-95 und VDE0805 vorgesehen.

Seagate ist ständi g bemüht, die Zulassungsfähigkeit von
Seagate-P rodukten im Rahme n der geg enwär tig ge ltenden
Standa rd s zu gewährleisten. Zu den typischen Anwendungen
dieser Festplattenwerke zählen Systemeinbau durch den
Kunden und die K on strukti on von Unter systemen. Sicherh eitsbe ­hörden gewähren eine bedingt e Zulass ung für Komponenten wie
das Barracuda-Festplattenlaufwerk vorbehaltlich der endgül tigen
Zulasssun g im E ndprod ukt . Design er von Un tersyst eme n sind
dafür verantwor tlich, die Voraussetzungen für die Einhaltung
sicherheits- oder aufsichtsbehördlicher Vo rschriften in ihren
Endprodukten und - falls ge setzlich vorgeschrieben - für die
Zulass ung zu scha ffen. Eine Gr un dvorau ss etzu ng zur E in hal­tung der Sicherheitsanforderungen ist die Bereitstellung eines
Überlastschutzes für die SELV-Versorgungsspannungen des
Laufwerks.

Dieses Gerät ist eine Baugruppe und unterliegt als solche ni cht
den Anforderungen der FCC oder ähnlicher nationaler Behörden
für eigenständige Geräte. Technische Testergebnisse zu elektro-
magnetische Str ahlung si nd für Designer von Unte rsyst emen auf
Anfrage von der Seagate-Sicherheitsabteilung erhältlich.

Barracuda 18LP Installation Guide, Rev. B 7

Regulatory agency compliance

Electromagnetic susceptibility

As a component assembly, the drive is not required to meet any
susceptibility performance requirements. It is the responsi bility o f
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.

Electromagnetic compliance

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 configurations include:

• 486, P entium, and PowerPC microprocessors

• 3.5-inch f loppy 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 guarant ee that all systems
will comply. The computer manufacturer or system integrator
shall confirm EMC compliance and provide CE Marking and C­Tick Marking for their product.

8 Barra cuda 18LP Installation Guide, Rev. B

Electromagnetic compliance for the European Union

If this model has the CE Mar king it complies with the European
Union requirements of the Electromagnetic Compatibility Dire c­tive 89/336/EEC of 03 M ay 1989 as amended b y Directive 92/31/
EEC of 28 April 1992 and Directive 93/68/EEC of 22 Jul y 1993.

Australian C-Tick

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

Barracuda 18LP Installation Guide, Rev. B 9

Seagate Technology support services

Online Se r vices

Internet

For online infor mation 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 ser vice is
availa ble world w ide.

:

is a computer bulletin board system that contains

or

DiscPresales@Seag ate.com

or

or

[e-mail]

or

[e-mail]

Automated S er vices

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 Barracuda 18LP Installation Guide, Rev. B
tips and specifications for disc drives and tape drives 24 hours

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

SeaFAX

touch-tone phone, you can obtain technical suppor t information
by retu rn FAX 24 hours daily. This service is available worldwide.

®

is Seagate's automated FAX delivery system. Using a

Presales Support

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

Seagate Express

You can purchase select tape products and tape accessories
through Seagate Expr ess 24 hours daily by calling 1-800-531­0968 or by faxing your or der to: [phone].

T e c hnical Support

If you need help installing your dr ive, 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 additi onal help, you ca n talk to a Se agate technical support
specialist. Before calling, note your system configuration and
drive model 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 time) Monday through Friday.

####).

is a telecommunications device

Barracuda 18LP Installation Guide, Rev. B 11

Customer Service (C SO)

Warranty Repai r

Seagate offer s worldwide customer support for Seagate drives.
Seagate direct OE M , Di stribution and System Integrat 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 l ive outside the US, you can contact an Authori zed Service
Cent e r for service or re pair.

USA/Canada/Latin America Support Services

Presales Support

Disc:

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

Tape:

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

Technical Suppor t (SeaFONE)

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

FAX:

Disc: +

SeaFAX
SeaTDD
SeaBOARD

1-405-936-1685;

1-800-SEAGATE
[phone]

Disc: +

Tape:

[phone]

1-405-936-1600;

Tape:

[phone]

12 Barracuda 18LP Installation Guide, Rev. B

Warranty Repai r

USA 1-800-468-3472 FAX: [phone]
Mexico an d
Latin America [phone] F AX: [phone]

Authorized Service Centers

Brazil

MA Informatica

[phone] F AX: [phone]

Canada

Memofix
Adtech

1

1

[phone] F AX: [phone]
[phone] or F AX: [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
located in Amsterdam, The Netherlands.

Call Center

Austria 0 800-20 12 90
Belgium 0 800-74 876
Denmark 80 88 12 66
Fr ance 0 800-90 90 52
Germany 0 800- 182 6831
Ireland 1 800-55 21 22

A.M

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

1

Authorized Service Centers

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

Netherlands 0 800-732 4283
Norwa y 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 European Countries

Presales/Technic al Support/Warranty Repair [phone]

Africa/Middle East Support Services

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

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

Netherlands.

Asia/Pacific East Support Services

Technical Suppor t

Australia [phone] F AX: [phone]
Hong Kong [phone] FAX: [phone]
Japan — F AX: [phone]
Singapore [phone] FAX: [phone]
Taiwan [phone] F AX: [phone]

14 Barracuda 18LP Installation Guide, Rev. B

SeaFAX

Australia [phone]

Warranty Repai r

Japan [phone] F AX: [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 digit al-data storage 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 external encl osure desi gned to house one or more di sc driv es
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

77767526) contains guidelines for a properly designed

enclosure.

Barracuda 18LP Product Manual

*

(part number

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

Figure 1. Barracuda 18LP famil y drive

16 Barracuda 18LP Installation Guide, Rev. B

Table 1. Drive ch aracteris tics

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 data heads

ST39175 5
ST318275 10

Access time [3]

Av erage read 6.9 msec
Av erage write 7.7 msec

Disk r o tation

RPM 7,200 r/min
Av erage latency 4.17 msec

Internal transfer rate (variable with zone)

ST39175 137–240 M b i ts /sec
ST318275 137–240 M b i ts/sec

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 controller overhead.

Barracuda 18LP Installation Guide, Rev. B 17

T able 2. DC power requirements (Amps), multimode

(SE/LVD)

ST39175LW/LC ST318275LW/LC

Voltage +5V +12V +5V +12V
Regulation [5] ±5% ±5%[2] ±5% ±5%[2]
Avg. idle curre nt

DCX

[1] 0.75 0.35 0.75 0.5

Max. starting current

(peak DC) [3]
(peak AC) [3]

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

Peak operating current

Ty pica l DCX
Maximum DC [1]
Maximum (peak)

[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 start of the spindle

but must return to ±5% before reaching 7,200 RPM. The
±5% must be maintained after the drive signifies that its
power-up sequen ce has been compl eted and that the drive is
able to accept selection by the host initiator.

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

Manual

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

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

[1][6]

(publication number 77767526).

1.0

—

1.0

1.3

1.7

1.3

2.4

0.7

1.4

2.1

1.05—1.6

1.05

1.4

1.7

Barracuda 18LP Product

2.4

0.8

1.5

2.4

18 Barracuda 18LP Installation Guide, Rev. B
[5] See “Conducted noise immunity” in the

Product Manual.

The specified voltage tolerance is inclusive

Barracuda 18LP

of ripple, noise, and transie nt re sponse.

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

tions with a block count of 64.

General Notes fr om Table 2.

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

than 4% of the maximum ope rating current shown.

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

3. Where power is provided to mult iple drives from a common

supply, carefully consider individual drive power require­ments. Wh ere multiple units are powered on simultaneously,
be sure the peak starting current is available to each device.

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

T able 3. Dimensions of the driv e

inches mm

Height 1.00 25.4
Width 4.00 101.6
Depth 5.75 146.05
Weight 1.5 pounds (0.589 kilograms)

Barracuda 18LP Installation Guide, Rev. B 19

Initial setup information

The general information 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 Page

ST39175LW ST318275LW 40
ST39175LC ST318275LC 45

General information

The foll owing general information topics are di scussed:

• SCSI ID jumpers

• Drive termination

• Terminator power

• Interf ace drivers and dat a path width notes

• Other applica ble jumper options

• Providing adequate cooling

• Mounting the drive and connecting cables

• Formatting t he drive

1

This mounting procedure does not apply to “LC” model drives.
To m ount an “LC” drive, plug the dr ive into the system’s single
connector attachment (SCA) position on the system’s back
panel.

1

20 Barracuda 18LP Installation Guide, Rev. B

SCSI ID jumpers

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 u sed for other SCSI devices such as this Barr acuda
disc drive.

Note.

Most SCSI control lers (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.

Note.

This drive is a SCAM (SCSI Configured Auto Magically)
compliant drive. If the system into which you are i nstalling
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 ma y 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 factor y set with the SCSI ID set
at 0. To change the SCSI ID, refer to t he appropriate drive sec­tion for your model.

If, af ter 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 vi olated its SCSI ID
numbering recomm endations.

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 i nternal hard disc at one
end of the SCSI bus with the SCSI controller at the other end
(both are terminated). The bottom e xample 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. 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 Barracuda 18LP Installation Guide, Rev. B
For infor mation 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

T erminator power

You usually will not need to change this option and can normally
leave the drive conf igured as it was shipped from the factory. For
information about how to change the terminator power option on
your drive, refer to the appropriate driv e-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 cont roller 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 vol tage differential (LVD) mode. If y our 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 oper ate with older SE controll ers, 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. How-
ever, the SE jumper on J2 forces “DIFFSNS” to nominal
ground (see Figure 12). The host device cannot override the
SE jump er. 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/dr ivers
operate in low voltage differential (LVD) mode.

•“LC” and “LW” mo dels 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 connect ions. The fol­lowing tables list the maximum cable lengths and number of
devices allowed on a daisy-chain cable for I/O data trans fer rates
shown.

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

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

strongly

twisted pai r cables are

recommended. For Fast-80 operation,

required

.

24 Barracuda 18LP Installation Guide, Rev. B

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

circuits

Maximu m distance betw ee 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) SC S I d evices 6 3 3 N/A

5 to 8 maximum capacitance
(25 pF) SC S I d evices 6 3 1.5 N/A

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

[1] F or en vir o nmen ts wher e a ll eleme nt s of the b u s (c abl e s, de vi ce i nt er-

faces, environmental noise and other parameters) are controlled to
be better than minim ally requi red, it may be po ssible to exte nd the
path length and device count.

[2] Exten di ng the device coun t beyond eig ht requ ire s spe cific atio n con -

trol beyo nd the minimum sp ecified in the ANS I T10/1142D docu ­ment. It is recommended that the devices be uniformly spaced
between termin ators with the end devices locate d 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. Cabl e characteristics for differential I/O circui ts

Maximu m distance betw ee 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 devices) [4] 15 15 15 12

[1] F or en vir o nmen ts wher e a ll eleme nt s of the b u s (c abl e s, de vi ce i nt er-

faces, environmental noise and other parameters) are controlled to
be better than minim ally requi red, it may be po ssible to exte nd 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 specification).

26 Barracuda 18LP Installation Guide, Rev. B

Power

Cable

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

Barracuda 18LP Installation Guide, Rev. B 27

“LW” Model

Drive

SCSI ID 1

[6]

SCSI ID 0

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

Terminator

[1]

2 through X

SCSI devices [4]

[2]

[2]

Pin 1

(check your

adapter for Pin 1 location)

SCSI ID 7 [5]

[1]

Host Adapter

PCB

[3]

[1] Closed end type 68 pin connector used. Terminator required.
[2] Open end type (in-line application) connector used. No terminator.
[3] Host ne ed not be on t h e en d of th e daisy c h ain . Anoth er device can

be on the end with the terminator, the host having no terminator .

[4] Total interfa ce cabl e lengt h must not ex ceed th at spe cifie d in AN SI

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

[5] SCSI ID7 has hi gh es t a r bi tr at io n prior ity. For “LW” mod els, priori ty is

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

[6] Last drive on the daisy chai n.

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

adapter

28 Barracuda 18LP Installation Guide, Rev. B

Note. This drive model plugs directly int o 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 adeq uate cooling

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 t he ti m 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 dri ve operation.

We recom mend 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 t he 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 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.

30 Barracuda 18LP Installation Guide, Rev. B

Kühlung des Systems

Die Gehäusekonstruktio n m uß ei ne ausreichende K ühlung des
Laufwerkes ge währlei sten. Die Umgebungstemperatur darf max­imal 50°C betragen.

Die Prod uk thand buch Barr acuda 18LP (Doku men t 77 7675 26 )
enthalten Anweisunge n zur Beur t eilung der Luftst romkonstru k­tion. Die Beurteilung muß sicherstellen, 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 lenken, daß der ger ingste Luftst romwiders 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 aufgewärmte Luft
zurücklegt, auf ein Minimum besc hränkt.

Abbildung 4 zeig t zwe i Konstr ukt ionsm öglic hkeite n, b ei de nen
ein oder mehrere Lüfter den Luftstrom erzeugen. Der Luftstrom­verlauf wird dur ch die Lüfter gesteuert, die entweder Luft einbla­sen oder abzie hen . Genere ll kann d er Lu ftstrom entweder von
vorne nach hinten oder von hinten nach v orne 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)

Above unit

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

Under unit

Figure 4. Suggested air flow
Abbildung 4. Empfohlener Luftstr om verlauf

32 Barracuda 18LP Installation Guide, Rev. B

Mounting the drive and connecting cables

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

The drive may be mounted in any or ientation (horizontal ly, verti­cally, and any com bination thereof); however, you must ensure
that the drive receives adequate air flow f or 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 i nch (3.81 mm), measured
from the outer surface of the chassis. Tighten the screws
down e venly. Do not over-tighten or force the screw if it does
not seem to screw in easily, because this means the threads
are not proper ly aligned. In this case, back the screw out
and try again.

Installation des Laufwerkes
und Ansch lu ß der K abel

Beachten Sie bei m Han dhaben 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) installier t werden; jedoch muß dafür gesorgt
werd en, d aß ei n ausreichender Luftstrom zur Kühlung des Lauf­werkes v orhanden ist.

Barracuda 18LP Installation Guide, Rev. B 33

1. Befestigen Sie das Laufwerk mit vier 6-32-UNC-Schrauben

am Gehäuse des Host-System s. Die beiden Seiten des
Laufwerkes sind mit jeweils zwei Befestigungslöchern
versehen, die Unterseite des Laufwerkes wei st vier weitere
Befestigungslöcher auf.

Gemessen von der Außenfläch e des Gehäuses dürfen die
Schrauben maximal 3,81 mm in die Befestigungslöcher des
Gehüuses hineinrag en. Die Schraube n müssen gl eich­mäßig, jedoch nicht zu fest, angezogen werden. Wenn sich
eine Schraube nicht ohne Widerstand einschrauben läßt,
sind die Gewinde nicht korrekt aneinander ausgerichtet. In
diesem Fall die Schrau be nich t in da s Gewi ndeloc h
forcieren, sondern die Schraube herausnehmen und erneut
in das Gewindeloch einführen.

2. Ver ify that all connections between the drive and the host

system are correctly install ed.

2. Prüfen Sie, ob alle Verbindungen zwischen dem Laufwerk

und dem Host -System korrekt hergestellt sind.

3. Verify that you have correctly install ed jumpers.

3. Stellen Sie sicher, daß die Kennungsbrücken in stalliert sind.

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

Take care not to stretch or cri m p this cable, and do not block
the system’s cooling air flow with the cabl e.

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 provid es the pin inform ation for

34 Barracuda 18LP Installation Guide, Rev. B

the DC power connect or. 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 Laufwer kes an. Da s Kabel dar f nicht ge dehnt o der
gedrückt w e rden und es darf den Luftstrom zur K ühlung 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 entsprechen . Abbildu ng 5 zeigt
die Steckerbelegung für den Gleichstromanschluß. Zum
Anschlu ß des G leichs tromk abels an das L aufwer k das
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

Figure 5. DC power connector
Abbildung 5. Gleichst romanschluß

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 t he HDA and PCB without electrically i solating
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 Barracuda 18LP Installation Guide, Rev. B

(electricall y isolating) method of mounting the drive in the
host system. This may increase radiat ed emissions and
is the system designer’s responsibility.

Hinweis:

Die Signalerde au f der Str omregel ungskar te (PCB) u nd
der Kopf- und Festp latt enein heit (HDA) sin d in dies em
Laufwerk miteinander verbunden und können nicht
getrennt werden. Das Gerät, in das Sie das Laufwerk
eingebaut haben, ist ohne elektrisch isolierende
Stoßdämpfer direkt an die HDA und PCB angeschlossen.
Die elekt romagnetische Strahlung kann reduziert wer­den, indem Sie eine möglichst große leitende Kontak­fläche zwischen der HDA-Erdung und der Systemerdung
vorsehen.

Wenn Sie da s System gehäuse ni cht an die H DA/PC B­Erdung anschließen wollen, müssen Sie das Laufwerk
auf nichtleitende Weise (galvanisch isoliert) im Host-Sys­tem einba uen. Die da raus u.U. resulti eren de vers tärkte
elektromagnetische Strahlung fällt in den Zuständigkeits-
bereich des Syste md esigners.

5. Replace the host sys tem’s cover .

5. Setzen Sie das Gehäuseoberteil des Host- Systems wieder

auf.

Barracuda 18LP Installation Guide, Rev. B 37

[3]

C

[1]

E

K

[2]

M [6]

J2

[6] N

H

S [8]

J6 LED

P [5]

A

B

J

R

[4] L

G

D

F

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
(.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]

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.

A
B
C

D
E
F
G

H

J

K

L
M
N
P
R
S

Dimension Table

Inches

5.75

± .025

4.00

± .015

1.002

+ .027

– .21

2.362

± .010

1.120

± .020

4.000

± .010

.250

+ .010
– .005

1.750

± .010

3.750

± .010

1.625

± .020
.143
.753
.165

[7] [7]

.405

2.265

2.350

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

Figure 6. Mounting configuration dimensions

± .64
± .25

+ .69

– .53

± .25
± .51
± .25

+ .25
– .12

± .25
± .25
± .51

38 Barracuda 18LP Installation 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 you
decide to perf orm 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 drive inoperable. Also, it i s 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 gigabyte to low l evel format the drive. Do not reboot
or otherwise disrupt the process .

Warning.

Note.

1. Turn on DC power.

2. Boot the system from a system floppy disc or from a previ-

3. Format the disc drive. Barracuda 18LP disc drives are

Quick reference desktop system notes
Note.

Formatting a drive erases all user data. Be sure t hat
you understand this principle before formatting any
hard disc drive. It is not necessary t o format a drive
that previously has been used to store data, unless
your intention is to erase all user dat a.

Seagate is not responsible for lost user dat a.

ously inst alled hard disc drive if there is one.

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
quick desktop system notes are provided below.

Refer to your system or uti lity manual for detailed instruc­tions)

Barracuda 18LP Installation Guide, Rev. B 39

• DOS. Set the drive type in CMOS to “

hard drive instal led

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 FORMAT.EXE. Sys-

Zero,” “None,”

or “

No

40 Barracuda 18LP Installation Guide, Rev. B

LW dr ives

Setting the SCSI ID jumpe rs

Use the J6 jumper block to set the SCSI ID (Figure 7). To change
the SCSI ID, install jumpers on the appropriate pins as shown in
the illustration. Optional connecti ons to switching circuits in host
equipment are provided on J1 auxiliary to set the SCSI ID (see
Figure 8).

Te rminating the drive

“LW” 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.

Barracuda 18LP Installation Guide, Rev. B 41

LW dr ives

Drive
Front

Jumper Plug

(enlarged to
show detail)

3

A2A1A

Pin 1

0

[1]

J6

R

L

Reserved

E

E

A

S

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

Figure 7. Setting the SCSI ID on model LW drives

42 Barracuda 18LP Installation 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
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

J5

Pin 1

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 8. Using J5 connector for model “LW” drive

alternate ID select and LED connection

Barracuda 18LP Installation Guide, Rev. B 43

LW dr ives

Other applicable jumper options

Other option jumpers are a vailable as illustrated 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

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

J6

Jumper Type

(enlarged to
show detail)

Pin 1

End

Pin 1

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.

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

Figure 9. Additional jumper options for “LW” drives

J2

[1]

Pin 1

(default)

(default)

(default)

(default)

44 Barracuda 18LP Installation Guide, Rev. B

LW dr ives

Pin 1

R

R

E

EST

S

P

[3]

Jumper

Positions

J2

SEDSMEWPP

D

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

No jumper allows host to select either
single-ended or LVD operation.

Term. Power to SCSI Bus (default)

(default)

[1]

Host adapter or other device provides
term. power to external terminator.

J2

J2 Jumper Plug

(enlarged to
show detail)

J6

Drive
Front

[1] TP not used on “LC” drive
[2] J umper not to be installe d for “LW” operat ion
[3] Jumper position names shown here are not marked on the PCB.

They are shown here for reference only.

Figure 10. Additional jumper option for “LW” drives

Barracuda 18LP Installation Guide, Rev. B 45

LC drives

WC/DC drives sectionSetting the SCSI ID jumpe rs

The SCSI ID for “LC” model drives is normally set over the SCSI
bus by the host system using connector contact s 39 (ID0), 40
(ID2), 79 (ID1), and 80 (I D3). Users need not install jumpers to
select SCSI ID.

Te rminating the 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 Barracuda 18LP Installation Guide, Rev. B

LC drives

J2

Jumper

Delay Motor Start option

Positions

[1]

The host system has complete control over
motor start functions. Do not install a jumper

SEDSMEWPP

D

R
E
S

R

R

E

E

S

S

Pin 1

(default)

on these pins.
Enable Motor Start option

The host system has complete control over
motor start functions. Do not install a jumper

(default)

on these pins.
Write Protect option

Write protect = Off (enables writing)

(default)

Write protect = On (disables writing)
Parity Check option

Enable parity check of SCSI bus.

(default)

Disable parity check.

J2

J2 Jumper Plug

(enlarged to
show detail)

J6

Drive
Front

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

They are shown here for reference only.

Figure 11. Jumper options for “LC” drives

Barracuda 18LP Installation Guide, Rev. B 47

LC drives

Single-ended/low-voltage-differential selection

The SE jumper, when installed on J2, forces 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
states that it should be i nstalled. The I/O bus can transfer data at
a much higher data rate in the LVD mode, but the system must
be designed to accomm odate a higher data rate.

48 Barracuda 18LP Installation Guide, Rev. B

LC drives

Pin 1

R

R

R

E

E

E

D

S

S

S

Single-Ended I/O

Jumper

Positions

J2

[1]

SEDSMEWPP

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

No jumper allows host to select either
single-ended or LVD operation.

J6

Drive

J2 Jumper Plug

(enlarged to
show detail)

Front

J2

(default)

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

They are shown here for reference only.

Figure 12. Additional jumper options for “LC” drives

Seagate Tech no logy, Inc.
920 Disc Drive, Scotts Val ley, CA 95066-4544, USA

Publication Number: 77767527, Rev. B, Printed in USA