Seagate CHEETAH 18 ST118202LW/LC, Cheetah 18, ST118202LW, ST118202LC Installation Manual

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Cheetah 18

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Disc Drive

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ST118202LW/LC

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Installation Guide

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Contents

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

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

Important safety informati on and precautions.. ....... .. ........... .... 2

Wich tige S ic h er h e itshin w ei se............. ... .......... .. ..... .. ... ..... .. ...... 4

Regula tory agency compliance................. ....... .. ....... ............... 7

Seagate Technology support services...................................... 9

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

Init ia l se tup in for ma tion . .... ... .. ..... ... ......... ... .......... .. ..... .. ... ..... . 1 9

Kühlung des Systems............................................................. 29

Inst allation des Laufwerk es und Anschluß der Kabel... ....... ... 31

LW d r ives se c tion ....... ... ......... ... ......... ... ..... .. ... ..... .. .......... .. .... 39

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

©1997, 1998 Seagate Technology, Inc. All right s reserved
Publication Number: 83329250, Rev. A
March 1998

Seagate, Seagate Technology, and the Seagate logo are regis­tered trademarks of Seag ate Technology, Inc. Ch eetah, 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 for m with-

out writt en permission from Seaga te Technolog y, Inc.

Cheetah 18 Installation Guide, Re v. A 1

Preface

This manual contains information for users of the Seagate®

Cheetah 18 SCSI disc drives. It provides support services, per-

formance specifications, and initial setup information. Additional

info rm atio n is ava ilabl e in th e

Cheetah 18 Product Manual

(par t
number 8332926 0). Contac t your Seagate sal es repres enta tiv e if
you need to order thi s publicat ion.

Electrostatic discharge protection

Cauti on.

All drive electronic assemblies are sensitive to static electricity,
due to the electrostatically sensitive devices used within the
drive circui try. Althou gh some devices such as metal-oxide semi ­conductors are extremely sensitive, all semiconductors, as well
as some resistors and capacitors, ma y be damaged or degra ded
by exposure to static electricity.

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

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

2 Cheetah 18 I nstallation Guide, Rev. A

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

cable.

• Do not remove any circuit boards from the drive.

• Never use an ohmmeter on any circuit boards.

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

rie r o r tray pr io r to ins e rting it into th e syst e m .

Importan t safety information and precau tions

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 ris k of pers onal injury. The warnings
point out conditions or practices that may endanger you or oth­ers . The cautions point out conditions or practices that may dam­age the uni t, possibly making it unsafe for use.

Always observe the following warnings and precautions:

• Follow al l cautions and war nings in t he 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 uni t befo re 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

Cheetah 18 Installation Guide, Re v. A 3

stacked vertically, pay special attention to the top where tem­peratures are usual ly 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 compo nents and may void the w arranty.

• Do not separate the head and disc assembly (HDA) from the

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

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

abl e. If t he sealed HDA is opened by personn el 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 cer tify component
assemblies, such as the Cheetah disc drive, based on their final
acceptability in the end-use product. The subsystem designers
are responsible for meeting these conditions of acceptability in
obtaining safety-regulatory agency compliance in their end-use
products and for certifying where required by law. A necessary
part of meeting safety requirement s is the provision for overcur­rent protection on drive SELV supply voltages.

4 Cheetah 18 I nstallation Guide, Rev. A
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 Depar tment to assist the subsystem
designer.

Wichtige Sicherheitshinweise

Vorsicht.

Beim Testen des Laufwerks auf dem Prüftisch ist
Fremdbelüftung vorzusehen, um eine ausreichende Kühlung der
Laufwerkkomponenten sicherzustellen.

Verwenden Sie geeignete Sicherheits- 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 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 Vor sichtshinweise sind nicht allumfassend! Es ist
uns einfach nicht möglich, alle Wartungsmethoden oder die
eventuellen Risiken j eder Methode zu kennen, zu beur teilen 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 gewä hlt e Verfahren weder Ihr e
persönliche Sicherheit noch die Leistung der Einheit gefährdet.

Cheetah 18 Installation Guide, Re v. A 5
Beachten Sie in jedem Fall die folgenden Warn-und Vorsicht-

shinweise:

• Beachten Sie alle Warn- und Vorsichtshinweise in diesem

Handbuch.

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

Entfernung der Einheit angemessene Sicherheitsvorkehrun­gen.

• Wenn eine Einheit unter Spannung steht, gehen Sie bei der

Fehlerdiagnose besonders vorsichtig vor. Schalten Sie die
Einheit aus, bevor Sie mit den Install ati ons-und Entfernungsar ­beit en beginnen.

• Wenn das Laufwerk in einem Einbaugestell oder Gehäuse

montier t ist, sorgen Sie dafür, daß die Temperatur im Inneren
des Gestells oder Gehäuses die für das Laufwerk vorgege­benen Grenzwerte nicht übersteigt. Wenn Einheiten vertikal
übereinander betestigt werden, achten Sie besonders auf den
oberen Stapelbereich, da dor t die Temperatur gewöhnlich am
höchsten ist.

• Befolgen Sie die oben unter “Electrostatic Discharge Protec-

ti on” angegebenen Sic herheitsmaßn ahm en.

• Nehmen Sie keine Platinen aus dem Laufwerk. Wenn eine

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

6 Cheetah 18 I nstallation Guide, Rev. A

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

dem Laufwerkgehäuse nehmen! Falls die HDA beschädigt ist,
schicken Si e das gesamte Laufwerk zur Reparatur ein.

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

dergenommen werden! Öffnen der versiegelten HDA durch
andere Personen als die für die werkseitige Reparatur zustän­digen hat eine Beschädigung der Komponenten und
Erlöschen des G aranti eanspruchs zur Folge.

Als Tei lkomponent e ist diese s Laufwer k für die Ins tallation und
den Betr ieb in Übe reinstimmun g mit UL 19 50, EN60950, C AN/
CSA C22.2 950-95 und VDE0805 vorgesehen.

Seagate ist ständig bemüht, die Zulassungsfähigkeit von
Seaga te-Produ kten im Rahm en de r gegenwär tig ge ltenden
Stan da rds z u gewäh rl eiste n. Zu d en typi sch en A nwe nd unge n
dieser Festplattenwerke zählen Systemeinbau durch den
Ku nden und di e Kon stru ktion v on Unter systemen. Sicherh eit sbe­hörden gewähren eine bedingte Zulassung für Komponenten wie
das Cheetah-Fest plattenlaufwerk vo rbehaltlich der endgültigen
Zulass sung i m Endp rod ukt. Desi gner von Unters ysteme n sind
dafür verantwortlich, die Voraussetzungen für die Einhaltung
sicherheits- oder aufsichtsbehördlicher Vorsch riften in ihren
Endprodukten und - falls gesetzlich vorg eschrieben - für die
Zula ss ung zu sc haf fen. E ine Gr und vorau ssetz u ng zu r Ein ha l­tung der Sicherheitsanforderungen ist die Bereitstellung eines
Überlastschutzes für die SELV-Versorgungsspannungen des
Laufwerks.

Dieses Gerät ist eine B augruppe und unter liegt als solche nicht
den Anforderungen der FCC od er ähnlicher nationaler Behörden
für eigenständige G eräte. Technische Testergebnisse zu el ektro-

Cheetah 18 Installation Guide, Re v. A 7
magneti sche Str ahlung si nd für Design er von Unte rsyst emen auf

Anfr age von der Seagate-Sic herheitsabteilung erhäl tl ich.

Regulatory agency compliance

Elect romagneti c susceptibil ity

As a component assembly, the drive is not required to meet any
susceptibili ty perform ance requi rem ents. It is the r esponsibilit y of
those integrating the drive within their systems to perfor m those
tests required and design their system to ensure that equipment
operating in the same system as the drive or external to t he sys­tem does not adversely affect the performance of the drive. See
DC power requirements on page 18.

Elect romagnetic compliance

Seagate uses an independent laboratory to confirm compliance
to the dir ectives/standard(s) for CE Marking and C- Tick Marking .
The drive was tested in a representative system for typic al appl i­cations. The selected system represents the most popular char­acteristics for test platforms. The sy stem configurations include:

• 486, Pentium, and PowerPC microprocessors

• 3 . 5 -inc h floppy di sc dr ive

• Keyboard

• Monitor/display

• Printer

• External mo dem

• 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

8 Cheetah 18 I nstallation Guide, Rev. A
shall confirm EMC compliance and provide CE Marking and C-

Tic k M arki ng for their product.

Elect romagn etic compliance for the European Union

If this model has the CE Marking it complies with the European
Union requirements of the Electromagnetic Compatibility Direc­ti ve 89/336/EEC of 03 M ay 1989 as am ended by Directiv e 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 Australia’s Spectrum Management Agency (SMA).

Cheetah 18 Installation Guide, Re v. A 9

Seagate Technology support services

Presales suppor t

To determine which Seagate products are best suited for your
specific application, cont act us about configuration and compati­bility and for current product availability. You can leave a voice
message after business hours or send an e-mail message—we
repl y during busi ness hours.

Disc Dri ves 405-936- 1210 Fax: [phone]

A.M

(8: 00
e-mail: [e-mail]

.

to 12: 15 P.M., 1:30 P.M. to 6:00

P.M

.

, central time, M-F)

Tape Pr oducts 1-800-626-66 37 or 714-641-2500

A.M

Fax: [phone]

e-mail: [e-mail]

Note.

You can purchase select tape products and tape acces­sories through Seagate Express 24 hours daily by calling
1-800-531-0968 or by faxing your order to 972-481-4812.

(6:00

.

to 5:00

P.M

.,

pacific time, M-F)

Technical support services

If you need assistance installing your drive, consult your dealer.
Dealers are familiar with their unique system configurations and
can help you with system conflicts and other technical issues. If
you need additional assistance with y our Seagate

®

driv e or other
Seagate produc ts, use one of the Seagate t echnical support ser­vices listed bel ow.

SeaFONE® 1-800-SEAGATE

Seagate’s 800 number (1-800-732-4283) allows toll-free access
to automated self-help services, providing answers to commonly

10 Cheetah 18 Installation Guide, Re v. A
asked questions, troubleshooting tips, and specifications for disc

drives and tape drives. This service is available 24 hours daily
and requires a touch-tone phone. International callers can reach
this automated self-help serv ice by dialing 405-936-1234.

Online servi ces

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

SeaNET

You can obtain technical information about Seagate products
over the Inter ne t fro m Se agat e’s World Wid e Web h ome pa ge

(http://www.seagate.com)
ftp.seagate .com)

DiscSupport @ Seagate.com

to

Seagate.com

.

. You can also send E-mail wi th your questions

or Seagate’s ftp server

or

TapeSupport @

(ftp://

Seagate CompuServe forum

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

seagate

. This forum provides information similar to that found on

go

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

SeaBOARD®

SeaBOARD is a computer bulletin board system that contains
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 st op bit (8-N-1).

Cheetah 18 Installation Guide, Re v. A 11

Location Phone number

Australia 61-2-9756-2359
France 33 1-48 25 35 95
Germany 49-89-140-9331
Taiwan 886-2-2719-6075
Thailand 662-531-8111
UK 44-1628-478011
USA Disc: 405-936-1600; Tape: 405-936-1630

FAX services

SeaFAX®

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

Location Phone number

Australia 61-2-9756-5170
Germany 49-89-1430-5102
UK 44-1628-894084
USA Disc: 405-936-1620; Tape: 405-936-1640

Techn ical support FAX

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

Location Phone number

Australia 61-2-9725-4052
France 33 1-46 04 42 50

12 Cheetah 18 Installation Guide, Re v. A

Location Phone number

Germany 49-89- 1430-5100
Hong Kong 852-2368 7173
Japan 81-3-5462-2979
Korea 82-2-556-4251/7395
Singapore 65-488-7528
Taiwan 886-2-2715-2923
UK 44-1628-890660
USA Disc: 405-936-1685; Tape: 405-936-1683

Direct-suppor t servi ces

Techn ical support

For one-on-one help, you can talk to a techni cal support special­ist during local business hours. Before calling, note your system
configuration and drive m odel number (ST

Location Phone number

Austra li a 61-2-9 725-3366 (9:00

A.M

xxxx

.

to 5:00

).

P.M

.

, eastern

tim e, M–F)

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

2:00

P.M

.

to 5:00

P.M

.

, M–F)

A.M

.

to 12:30

P.M

.

,

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

(9:30

A.M

.

to 12:30

P.M

.

, 2:00

P.M

.

to 4:00

P.M

.

,

M–F)
Hong Kong 852-2368 9918
Korea 82-2- 531-5800 (9:00

P.M

.

to 6:00

Singap ore 65-488- 7584 (9:00

to 5:00
Taiwan 886-2-2514-2237

P.M

P.M

.

, M–F )

.

, M–F )

A.M

A.M

.

to 12:00

.

to 12:00

P.M

P.M

.

, 1:00

.

, 2:0 0

P.M

.

Cheetah 18 Installation Guide, Re v. A 13

Location Phone number

UK 44-1628- 894083 (10:00

2:00

P.M

.

to 5:00

P.M

.

, M–F)

A.M

.

to 1:00

P.M

.

,

USA Please dial 1-800-SEAGATE or 405- 936-1234

for the specific product telephone number.

(8:00

A.M

.

to 12:15

P.M

.

, 1:30

P.M

.

to 6:00

P.M

.

,

ce n tra l time, M– F )

SeaTDD™ 405-936- 1687

Using a telecommunicat ions device for the deaf (TDD), you can
send questions or comments 24 hours daily and exchange mes-

A.M

sages with a technical support specialist between 8:00
12:15

P.M

. and 1:30 P.M. to 6:00

P.M

.

(central time) Monday

.

to

thr ough Friday.

Customer service centers

Seagate direct OEM, Distribution, and Systems Integrator cus­tomers should contact their Seagate service representative for
warranty information. Other custom ers shoul d contact thei r place
of purchase. Seagate offers comprehensive customer support
for all Seagate dr ives. These services are availabl e worldwide.

Location Phone number FAX number

Asia Pacific and Australia 65-485- 3595 65-488-7 503
Europe, Middle East,

and Africa 31-2031- 67300 31-2065-34320
Japan 81-3-54 62-2904 81-3- 5462-2979
USA 1-800-4 68-3472 405-949-6740

Other Americas (Brazil,

Canada, Mexico) 405-949-6706 405-949-6738

14 Cheetah 18 Installation Guide, Re v. A

Location Phone number FAX number

Man ufacturer’s representati ves

Braz il

MA Infor matica 55-21-516-6649 55-21-516-5280
Canada

Memofix

Adtech

905-660-4936
905-812-8099

905-660-8738
905-812-7807

1-800-624-9857

Mexico

Abicom Seamax

SA DE CV 525-546- 4888 525-546- 4888

Southe rn Europe

Caesar Italia 39-688-18149 39-688-0 2103

Cheetah 18 Installation Guide, Re v. A 15

General description

Cheetah 18 SCSI disc drives are high-speed, random-access
digital-data storage devices capable of operat ing in single-ended
(SE) or low voltage di fferential (LVD) modes .

These two modes are offered to allow you to use this drive in
systems that use the traditional SE technology or to use it in
LVD-capable systems. Refer to page 20 for additional informa­tion about LVD technology.

The drive is a component for installation in an enclosure
designed fo r the drive. This is often a rack within the system or
an ex ternal encl osure desi gned to house one or more di sc driv es
or other peripheral u nits. 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

Cheetah 18 Product Manual

(part number 83329260)

contains guidelines for a properly desi gned enclosure.

Attention.

This high performance Cheetah disc dri ve must have
proper power and cooling for reliable operation.

16 Cheetah 18 Installation Guide, Re v. A

Figur e 1. Cheetah 18 famil y drive (ST11820 2LW show n)

Cheetah 18 Installation Guide, Re v. A 17

Characteristics ST118202L W/LC

Interface Ultra2 SCSI
Capacity

Unformatted (Gbytes)
Formatted (Gbytes)

2

22.54

18.21

Recording

Cy l ind ers (us er )
Read/write data heads
Avg byt es /tr a ck

Access time

3

Average read (msec)
Average write (msec)

6,96 2
24
104,840-159,008

5.9

6.7

Disc rotation

RPM
Average lat ency (msec)

10,025

2.99

1

Synchronous data transfer rate

Maximum instantaneous (Mbytes/sec)

40 (SE mode)
80 (LVD mode)

Asynchronous data transfer rate
Maximum instantane ous (2 bytes wide)

10.0

(Mbytes/sec)
Multi-segmented cache (kbytes) 1,024 standard

4,096 optional

1. Also operates per SCSI-1/SCSI-2/SCSI-3 protocols.

2. The specified formatted capacities are calculated with the standard

OEM sector size (512 bytes per logical block) and sparing.

3. Includes on-board controller overhead.

18 Cheetah 18 Installation Guide, Re v. A

ST118202LW/LC

Low voltage

DC power requirements (±5%)

Single-ended (SE)
mode

1

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

differential (L VD)
mode

Maximum start current
Maximum operating current
Aver ag e id le cu r rent

1. For more detailed power information, refer to the Cheetah 18 Product

Manual, publication number 83329260.

0.89A

0.88A

0.72A

2.5A

1.22A

0.98A

0.90A

0.95A

0.74A

2.5A

1.22A

0.98A

Cheetah 18 Installation Guide, Re v. A 19

Initial setup info rmation

The general information beginning on this page applies to all of
the Cheetah 18 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 partic ular model.

Drive models P age

ST118202LW 39
ST118202LC 45

Gener a l inform a tion

The following gener al i nformation topics are di scussed:

• Single-ended and low vol tage differential modes

• SCSI ID jumpers

• Driv e termination

• Terminator power

• Int erface drivers and data path width notes

• Other applicabl e jumper opti ons

• 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 mount an “LC” drive, pl ug t he dr ive into the syst em’s single
connector attachment (SCA) position on the system’s back
panel.

20 Cheetah 18 Installation Guide, Re v. A

Single-ended and low voltage differential mod es

This drive incorporates two different transceivers to allow you to
use it in traditional systems which may use single-ended (SE)
drivers and receivers , or to use it in low voltage diff erenti al (LVD)
capable system s which use LVD drivers and rece ivers .

You can configure the drive to switch between SE and LVD
modes automatically or force it to operate in SE mode only as
descri bed later in this guide.

LVD technology enhances parallel SCSI I/O performance,
reduces power consumption, increases allowable cable lengths,
and improv es device connectivity beyond SE capabilities.

Note.

To operate at the Ultra2 SCSI rates in LVD mode, all
de vices on th e same bus must be running i n LVD mode . If
you add any single-ended device to a bus that is operat­ing in LVD mode, all devices drop back to operating in
single-ended mode. This eliminates the possibility of
reaching Ultra2 SCSI transfer rates.

Warning.

Do not mix LVD drives on the same daisy chain with
devices having high voltage differential (HVD) inter­face circuits.

SC SI ID jum pe r s

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 has the lowest priority in an 8-bit I/O system. ID8
has the lowest priority in a 16-bit I/O system. The lower priority
SCSI IDs are normally used for other SCSI devices such as this
Cheetah disc drive.

Cheetah 18 Installation Guide, Re v. A 21
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
ins talla t ion .

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

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

Most Cheetah disc drives are factor y 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
the case, change the ID so that each device on the SCSI chain
has its own unique ID. Also check your system or controller
user’s manual to ensure that you have not violated its SCSI ID
numbering recommendat ions.

22 Cheetah 18 Installation Guide, Re v. A

Drive termination

If you are installing a Cheetah 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.

Note.

Use active (ANSI SCSI-2 Alter native 2) single-ended ter­minators when terminating a bus operating in single­ended mode. Use SPI-2-compliant active low voltage dif­ferential terminators when terminating a SCSI Ultra2 bus
operating in LVD mode.

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
(both are terminated). The bottom example shows two additional
SCSI devices connected externally—this means the SCSI con­troller is no longer on the end of the SCSI chain and should not
be terminated.

Note.

Some controllers prefer to remain terminated even if they
are in the m iddle of the ch ain. Also, some c ontroll ers trea t
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.

These dri ves do not have on-board terminator s, so you must ter­minate external to the drive when termination is required. For
ST118202LC drives, this is normally accomplished by terminat-

Cheetah 18 Installation Guide, Re v. A 23
ing the bus at t he backpanel. For ST118202LW driv es, use an in-

lin e t e rmina tor on th e c able.

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

Term i nator power

You usually will not need to change this option and can normally
lea ve the drive conf igured as it was shipped from the f actory. For
inform ation 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

• These driv es can be used in single-ended or lo w volt age differ -

ential interface systems; however, do not attempt to mix these
drives on the same daisy chain with high voltage differential
devices. The circuits are not compatible and drive damage
may occur.

• These drives have a “wide” (16-bit) SCSI data bus rather than

the standard (non-wide) 8-bit SCSI data bus; however, you

24 Cheetah 18 Installation Guide, Re v. A

can use these wide drives on a standard (non-wide) 8-bit data
bus if you provide proper termination to the upper 8-bit data
lines. This is often referred to as providing “high-9 termina-

tion.”
Figur es 3, 4, and 5 show typical drive connections.
The following table lists the maximum cable lengths and number

of devices using single-ended and LVD I/O circuits allowed on a
daisy-chain cable for 10, 20, and 40 Mtransfers/sec I/O data
tran s fer ra te s.

Table 1. Cable characteristics for SE and LVD circuits

Maximum

SCSI
driver
type

I/O tran sfer rate
(Mt ransfers/s)

number of

Ma xi mum ca ble

devices on

length allowed

bus

SE 10 16 6 meters (19.7 f t.)
SE 20 4 3 me te rs (9.8 ft.)
SE 20 8 1.5 meters (4.9 ft.)
LVD 40 16 12 meters (39.4 ft. )

A maximum of 16 devices can be connected on a 16-bit wide
data bus.

Cheetah 18 Installation Guide, Re v. A 25

Figure 3. 68-pin I/O connection to drive (LW model)

Figure 4. 80-pin I/O connection to drive (LC m odel)

26 Cheetah 18 Installation Guide, Re v. A

“LW” Model

Drive

Note:

Do not mix
“LW” and “WD”
model drives
on the daisy
chain.

SCSI ID 1

Terminator

[2]

2 through X
SCSI devices [1]

Pin 1

(check your

adapter for Pin 1 location)

SCSI ID 7

SCSI ID 0

[1] “X” means up to 15 or the maximum allowable number of devices on

the SCSI bus. See system documentation and Table 1.

[2] External terminator. Used only on end “LW” drive. Use only SPI-2-

compliant active LVD terminators on SCSI Ultra2 buses.

Figure 5. Multiple-drive connection to host adapter

Terminated

Host Adapter

PCB

Cheetah 18 Installation Guide, Re v. A 27

80-pin

SCSI I/O

Connector

Pin 1

J2

J6

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

tor and therefore does not use cables.

Figure 6. Drive model “LC” with single 80-pin I/O and

power connector

28 Cheetah 18 Installation Guide, Re v. A

Providing adequate cooling

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

The drive’s product manual ( 83329260) describes how to eval u­ate the air-flow desi gn. 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 7 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 drawing air. The overall flow pattern
can be directed from fr ont to back, back to front, or side to side.

Cheetah 18 Installation Guide, Re v. A 29

Kü hlung des System s

Die Gehäusekonstr uktion muß eine ausreichende K ühlung des
Laufwerkes gewährlei sten. Di e Umgeb ungstemperatur d arf max­imal 50°C betragen.

Die Produkthandbuch Cheetah 18 (Dokument 83329260)
enthalten An weisunge n zur Beur teilun g der Luftstromkonstru k­tion. Die Beurt eilung muß sicherstellen, daß sich die Gehäuse­temperatur bestimmter kritischer Komponenten bei
Laufwerkbetrieb innerhalb zugelassener Grenzen hält.

Wir empfehlen, das Laufwerk so zu or ientieren oder den Luft­strom so zu len ken, d aß d er geri ngste L uftstrom widers tand
erzeugt wird und gleichzeitig ein Luftstrom über den Platinen
und um die Kopf- und Festplatteneinheit (HDA) gegeben ist.
Wählen Sie einen m öglichst kurzen Weg zwischen Lufteinlaß
und -auslaß. Dadurch wird die Strecke, die die vom Laufwerk
und anderen nahegelegenen Hitzequellen aufgewärmte Luft
zurüc klegt, auf ein Minimum beschränkt.

Abbil dung 7 zeig t zwei Konstruk tions mögl ichkei ten, bei de ne n
ein oder mehrere Lüfter den Luftstrom erzeugen. Der Luftstrom­verlauf wird durch die Lüfter gesteuert , die entweder Luft einbl a­sen ode r abzie hen. Genere ll kann d er Luf tstrom ent weder von
vorne nach hinten oder von hinten nach vorne verl aufen.

30 Cheetah 18 Installation Guide, Re v. A

.

Above unit

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

Above unit

Under unit

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

Figure 7. Suggested air flow
Abbil dung 7. Empf ohlener Luftstromverlauf

Under unit

Cheetah 18 Installation Guide, Re v. A 31

Mounting the drive and connecting cables

Do not touch the connector pins or any component s on the con­trol board without observing static-discharge precautions.
Always handle the drive by the fram e only.

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

1. Mount the driv e to the host sys tem’s chassis using four 6-32

UNC screws. Two mounting holes are in each side of the
drive and there are four mounting holes in the bottom of the
drive.

The maximum length that the screws should extend into the
chassis mounting holes is 0.15 inch (3.81 mm), measured
from the outer surface of the chassis. Tighten the screws
down evenly. Do not over-tighte n or force the scre w if it does
not s eem to scre w in easi ly, b ecause this means the thre ads
are not properly aligned. In this case, back the screw out
and tr y again.

Installation des Laufwerkes
und A nschluß der K a b e l

Beacht en Sie beim Handhaben und Anfassen der Anschlußstift e
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.

32 Cheetah 18 Installation Guide, Re v. A

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

am Gehäu se des Host-Systems. Die beiden Sei ten des
Laufwerkes sind mit jeweils zwei Befestigungsl öchern
versehen, die Unterseite des Laufwerkes weis t vier weitere
Befestigungslöcher auf.

Gemess en von der Außenfläche des G ehäuses dürfen die
Schrauben maximal 3,81 mm in die Befestigungslöcher des
Gehü uses hi neinragen . Die S chraube n müsse n gleic h­mäßig, jedoch nicht zu fest, angezogen werden. Wenn sich
eine Schraube nicht ohne Widerstand einschrauben läßt,
sind die Gewinde nicht korrekt aneinander ausgericht et. 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 correctly 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 installiert sind.

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

Take care not to stretch or crimp th is cable, 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

Cheetah 18 Installation Guide, Re v. A 33

defined in IEC 950. Figure 8 provides the pin information for
the DC power connector. To connect the DC power cable to
the drive, simply insert the cable end into the drive’s DC
power connect or.

4. Schließen Sie das SCSI-Kabel an den SCSI-Steckv erbinder

des Lau fwerkes a n. Das Kabe l darf nic ht gedehnt oder
gedrückt werden und es darf d en Luftstrom 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 8 zeigt
die Stecker belegung für den Gleichstromanschluß. Zum
Ansc hluß d es Glei chstr omkab els an da s Lau fwerk d as
Kabelende in den Gleichstromanschluß des Laufwerkes
ste cken.

Pin

1
2
3
4

Power

+12V
+12V return
+ 5V return
+ 5V

Pin

1
2
3
4

Gleichstrom

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

4321

Figur e 8. DC power connector
Abbil dung 8. Gleichstrom anschluß

34 Cheetah 18 Installation Guide, Re v. A
Note. Signal ground on the power control board assembly

(PCBA) and the head and disc assembly (HDA) are con­nected together in this drive and you cannot separate
them. The equipment in which you have mounted the
drive is connected directly to the HDA and PCBA without
electrically isolating shock mounts. Maximizing the con­ductive contact area between HDA ground and system
ground may reduce radi ated emissions.

If you do not want the system chassis to be connected to
the HDA/PCB ground, you must provide a nonconductive
(el ectrically isolating) method of mountin g the drive in the
host system. This may increase radiated emissions and
is the system designer’s responsibility.

Hinwei s.

Die Signalerde auf der Stromregelungskar te (PCBA) und
der Kopf - und Fes tplat tene inh eit (HDA ) sind i n dies em
Laufwerk miteinander verbunden und können nicht
getrennt werden. Das Gerät, in das Sie das Laufwerk
eingebaut haben, ist ohne elektrisch isolierende
Stoßdä mpfer 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 das Systemgehäuse nicht an die HDA /PCBA­Erdung anschließen 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

Cheetah 18 Installation Guide, Re v. A 35

elektromagnetische Strahlung fällt in den Zuständigkeits­berei ch des Systemdesi gners.

5. Replace the host system’s cover.

5. Setzen Sie das Gehäuseoberteil des Host-Systems wieder

auf.

36 Cheetah 18 Installation Guide, Re v. A

K

-Z-T//

S

HL

A

-Z-

M

U

-X-

P

[1]

G

F

DE

[1]

J

B

R

C

-Z-

Notes:

Mounting holes are 6-32 UNC 2B, three

[1]

on each side and four on the bottom.
Max screw penetration into side of drive
is 0.15 in. (3.81 mm). Max screw
tightening torque is 6.0 in-lb (3.32 nm)
with minimum full thread engagement of

0.12 in. (3.05 mm).

Dimension Table

Millimeters

42.01

147.00

101.60

92.25

3.18

44.45

41.28

28.50

101.60

6.35

41.60

4.60

41.28

6.73

7.00

0.38

0.38

± .25

M

R

U

Inches

A

1.654

B

5.787

C

4.000

D

3.750
E
F

1.750
G

1.625
H

1.122

J

4.000
K
L

1.638

P

1.625
S

T

.125

.250
.181

.265
.315
.015
.015

max
max

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

± .020
± .010
± .040

max
max

max
max
± .25

± .25

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

± .50
± .25
± .10

max
max

Figure 9. Mounting configuration dimensi ons (LW model)

-X-

Cheetah 18 Installation Guide, Re v. A 37

K

-Z-T//

S

HL

R

A

-Z-

M

-X-

U

P

[1]

G

F

[1]

J

B

-Z- -X-N

-Z-

Notes:

Mounting holes are 6-32 UNC 2B, three

[1]

on each side and four on the bottom.
Max screw penetration into side of drive
is 0.15 in. (3.81 mm). Max screw
tightening torque is 6.0 in-lb (3.32 nm)
with minimum full thread engagement
of 0.12 in. (3.05 mm).

Dimension Table

M
N

R

U

Inches

A

1.654

B

5.787

C

4.000

D

3.750

E
F

1.750

G

1.625

H

1.122
J

4.000

K
L

1.638

P

1.625

2.618

S
T

.125

.250
.181

.040

.276
.015
.015

max
max

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

max

± .020
± .010
± .040

max
max

Millimeters

42.01

147.00

101.60

92.25

3.18

44.45

41.28

28.50

101.60

6.35

41.61

4.60

1.20

41.28

66.50

7.00

0.38

0.38

max
max
± .25

± .25

± .25

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

max

± .50
± .25
± 1.02

max
max

Figure 10. Mounting configuration dimensi ons (LC model)

DE

C

-X-

38 Cheetah 18 Installation Guide, Re v. A

Formatting the drive

Warning.

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

Note.

Seagate is not responsible for lost user data.

1. Turn on DC power.

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

3. Format the disc dr ive. Cheetah 18 disc drives are designed
to operate with a variety of operating systems. Please refer
to your system or SCSI controller manual for information
about for matting and setting up the drive. Some quick desk­top sys tem notes are pro vided belo w.

Quick refer ence desktop system notes

• Hardware platform, operating system, and host adapter varia-

tions can limit access to the full capacity of this and other high
capacity drives. Refer to your system or utility manual for
detai led instructions.

• DOS/Windows 3.1/Windows 95. Set the drive type in CMOS to

“

Zero,” “None,”

or “

No hard drive installed

.” Use FDISK.EXE

and FORMAT.EXE.

• Macint osh. Use a third-party dri ve utility or Apple’s Drive Setup

(version 1.3.1 or later) to initialize the drive. Note: versions of
Apple Drive Setup prior to version 1.3.1 do not recognize non­Apple drives.

Cheetah 18 Installation Guide, Rev. A 39

LW drives

LW drives sectionSetting the SCSI ID jumpers

Use the J6 connector to set the SCSI ID (see Figure 11). To
change t he SCSI ID, install jumpers as shown in the illu str ation.

Drive
Front

Jumper Plug

(enlarged to
show detail)

Pin 1

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

J6

Figur e 11. Set ting the SCSI ID on ST118202LW drives

SCSI ID = 13
SCSI ID = 14
SCSI ID = 15

40 Cheetah 18 Installation Guide, Re v. A

LW drives

Terminat ing the drive

ST118202LW drives do not have internal terminators or any
other way of adding internal termination to the drive. You must
provide external termination to these drives when termination is
required. This is normally done by adding an in-line terminator
on the cable.

Note.

Use active (ANSI SCSI-2 Alter native 2) single-ended ter­minators when terminating a bus operating in single­ended mode. Use SPI-2-compliant active l ow voltage dif­ferential terminators when terminating a SCSI Ultra2 bus
operating in LVD mode.

Cheetah 18 Installation Guide, Rev. A 41

LW drives

Term i nator power

You can configure this drive to supply termination power to the
SCSI bus by placing a jumper on J2 pins 1 and 2. The default
sett ing is no jumper, meaning that som e other source (other than
this drive) is suppl ing termination po wer to the SCSI bus.

Pin 1

J2

Term. Power to SCSI Bus
Host adapter or other device provides

term power to external terminator

TEDSMEWPP

D

R
E
S

Pin 2
R
EST

P

J2

J6

Drive

J2 Jumper Plug

(enlarged to
show detail)

Front

Figure 12. Setting terminator power jumpers

42 Cheetah 18 Installation Guide, Re v. A

LW drives

Othe r appl i ca bl e jumper op tion s

Several other jumper options are available as illustrated.

J2

Reserved
Single-Ended Mode option

Use single-ended or low voltage differential mode.
Force the drive to operate only in single-ended mode.

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

Disable the Delay Motor Start option (default).
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.

SEDSMEWPP

Pin 1

R
E

D

S

Pin 2
R
EST

P

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 Jumper Plug

(enlarged to
show detail)

J2

J6

Drive
Front

Cheetah 18 Installation Guide, Rev. A 43

LW drives

68 Pin

SCSI I/O Connector

J1

Pin 1

J5/J1A [2][4]

Pin 1

1P2P3P4P

Pin 12

SCSI Address A0
SCSI Address A1
SCSI Address A2

SCSI Address A3
No connection
+5V
Fault LED*
Vendor Unique*
Reserved

Activity LED*

J1A Pin 1

J1-DC Power

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

Ground

These pins are driven low for

*

250 ms after PWR ON or
RESET to allow jumper
selectable SCSI ID as shown
to the right.

Figur e 13. Addit ional jumper options
Figur e 14. Al ternate ID select and LED connection

SCSI ID = 11
SCSI ID = 12
SCSI ID = 13
SCSI ID = 14
SCSI ID = 15

44 Cheetah 18 Installation Guide, Re v. A

LW drives

Drive Active indicator

The drive Active LED indicator connections are shown below.

Drive
Front

Jumper Plug

(enlarged to
show detail)

J6

Reserved
Activity LED

Reserved
The shaded pins are shipped
with a cover installed. Do not
install jumpers on these pins.
Retain the cover unless you
install a 20-pin plug.

Note: On some LEDs the flat
side of indicator is cathode.

Pin 1

CATH

Figure 15. Drive Active LED indicator connections

Cheetah 18 Installation Guide, Rev. A 45

LC dr ives

LC drives sectionSetting the SCSI ID jumpers

The SCSI ID for ST118202LC drives is normally set over the
SCSI bus by the host system. You can also use the J6 jumper
bl ock to set the SCSI ID (s ee Figure 16).

Drive
Front

Jumper Plug

(enlarged to
show detail)

Pin 1

J6

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

Note:

[1] Do not remove
cover from pins
13 through 20
(darkened area).

Figure 16. Setting t he SCSI ID on ST118202LC drives

SCSI ID = 12
SCSI ID = 13
SCSI ID = 14
SCSI ID = 15

46 Cheetah 18 Installation Guide, Re v. A

LC dr ives

Terminat ing the drive

LC model drives do not have internal terminators or any other
way of adding internal termination to the drive. You must provide
external termination to these drives when termination is
required. Since this drive is designed to be plugged into a back­panel or other host enclosure without cabling, this is normally
done by enabling termination on the backpanel or plane.

Note.

Use active (ANSI SCSI-2 Alter native 2) single-ended ter­minators when terminating a bus operating in single­ended mode. Use SPI-2-compliant active l ow voltage dif­ferential terminators when terminating a SCSI Ultra2 bus
operating in LVD mode.

Term i nator power

ST118202LC drives cannot be configured to provide termination
power.

Cheetah 18 Installation Guide, Rev. A 47

LC dr ives

Ot her appli c abl e jump e r options

Other option jumpers are av ailable as illustrated below.

J2

Reserved
Single-Ended Mode option

Use single-ended or low voltage differential mode.
Force the drive to operate only in single-ended mode.

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

Disable the Delay Motor Start option (default).
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.

SEDSMEWPP

Pin 1

R
E

D

S

Pin 2

R

R

E

E

S

S

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 Jumper Plug

(enlarged to
show detail)

J2

J6

Drive
Front

Figur e 17. Additional jumper options

48 Cheetah 18 Installation Guide, Re v. A

LC dr ives

WC/DC drives sectionDrive A ctive indicator

The drive Active LED indicator connections are shown below.

Drive
Front

Jumper Plug

(enlarged to
show detail)

J6

Reserved
Activity LED

Reserved
The shaded pins are shipped
with a cover installed. Do not
install jumpers on these pins.
Retain the cover unless you
install a 20-pin plug.

Note: On some LEDs the flat
side of indicator is cathode.

Pin 1

CATH

Figure 18. Drive Active LED indicator connections

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

Publ ication Number: 83329250, Rev. A, Printed in USA