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~Seagate
WREN™ 7 DISC DRIVE SCSI
PREFACE
This manual provides the basic Information and Instructions for lnstaUlng and operating Seagate WREN™7 SCSI Disc
Drive; Model 94601. It also provides information to aid In servicing those parts of the drive external to the sealed head.
disc assembly (HOA).
WARNINGS
~:
This equipment generates. uses. and can radiate radio frequency energy and If not Installed and used
In accordance with these Instructions. may cause Interference to radio communications. The WREN 7. as delivered.
Is
designed to provide reasonable protection against Interference when Installed In a suitable enclosure.
~:
This product
Is
an electromechanical device which could present hazards If lmproperty handled. The
device should be maintained only by quallfled persorioel. Careless disassembly
or
maintenance procedvres moy
result In damage to the device or Injury to personnel. Observe all WARNINGS and CAUTIONS attached to the device
and contained In this manual.
These WARNINGS and CAUTIONS are not exhaustive. The manufacturer cannot know In advance all possible
maintenance procedures. or tools. which may be devised by persons who choose not to follow the Instructions In
this manual. Any deviation from the prescribed procedures may entail
risks
which have not been evaluated by the
manufacturer. Any persons who use a nonapproved procedure or tool must satisfy themselves that no Injury to
persomel. no damage to the device. and no deterioration of device performance will result.
DESCRIPTION
The WREN 7 SCSI
Is
a 5 1 /4 Inch form factor. low cost. high performance. random access rotating disc. mass memory
device designed to record and recover data on eight rigid fixed disc media. The WREN uses low mass flying read/
write heads attached to a precisely controlled rotary posltloner.
Model 94601 has a typical unformatted storage capacity of 1200 megabytes. The formatted capacity varies with
the data block size and the sparing scheme used. It has 15 data heads and 1931 cylinders. Model 94601 supports
the Small Computer System Interface (SCSI) as described In the lmprimls WREN 7 SCSI Specification 77765417.
MODEL
.t::illM.aEB.
94601-12G
94601-120
94601-767H
UNFORMATTED
.MEGAaYIES
1200
DATA BLOCK NUMBER OF
NUMBER OF
FORMATTED
MEGABYIJS'
1035
SIZE.!aYIESl
~
DATA HEADS
512
1931
15
1200
512
1931
15
1035 (Dlfferentiol 1/0)
676 (Faster Access)
767
512
1356
15
STANDARD FEATURES
The WREN 7 has the following standard features:
o
Industry Standard Interface
o
Sealed head. disc. and actuator chamber
o
No preventive maintenance required
o
No adjustments required
o
LSI circuitry for high rellablllty
o
Low audible noise for office environments
o
Vertical (side) or horizontal (bottom) mounting
o
Single ended or dlfferenttol SCSI drivers
and receivers
o
240 K byte data buffer
o
Flawed sector reallocation at format time
o
Reallocation of defects on command
(post format)
o
Dato recovery circuitry contained In the WREN
o
Command quelng of up to one command per
Initiator
o
User selectable reallocatton sector locations:
On each Track. or
within a cylinder. or
within dedicated tracks. or
none of the above
o
Low power consumption
o
Balanced low moss rotary voice coll actuator
o
Automatic shipping lock and dynamic spindle brake
o
Easy access terminator
o
Integral HOA shock and vibration Isolation mounts
o
Dedicated head landing zone
o
Integrated SCSI controller
o
Asynchronous or synchronous SCSI bus data transfer
protocol
o
User selectable byte data block size from 256 to 4096
bytes In one byte Increments'
o
Error correction
o
1: 1 sector Interleave
o
Automatic retries on seek or data read errors
(Automatic read retries may be disabled by users)
o
Automatic single track seek error correction
copablllty
o
Automatic Adoptive Thermal Compensation
o
Zone Bit Recording
™
o
Delayed Motor Start
'Units ore formatted at the factory with 512 byte data blocks with one spare sector
per
track. giving a capacity (for
15 data heads) of 1035 MB. However, the user can reformat the drives using any Integral data block size between
256 and 4096 bytes and with a different sporing scheme. Drive formatted capacity varies from the 1035 MB
If
other
than 512 data block size or other sporing scheme
Is used.
ACCESSORIES
The following accessories ore available for WREN 7:
o
Front Panel Kit
o
Single Unit Shipping Pock Kit
CAUTIONS
~:The
circuit assemblies and components contained In this equipment can be degraded or destroyed by
Electrostatic Overstress (EOS) or by Electrostatic Discharge (ESD).
Static electrical charges can accumulate quickly on personnel. clothing. and synthetic materials. The electrostatic
fields due to these charges cause EOS or ESD which. when brought in close proximity to susceptoble circuit
assemblies and components. can result In degraded reliability or Immediate failure of the affected component or
assembly.
To Insure optimum reliable equipment operation, it
Is
required that technical support personnel discharge
themselves by wearing a grounding strap around the wrist and be connected too grounding terminal while working
In the vicinity of. and while handling. EOS/ESD susceptible assemblies/parts. This procedure
Is
especially important
when handling printed wiring assemblies (PWAs).
PWAs should be placed on a static dissipative work surface during all maintenance procedures on these PWAs. If
possible. all persons coming near the equipment should stand on a static dissipative floor mat installed according
to established procedures. PWAsshould be handled or transported In electrically conductive plastic bags to Insure
optimum protection against potential EOS/ESD damage. Delicate components soldered into circuits are NOT
immune to EOS/ESD damage.
~:To
avoid potential repair problems, observe the following precautions:
o
Labels must not be put over the breather holes on the top of the drive. (See Figure 1 ).
o
If a label has been placed over the breather holes. do not poke holes through the lobel. as the filter under-
neath
Is
certain to be damaged. allowing contamination to enter the HOA. REMOVE THE LABEL. Do not use
solvents to remove the adhesive residue. Solvent may migrate down the breather holes and contaminate the
HOA.
MODEL 94601
INSTALLATION
MANUAL
77765375
Revision A
January 1990
o
Manufacturers Installed labels must not be removed from the drive or covered w!th add!t!ona! !obe!s. os they
contain Information required when repairing.
o
DC power should not be switched on to the drtve by plugging on electrically "live" DC source cable Into the
drive power connector. This practice adversely affects the rellablllty of the connector contacts and may
damage other susceptable components.
UNPACKING
Visually Inspect the shipping container for any obvious damage. Exercise care so that any tools being used do not
damage the unit.
As the WREN
Is
unpacked. Inspect
It
for possible shipping damage. All claims of this type should be flied promptly
with the transporter involved. If a claim Is filed for damages. save the original packing materials.
After the drive Is unpacked. Inspect the drive for any visible damage. Verify all parts listed on the shipping bill are
received with the equipment. Discrepancies or damage should be reported to the shipping company. Save the
packing materials; they can be used for reshipment.
OPERATING ENVIRONMENT
The environmental condtttons required tor optimum performance of the disc drtve are. In general. the same as those
In an office environment w!th minima! envlronmenta! control. These conditions are:
Temperature
50• to 122°F (10° to 50°C)
Altitude -1000to+10.cxxl feet
(-305
to +3.()48 metres)
Humidity
Wet Bulb
The room temperature should not change more than 36"f (20°C) per hour.
Avoid high relative humidity as much as possible since
It
can result In con-
densation In the drive under adverse conditions.
COOLING
A sometimes overlooked consideration when mounting several drives
In the some enclosure Is heat dissipation. Because power supplies. for
example. are typically heavy. they are frequently mounted In the bot-
8%to80%
82°F (28°C) maximum
tom of an enclosure. where they produce heat. This heat rises to the top
~
of the cabinet or enclosure and the temperature can reach very high
levels. Cabinet ventilation, by natural convection or forced cooling,
must be provided to keep the Internal air temperature adjacent to the disk
drive within the Hmits specified above. .
FIGURE l.
Temperature of the top cover. when measured at the center of the cover. (FIGURE
1)
should not exceed 140· F
(60.4°C) during operation. Large
(>2"F)
external thermal gradients acrOliS
the
top cover should be avoided.
SAFETY INSTRUCTIONS
1.
The WREN
Is
to be Installed In a customer supplied enclosure where the surrounding air does not exceed
so·c.
2.
Four(4) 6-32 UNC-2A screws are required for Installation. maximum screw length Into chassis mounting holes
Is
0.12 In (3.17 mm).
3.
The power requirements are:
+5 V ±5% 1.0 A (1.8 A for differential 1/0 circuits)
+ 12 V ± 5% 2.0A(4.5A.+12 V ± 10% regulation. for a maximum of 10 seconds at power up)
4.
The power supply must satisfy the safety requirements for SELV (Safety Extra Low Voltage) circuits.
5.
Service Is to be provided only by trained service personnel.
6.
The Incorporation of the WREN Into a customer supplied enclosure must meet the appropriate safety
requirements of the country In which
It
Is to be used (e.g. UL. 478. CSA 22.2 No. 220 and IEC950).
NOTE: Power off when connecting or disconnecting.
SICHERHEITSANLEITUNG
1.
Das GerOt
1st
eln ElnbaugerOt. vorgesehen fUr elne maxlmale Umgebungstemperatur von
so·c.
2.
Zur Befestlgung der Wren Drtve warden 4 Schrauben benOtlgt (6-32 UNC-2A). Die maxlmale LOnge der
Schrauben In der unteren Selte des Chassis dart nlcht mehr als 0.12 In (3.17 mm) betragen. die In der oberen
0.12 In (3.17 mm).
3.
Als Versorgungsspannungen warden beootlgt:
+ 5 V ±5% 1.0 A ( 1.8 A FOr Dlfferentlale Schnlttstelle)
+ 12V±5%2.0A(SpllzenstromzurZeitderElnschaltung:4.5Amp. + 12V± 10%Regelung fOr lOSekunden max.)
4.
Die Versorgungsspannung muss SELV entsprechen.
•
5.
Alie Arbeiten dOrfen nur von ausgeblldetem Service personnel durchgefUhrt warden.
6.
Der Einbau des Drives muss den Anforderungen gemoss DIN IEC 380/VDE 0806/8.81 oder EN60 950 entsprechen.
EMI CONSIDERATIONS
The WREN 7. as delivered. is designed for system Integration and Installation Into a suitable enclosure prior to use.
As such the WREN 7 Is supplied as a sub-assembly and
Is
not subject to Subpart
J
of Part 15 of the FCC Rules and
Regulations nor the Radio Interference Regulations of the Canadian Department of Communications. However.
the
unit has been tested using proper shielding and grounding and found to be compliant with Class A limits of of
the
FCC Rules and the Regulatlons of The Canadian Department of Communications.
The physical design characteristics of the WREN 7 serve to minimize radiation when Installed in an enclosure that
provides reasonable shielding. As such. the WREN 7 is capable of meeting the Class A limits of the FCC Rules and
Regulations of the Conodian Department of Communication. However. It
Is
the users responsibility to assure that the
WREN 7 meets the appropriate EMI requirements in their system. Shielded 1/0 cables may be required If the enclosure
does not provide adequate shielding. If the
1/0
cables are external to the enclosure. shielded cables should be
used.
with the shields grounded to the enclosure and to the host controller.
DRIVE MOUNTING ORIENTATION
The WREN 7 may be mounted with a horizontal orientation (PCB down) or with either of two vertical orientations (on
side orientation). Four 6-32 tapped hales are provided In the bottom of the chassis and two on each side.
(See
Figure
1).
The drive may be mounted using four bottom screws or four side screws (two In each side). Four bottom screws
are preferred and recommended. Screws must be of sufficient length to engage the threaded holes. but must not
penetrate more than 0.14 In. (3.55 mm) Into the chassis. A sway space of O.Q75 In. (1.9 mm) is required for the HOA
on all sides. regardless of mounting orientation.
SCSI INTERFACE CONFIGURATION
The WREN 7 can be connected in a daisychain configuration In which a maximum of seven drives can
be
con-
nected. The Logical Address of each drive in the dalsychaln
Is
determined by the drive select jumper plug(s) on the
Main PWA. See Figures 3 and 4.
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