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Hard Drive: CDC: WREN VIIFH 94601-12G 1050MB 5.25"/FH SCSI2 SE

W R E N   V I I F H   9 4 6 0 1 - 1 2 G    CDC
NO MORE PRODUCED                                      Native|  Translation
Form                 5.25"/FH              Cylinders    1931|     |     |
Capacity form/unform  1050/ 1201 MB        Heads          15|     |     |
Seek time   / track  15.0/ 2.5 ms          Sector/track     |     |     |
Controller           SCSI2 SINGLE-ENDED    Precompensation
Cache/Buffer           256 KB              Landing Zone
Data transfer rate    2.875 MB/S int       Bytes/Sector      512
                      4.800 MB/S ext SYNC
Recording method     RLL 1/7                        operating  | non-operating
Supply voltage     5/12 V       Temperature *C        10 50    |    -40 70
Power: sleep              W     Humidity     %         8 80    |      5 95
       standby            W     Altitude    km    -0.305  3.048| -0.305 12.210
       idle          24.0 W     Shock        g         2       |     32
       seek               W     Rotation   RPM      3600
       read/write         W     Acoustic   dBA
       spin-up            W     ECC        Bit   48
                                MTBF         h     150000
                                Warranty Month
Lift/Lock/Park     YES          Certificates     CSA,SDA,FCC,IEC950,UL1950,...


SEAGATE ST41200N/ND PRODUCT MANUAL 77765374-D (1/92)

  | +-+                                                     |+-1
  | | | J6                                                  || |J4
  | +-+                                                     |+-+
  |                                                     ++  |XX
  |                                                     ||  |XX
  |                                                     ||  |XX
  |                                     Terminator      +1  |XX J3
  |                                     resistor        ++  |XX SCSI
  |                                     (SIPs)          ||  |XX I/O
  |                                                     ||  |XX
  |                                                     +1  |XX
  |                                                     ++  |XX
  |                                                     ||  |XX
  |                                                     ||  |X1
  |                                                     +1  |
  | +-+J7                                                   |XX Power
  | +-+ LED                                                 |XX
  +---------------------------------------------------------+  1


SEAGATE ST41200N/ND PRODUCT MANUAL 77765374-D (1/92)

Jumper setting

  J4  SCSI ID/Option Select Header
           | o  o  o  o  o  o  o  o |
           | 1  o  o  o  o  o  o  o |
            TP TP  4  2  1 (2) (3) (6)

      |            | 4  2  1  |
      +------------+----------+  Drive ID in binary coded jumper
      |SCSI ID = 0 | o  o  o  |  position (most significant bit on
      |            | o  o  o  |  left), i.e., jumper in position 1
      +------------+----------+  would be Drive ID 1, no jumpers means
      |SCSI ID = 1 | o  o  x  |  ID 0.
      |            | o  o  X  |
      |SCSI ID = 2 | o  x  o  |
      |            | o  X  o  |
      |SCSI ID = 3 | o  x  x  |
      |            | o  X  X  |
      |SCSI ID = 4 | x  o  o  |
      |            | X  o  o  |
      |SCSI ID = 5 | x  o  x  |
      |            | X  o  X  |
      |SCSI ID = 6 | x  x  o  |
      |            | X  X  o  |
      |SCSI ID = 7 | x  x  x  |
      |            | X  X  X  |

 (2)  CLOSED  Enables the Motor Start Option. In this mode of
              operation the drive will wait for a Start Unit Command
              from the Host before starting the Motor.
      OPEN    see Note (6) below for description of delayed motor
              start feature.

(3) CLOSED Parity checking by the WREN 7 is enabled.

 (4)  If the unit is not be terminated, remove terminator resistor
      module SIPs. TP Jumper in left vertical position means
      terminator power (+5V) is from WREN 7 power connector. Jumper
      in horizontal position means terminator power is taken from
      interface cable. Jumper in right TP position means +5V is
      supplied to the interface cable pin 26. Jumpers can be in both
      vertical positions at same time. If the drive is not terminated,
      the TP jumper need not be installed.

 (6)  Jumper on enables delayed motor start (Motor Start jumper (2)
      must be off). Motor start up is delayed 16 times drive ID number
      in seconds; i.e., Drive 0 starts immediately, Drive 1 starts 16
      seconds later, Drive 2 starts 16 seconds after Drive 1, etc.

 J6  Write Protect/Remote LED Header
                +------- GND              Pin 1 (+5V)
           +----+----+                    Pin 2 LED ON/OFF signal
           | 2  o  x +---- Reserved
           | 1  o  x +---- Reserved
                +------- Write Protect

The Write Protect/Remote LED Header is a 6-pin, 3 jumper (or
connector) position header behind the front panel at the right side
of the drive, opposite the LED. The pins are on 0.100 inch (2.54 mm)
centers both vertically and side to side. A suggested mating two pin
connector is the DuPont Mini Latch housing P/N 65291-008 or
equivalent. The drive front panel must not be present in order to
access the header. For a remote LED capability, plug the remote LED
cable connector vertically to the leftmost two pins of the header.
The center two pins provide a drive write protect capability. A
shorting jumper plug may be plugged vertically onto these two pins to
write protect the drive or a two-pin cable connector may be plugged
there to connect the two pins to a remote Write Protect switch. The
rigthmost two pins are RESERVED for factory use only.

 DC Power and pin connector assignments
    --+------------+-- pin 1    +12 VDC
      | 4  3  2  1 |   pin 2    +12 Volts Return
      +------------+   pin 3    + 5 Volts Return
                       pin 4    + 5 VDC

Note: Pins on the drive select and configuration select header are
provided to facilitate manual drive configuration. No devices other
than jumpers should be connected to these pins. Improper connection
to external devices (switches, connectors, etc.) could adversely
affect drive performance. Exact location of these pins and headers
may change without notice.


SEAGATE ST41200N/ND PRODUCT MANUAL 77765374-D (1/92)

Notes on installation

Drive Orientation
The balanced rotary arm actuator design of the WREN 7 allows it to
be mounted in any orientation. All drive performance characterization
however, has been done with the drive in horizontal (disc level) and
vertical (drive on its side) orientations, and these are the two
preferred mounting orientations.

The WREN 7 is designed, manufactured, and tested with a "Plug-in and
Play" installation philosophy. This philosophy minimizes the
requirements for highly trained personnel to integrate the WREN 7
into the OEM's system, whetherin a factory or field environment.

Mounting Holes
Four on bottom. Two on each side. 6-32-INC. max. screw length into
side of chassis 3.17 mm (0.125 in). Max. screw length into bottom of
chassis is 3.17 mm (0.125 in).

Cabinet cooling must be designed by the customer so that the
ambient temperature immediately surrounding the WREN 7 will not
exceed temperature conditions. Specific consideration should be given
to make sure adequate air circulation is present around the PWAs.

Service Tools
No special tools are required for site installation or recommended
for site maintenance. The depot repair philosophy of the WREN 7
precludes the necessity for special tools. Field repair of the drive
is not practical since there are no user purchasable parts in the

Air Cleanliness
The WREN 7 is designed to operate in a typical office environment
with minimal environment control.

Drive Termination
This option may be incorporated during manufacture at the request of
the customer. For single ended interface drives, termination consists
of three 220/330 ohm resistor modules (SIPs) which are installed on
the Main PWA via sockets.

Power Sequencing
Power sequencing is not required for the WREN 7. The WREN 7 protects
against inadvertent writing during power up and down. Daisychain
operation requires that power be maintained on the terminated WREN 7
to ensure proper termination of the peripheral I/O cables.


SEAGATE ST41200N/ND PRODUCT MANUAL 77765374-D (1/92)

The ST41200N/ND has been developed as a system peripherals to the
highest standards of design and construction. The ST41200N/ND depends
upon its host equipment to provide adequate power and environment in
order to achieve optimum performance and compliance with applicable
industry and governmental regualations. Special attention must be
given in the areas of safety, power distribution, shielding, audible
noise control, and temperature regulation.

The ST41200N/ND is a UL Recognized component per UL478 or UL1950,CSA
C22.2, No. 220-M1986 or CAN/CSA-C22.2 No. 950-M89, DIN VDE 0805/08.90
and EN60950:1988 (IEC 950).

The ST41200N/ND, as delivered, is designed for system integration
before use. It is supplied as a component or subassembly as defined
in the FCC Rules and Regulations, Part 15, Subpart J governing EMI
of computing devices end the Radio Interference Regulations of the
Canadian Department of Communications. The ST41200N/ND is, therefore,
not directly subject to the FCC rules and regulations or the Radio
Interference Regulations of the Canadian Department of

The head, disc and actuator chamber (HDA) is environmentally sealed
at the factory. Air is recirculated within the HDA and passes through
a nonreplaceable filter to ensure the maintenance of a contamination
free disc/actuator environment.

The WREN 7 uses a dedicated landing zone at the innermost radius of
the media thus eliminating the possibility of destroying or degrading
data by landing in the data zone. The drive automatically disengaged
when power is applied to the drive.

The WREN 7 incorporates an automatic shipping look which prevents
potential damage to the heads and discs caused by movements during
shipping and handling. The shipping lock is automatically disengaged
when power is applied to the drive.

The WREN 7 decode Track 0 location from the dedicated servo surface
thereby eliminating mechanical transducer adjustments and related
reliability concerns.

The WREN 7 use a high performance actuator assembly consisting of a
low inertia, balanced, patented, straight arm design which provides
excellent performance with minimum power dissipation.

Media Description
The media used in the WREN 7 has a diameter of approximately 5
inches (130 mm). The aluminum substrate is coated with a thin film
magnetic material, overcoated with a proprietary protective layer for
improved durability and environmental protection.

Defect and Error Management
The WREN 7, as delivered, complies with this specification. The read
error rate and specified storage capacity are not dependent upon use
of defect management routines by the host (initiator).

Defect and error management in the SCSI system involves the WREN 7
internal defect/error management and SCSI systems error
considerations (error in communications between host and WREN 7).
Tools for use in designing a defect/error management plan are briefly
outlined in this section, with references to other sections where
further details are given.

WREN 7 Internal Defect/Errors
Identified defects are recorded on the WREN 7 defects list tracks
(referred to as the primary or ETF defect list). These known defects
are reallocated during the initial WREN 7 format operation at the
factory. The WREN 7 internal retries and data correction by ECC
should be enabled to recover data from additional flaws if they
occur. If data correction by ECC is required to recover data, the
host should immediately reallocate this sector by use of the Reassign
Blocks command. If the WREN 7 automatic retries and data correction
by ECC are disabled, defects are usally unrecoverable and need to be
reallocated as they are discovered. For reallocation of bad sectors,
the number of spare sectors per track or cylinder and the number of
spare tracks per volume is programmable. After formatting, defects
can be automatically reallocated by the WREN 7, or can be reallocated
when the host sends the Reassign Blocks Command.

 Seek Time
        Track-to-Track         msec. typ. |   2.5  |
                               msec. max. |   4.0  |
                       Average msec. typ. |  15    |
                       Average msec. max. |  16.5  |
        Maximum Seek Time      msec. typ. |  34    |
                               msec. max. |  37    |
        Latency                msec. avg. |   8.33 |

    Including Controller Overhead
        Track-to-Track         msec. typ. |   3.20 |
                               msec. max. |   4.75 |
                       Average msec. typ. |  15.75 |
                       Average msec. max. |  17.30 |
        Maximum Seek Time      msec. typ. |  34.85 |
                               msec. max. |  37.90 |
        Latency                msec. avg. |   8.33 |

The drive will meet all specifications over a 50*F to 122*F (10*C to
50*C) drive ambient temperature range with a maximum gradient of 36*F
(20*C) per hour. The enclosure for the drive should be designed such
that the temperatures at the locations are not exceeded. Air flow may
be needed to achieve these temperature values. Operation at case
temperatures above these values may adversely affect the drives
ability to meet specification.

Heat/Power Dissipation
For drives with single ended interface circuits, typical dissipation
is 31 watts (106 BTUs per hour) of DC power average at nominal
voltages. Typical power dissipation under idle conditions is 24 watts
(82 BTUs per hour).

For drives having differential interface circuits, typical power
dissipation is 32 watts (109.2 BTUs per hour) of DC power average
at nominal voltages. Typical power dissipation under idle conditions
is 25 watts (85.3 BTUs per hour).

The following reliability specifications assume correct host/drive
interface including all interface timings, power supply voltages,
environmental requirements.

MTBF 100,000 hours
Service Life 5 years
Preventive Maintenance None required

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