
W R E N   I I I   9 4 1 6 1 - 8 6    CDC
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 5.25"/FH              Cylinders     969|     |     |
Capacity form/unform    86/      MB        Heads           5|     |     |
Seek time   / track  16.5/ 4.0 ms          Sector/track   35|     |     |
Controller           SCSI1 SINGLE-ENDED    Precompensation
Cache/Buffer             8 KB FIFO BUFFER  Landing Zone
Data transfer rate    1.250 MB/S int       Bytes/Sector      512
                            MB/S ext
Recording method     RLL 2/7                        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               W     Shock        g         2       |     32
       seek          24.0 W     Rotation   RPM      3597
       read/write         W     Acoustic   dBA
       spin-up            W     ECC        Bit   64
                                MTBF         h     100000
                                Warranty Month
Lift/Lock/Park     YES          Certificates     CSA,FCC,IEC380,UL478,VDE


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                        L   A   Y   O   U   T
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SEAGATE  ST4182N  PRODUCT MANUAL 77738270-J



  REAR    3 by 5 configuration jumper block
    +------------------------------------------------------------+
    |                                                            |
    |   J4                                        Terminator     |
    |Option/Drive                                 Header         |
    |Select               J3                  J2    +-------J10+ |
    | +----+        Cable Connector       1  Power  |xxxxxxxxxx| |
    | ++---+---XXXXXXXXXXXXXXXXXXXXXXXXXXXX-XXXXXXX-+----+----++ |
    |  |                                                ++    |  |
    |  |                                          Terminator  |  |
    |  +------------------------Data-PWA-------------xx--xx-x-+  |
    |  |                                           W3     W4 Ground
    +--+------------------------------------------------------+--+






  REAR    2 by 7 configuration jumper block
    +------------------------------------------------------------+
    |                                                            |
    |   J4                                        Terminator     |
    |Option/Drive                                 Header         |
    |Select               J3                  J2    +-------J10+ |
    | +--------+    Cable Connector       1  Power  |xxxxxxxxxx| |
    | ++-------+XXXXXXXXXXXXXXXXXXXXXXXXXXX-XXXXXXX-+----+----++ |
    |  |                                                ++    |  |
    |  |                                          Terminator  |  |
    |  +------------------------Data-PWA-------------xx--xx-x-+  |
    |  |                                           W3     W4 Ground
    +--+------------------------------------------------------+--+



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                      J   U   M   P   E   R   S
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SEAGATE  ST4182N  PRODUCT MANUAL 77738270-J

 Jumper setting
 ==============

 x = Jumpers set at factory


 3 by 5 Configuration Jumper Block
 ---------------------------------
       J4

      Drive Select
      +---------------+     Drive ID is binary coded jumper position
      | o  o  x  x  o |     (most significant bit on left).
      | x  o  o  o  o |
      | X  o  o  o  o |
      +-4--2--1-------+


      +------------+----------+
      |logical Add.| 4  2  1  |
      +------------+----------+
      |     0      | o  o  o  |
      |            | o  o  o  |
      +------------+----------+
      |     1      | o  o  x  |
      |            | o  o  X  |
      +------------+----------+
      |     2      | o  x  o  |
      |            | o  X  o  |
      +------------+----------+
      |     3      | o  x  x  |
      |            | o  X  X  |
      +------------+----------+
      |     4      | x  o  o  |
      |            | X  o  o  |
      +------------+----------+
      |     5      | x  o  x  |
      |            | X  o  X  |
      +------------+----------+
      |     6      | x  x  o  |
      |            | X  X  o  |
      +------------+----------+
      |     7      | x  x  x  |
      |            | X  X  X  |
      +------------+----------+



      Motor Start Option
      +---------------+
      | xxxx  x  x  o |     Jumper plug installed enables the Motor
      | o  o  o  o  o |     Start Option. In this mode of operation,
      | o  o  o  o  o |     the drive will wait for a Start Unit
      +-4--2--1-------+     command from the Host before starting the
                            motor. If the jumper plug is not installed
                            the motor will Start as soon as DC power
                            is applied to the unit.


      Terminator Power From J3-26
      +---------------+
      | o  o  x  x  x |     Jumper in upper position means terminator
      | o  o  o  o  X |     power is taken from interface cable.
      | o  o  o  o  o |     If unit is not terminated, TP jumper is to
      +-4--2--1-------+     be left off.


      Terminator Power From Internal +5V
      +---------------+
      | o  o  x  x  o |     Jumper in lower position means terminator
      | o  o  o  o  x |     power (+5V) is from WREN III power
      | o  o  o  o  X |     connector. If unit is not terminated, TP
      +-4--2--1-------+     Jumper is to be left off.

  When a jumper is installed, it must only be in one of the Positions
  shown. Two jumper must be not installed in the "TP" position at the
  same time.


      Parity Check
      +---------------+
      | o  o  x  x  o |     Jumper plug installed means parity check-
      | o  o  o  x  o |     ing by the WREN III is enabled.
      | o  o  o  X  o |
      +-4--2--1-------+

 x = N/A



 2 by 7 Configuration Jumper block
 ---------------------------------
         J4
                         Terminator Power from Bus (horizontal)
                        |
      +-----------------+---+
      | o  o  o  o  o  o+-o |
      | o  o  o  o  o  x  o |
      +-M--4--2--1--P--T--T-+
        |  +--+--+  |     +------ Terminator Power (+5V) from drive
        |     |     |             (lower 2 pins)
        |     |     +------------ Parity Check Option Enable
        |     |                   (vertical)
        |     +------------------ Drive Select ID's (vertical)
        +------------------------ Motor Start Option Enable

 x = N/A


 DC Power Connector
 ------------------

          +---+---+---+---+
          | 1 | 2 | 3 | 4 |
          +--++--++--++--++
             |   |   |   +---------- + 5V
             |   |   +-------------- + 5V Return
             |   +------------------ +12V Return
             +---------------------- +12V



 Signal/Chassis Ground
 ---------------------
 The WREN 3 Disc Drives are manufactured with the signal and chassis
 grounds common. Zero ohm resistors (designated W3 and W4) on the
 Data board allows modification of this relationship at the customer's
 option. The customer can select any of these (see table below)
 grounding options by removing W3 and/or W4.

   W4         W3        Result
   -----------------------------------------------------------
 x X         X         Grounds common, quick connect terminal tied to
                       common ground

   X         O         Grounds separate, quick connect terminal tied
                       to chassis ground

   O         X         Ground separate, quick connect terminal tied to
                       signal ground

   O         O         Grounds separate, quick connect terminal float-
                       ing

 X = Connected
 O = Not Connected



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                      I   N   S   T   A   L   L
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SEAGATE  ST4182N  PRODUCT MANUAL 77728270-J

 Notes on installation
 =====================

 Drive mounting
 --------------

     horizontally             vertically
   +-----------------+   +--+             +--+ +------------------+
   |                 |   |  +-----+ +-----+  | |                  | x
   |                 |   |  |     | |     |  | x+----------------+x
 +-+-----------------+-+ |  |     | |     |  | ||x              x||
 +---------------------+ |  |     | |     |  | ||  x          x  ||
                         |  |     | |     |  | ||    x      x    ||
      x          x       |  |     | |     |  | ||      x  x      ||
 +------x------x-------+ |  +-----+ +-----+  | ||       xx       ||
 +-+------x--x-------+-+ +--+             +--+ ||     x    x     ||
   |       xx        |                         ||   x        x   ||
   |     x    x      |                         || x            x ||
   +---x--------x----+                         |x                x|
     x            x                           x++----------------++x
      UNACCEPTABLE!                                UNACCEPTABLE!



 Drive Orientation
 -----------------
 Only two drive mounting orientations are permitted: discs in the
 horizontal plane and discs in the vertical plane. The uppermost
 surface must be maintained in a level position or drive performance
 may be adversely affected. Mounting with either end down (front or
 rear) is not permissible. In the horizontal orientation, the spindle
 axis must be vertical with the discs on the top. It is recommended
 for optimum performance that data written in a given orientation be
 read in that same orientation.


 The WREN 3 is designed, manufactured, and tested with a "Plug-in and
 Play" installation philosophy. This philisophy minimizes the
 requirements for highly trained personnel to integrate the WREN 3
 into an OEM's system, wether in a factory or field environment.


 Cooling
 -------
 Cabinet cooling must be designed by the customer so that the ambient
 temperature immediately surrounding the WREN 3 will not exceed
 temperature conditions. Specific consideration should be given to
 make sure adequate air circulation is present around the circuit
 board at the rear of the drive.


 Physical Description
 --------------------
 Model 94161 WREN may be daisychained together or with other
 compatible SCSI devices using a common cable. Both ends of the cable
 must be terminated. All signals are common between all SCSI devices.
 The Model 94161 WREN 3 may be daisychained only with SCSI devices
 with single-ended drivers and receivers. A maximum of 8 SCSI devices
 (including the Host) may be daisychained together. The SCSI devices
 at both ends of the daisychain are to be terminated. SCSI devices
 shall not be terminated.


 Cable Requirements
 ------------------
 Only non-shielded cable connectors are applicable. A 50 conductor
 flat cable or 25 twisted pair cable shall be used. The maximum total
 cable length shall be 6.0 metres. A stub length of no more than 0.1
 metres is allowed off the mainline interconnection within any
 connected equipment.

 A minimum conductor size of 28 AWG should be used to minimize noise
 effects.

 Recommended nonshielded flat cable part numbers are:

 Flat cable: 3M-3365-50
 Twisted pair: Spectra Twist in Flat 455-248-50
 Equivalent parts may be used.


 Connector Requirements
 ----------------------
 The nonshielded cable connector shall be a 50 conductor connector
 consisting of two rows of 25 female contacs with adjacent contacts
 100 mils apart.

 Recommended Mating Flat Cable Connector Part Numbers are:

 Closed end*       3M-3425-7000    W/O Strain Relief
 (for Cable end)   3M-3425-7050    With Strain Relief
 Open end*         3M-3425-6000    W/O Strain Relief
 (in daisychain)   3M-3425-6050    With Strain Relief

 The Model 94161 WREN device connector is a nonshielded 50 conductor
 connector consisting of two rows of 25 male pins with adjacent pins
 100 mils apart. The connector is keyed.

 Drive Connector Part Number: Berg - 65496 - 031 or equivalent.



 Interface Cabling Options
 -------------------------

    +----------SCSI-DEVICE---------------------+
    |   +--+HOST ADAPTER/INITIATOR             |
    |   |T |                                   |
    +---+-++-----------------------------------+
          |*
          +----**------+**----------+*
     +----+------++----+------++---++-+----+
     |WREN or    ||WREN or    ||   | T|    |WREN or other SCSI
     |other SCSI ||other SCSI ||   +--+    |device.
     |Device     ||Device     ||           |
     +-----------++-----------++-----------+

 Total interface cable length must not exceed 6.0 m (20 feet).
 (Including Host Adapter/Initiator)


   T  indicates termination required.
   *Closed end connector type used
   **Open end connector type used (Inline application)


 DC Cable and Connector
 ----------------------
 The WREN 3 receives DC power through a 4 pin right angle connector
 mounted on the PWA. Recommended part number for the mating connector
 are listed, but equivalent parts may be used.

 Type of cable:      14 AWG
 Connector:          AMP 1-480424-0
 Contacts:           AMP 60619-4 (Loose Piece); AMP 61117-4 (Strip)


 Electrical Description
 ----------------------
 All interface signals with the Model 94161 WREN 3 are single ended
 and must be terminated with 220 ohms to +5V and 330 ohms to ground at
 each end of the total cable. All signals use open collector or three
 state drivers. Optional termination is available to the WREN 3.


 Single Ended Drivers/Receivers
 ------------------------------
 Single ended drivers and receivers are used by the WREN 3.


 Transmitter Characteristics
 ---------------------------
 The WREN 3 uses an ANSI SCSI compatible open collector single ended
 driver. This driver is capable of sinking a current of 48 mA with a
 low level output voltage of 0.4 volt.


 Receiver Characteristics
 ------------------------
 The WREN 3 uses a ANSI SCSI single ended receiver with hysteresis
 gate or equivalent as a line receiver.


 Terminator Requirements
 -----------------------
 Internal WREN 3 I/O termination consist of three resistor modules
 which plug into sockets on the Servo PWA. The WREN 3 may be ordered
 with or without these termination resistors to facilitate a
 particular application. All single initiator/single target
 (nondaisychain) applications require that the initiator and WREN 3 be
 terminated. Daisychain applications require that only the last
 physical unit at each end of the daisychain be terminated. All other
 peripherals on the chan should not be terminated. Physically remove
 terminator resistor packs where terminators are not required.
 Removal of power source selection jumper 4 does not disconnect the
 terminator resistors from the circuit.


 Termination Power
 -----------------
 The WREN 3 does not supply terminator power for the SCSI bus. The
 WREN 3 may be optionally configured to accept terminator power via
 Pin 26 of the SCSI bus or to provide terminator power for optional
 internal termination resistors via the WREN 3 power connector.

 Interface signals and logical sense at the WREN I/O Controller are
 defined as follows:

 Logic Level        Drive Output        Receiver Output
 ------------------------------------------------------
 Negated (0)         2.5V;  5.25V        2.0V;  5.25V
 Asserted (1)        0.4V;  0.0V         0.8V;  0.0V

 The difference in the voltages between input and output signals is
 duo to the losses in the cable.


 AC/DC Ground Separation
 -----------------------
 The 94161 WREN 3 is provided with the AC ground (chassis) tied to DC
 logic ground. An option is provided for the user to isolate the AC
 and DC grounds by removing the appropriate zero resitance shunt.
 This option may be beneficial in reducing ground induced noise in
 some systems applications.



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                      F   E   A   T   U   R   E  S
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SEAGATE  ST4182N  PRODUCT MANUAL 77738270-J

 Standards
 ---------
 The WREN 3 has been developed as a system peripherals to the highest
 standards of design and construction. The WREN 3 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 WREN 3 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 WREN 3 is already low-level formatted at the factory.

 The WREN 3 complies with Seagate standards.

 The WREN 3 is a UL Recognized component per UL478 and a CSA Certified
 Component per CSA C22.2, No. 154-M1983. It also meets the
 requirements of DIN IEC 380/VDE 0806/8.81.

 The WREN 3, as delivered, is designed for system integration before
 use. It is supplied as a Class A Computing Device per the FCC
 Rules and Regulations, Part 15, Subpart J governing EMI of computing
 devices.


 Media Description
 -----------------
 The media used in the WREN 3 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
 ---------------------------
 WREN 3, 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.

 Defect and error management in the SCSI system involves WREN 3 inter-
 nal defect/error management and SCSI systems error considerations
 (errors in communications between initiator and WREN 3). Tools for
 use in designing a defect/error management plan are briefly outlined
 in this section.


 WREN 3 Internal Defects/Errors
 ------------------------------
 Identified defects are recorded on the WREN 3 defect list tracks
 (referred to as the primary or ETF defect list). It is recommended
 that these known defects be reallocated during the initial WREN 3
 format operation. The WREN 3 internal retries and data correction by
 ECC is required to recover data, the host should immediately reallo-
 cate this sector by use of the Reassign Blocks command. If the WREN 3
 automatic retries and data correction by ECC features are not used,
 defects are usually unrecoverable and need to be reallocated as they
 are discovered. One spare sector per track and up to X (where "X" is
 the number of R/W heads installed) spare sectors per cylinder are
 available for reallocation of bad sectors. After formatting, defects
 can be automatically reallocated by the WREN 3, or can be reallo-
 cated when the host sends the Reassign Blocks command.


 Seek Time
 ---------

                                          | WREN 3 |
        ----------------------------------+--------+
        Track-to-Track         msec. typ. |   4    |
                               msec. max. |   5    |
                       Average msec. typ. |  16.5  |
                       Average msec. max. |  18    |
        Full-Stroke            msec. typ. |  40    |
                               msec. max. |  43    |
        Latency                msec. avg. |   8.33 |
        ----------------------------------+--------+
        Not including Controller Overhead



 Start/Stop Time
 ---------------
 After DC power has been applied to the WREN 3 the Unit will become
 ready within 38 seconds if the Motor Start Option is disabled (i.e.
 the motor starts as soon as the power has been applied. During this
 time the internal controller will not respond to the SCSI interface
 until the drive has loaded the heads and positioned them to track
 zero. Stop time will be less than 30 seconds from removal of DC
 power.


 Power Sequencing
 ----------------
 Power sequencing is not required for the WREN 3. The drive protects
 against inadvertent writing during power up and down. Daisychain
 operation requires that power be maintained on the terminated unit
 to ensure proper termination of the peripherals I/O cables.


 Temperature
 -----------
 50*F to 122*F (10*C to 50*C) operating ambient with a maximum
 gradient of 18* F (10* C) per hour. Above 1000 feet (305 metres)
 altidude the maximum temperature is derated linearly to 112* F
 (44.4*C) at 10,000 feet (3048 metres). Cabinet packaging designs must
 provide ample air circulation around the WREN 3 to ensure
 environmental limits are not exceeded as a result of heat transfer
 from other system components. Operating ambient for specification
 purposes is defined as the environment immediately surrounding the
 WREN 3. The temperature of the base deck must not  exceed 135* F when
 measured at the isolation mount adjacent to the front panel LED.


 Heat/Power Dissipation
 ----------------------
 Each WREN 3 will dissipate no more than 36.0 watts (123 BTUs per
 hour) of DC power average. Typical power dissipation under idle
 operating conditions is less than 24 watts.

 Air Cleanliness
 ---------------
 The WREN 3 is designed to operate in a typical office environment
 with minimum environmental control.


 Options
 -------
 All options are either incorporated or packaged at the manufacturing
 facility. Ground isolation capability is provided on every Data PWA
 shipped, and the user may exercise his option to isolate grounds at
 his convenience.


 Front Panel
 -----------
 The front panel is available black plastic. Each panel has a single
 red rectangular LED which, when glowing indicates the drive is
 selected.


 Reliability
 -----------
 The following reliability specifications assume correct host/drive
 operational interface has been implementated, including all interface
 timings, power supply voltages, and environmental conditions.

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


