
W R E N   I I   9 4 1 5 6 - 4 8    IMPRIMIS
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 5.25"/FH              Cylinders     925|     |     |
Capacity form/unform    40/   48 MB        Heads           5|     |     |
Seek time   / track  28.0/ 5.0 ms          Sector/track   17|     |     |
Controller           ESDI                  Precompensation 65535
Cache/Buffer               KB              Landing Zone
Data transfer rate    0.625 MB/S int       Bytes/Sector      512
                            MB/S ext
Recording method     MFM                            operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C        10 50    |    -40 70
Power: sleep              W     Humidity     %        20 80    |      5 95
       standby            W     Altitude    km    -0.305  3.048| -0.305 12.192
       idle               W     Shock        g         2       |     32
       seek          33.5 W     Rotation   RPM      3600
       read/write         W     Acoustic   dBA
       spin-up            W     ECC        Bit
                                MTBF         h      40000
                                Warranty Month
Lift/Lock/Park     YES          Certificates     CSA,FCC,IEC380,IEC435,UL47...

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                        L   A   Y   O   U   T
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SEAGATE  ST4086E  PRODUCT MANUAL 77738019-H

  REAR
 +------------------------------------------------------------+
 |                                                            |
 |                                                            |
 |Drive                                                       |
 |Select    Terminator                                        |
 | +----+   +--------+      Control Cable            Power  AC|
 +-+----+---+--------+------XXXXXXXXXXXXXXXXXXXX----XXXXXXX--x+
 |                                                            |
 |        Data Cable                                          |
 +--------XXXXXXXXXXXXXXX------------------------------x------+
 |                                                      W4    |
 +------------------------------------------------------------+





  FRONT
 +------------------------------------------------------------+
 |                                                            |
 |                                                            |
 |                                        +-------+SW1        |
 |                                        +-------+           |
 +------PCB---------------------------------------------------+
 |                                                            |
 |                                                            |
 +------PCB---------------------------------------------------+
 |                                                            |
 +------------------------------------------------------------+



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                      J   U   M   P   E   R   S
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SEAGATE  ST4086E  PRODUCT MANUAL 77738019-H

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

 x = Jumpers set at factory



 Drive Select Header
 -------------------

        Drive |  1   |  2   |  3   |
        ------+------+------+------+
   x      1   |CLOSED|OPEN  |OPEN  |
          2   |OPEN  |CLOSED|OPEN  |
          3   |CLOSED|CLOSED|OPEN  |
          4   |OPEN  |OPEN  |CLOSED|
          5   |CLOSED|OPEN  |CLOSED|
          6   |OPEN  |CLOSED|CLOSED|
          7   |CLOSED|CLOSED|CLOSED|


 Drive Select 0 is not allowed!


 Drive Select
 ------------
 The following characteristics apply to the Drive Select lines:

  1.   Logical unit designation for up to 7 drives is performed during
       installation by installing the jumper on the baseboard
       assembly.
  2.   The controller shall not attempt to select the drive until 1
       second after DC power is applied. The Ready output will be
       valid (whether true or false) within 500 ns after the drive
       is selected.

  3.   The drive will be selected (and the Drive Selected Signal
       true) within 1 us after the Drive Select lines contain that
       unit's select address. The drive will be deselected (and the
       Drive Selected signal false) within 1 us after the Drive
       Select lines contain another unit's select address.

  4.   The Drive Select lines must remain asserted for 1 us after a
       write operation.

  5.   When the Drive Select lines are asserted, a head change will
       occur, requiring a delay before a read or write operation can
       be initiated.



 SW1  Configuration switch setting
 ---------------------------------
 The WREN 2 is configured by turning on/off the switches in SW1 on the
 Servo PWA. SW1 is located behind the fron panel.

 Switch            ON                 OFF
 ------            --                 ---
 SW1-1             Factory Test       Normal

 SW1-2             Motor Control*     Motor Control
                   Implemented        Not Implemented

 SW1-7             Serial Mode        Not Used
                                      Do not position switch to this
                                      setting


 Sectors/Track     SW1-3              SW1-4
 -------------     -----              -----
      17           ON                 ON
      16           OFF                ON
      34           ON                 OFF
      32           OFF                OFF


 Format Mode       SW1-5              SW1-6
 -----------       -----              -----
 Address Mark      ON                 ON
 Byte Clock        OFF                ON
 Sector Pulse      OFF                OFF
 Sector Pulse      ON                 OFF

 * When the SW1-2 switch is on, a Motor ON command is required from
   the controller to start the spindle motor. When power is applied to
   the drive, the drive will generate an Attention signal and assert
   Standard Status Bits 8 and 9 signifying "Power On Reset Conditions
   Exist" and "Spindle Motor Stopped". The controller must then
   respond with a command to Reset the Interace Attention line and
   also the Start Motor command in order to start the spindle motor.

   Note: This procedure is required every time the "Power On Reset
   Condition Exist" status bit is received by the controller if the
   "Motor Control Implemented" switch is on.


 AC/DC Ground
 ------------
 The WREN 2 can be provided with the AC ground (chassis) isolated from
 the DC logic ground. This option may be benefical in reducing ground
 induced noise in some system applications.

 The WREN 2 is shipped with the DC ground and the chassis ground
 joined together. These two ground planes may be separated by removing
 W4 from the Data PWA.


 Power Connector
 ---------------

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



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                      I   N   S   T   A   L   L
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SEAGATE  ST4086E  PRODUCT MANUAL 77738019-H

 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!
      Never install PC board on the Top!



 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. In the vertical plane, the drive may be
 mounted on either side, but not on either end. The drive may be not
 mounted inverted (upside down) in the horizontal orientation. It is
 recommended for optimum performance that data written in a given
 orientation be read in that same orientation.


 WREN 2 is designed, manufactured, and tested with a "Plug-in and
 Play" installation philosophy. This minimizes the requirements for
 highly trained personnel to integrate the WREN 2 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 2 will not exceed
 temperature limits. Specific consideration should be given to
 make ensure adequate air circulation around the heat sinks on the
 circuit board on the rear of the drive.


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

 View A
    +---------------------Host-Controller---------------------+
    |                                                         |
    |Data Control   Data Control  Data Control   Data Control |
    +--+-----+--------+-----+--------+-----+--------+-----+---+
       |     |        |     |        |     |        |     |
       |     |        |     |        |     |        |     |
       |     |        |     |        |     |        |     |
       |     |        |     |        |     |        |     |
    +-++-+--++-+-+ +-++-+--++-+-+ +-++-+--++-+-+ +-++-+--++-+-+
    | |T |  |*T| | | |T |  |*T| | | |T |  |*T| | | |T |  |*T| |
    | +--+  +--+ | | +--+  +--+ | | +--+  +--+ | | +--+  +--+ |
    |    WREN    | |    WREN    | |    WREN    | |    WREN    |
    +------------+ +------------+ +------------+ +------------+

    Each control cable length must not exceed 10 feet (3.00m). Each
    data cable length must not exceed 10 feet (3.00m).


   *T  indicates removable terminator resistor pack.
    WREN data ports are permanently terminated.


 Radial Configuration
 --------------------
 View A shows each drive interfaced to its own control cable, which
 allows interfacing an arbitrary number of drives and a variety of
 system operational techniques. Each drive has its data cable and
 control cable radially connected to the host controller. The length
 of each individual cable must not exceed 10 feet (3.00 meters).
 Terminator resistors must be installed in the host controller for
 each data cable and for each control cable. For this configuration, a
 terminator resistor pack must be installed in each WREN 2 Disc Drive.



 View B
    +--------------Host Controller-------------+
    |                                          |
    |Data Control   Data          Data         |
    +-+------+-------+--------------+----------+
      |      |       |              |
      |      |       |              |
      |      |       |              |
      |      +--**---+-------+------+-------+
    +++-+----+---+ +++-+-----+--+ +++-+-----+--+
    ||T |        | ||T |        | ||T |        |
    |+--+        | |+--+        | |+--+        |
    |   WREN #1  | |   WREN  #6 | |   WREN  #7 |
    +------------+ +------------+ +------------+

    Total control cable length must not exceed 10 feet (3.00m). Each
    data cable length must not exceed 10 feet (3.00m).

   *T  indicates removable terminator resistor pack.
   WREN data ports are permanently terminated.


 Daisychain Configuration
 ------------------------
 A daisychain configuration incorporates parallel interfacing of the
 drives on a common control cable. A maximum of seven drives may
 be daisychained on the control cable in the serial mode of operation.
 Only the drive selected by the host system has its control signals
 enabled through this common interface. View B illustrates a
 daisychain of WREN 2 Disk Drives. A terminator resistor pack is
 required in the host controller for each data cable. Only the last
 WREN 2 in the daisychain requires a terminator resistor pack for the
 control cable. Terminator resistor packs for the control cable or
 other drives must be removed. The total combined control cable
 length (from the controller to the first drive, to the second and
 subsequent drives) must not be more than 10 feet (3.00 meters).


 DC Cable and Connector
 ----------------------
 The WREN 2 receives DC power through a 4 pin right angle connector
 mounted on the Servo PWA. Recommended part numbers of the mating
 connector are provided, but equivalent parts may be used.

 Type of cable:      18 AWG
 Connector:          AMP 1-480424-0
 Contacts:           AMP 60619-4 (Loose Piece); AMP 61117-4 (Strip)


 DC ground Connector
 -------------------
 The WREN 2 is shipped with the DC ground and the chassis ground
 joined together. These two ground planes may be separated by re-
 moving W4 from the Data PWA.


 Data Cable and Connector
 ------------------------
 The I/O connector for the data interface is a 20 pin board edge
 connector. The odd pins are located on the noncomponent side of the
 PWA. The even pins are on the component side of the PWA. A key slot
 is provided between pins 3 and 5. Seagate recommends keying this
 connector to prevent installing it upside down. However, the WREN
 will not be damaged if the connector is installed upside down.

 Recommended part numbers for the mating connector are listed below,
 but equivalent parts may be used.

 Connector:          20 pin, 3M-3461-0001, AMP 88373-6
 Cable:              Flat Cable (Stranded AWG 28) 3M-3365-20
                     Flat Cable (Stranded AWG 28) 3M-3517-20 (Shielded
                     Cable)
 Key:                AMP 583274-1, 3M-3439-0000


 Control Cable and Connector
 ---------------------------
 The I/O connector for the control interface is a 34 pin board edge
 connector. The odd pins are located on the component side of the
 PWA and are connected to the ground plane. The even pins are on the
 noncomponent side of the PWA. A key slot is provided between pin 3
 and 5. Seagate recommends keying this connector to prevent installing
 it upside down. However, the WREN will not be damaged if the
 connector is installed upside down.

 Recommended part numbers for the mating connector are included below,
 but equivalent parts may be used.

 Connector:          34 pin, 3M-3463-0001, AMP 88373-3
 Key:                AMP 583274-1, 3M-3439-0000
 Cable:              Flat cable (Stranded AWG 28) 3M-3365-34
                     Flat cable (Stranded AWG 28) 3M-3517-34 (Shielded
                     Cable)
                     Spectra Strip Twist'n Flat 455-248-34 (Stranded
                     AWG 28 Twisted Pair)


 Interface Drivers/Receivers
 ---------------------------
 The WREN 2 uses two types of signals -- single ended and balanced
 differential. The data and clock signals use balanced differential
 drivers and receivers. All other signals use single ended drivers and
 receivers.

 Single Ended Drivers/Receivers
 -------------------------------
 Transmitter Characteristics
 The WREN 2 uses the 7438 open collector quad-2-input driver to
 transmit status to the host. This driver is capable of sinking a
 current of 48 mA with a low-level output voltage of 0.4V.

 Receiver Characteristics
 The WREN 2 uses the 74LS14 Hex Inverter with hysteresis gate as a
 line receiver. The input of each receiver is terminated in a 150 ohm
 pullup resistor.

 Terminator Characteristics
 The terminator is a resistor module that plugs into a socket in the
 last drive in a daisychain. Each drive is furnished with a
 terminator. Terminators must be removed from all except the last
 drive on the cable prior to daisychain operation. An equivalent
 terminator must be provided in the controller on each input signal
 line from the drive to the controller. Only the control cable
 resistor module is removable.


 Balanced Differential Drivers/Receivers
 ---------------------------------------
 Transmitter Characteristics
 The WREN 2 uses 26LS31 balanced differential driver. A logic 1 on
 the interface is defined when "+" output is more positive than the
 "-" output.

 Receiver Characteristics
 ------------------------
 The WREN 2 uses 26LS32 type balanced differential receivers. A logic
 1 one on the interface is defined when the "+" input is more positive
 than the "-" input.

 Terminator Requirements
 -----------------------
 Each differential receiver in the drive is terminated with a 100 ohm
 resistor. An equivalent terminator must be provided in the controller
 on each input signal line from the drive to the controller.



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                      F   E   A   T   U   R   E  S
**********************************************************************
SEAGATE  ST4086E  PRODUCT MANUAL 77738019-H

 Standards
 ---------
 The WREN 2 has been developed as a system peripherals to the highest
 standards of design and construction. The WREN 2 depends upon its
 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 2 complies with Seagate standards.

 The WREN 2 is a UL Recognized component per UL478 and a CSA Certified
 product per CSA C22.2, No. 220-M1986. It also meets the requirements
 of DIN IEC 380/VDE 0806/8.81, DIN IEC 435/VDE 0805/11.84 and EN
 60950/09.87.

 The WREN 2, 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, and the Radio Interference Regulations of the Canadian
 Department of Communications. However, the WREN 2 has been tested and
 found to comply with the Calss B requirements of the referenced FCC
 Rules and Regulations when installed in a typical commercial
 computing system.


 Media Description
 -----------------
 The media used in the WREN 2 has a diameter of approximately 5
 inches (130 mm). The aluminum substrate is coated with lubricated
 ferrous oxide to permit the heads to contact the surface when
 starting and stopping.

 Each data surface has a total of 925 tracks and is capable of
 recording 9,657,000 bytes of unformatted data.

 Media defects are characterized as correctable or uncorrectable de-
 pending on the type and magnitude of the media flaw. Various error
 correction codes may be implemented. The code chosen should be
 consistent with Seagate media testing and certification methods. In
 the WREN 2 media certification is performed using the following
 standards:
            An error burst of 11 bits or less is a correctable error.

            An error burst greater than 11 bits in length is an un-
            correctable error.

 Host systems using the WREN 2 should have, as a minimum, resident
 capabilities to recognize and map defective tracks and perform track
 reallocation routines.

       1. 925 total tracks per surface.

       2. Track 0 to be error free on each data surface.

       3. 15 defects per surface maximum.

       4. Cumulative defects not to exceed 1 per megabyte, based on
          total available unformatted drive capacity.


 Defect and Error Management
 ---------------------------
 The WREN 2, as delivered, complies with this specification. The read
 error rate and specified storage capacity are not dependent upon
 defect management routines. However, a carefully chosen defect
 management plan can significantly enhance overall system performance.

 Identified defects are recorded on the defects list tracks per ESDI
 specification. It is recommended that these known defects be re-
 allocated during the initial format operation. Sector reallocation is
 suggested because, in general, it is more efficient and may offer
 significant performance improvement. Error Correction Code (ECC)
 should be used to correct additional flaws as they occur. ECC is re-
 commended since most of the defects are recoverable with ECC. If ECC
 is not used, defects are usually unrecoverable and need to be re-
 allocated as they are discovered.


 Custom Formatting
 -----------------
 The WREN 2 is formatted during production. Seagate maintains custom
 formatting capability which can incorporate many of the unique
 formats used in the Winchester marketplace. A majority of special
 format requirements can be implemented as specified.


 Drive/Receiver Characteristics
 ------------------------------
 Logic Level                   Drive Output         Receiver Input
 --------------------------------------------------------------------
 High (false/deactivated) (0)    2.4 V;   5.25 V      2.0 V;   5.25 V
 Low (true/activated)   (1)      0.4 V;   0.0 V       0.8 V;   0.0 V

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


 Seek Time
 ---------

                                          | WREN 2 |
        ----------------------------------+--------+
        Track-to-Track         msec. typ. |   5    |
                               msec. max. |   7    |
                       Average msec. typ. |  28    |
                       Average msec. max. |  32    |
        Latency                msec. avg. |   8.33 |
        ----------------------------------+--------+

 Seek time is defined as the elapsed time from the receipt of a seek
 command by the WREN 2 until the drive signals the controller that it
 is ready to  perform another seek or a read/write function on the new
 cylinder. Average seek time is determined by dividing the sum of the
 time for all possible movements by the total number of movements.


 Spindle Speed and Latency
 -------------------------
 The spindle speed is 3600   0.5% r/min. The speed tolerance includes
 motor performance and motor control circuit tolerances.

 The average latency time is 8.33 milliseconds, based on a nominal
 disc speed of 3600 r/min. The maximum latency time is 16.74 milli-
 seconds based on a minimum disc speed of 3582 r/min.


 Read Data Transfer Rate
 -----------------------
 The read serial data transfer rate is 5.0 Mbits per second.


 Power Sequencing
 ----------------
 Power sequencing is not required for the WREN 2. 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 95* F (35*C)
 at 10,000 feet (3048 metres). Cabinet packaging designs must provide
 ample air circulation around the WREN 2 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 2. The
 temperature of the base casting should not be allowed to exceed 135*
 F (57* C) at the hottest point. The hottest point may vary dependent
 upon application.


 Air Cleanliness
 ---------------
 The WREN 2 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. However, separation of AC and DC ground can be accomplished
 by the user at some later time if desired.


 Front Panel
 -----------
 The WREN 2 is available with a black front panel. The panel has a
 single red rectangular LED indicator which, when glowing, indicates
 the drive is selected. A flashing indication displays the presence of
 a nonrecoverable fault. A fault indication is displayed irrespective
 of Drive Select status.


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

 MTBF                     40,000 hours
 Service Life             5 years
 Preventive Maintenance   None required


