
W R E N   V I   9 4 1 9 6 - 3 8 3    CDC
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 5.25"/FH              Cylinders    1632|     |     |
Capacity form/unform   338/  383 MB        Heads           7|     |     |
Seek time   / track  17.0/ 3.0 ms          Sector/track   54|     |     |
Controller           ESDI                  Precompensation 65535
Cache/Buffer               KB              Landing Zone
Data transfer rate    1.875 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               W     Rotation   RPM      3600
       read/write    20.0 W     Acoustic   dBA
       spin-up            W     ECC        Bit
                                MTBF         h     100000
                                Warranty Month
Lift/Lock/Park     YES          Certificates     CSA,IEC380,IEC435,UL478,VDE  

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                        L   A   Y   O   U   T
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SEAGATE  ST4766E  PRODUCT MANUAL 77765358-K

  +--------------------------------------------------------+
  |                                                    +-+ |XX J4
  |                                                  J9| | |XX Data
  |                                                    | | |XX Cable
  |                                                    +-+ |XX
  |                                                   ++1  |X1
  |                                        Terminator ||   |
  |                                        Resistor   ||   |XX
  |                                        Pack       ||   |XX J3
  |                                                   ++   |XX Control
  |                                                    +-1 |XX Cable
  |                                                  J12-+ |XX
  |                                                    +-+ |XX
  |                                                  J8| | |XX
  |                                                    | | |X1
  |                                                    +-+ |
  |                                                        |XX Power
  |                                                        |XX J1
  +--------------------------------------------------------+  1



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                      J   U   M   P   E   R   S
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SEAGATE  ST4766E  PRODUCT MANUAL 77765358-K

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

 x = Jumpers are set at factory



 J1  Power Connector
 -------------------

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



 J8  Drive Select
 ----------------

          +--+--+--+--+--+--+--+
        J8|o |o |o |o |o |o |x |
          ++-++-++-++-++-++-++-+
           |  |  |  |  |  |  +----- Drive Select 1
           |  |  |  |  |  +-------- Drive Select 2
           |  |  |  |  +----------- Drive Select 3
           |  |  |  +-------------- Drive Select 4
           |  |  +----------------- Drive Select 5
           |  +-------------------- Drive Select 6
           +----------------------- Drive Select 7


   Note: Unit select zero (no jumper) is invalid!

 Pins on the drive ID select and configuration select header are
 provided to facilitate manual drive configuration. No devices other
 than jumpers should be connected to these pins. Connection to
 external devices (Switches, Connectors, etc.) could adversely
 affect drive performance. Exact location of these pins and header
 may be changed without notice.


 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 jumpers on pins on a connector
       header on the main PWA. The jumpers are installed in a 1
       through 7 position configuration to select device addresses 1
       through 7. Zero is not a valid address.

  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 asserted or negated) within 1 us after the drive
       is selected.

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


 J9 Sector Configuration
 -----------------------
 +-----------+-------------------------------------------------+ (1)
 |           |                  Jumper Plug                    |
 +-----------+-------------------------------------------------+
 | Sectors   |    1       2       3       4       5      6     |
 +-----------+-------------------------------------------------+
 |    96     |   (3)     OFF     OFF     OFF     (5)     (6)   |
 |    53     |   (3)     OFF     OFF     ON      (5)     (6)   | (2)
 | Undefined |   (3)     OFF     ON      OFF     (5)     (6)   |
 |  Special  |   (3)     OFF     ON      ON      (5)     (6)   | (7)
 |    54     |   (3)     ON      OFF     OFF     (5)     (6)   |
 |    51     |   (3)     ON      OFF     ON      (5)     (6)   |
 | Undefined |   (3)     ON      ON      OFF     (5)     (6)   |
 |  Address  |   (3)     ON      ON      ON      (5)     (6)   | (4)
 |  Mark     |                                                 |
 +-----------+-------------------------------------------------+

 (1)  ON - Plug installed; OFF - plug removed

 (2)  The configurations of installed jumper plugs are selected
      according to a customer configurator document. However, this
      configuration is the most commonly shipped configuration.

 (3)  Motor Start Option Jumper - If installed the drive requires a
      motor start command to spin up.

 (4)  Soft Sector Option
      The WREN 6 supports the use of the soft sector format as
      described in the ESDI Specification, 77738076, Section 5.4.4.

      To implement the optional soft sectored format operation, select
      "Address Mark" mode in the WREN 6 by installing option jumper
      plugs 2, 3, and 4.

 (5)  Factory use only.

 (6)  Reserved

 (7)  Special sector switch setting that can be factory configured to
      customer requirements.


 J12  Write Protect
 ------------------
 The WREN 6 has available a write protect feature that will allow the
 entire drive to be write protected. The write protection is enabled
 by connecting pins 1 and 3 on header J12, or alternately, connecting
 pin 2 of header J12 to DC ground. When the write protection is
 enabled the drive will inhibit the controller from writing to any
 cylinder or head, however the drive will still be fully capable of
 performing all other protected by responding to a Standard Status
 request (2000H) with bit 12 set to one.

 If the controller asserts WRITE GATE while the write protection is
 enabled the drive will respond with setting ATTENTION and by indicat-
 ing a write fault (setting bit one) in response to a Standard Status
 request (2000H).

 Write protection can be removed by disconnecting pin 2 of header J12
 from pin 1 or from DC ground.



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                      I   N   S   T   A   L   L
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SEAGATE  ST4766E  PRODUCT MANUAL 77765358-K

 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. Mounting with either end down (front or
 rear) is not permissible. 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.


 The WREN 6 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 6
 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 6 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.


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

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

    Each cable control 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 connected to the host controller. The length of each
 individual cable must not exceed 10 feet (3.0 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 6 Disc Drive.
 The orientation of Pin 1 of the terminator resistor matters.



 View B
    +--------------Host Controller-------------+
    |                                          |
    |Data Control   Data          Data         |
    +-+------+-------+--------------+----------+
      |      |       |              |
      |      |       |              |
      |      |       |              |
      |      +--**---+-------+------+-------+
    +++-+----+---+ +++-+-----+--+ +++-+----++-++
    ||T |        | ||T |        | ||T |    |*T||
    |+--+        | |+--+        | |+--+    +--+|
    |WREN OR ESDI| |WREN OR ESDI| |WREN OR ESDI|
    +------------+ +------------+ +------------+

    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.
   ** A maximum of 7 devices may be interconnected.


 Daisychain Configuration
 ------------------------
 A daisychain configuration connects a maximum of seven drives in
 parallel on a common control cable. Only the drive selected by the
 host system has its control signals enabled through this
 common interface. View B illustrates a daisychain of WREN 6 disk
 drives or other ESDI devices. A terminator resistor pack is required
 in the host controller for each data cable. Only the last ESDI device
 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 6 receives DC power through a 4 pin right angle connector
 mounted on the main circuit board. Recommended part number 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)


 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 back (up) side of the
 printed circuit board. The even pins are on the front (down) side of
 the printed circuit board. 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 included 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 back (up) side of the
 printed circuit board and are connected to the ground plane. The even
 pins are on the front (down) side of the printed circuit board. 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 provided, 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 6 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 6 uses the 74F38 open collector buffer/driver to
 transmit status to the host. This driver is capable of sinking a
 current of 40 mA with a low-level output voltage of 0.7 V.

 Receiver Characteristics
 The WREN 6 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. Note orientation of pin 1. 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 6 uses 8923 type balanced differential driver. An
 assertion on the interface is defined when "+" output is more
 positive than the "-" output.

 Receiver Characteristics
 ------------------------
 The WREN 6 uses 8923 type balanced differential receivers. An
 assertion 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
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SEAGATE  ST4766E  PRODUCT MANUAL 77765358-K

 Standards
 ---------
 The WREN 6 has been developed as a system peripherals to the highest
 standards of design and construction. The WREN 6 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 6 complies with Seagate standards.

 The WREN 6 is a UL Recognized component per UL478 and a CSA Certified
 Component per CSA C22.2, No. 220-M1986. It also meets the
 requirements of DIN IEC 380/VDE 0806/8.81.

 The WREN 6, as delivered, is designed for system integration before
 use. It is supplied as a sub-assembly. As such, it is not directly
 subject to the FCC Rules and Regulations, Part 15, Subpart J govern-
 ing EMI of computing devices end the Radio Interference Regulations
 of the Canadian Department of Communications.


 Media Description
 -----------------
 The media used in the WREN 6 has a diameter of approximately 5
 inches (130 mm). The aluminum substrate is coated with a thin film
 magnetic material, and lubricated to permit the heads to contact the
 surface when starting and stopping.

 Each data surface has a total of 1632 tracks (Model 94196-766) and
 is capable of recording 51,144,240 bytes of unformatted data. The
 Model 94196-383 has 1747 tracks and 54,716,04 data bytes per surface.

 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.
 WREN 6 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 6 should have, as a minimum, resident
 capabilities to recognize and map defective tracks and perform track
 reallocation routines.

 At the time of shipment from the point of manufacture, the WREN 6
 recording surfaces will meet the following requirements.

       1. 1632 (Model 94196-766) or 1747 (Model 94196-383) total
          tracks per surface.

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

       3. 50 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 6, as delivered, complies with this specification. The read
 error rate and specified storage capacity are not dependent upon use
 of defect management routines. The error rate specification does
 assume that the sectors with defect in the defect log are de-
 allocated. However, a carefully chosen defect management plan can
 significantly enhance overall system performance. Identified defects
 are recorded on the defects list tracks per Seagate ESDI
 specification. It is recommended that these known defects be
 reallocated 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
 recommended since most of the defects are recoverable with ECC. If
 ECC is not used, defects are usually unrecoverable and need to be
 reallocated as they are discovered.


 The WREN 6 defect list is written on maximum track, maximum track
 minus eigth and a special track 4095 on each surface in the format
 given in the ESDI Specification, with the write splice byte omitted
 from the format. To successfully read the drive defect list on the
 standard drive the Read Gate must be asserted only at the first bit
 of the first byte of the PLO sync field that follows the drive ISG
 field immediately following Index. Read gate should not be toggled
 and reasserted after the address field and before the data field.
 The ISG field can be determined by using the Request Configuration
 Command (code 3700H). An option is available upon customer request to
 have the defect list formatted with a write splice byte between the
 address and data fields. This would then allow for the reassertion
 of Read Gate after the address field and prior to the data field.


 Custom Formatting
 -----------------
 The WREN 6 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
 ------------------------------
 Interface signal levels and logical sense at the WREN I/O connector
 are defined as follows:

 Logic Level            Drive Output         Receiver Input
 -------------------------------------------------------------
 High (negated)  (0)      2.5 V;   5.25 V      2.0 V;   5.25 V
 Low  (asserted) (1)      0.7 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
 ---------

                                          |94196-766|94196-383
        ----------------------------------+---------+---------
        Track-to-Track         msec. typ. |   3     |   3
                               msec. max. |   4     |   4
                       Average msec. typ. |  15.5   |  17
                       Average msec. max. |  17.5   |  19
        Latency                msec. avg. |   8.33  |   8.33
        ----------------------------------+---------+---------

 Seek time is defined as the elapsed time from the receipt of a seek
 command 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 times for
 all possible movements by the total number of movements.


 Spindle Speed and Latency
 -------------------------
 The spindle speed is 3600   1% 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 16.67 milli-
 seconds based on a minimum disc speed of 3564 r/min.


 Read Data Transfer Rate
 -----------------------
 The read serial data transfer rate is 15.0 Mbits per second, 1.875
 Megabytes per second.


 Start/Stop Time
 ---------------
 The WREN 6 will become ready less than 35 seconds after application
 of DC power. Stop time will be less than 30 seconds after removal of
 DC power.

 There is no power control switch on the WREN 6.


 Power Sequencing
 ----------------
 Power sequencing is not required for the WREN 6. 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 36* F (20* C) per hour. The maximum temperature is
 derated linearly 1.8* F per 1640 feet (1* C per 500 metres). Cabinet
 packaging designs must provide ample air circulation around the WREN
 6 to ensure environmental limits are not exceeded as a result of heat
 transfer from other system components. Operating ambient is defined
 as the average temperature 0.25 inch outward from the top of the
 drive chassis at the middle of the drive (lengthwise). The
 temperature of the top cover must not exceed 140* F (60* C) when
 measured at the center of the drive.


 Heat/Power Dissipation
 ----------------------
 Each WREN 6 will dissipate no more than 27.0 watts (105.8 BTUs per
 hour) of DC power average. Typical power dissipation under idle
 operating conditions is less than 20 watts.

 Air Cleanliness
 ---------------
 The WREN 6 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.


 Front Panel
 -----------
 The WREN 6 is available with a black front panel. The panel has a
 window through wich a single red* LED shows from its mounting on the
 Main PWA. The LED, when glowing, indicates the presense of a non-
 recoverable fault. A fault indication is displayed irrespective of
 Drive Select status.

 *Green for Amber LED indicator will be available, but must be
  specified when ordering units.


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

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


