W R E N   I I I H H   9 4 2 1 6 - 1 0 6    IMPRIMIS
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 5.25"/HH              Cylinders    1024|     |     |
Capacity form/unform    94/  106 MB        Heads           5|     |     |
Seek time   / track  18.0/ 4.0 ms          Sector/track   34|     |     |
Controller           ESDI                  Precompensation
Cache/Buffer               KB              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          15.0 W     Shock        g         2       |     32
       seek               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,SDA,FCC,IEC380,UL478,VDE


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SEAGATE  ST2106E  PRODUCT MANUAL 77765276-E

  +---------------------------------------------------------+
  |                                      Option 1----+      |XX
  |                                      Select +----+      |XXData
  |                                      Header             |XXCable
  |                                                         |X1
  |                                                         |
  |                                                     ++  |XX
  |                                           Terminator||  |XXControl
  |                                           Resistor  ||  |XXCable
  |                                           Pack      ||  |XX
  |                                                     ++  |XX
  |                                                         |X1
  |                                                         |
  |                                                         |+-+Drive
  |                                                         || |Select
  |                                                         |+-1
  |                                                         |X1 Power
  |                                                         |XX
  +---------------------------------------------------------+



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                      J   U   M   P   E   R   S
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SEAGATE  ST2106E  PRODUCT MANUAL 77765276-E

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

 x = Jumper set at factory


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

        +------------+
        | o  o  o  o |
        | o  o  o  o |
        +------------+
          T  4  2  1 (Drive logical address
                      jumper positions)


 T = Test Seek Jumper position
 Jumper must not be installed during normal operation.

 Select           Jumper 1   Jumper 2   Jumper 4
 -------------------------------------------------
 Drive select 0   OPEN       OPEN       OPEN
 Drive select 1   CLOSED     OPEN       OPEN
 Drive Select 2   OPEN       CLOSED     OPEN
 Drive Select 3   CLOSED     CLOSED     OPEN
 Drive Select 4   OPEN       OPEN       CLOSED
 Drive Select 5   CLOSED     OPEN       CLOSED
 Drive Select 6   OPEN       CLOSED     CLOSED
 Drive Select 7   CLOSED     CLOSED     CLOSED


 Drive Select 0 is not valid!

 Drive ID is binary coded by jumper position (most significant bit on
 left), i.e., jumper in position 4 would be Drive Logical Address 4,
 no jumper means Logical Address 0, which is not a Valid Address in
 the ESDI System.

 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. Connection to
 external devices (switches, connectors, etc.) could adversely affect
 drive performance. Exact location of these pins and headers may
 change without notice.


 Option Select Header
 --------------------
 x Plug-1  CLOSED  Motor start on power up
           OPEN    Motor start with CMD

 When the jumper plug-1 is installed, 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 interface Attention line, and the Start
 Motor command in order to start the spindle motor.

 Note: This procedure is required anytime the "Power On Reset
 Condition Exists" status bit is received by the controller if the
 "Motor Control Implemented" jumper plug is installed.


 Option Select Header
 --------------------
                       Plug-2  Plug-3  Plug-4   Sectors per Track
   Fixed Sector Mode   CLOSED  CLOSED  CLOSED         64
   Select and          CLOSED  OPEN    CLOSED         36
 x Default Sector      OPEN    OPEN    CLOSED         34
   Size                OPEN    CLOSED  CLOSED         35*
                       OPEN    CLOSED  OPEN           19*

       OR

   Address Mark Mode   OPEN    OPEN    OPEN     Soft Sector Operation
   Select

 All other jumper combinations are undefined.

 * 4th Qtr. 1987. Exact date TBD.


 Soft Sector Option
 ------------------
 The WREN III supports the use of the soft sector format as described
 in the CDC ESDI Specification, 77738076, Section 5.4.4.

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


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



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                      I   N   S   T   A   L   L
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SEAGATE  ST2106E  PRODUCT MANUAL 77765276-E

 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. Horizontal mounting
 with the front raised at an angle of 15* is acceptable. Mounting with
 with either end down (front or rear) or upside down is not
 permissible. It is recommended that data written in a given orienta-
 tion be read in that same orientation.


 The WREN III HH 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 III
 HH 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 III HH will not exceed
 temperature conditions. Specific consideration should be given to
 make sure adequate air circulation is present around the PWAs 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 III HH Disc
 Drive.



 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 III HH 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).


 Service Tools
 -------------
 No special tools are required for site installation or recommended
 for site maintenance. The depot repair philosophy od WREN III HH
 precludes the necessity for special tools. If field repair of items
 external to the HDA is desired, a 6 point Torx driver is required
 (T10). It may be purchased through most commercial tools catalogs.


 DC Cable and Connector
 ----------------------
 The WREN III HH 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)


 System Ground Quick Connect Terminal
 ------------------------------------
 System ground may be connected to the Quick connect terminal.
 Recommended part numbers for this connector and the mating ground
 cable connector are listed, but equivalent parts may be used.

 Drive Connector Terminal:  AMP P/N 61664-1
 Cable Connector Terminal:  AMP P/N 62137-2


 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 front (component) side of
 the printed circuit board. The even pins are on the noncopmponent
 side of the main printed circuit board. A key slot is provided
 between pins 3 and 5. CDC 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.

 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
 Strain Relief:      3M-3448-54
 Cable:              Flat Cable (Stranded AWG 28) 3M-3365-20
                     Flat Cable (Stranded AWG 28) 3M-3517-20 (Shielded
                     Cable)
 Key:                AMP 583274-1, 3M-3439-2


 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 front (component) side of
 the main printed circuit board and are connected to the ground plane.
 The even pins are on the front noncomponent side of the printed
 circuit board. A key slot is provided between pin 3 and 5. CDC
 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 111109-3
 Strain Relief:      3M-3448-56
 Key:                AMP 583274-1, 3M-3439-2
 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 III HH 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 III HH uses the 7406 open collector hex inverter to buffer/
 driver 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 III HH uses the 74LS14 Hex Inverter with hysteresis gate as
 a line receiver. The input of each receiver is terminated in a 150ohm
 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 III HH uses 75158 or equivalent type balanced differential
 drivers. An assertion on the interface is defined when the "+" output
 is more positive than the "-" output.

 Receiver Characteristics
 The WREN III HH uses 75157 or equivalent 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  ST2106E  PRODUCT MANUAL 77765276-E

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

 The WREN III HH 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 and EN 60 950/1.1.88

 The WREN III HH, 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 end the Radio Interference Regulations of the Canadian
 Department of Communications EMI of computing devices.


 General Description
 -------------------
 The WREN III HH is a member of a family of low cost, high
 performance, highly reliable, random access storage devices designed
 to meet the needs of the OEM marketplace.

 The Head/Disc/Actuator Assembly (HDA) is environmentally sealed at
 the factory. Air is recirculated within the HDA through a nonreplace-
 able filter to maintain a contamination free disc/actuator
 environment.

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

 The WREN III HH uses 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 III HH 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 abd environmental protection.

 Each data surface has a total of 1024 tracks and is capable of
 recording 21,381,120 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 Control Data media testing and certification methods.
 WREN III HH 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 III HH 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 III
 HH recording surfaces will meet the following requirements.

       1. 1024 total tracks per surface.

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

       3. 30 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 III HH, as delivered, complies with this specification. The
 read error rate and specified storage capacity are not dependent upon
 use of 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 CDC
 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.


 Custom Formatting
 -----------------
 The WREN III HH is formatted during production. CDC 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.


 Driver/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
 ---------

        ----------------------------------+---------+
        Track-to-Track         msec. typ. |   4     |
                               msec. max. |   6     |
                       Average msec. typ. |  18     |
                       Average msec. max. |  20     |
        Max. Seek Time (1024)  msec. typ. |  35     |
                               msec. max  |  40     |
        Latency                msec. avg. |   8.34  |
        ----------------------------------+---------+

 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 3597   0.5% r/min. The speed tolerance includes
 motor performance and motor control circuit tolerances.

 The average latency time is 8.34 milliseconds, based on a nominal
 disc speed of 3597 r/min. The maximum latency time is 16.76 milli-
 seconds based on a minimum disc speed of 3579 r/min.


 Read Data Transfer Rate
 -----------------------
 The read serial data transfer rate is 10.0 Megabits per second.


 Start/Stop Time
 ---------------
 The WREN III HH will become ready less than 28 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 III HH.


 Power Sequencing
 ----------------
 Power sequencing is not required for the WREN III HH. 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* to 122* F (10* to 50* C) operating ambient with a maximum
 gradient of 18* F (10* C) per hour. Above 1000 feet (305 metres)
 altitude 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 III HH 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 III HH. The temperature of the HDA is restricted to a maximum of
 142*F (61.4* C) during operation.


 Heat/Power Dissipation
 ----------------------
 Each WREN III HH will dissipate no more than 25.0 watts of DC power
 average. Typical power dissipation under idle operating conditions is
 less than 15 watts.


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


 Front Panel
 -----------
 The WREN III HH 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 drive is selected. A
 flashing LED indicates the presense 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, including all interface timings, power supply
 voltages, and environmental conditions.

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