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Hard Drive: IMPRIMIS: WREN III 94161-86 86MB 5.25"/FH SCSI1 SE

W R E N   I I I   9 4 1 6 1 - 8 6    IMPRIMIS
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   8
                                MTBF         h     100000
                                Warranty Month
Lift/Lock/Park     YES          Certificates     CSA,FCC,IEC380,UL478,VDE



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



Jumper setting

x = Jumpers set at factory

 3 by 5 Configuration Jumper Block

      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 |

      |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 |

x = N/A

 2 by 7 Configuration Jumper block
                         Terminator Power from Bus (horizontal)
      | o  o  o  o  o  o+-o |
      | o  o  o  o  o  x  o |
        |  +--+--+  |     +------ 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-

X = Connected
O = Not Connected



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, whetherin a factory or field environment.

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

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

    |   +--+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.



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

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 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.

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.

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

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

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