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Hard Drive: IMPRIMIS: WREN VIHH 94241-383 337MB 5.25"/HH SCSI1 SE

W R E N   V I H H   9 4 2 4 1 - 3 8 3    IMPRIMIS
NO MORE PRODUCED                                      Native|  Translation
Form                 5.25"/HH              Cylinders    1261|     |     |
Capacity form/unform   337/  383 MB        Heads           7|     |     |
Seek time   / track  14.0/ 3.0 ms          Sector/track     |     |     |
Controller           SCSI1 SINGLE-ENDED    Precompensation
Cache/Buffer            32 KB              Landing Zone
Data transfer rate    2.750 MB/S int       Bytes/Sector      512
                      4.700 MB/S ext SYNC
Recording method     RLL 1/7                        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          16.0 W     Shock        g         2       |     40
       seek          20.0 W     Rotation   RPM      3600
       read/write         W     Acoustic   dBA
       spin-up            W     ECC        Bit
                                MTBF         h     100000
                                Warranty Month
Lift/Lock/Park     YES          Certificates     CSA,SDA,FCC,IEC380,IEC435,...


SEAGATE ST2383N/2502N PRODUCT MANUAL 77765414-C (12-91)

  |                                                      || |Drive
  |                                                      || |Select/
  |                                                      |+-+Option
  |                                                 +-1  |XX
  |                                                 | |  |XX SCSI
  |                                                 +-+  |XX Interface
  |                                      Resistor   +-1  |XX J3
  |                                      Terminator | |  |XX
  |                                      Packs      +-+  |XX
  |                                                 +-+  |XX
  |                                                 | |  |XX
  |                                                 +-1  |XX
  |                                                      |
  |                                                      |XX Power
  |                                                      |XX


SEAGATE ST2383N/2502N PRODUCT MANUAL 77765414-C (12-91)

Jumper setting

  SCSI ID/Option Select Header
           | o  o  o  o  o  o  o  o  o  1 |
           | o  o  o  o  o  o  o  o  o  o |
            (6)(6)(6)(3)(2) 4  2  1  TP TP

      |            | 4  2  1  |
      +------------+----------+  Drive ID in binary coded jumper
      |SCSI ID = 0 | o  o  o  |  position (most significant bit on
      |            | o  o  o  |  left), i.e., jumper in position 1
      +------------+----------+  would be Drive ID 1, no jumpers means
      |SCSI ID = 1 | o  o  x  |  ID 0.
      |            | o  o  X  |
      |SCSI ID = 2 | o  x  o  |
      |            | o  X  o  |
      |SCSI ID = 3 | o  x  x  |
      |            | o  X  X  |
      |SCSI ID = 4 | x  o  o  |
      |            | X  o  o  |
      |SCSI ID = 5 | x  o  x  |
      |            | X  o  X  |
      |SCSI ID = 6 | x  x  o  |
      |            | X  X  o  |
      |SCSI ID = 7 | x  x  x  |
      |            | X  X  X  |

 (2)  CLOSED  Enables the Motor Start Option. In this mode of
              operation the drive will wait for a Start Unit Command
              from the Host before starting the Motor.
      OPEN    The motor will start as soon as DC power is applied
              to the unit.

(3) CLOSED Parity checking by the WREN 6HH is enabled.

 (4)  If the unit is not be terminated, remove terminator resistor
      module SIPs. If installed, the TP jumper must be installed in
      either Position 1 or Position 3 as indicated.
                                      Position 2
           | o  o  o  o  o  o  o  o  X  X-+--Position 1
           | o  o  o  o  o  o  o  o  XxxX |
            (6)(6)(6)(3)(2) 4  2  1  TP|TP
                                       +-------Position 3

 With jumper in Position 1, terminator power (+5V) is taken from WREN
 6HH power connector.
 With jumper in Position 2, terminator power is supplied to the
 interface cable by the WREN 6 through an isolation diode and fuse
 With the jumper in Position 3, terminator power is taken from the
 interface cable Pin 26 through a fuse.

If the drive is not terminated, the TP jumper in position 1 need not
be installed.

(6) Factory use only (8,9) and (10) reserved jumper position.

(7) ON Entire drive is write protected.

 (8)  Jumper on enables delayed motor start (Motor Start jumper (2)
      must be off). Motor start up is delayed 16 times drive ID number
      in seconds; i.e., Drive 0 starts immediately, Drive 1 starts 16
      seconds later, Drive 2 starts 16 seconds after Drive 1, etc.
      No Motor Start command is needed to start drives with this
      jumper on.

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

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


SEAGATE ST2383N/ST2502N PRODUCT MANUAL 7776514-C (12-91)

Notes on installation

Drive Orientation
The balanced rotary arm actuator design of the Wren 6 HH allows it to
be mounted in any orientation. All drive performance characterization
however, has been done with the drive in horizontal (disc level) and
vertical (drive on its side) orientations, and these are the two
preferred mounting orientations.

WREN 6 HH 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 6 HH into an OEM's
system, whetherin a factory or field environment.

Mounting Holes
Mounting Holes (6-32 UNC-2B). Four on bottom, four on each side. Max.
screw length into chassis 0.125 in. (3.17 mm).

Cabinet cooling must be designed by the customer so that the ambient
temperature immediately surrounding the WREN 6 HH will not exceed
temperature conditions.

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

Physical Description
Model ST2383N/502N WREN may be chained together or with other
compatible SCSI devices using a common cable. Both ends of the cable
must be terminated. The WREN 6HH implements single ended drivers and
receivers, which allow a maximum cable length of six metres
(primarily for connection within a cabinet). All signals are common
between all SCSI devices. The Model ST2383N/502N WREN 6HH 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 terminated. Intermediate SCSI devices shall not be
terminated. Remove the terminator resistor packs, not the terminator
power source selector jumper.

Cable Requirements
Only nonshielded 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 metre
is allowed off the mainline interconnection within any connected
equipment. An ideal impedance match with cable terminators implies a
cable characteristic impedance of 132 ohm (single ended option). In
general, cables with this high of a characteristics impedance are not
available; however, impedances that are somewhat lower are satis-
factory. A characteristic impedance of 100 ohm 10% is recommended
for unshielded flat or twisted pair ribbon cable. However, most
available cables have a somewhat lower characteristic impedance. To
minimize discontionuities and signal reflections, cables of different
impedances should not be used in the same bus. Implementations may
require trade-offs in shielding effectiveness, cable length, the
number of loads, transfer rates, and cost to achieve satisfactory
system operation. If shielded and unshielded cables are mixed within
the same SCSI bus, the effect of impedance mismatch must be carefully

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

Suggested 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
constisting of to rows of 25 female contacts with adjacent contacts
100 mils apart.

Recommended Mating Flat Cable Connector Part Numbers are:

Closed end 3M-3425-7000 W/O Strain Relief, No Center Key
(for cable 3M-3425-7050 With Strain Relief, No Center Key
ends) Dupont-66900-290 With Strain Relief, With Center Key

Open end 3M-3425-6000 W/O Strain Relief, No Center Key
(In Daisy- 3M-3425-6050 With Strain Relief, No Center Key
chain) Dupont-66900-250 With Strain Relief, With Center Key

The Model ST2383N/502N WREN 6HH device connector is a nonshielded 50
conductor connector consisting of two row of 25 male pins with
adjacent pins 100 mils apart. The connector is keyed.

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

    |       +--+ HOST ADAPTER/INITIATOR ***    |
    |       |T |                               |
             |                1 thru 8 SCSI devices
           **|             **|              |*
    +--------+---+ +---------+--+ +--------++-++
    |WREN        | |WREN        | |WREN    | T||
    |or other    | |or other    | |or other+--+|
    |SCSI device | |SCSI device | |SCSI device |
    +------------+ +------------+ +------------+

 *    Closed end type connector used
 **   Open type (in-line application) Connector used.
 ***  Host need not beon the end of the daisy chain. Another device
      can be on the end with the terminator, the host having no

T indicates termination required.

DC Cable and Connector
The WREN 6 HH receives DC power through a 4 pin right angle connector
mounted on the servo PWA. Recommended part number for the
mating connector are listed below, 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 ST2383N/502N WREN 6HH are
 single ended and must be terminated with 220 ohm to +5 V and 330 ohm
 to ground at each end of the total cable. All signals use open
 collector or three state drivers. Optional termination is available
 internal to the WREN 6HH.

Single Ended Drivers/Receivers
Single ended drivers and receivers are used by the WREN 6HH.

Transmitter Characteristics
The WREN 6HH 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 6HH uses a ANSI SCSI single ended receiver with hysteresis
gate or equivalent as a line receiver.

Terminator Requirements
Internal WREN 6HH I/O termination consist of three resistor modules
which plug into sockets on the Main PWA. The WREN 6HH may be ordered
with or without these termination resistors to facilitate a
particular application. All single initiator/single target (non-
daisychain) applications require that the Initiator and WREN 6HH be
terminated. Daisychain applications require that only the unit at
each end of the daisychain be terminated. All other peripherals on
the chain should not be terminated.
Note: Remove terminator resistor packs where terminators are not
required. Removal of terminator power source selection jumper does
not disconnect the terminator resistor from the circuit.

Drive Termination
This option may be incorporated during manufacture at the request of
the customer. Termination consists of three 220/330 ohm Sip
resistor modules which are installed on the Main PWA via sockets. The
user may install or remove these as desired.

Terminator Power
The WREN 6HH may be configured to power the internal termination
resistors via Pin 26 of the SCSI bus or via the wREN 6HH power
connector. Termination power may also be supplied to Pin 26 of the
SCSI bus through an isolation diode and fuse network.

Single ended SCSI devices providing termination power (TERMPWR) shall
have the following characteristics:

     V TERM = 4.0V to 5.25V
     800 mA min source drive capability
     1.0 A maximum


SEAGATE ST2383N/2502N PRODUCT MANUAL 77765414-C (12-91)

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

The WREN 6HH is a UL Recognized component per UL 478 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, DIN IEC 435/VDE 0805/11.84
and EN 60950/09.87.

The WREN 6HH product as delivered, is designed for system integration
and installation into a suitable enclosure prior to use. As such, the
WREN 6HH is supplied as a sub-assembly and is not subject to Subpart
J of Part 15 of the FCC Rules and Regulations nor the Radio
Interference Regulations of the Canadian Department of
Communications. However, the unit has been tested using proper
shielding and grounding and found to be compliant with the Class A
limits of the FCC Rules and the Regulations of the Canadian Depart-
ment of Communications.

The physical design characteristics of the WREN 6HH serve to minimize
radiation when installed in an enclosure that provides reasonable
shielding. As such, the WREN 6HH is capable of meeting the Class B
limits of the FCC Rules and the Regulations. of the Canadian
Department of Communications. However, it is the end user's
responsibility to assure that the WREN 6HH meets the appropriate EMI
requirements in their system. Shielded I/O cables may be required if
the enclosure does not provide adequate shielding. If I/O cables are
external to the enclosure, shielded cables should be used, with the
shields grouned to the enclosure and to the host controller.

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

The WREN 6HH 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 6HH 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 6HH decodes Track 0 location from the dedicated servo
surface thereby eliminating mechanical transducer adjustments and
related reliability concerns.

The WREN 6HH 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 on the WREN 6HH 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 6HH, 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 (initiator).

Defect and error management in the SCSI system involves WREN 6HH
internal defect/error management and SCSI systems error
considerations (errors in communications between Initiator and WREN
6HH). Tools for use in designing a defect/error management plan are
briefly outlined in this section, with references to other sections
where further details are given.

WREN 6HH Internal Defects/Errors
Identified defects are recorded on the WREN 6HH defects list tracks
(referred to as the promary or ETF defect list). It is recommended
that these known defects be reallocated during the initial WREN 6HH
format operation. The WREN 6HH internal retries and data correction
by ECC should be enabled to recover data from additional flaws if
they occur. If data correction by ECC is required to recover data,
the host should immediately reallocate this sector by use of the
Reassign Blocks command. If the WREN 6HH automatic retries and data
correction by ECC features are not used, defects are usually un-
recoverable and need to be reallocated as they are diacovered. For
reallocation of bad sectors, the number of spare sectors per track or
cylinder and the number of spare tracks per volume is programmable.
After formatting, defects can be automatically reallocated by the
WREN 6HH, or can be reallocated when the host sends the Reassign
Blocks Command.

Seek Time

        Track-to-Track         msec. typ. |   3     |    3    |
                               msec. max. |   5     |    5    |
                       Average msec. typ. |  14     |   16    |
                       Average msec. max. |  16     |   18    |
        Full Stroke            msec. typ. |  24     |   33    |
                               msec. max. |  28     |   38    |
        Latency                msec. avg. |   8.33  |    8.33 |

Read Look-Ahead/Cache Control
The WREN 6HH Model ST2383N/502N provides a Read Look-ahead multi-
segmented cache control algorithm which can in may cases enhance
system performance. This feature may be selected by issuing a Mode
Select Command with the proper values in the applicable bytes in page

Power Sequencing
Power sequencing is not required for the WREN 6HH. The WREN 6HH
protects against inadvertent writing during power up and down.
Daisychain operation requires that power be maintained on the
terminated WREN 6HH to ensure proper termination of the peripheral
I/O cables.

Start/Stop Time
After DC power has been applied, the WREN 6HH will become ready
within 20 seconds if the Motor Start Option is disabled. During this
time, the drive will respond to the SCSI interface. Stop time will be
less than 25 seconds from removal of DC power.

If the Motor Start Option is enabled, the internal controller will
accept the commands three seconds after DC power has been applied.
After the Motor Start Command has been received the WREN 6HH will
become ready for normal operations within 18 seconds. During this
time the drive will respond to the SCSI interface in accorance with
the rules for Command Queing.

The drive will meet all specifications over a 50*F to 122*F (10*C to
50*C) ambient temperature range with a maximum gradient of 36*F
(20*C) per hour. The enclosure for the drive should be designed such
that the temperatures at the locations are not exceeded. A small
amount of air flow may be needed to achieve these temperature values.

Air Cleanliness
The WREN 6HH is designed to operate in a typical office environment
with minimal environmental control.

The following reliability specifications assume correct host/drive
operational interface, including all interface timings, power supply
voltages, environmental conditions, and appropriate data handling
circuit to the host system.

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

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