
S T 3 2 5 N    SEAGATE
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 3.5"/SLIMLINE         Cylinders        |     |     |
Capacity form/unform    21/      MB        Heads           2|     |     |
Seek time   / track  31.5/10.0 ms          Sector/track   32|     |     |
Controller           SCSI1 SINGLE-ENDED    Precompensation
Cache/Buffer             2 KB              Landing Zone
Data transfer rate    1.150 MB/S int       Bytes/Sector      512
                      1.500 MB/S ext ASYNC
Recording method     RLL 2/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C        10 50    |    -40 60
Power: sleep              W     Humidity     %         8 80    |      5 90
       standby        1.4 W     Altitude    km    -0.305  3.048| -0.305  9.144
       idle           2.4 W     Shock        g        10       |     70
       seek           7.0 W     Rotation   RPM      3600
       read/write     6.3 W     Acoustic   dBA        40
       spin-up            W     ECC        Bit   32
                                MTBF         h      50000
                                Warranty Month        12
Lift/Lock/Park     YES          Certificates     CSA,IEC380,TUV,UL478,VDE     

**********************************************************************
                        L   A   Y   O   U   T
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SEAGATE  ST325N  PRODUCT MANUAL 36144-001, REV. A

  +---------------------------------------------------------+
  |                                            1-------+J2  |
  |                                            +-------+    |XX
  |                                                     ++  |XX J1
  |                                                     ||  |XX SCSI
  |                                                     ||  |XX C
  |                                         Resistor    ++  |XX O
  |                                         Termination ++  |XX N
  |                                         Packs       ||  |XX N
  |                                                     ||  |XX E
  |                                                     ++  |XX C
  |                                                     ++  |XX T
  |                                                     ||  |XX O
  |                                                     ||  |XX R
  |                                                     ++  |
  |                                                         |XX Power
  |                                                         |XX J3
  +---------------------------------------------------------+



**********************************************************************
                      J   U   M   P   E   R   S
**********************************************************************
SEAGATE  ST325N  PRODUCT MANUAL 36144-001, REV. A

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

 J2   SCSI Bus Adress and Parity Check
 -------------------------------------
 Select the desired SCSI ID with jumpers. Install the optional
 P-jumper to enable parity.

      +-------+---------------+
      |SCSI ID| P LT  4  2  1 |  Jumpers are provided on the drive for
      +-------+---------------+  selecting the SCSI bus address. The
      |   0   | o  o  o  o  o |  microprocessor accesses this informa-
      |   1   | o  o  o  o  x |  tion at power-on. The address jumpers
      |   2   | o  o  o  x  o |  are accessed only during the power-on
      |   3   | o  o  o  x  x |  sequence. If the SCSI address is
      |   4   | o  o  x  o  o |  changed, the drive must be powered
      |   5   | o  o  x  o  x |  off and on.
      |   6   | o  o  x  x  o |
      |   7   | o  o  x  x  x |
      +-------+---------------+
                |  |
                |  +---- Life Test
                |
                +------- Parity Bit Option
                         Some host systems require parity bit checking
                         Install the P-Jumper to enable Parity


 Life Test
 ---------
 This is a test function used during the manufacturing process and is
 not recommended for field use. When the Life Test jumper is installed
 the stepper motor will continuosly seek between Track 0 and the
 maximum data cylinder and will ignore control signals sent via the
 interface.



 50-Pin SCSI Connector Pin Assignments
 -------------------------------------
    Signal    Pin No.    Signal     Pin No.
    ----------------------------------------
    -DB(0)       2       Ground       28
    -DB(1)       4       Ground       30
    -DB(2)       6       -ATN         32
    -DB(3)       8       Ground       34
    -DB(4)      10       -BSY         36
    -DB(5)      12       -ACK         38
    -DB(6)      14       -RST         40
    -DB(7)      16       -MSG         42
    -DB(P)      18       -SEL         44
    Ground      20       -C/D         46
    Ground      22       -REQ         48
    Ground      24       -I/O         50
    Terminator  26
    Power

  Note: All odd pins, except pin-25 are connected to ground. Pin-25
        is not connected.


 J3   DC Power and pin connector assignments
 -------------------------------------------
      +------------+     1 = + 12 VDC
      | 1  2  3  4 |     2 = + 12 Volts return
      +------------+     3 = +  5 Volts return
                         4 = +  5 VDC



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                      I   N   S   T   A   L   L
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SEAGATE  ST325N  PRODUCT MANUAL 36144-001, REV. A

 Notes on installation
 =====================

 Installation direction
 ----------------------

     horizontally                           vertically
   +-----------------+             +--+                       +--+
   |                 |             |  +-----+           +-----+  |
   |                 |             |  |     |           |     |  |
 +-+-----------------+-+           |  |     |           |     |  |
 +---------------------+           |  |     |           |     |  |
                                   |  |     |           |     |  |
      x           x                |  |     |           |     |  |
 +------x------x-------+           |  +-----+           +-----+  |
 +-+------x--x-------+-+           +--+                       +--+
   |       xx        |
   |     x    x      |
   +---x--------x----+
     x            x

 The drive may be mounted horizontally with the PC board down or on
 either side (edge). The drive may not be tilted front or back, in any
 position, by more than 5*.

 For optimum performance, the drive should be formatted in the same
 position as it will be mounted in the host system.


 There are 4 mounting holes on the bottom of the drive. There are no
 side mounting points on the ST325N.

 Required mounting screws:  4-40 UNC-2A.

 Warning: The mounting screws must not extend beyond the inside of the
 chassis mounting surface (or into drive mounting points) more than
 0.093-inches max.


 Mounting Screw Torque Requirements
 ----------------------------------
 Do not exceed 3 inch-Ibs.


 Shock and vibrations
 --------------------
 All shock and vibration specifications assume that the drive is moun-
 ted in an approved orientation with the input levels at the drive
 mounting screws. Shock measurements are based on a 11 msec., half-
 sine-wave shock pulse. Nonoperating specifications assume that the
 read/write heads are positioned in the shipping zone.


 Read/Write Head Auto-Park
 -------------------------
 Upon power-down, the read/write heads automatically move to the ship-
 ping zone. All portions of the head/slider assembly will park inboard
 of the maximum data cylinder.

 When power is applied, the heads will recalibrate to Track 0.


 FCC Verification
 ----------------
 The ST325N is a device intended to be contained solely
 within a personal computer or similar enclosure (not attached to
 an external device). As such, it is considered to be a subassembly
 even when individually marketed to the customer. As a subassembly, no
 Federal Communications Commission authorization, verification or
 certification of the device is required.


 Formatting and defect management
 --------------------------------
 Media defects are identified and recorded on the disc during the ma-
 nufacturing process. This defect map is used during formatting and
 enables the drive to bypass these defects. During the formatting
 operation, the controller uses the sector-slip technique to reassign
 defect sectors.


 DC Power specifications
 -----------------------
 Power may be applied/removed in any sequence without loss of data
 or damage to the drive. Typical seek currents are measured on re-
 petitive one-third stroke buffered seeks with two spindle rotations
 between each seek.

 Voltage tolerance, all conditions, including ripple:   5%.

 Typical seeking/nonseeking current and power specifications assume
 nominal voltages applied, 25* C ambient temperature, sea level and
 spindle rotating.


 Input Noise
 -----------
 Maximum permitted input noise ripple: 100 mV (peak-to-peak)
 Maximum permitted input noise: 20 MHz.

 (Measured at the host system power supply across an equivalent
 20  resistive load on the +12 V line and an equivalent 8  load on the
 +5 V line.)


 Cable specification
 -------------------
 A 50-conductor flat cable or 25-conductor twisted pair cable is
 required. The maximum cable length is 6 meters (19.7 ft). Each SCSI
 bus connection may have a 0.1 meter (0.33 ft) maximum stub length.

 The characteristic impedance for unshielded flat or twisted pair
 ribbon cable should be 100    10%. A characteristic impedance greater
 than 90  is preferred for shielded cables.
 To minimize discontinuities and signal reflections it is desirable
 to minimize the use of cables of different impedances in the same
 bus.


 Connector Requirements
 ----------------------
 The drive connector is a 50-conductor connector with two rows of 25
 male pins on 100 mil centers.

 The cable connector is a 50-conductor nonshielded connector
 consisting of two rows of 25 female contacts on 100 mil centers.
 Recommended strain-relief connectors are AMP part number 1-499506-2
 or DUPONT part number 66900-X50.



 Onboard Drive Diagnostics
 -------------------------
 At power-on the drive will execute a series of diagnostic tests. Any
 failure will be indicated by a series of LED (front panel) flashes.
 The first failure will be preserved. The drive is ready to read/write
 if no error codes are received within 22 seconds.

 +-------+---------------------------------------------------------+
 |Flashes|Failures codes                                           |
 +-------+---------------------------------------------------------+
 |   1   |Microprocessor/Internal Memory Test                      |
 +-------+---------------------------------------------------------+
 |   2   |Microprocessor ROM Checksum Test                         |
 +-------+---------------------------------------------------------+
 |   3   |Controller Chip Test                                     |
 +-------+---------------------------------------------------------+
 |   4   |Read Record ID Mark/Microprocessor RAM Test              |
 +-------+---------------------------------------------------------+
 |   5   |Data Buffer RAM Test                                     |
 +-------+---------------------------------------------------------+
 |   7   |Drive Ready Test                                         |
 +-------+---------------------------------------------------------+
 |   8   |Read Operating System Microcode From Drive               |
 |       | If the controller is unable to read the operating system|
 |       | from the drive                                          |
 +-------+---------------------------------------------------------+


 Drive formatting
 ----------------
 All Seagate SCSI interfaces drives are low-level formatted at the
 factory. You may wish to low-level format the drive to optimize its
 performance for your system. Consult the controller documentation for
 information on low-level formatting.

 Partitioning and high-level formatting can be done through DOS.



**********************************************************************
                      F   E   A   T   U   R   E  S
**********************************************************************
SEAGATE  ST325N  PRODUCT MANUAL 36144-001, REV. A

 ST325N Configuration
 --------------------
 Seagate intelligent drive feature an onboard SCSI-compatible
 controller. This embedded controller performs all of the functions
 that were previously implemented by the host-supplied controller.
 With the controller onboard, the diagnostic capabilities of the
 drive are enhanced because the controller is able to optimize drive
 performance and error recovery.

 The embedded controller supports the SCSI interface as defined in the
 ANSI X3T9.2/82-2 document. The interface hardware is capable of
 transferring up to 12 Mbits/sec. using asynchronous data transfer.
 Devices on the SCSI interface are daisy-chained together using a
 common cable. Both ends of the cable are terminated. All signals on
 the interface are common between all devices.


 Formating and Defect Management
 -------------------------------
 Because Seagate SCSI interface drives have the controller onboard,
 bad sectors are mapped out and become transparent to the user; this
 allows Seagate to specify "guaranteed megabytes" for SCSI drives and
 eliminates the requirement for a media defect specification.


 Error Recovery
 --------------
 The controller provides error recovery routines which are necessary
 to assure data integrity. These techniques include ECC, seek-retry,
 read-retry, head-offset and defect management. To assure a high de-
 gree of data reliability, the controller utilizes a 32-bit error
 checking and correction polynominal.


 RAM Buffer
 ----------
 The drive may be purchased with a standard 2K RAM Buffer or an
 optional 8K RAM buffer.

 UL/CSA Listing
 --------------
 The ST325N is listed in accordance with UL 478 and CSA C22.2
 (0-M1982), and meets all applicable sections if IEC 380 and
 VDE 0806/08.81, as tested by TUV-Rheinland, North America.


