D K 3 1 2 C - 2 0    HITACHI
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 3.5"/HH               Cylinders    1076|     |     |
Capacity form/unform   209/      MB        Heads          10|     |     |
Seek time   / track  16.8/ 7.0 ms          Sector/track   38|     |     |
Controller           SCSI1 SINGLE-ENDED    Precompensation
Cache/Buffer            32 KB LOOK-AHEAD   Landing Zone
Data transfer rate    1.770 MB/S int       Bytes/Sector      512
                      4.000 MB/S ext SYNC
Recording method     RLL 2/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C         5 45    |    -20 60
Power: sleep              W     Humidity     %         8 80    |      8 90
       standby            W     Altitude    km                 |
       idle               W     Shock        g         3       |     40
       seek               W     Rotation   RPM      3600
       read/write         W     Acoustic   dBA
       spin-up            W     ECC        Bit
                                MTBF         h     150000
                                Warranty Month
Lift/Lock/Park     YES          Certificates                                  

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                        L   A   Y   O   U   T
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HITACHI  DK312C-20/25  PRODUCT MANUAL K2500324

  +------------------------------------------------------------+
  |                         +-J5----1 4---6                 +--+
  |                        12-------+ 3---1 JP126  JP121 1-+XXX
  22-+                                                   3-+XXX
  || |                                                +-+-+ XXX
  || |J3                                         TM117|   | XXX
  || |                                                |   | XXX
  || |                                                |   | XXX
  |+-1                                                +---+ XXX
 ++                                                         XXX J1
 ++LED                                                      XXX
  |                                                         XXX
  |                                                         XXX
  |                                                         2 1
  |                                                         +--+
  |       JP114                                            1--2|
  |   +----------------1 +------1                          |J6||
  |  26----------------+ 10-----+ JP109                   11--12
  +------------------------------------------------------------+



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                      J   U   M   P   E   R   S
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HITACHI  DK312C-20/25  PRODUCT MANUAL K2500324

 Jumper Setting
 ==============

 Jumper Plug Installation
 ------------------------
 The following jumpers are accessible to the user:

 JP114 9 14 or J6 1 6 SCSI ID setting jumper
 JP114 15 16          SCSI bus parity jumper
 JP121 1 4            Terminator power on/off
 J6 9 10              WRITE PROTECTED setting jumper
 JP114 3 4            MOTOR START/STOP setting jumper
 JP114 1 2            Look ahead cache function setting jumper
 JP126 1 6            Look ahead cache function segment setting jumper
 J6 7 8               SCSI ID POLARITY INVERTED setting jumper

 The DK312C jumpers other than listed above are installed by the
 manufacturer and must not be replaced by the user.


 JP114 SCSI ID setting jumper
 ----------------------------
  26----25 +
   +----+  + 23 26 Drive type setting jumper
   +----+  +
   +----+
  18xxxx17   17-18 Jumper plug always installed (Factory use)
   +----+    15-16 SCSI bus parity setting jumper
  14xxxx13 +                   13-14 SCSI ID 4
   +xxxx+  + 9 14 SCSI ID set  11-12 SCSI ID 2
  10xxxx9  +                    9-10 SCSI ID 1
   +----+
   +----+
   +xxxx+    3-4 MOTOR Start/Stop Option set
   2xxxx1    1-2 Look ahead cash function set.
   +----+

 SCSI ID JP114, J6
 -----------------
           Pins
   9-10 |11-12 |13-14 |SCSI ID#
  ------+------+------+---------  This table shows SCSI ID Setting
  CLOSED|CLOSED|CLOSED|SCSI ID 0  Jumpers without setting SCSI ID
  OPEN  |CLOSED|CLOSED|SCSI ID 1  Polarity inverted by the jumper plug
  CLOSED|OPEN  |CLOSED|SCSI ID 2  between J6 No. 7 and No. 8.
  OPEN  |OPEN  |CLOSED|SCSI ID 3
  CLOSED|CLOSED|OPEN  |SCSI ID 4
  OPEN  |CLOSED|OPEN  |SCSI ID 5
  CLOSED|OPEN  |OPEN  |SCSI ID 6
  OPEN  |OPEN  |OPEN  |SCSI ID 7

 SCSI ID can be set either JP114 or J6. Please avoid setting SCSI ID
 by both JP114 and J6. No jumper plug must be installed in either
 JP114 (No. 9-14) or J6 (No. 1-6).

    J6 |
  1----+2 +                 1-2 SCSI ID 1
  +----+  +    1 6 SCSI ID  3-4 SCSI ID 2
  +----+  +                 5-6 SCSI ID 4
  7----+      7- 8 SCSI ID POLARITY INVEVTED set
  +----+      9-10 Write Protected set
 11----+12   11-12 External LED terminal
  +----+        (11 o---+<----o 12)
       +--+
       +--+J2


 JP114 23-26 Drive type setting jumper
 -------------------------------------
 26+----+25        26+----+25  The drive type setting jumpers are
   +----+            +xxxx+    numbered as shown according to each
 24+----+23        24+----+23  model. These jumpers are set by the
  DK312C-25         DK312C-20  manufacturer at shipment and changing
                               the setting positions are not allowed.


 JP114 15-16 SCSI bus parity jumper
 ----------------------------------
 15-16 CLOSED  Disables SCSI bus parity
       OPEN    Enables SCSI bus parity


 JP121  Terminator Power on/off
 ------------------------------
 Pins 3-4
     CLOSED +5V source for terminator is supplied only from the SCSI
            bus.
 Pins 1-2
  x  CLOSED +5V source for terminator is supplied only from the
            drive controller.

 The jumper plug between NO.3 and 4 will not be inserted (no
 terminator provided) at shipment.

 NOTE
 Terminator power source is supplied to the terminator register
 module from the host that pulls up the SCSI interface signald in the
 controller so that the SCSI bus lines will not be pulled down when
 DK312C power is turned on.


 J6 9-10 Write Protection jumper
 -------------------------------
 9-10 CLOSED  Write protected. The disk can be only read and cannot be
              written.
 9-10 OPEN    Read or write. The disk is enabled for both read and
              write. (Shipment)


 JP114 3-4 Motor Start/Stop jumper
 ---------------------------------
 3-4 CLOSED  The motor start/stop option is not selected. The spindle
             motor is started when DK312C power is turned on.
             (Shipment)
     OPEN    The motor start/stop option is selected. The spindle
             motor can be started or stopped by using SCSI command.

 When the motor start/stop option is selected, the drive enters the
 motor stop state when its power is turned on. Use the Start/Stop Unit
 (1BH) command to start or stop the drive.

 NOTE
 When motor start/stop option is not used, the controller does not
 respond to the host about 35 sec from Power turn-on to Drive Ready.


 JP114 1-2 Look Ahead Cache Jumper
 ---------------------------------
 1-2 CLOSED The Look Ahead Cache function is not selected. The DK312C
            uses a 32 KB buffer size.
            NOTE: Sets 1 for the number of the segments when not-
            selecting the Look Ahead Cache function.
     OPEN   Selects the Look Ahead Cache function. The DK312C operates
            with the buffer size (number of the segments) specified on
            JP126.

 JP114 is set at the factory not to select the Look Ahead Cache
 function. Setting the Look Ahead Cache function operates immediately
 after turning on the power.
 Use the MODE SELECT (15) command to execute or stop this function.


 JP126 1 6 Look Ahead Cache function
 -----------------------------------
   +---+
  3|o o|4   Sets 1 for the number of the Look Ahead Cache function
  2|x x|5   segments. The unit uses a 32KB buffer size.
  1|X X|6
   +---+
   +---+
  3|o X|4   Sets 2 for the number of the Look Ahead Cache function
  2|x x|5   segments. The unit uses a 16KB buffer size.
  1|X o|6
   +---+
   +---+
  3|x x|4   Sets 4 for the number of the Look Ahead Cache function
  2|X X|5   segments. The unit uses a 8KB buffer size.
  1|o o|6
   +---+

 The terminator of the DK312C other than the last drive of SCSI Daisy
 Chain MUST be removed.

 Number of the Look Ahead Cache function segments is set to 1 at the
 factory.

 NOTE
 The jumper setting for Look Ahead Cache function has priority to the
 Mode Select (15) command. When changing the jumper setting, re-issue
 the Mode Select (15) command to match the command to the number of
 the segments.


 J6 7-8 SCSI ID Polarity Inverted setting jumper
 -----------------------------------------------
 7-8 OPEN            Pins (JP114, J6)
          ID 1 | ID 2 | ID 4 |SCSI ID#
         ------+------+------+---------
         CLOSED|CLOSED|CLOSED|SCSI ID 0
         ------+------+------+---------
         OPEN  |CLOSED|CLOSED|SCSI ID 1
         ------+------+------+---------
         CLOSED|OPEN  |CLOSED|SCSI ID 2
         ------+------+------+---------
         OPEN  |OPEN  |CLOSED|SCSI ID 3
         ------+------+------+---------
         CLOSED|CLOSED|OPEN  |SCSI ID 4
         ------+------+------+---------
         OPEN  |CLOSED|OPEN  |SCSI ID 5
         ------+------+------+---------
         CLOSED|OPEN  |OPEN  |SCSI ID 6
         ------+------+------+---------
         OPEN  |OPEN  |OPEN  |SCSI ID 7


 7-8 CLOSED          Pins (JP114, J6)
          ID 1 | ID 2 | ID 4 |SCSI ID#
         ------+------+------+---------
         CLOSED|CLOSED|CLOSED|SCSI ID 7
         ------+------+------+---------
         OPEN  |CLOSED|CLOSED|SCSI ID 6
         ------+------+------+---------
         CLOSED|OPEN  |CLOSED|SCSI ID 5
         ------+------+------+---------
         OPEN  |OPEN  |CLOSED|SCSI ID 4
         ------+------+------+---------
         CLOSED|CLOSED|OPEN  |SCSI ID 3
         ------+------+------+---------
         OPEN  |CLOSED|OPEN  |SCSI ID 2
         ------+------+------+---------
         CLOSED|OPEN  |OPEN  |SCSI ID 1
         ------+------+------+---------
         OPEN  |OPEN  |OPEN  |SCSI ID 0


 SCSI ID can be set either JP114 or J6. Please avoid setting SCSI ID
 by both JP114 and J6. No jumper plug must be installed in either
 JP114 (No. 9-14) or J6 (No. 1-6).