
D 3 8 8 1    NEC
                                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 3.5"/HH               Cylinders    1468|     |     |
Capacity form/unform   420/  522 MB        Heads           9|     |     |
Seek time   / track  14.0/ 4.0 ms          Sector/track   63|     |     |
Controller           SCSI1 SINGLE-ENDED    Precompensation
Cache/Buffer            32 KB LOOK-AHEAD   Landing Zone
Data transfer rate    2.365 MB/S int       Bytes/Sector      512
                      5.000 MB/S ext SYNC
Recording method     RLL 1/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C         5 50    |    -40 60
Power: sleep              W     Humidity     %         8 80    |      8 80
       standby            W     Altitude    km            3.000|        12.000
       idle               W     Shock        g        10       |     40
       seek               W     Rotation   RPM      3600
       read/write         W     Acoustic   dBA
       spin-up            W     ECC        Bit   56
                                MTBF         h      50000
                                Warranty Month
Lift/Lock/Park     YES          Certificates


**********************************************************************
                        L   A   Y   O   U   T
**********************************************************************
NEC      D3872/D3881 PRODUCT DESCRIPTION 806-521359-0 REV. 1

  +---------------------------------------------------------+
  |                                             A2+--+DSW   |XX
  |                                             A1|  |2A    |XX
  |                                             A0|  |  ++  |XX
  |                                             SC+--+  ||  |XX
  |                                                 TER3||  |XX J1
  |                                                     ++  |XX
  |                                                     ++  |XX
  |                                                     ||  |XX
  |  J9                                             TER2||  |XX
  | +---+2                                              ++  |XX
  | +---+1                                              ++  |XX
  |                                                     ||  |XX
  |                                                 TER1||  |XX
  |                                                     ++  |XX
  |12+--+6                                   JP2+++JP1      |
  |  |  |   J2                                  +++         |XX Power
  | 7+--+1                                                  |XX J3
  +---------------------------------------------------------+



**********************************************************************
                      J   U   M   P   E   R   S
**********************************************************************
NEC      D3872/D3881  PRODUCT DESCRIPTION 806-521359-0 REV. 1

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

 x = Jumper set at factory


 J1  Signal Names and Pin Arrangement of SCSI Bus
 ------------------------------------------------

    +-----------+-----+-----+-----------+--------------------+
    | Signal    | Pin | Pin | Signal    | Signal Direction   |
    | Name      | No. | No. | Name      | (Initiator -D38**) |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    |  1  |  2  | -DB (0)   |      <--- --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    |  3  |  4  | -DB (1)   |      <--- --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    |  5  |  6  | -DB (2)   |      <--- --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    |  7  |  8  | -DB (3)   |      <--- --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    |  9  | 10  | -DB (4)   |      <--- --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 11  | 12  | -DB (5)   |      <--- --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 13  | 14  | -DB (6)   |      <--- --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 15  | 16  | -DB (7)   |      <--- --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 17  | 18  | -DB (P)   |      <--- --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 19  | 20  | GROUND    |                    |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 21  | 22  | GROUND    |                    |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 23  | 24  | GROUND    |                    |
    +-----------+-----+-----+-----------+--------------------+
    | -------   | 25* | 26  | TERMPWR   |      <--- --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 27  | 28  | GROUND    |                    |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 29  | 30  | GROUND    |                    |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 31  | 32  | -ATN      |           --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 33  | 34  | GROUND    |                    |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 35  | 36  | -BSY      |      <--- --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 37  | 38  | -ACK      |           --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 39  | 40  | -RST      |           --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 41  | 42  | -MSG      |      <---          |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 43  | 44  | -SEL      |      <--- --->     |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 45  | 46  | -C/D      |      <---          |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 47  | 48  | -REQ      |      <---          |
    +-----------+-----+-----+-----------+--------------------+
    | GROUND    | 49  | 50  | -I/O      |      <---          |
    +-----------+-----+-----+-----------+--------------------+
    * Pin 25 is left open for prevention of damage in case of wrong
      insertion.



 DSW 2A  Options Function Setting
 --------------------------------
                       OFF ON
                    +--------+
   SCSI Address 2 --|1     x |
   SCSI Address 1 --|2     x |
   SCSI Address 0 --|3     x |
   Start Command  --|4     x |
                    +--------+

 The disk drive has the switch bit, which sets Use or Non-use of the
 Start/Stop Unit of the SCSI command, and the plug, which sets the
 method of using the parity check of the SCSI interface bus. When
 using it in the mode thats starts the spindle motor by receiving the
 Start Unit command, set the switch bit to "1". When shipping out the
 disk drive, the switch is set to "0", in which case the spindle motor
 is started by the disk drive itself after the power is turned on.


 JP2  Parity Check
 -----------------
 It is possible to use the plug (JP2) in setting of Use or Non-use of
 parity check of the SCSI interface bus. When shipping out the disk,
 it is set to "OFF" of the plug which applies parity check. It is
 possible to set the disk drive to Non-use of parity check by setting
 this plug to "ON". However, for the purpose of improving the system
 reliability, it is recommended that parity check applied.


 J2   SCSI Address Setting
 -------------------------
 The printed wiring assembly of this magnetic disk drive consists of
 SCSI ID address setting switch, terminating resistor ON/OFF switch
 and plug.

         +--------+--------------+----------------------------------+
         |SCSI ID | SWITCH BIT *1|       CONNECTOR PIN NO. *2       |
         |        +----+----+----+-----------+----------+-----------+
         |        | 2  | 1  | 0  |   J2-3    |   J2-2   |   J2-1    |
         +--------+----+----+----+-----------+----------+-----------+
  x      |   0    | 0  | 0  | 0  |   OPEN    |   OPEN   |   OPEN    |
         +--------+----+----+----+-----------+----------+-----------+
         |   1    | 0  | 0  | 1  |   OPEN    |   OPEN   |   GND     |
         +--------+----+----+----+-----------+----------+-----------+
         |   2    | 0  | 1  | 0  |   OPEN    |   GND    |   OPEN    |
         +--------+----+----+----+-----------+----------+-----------+
         |   3    | 0  | 1  | 1  |   OPEN    |   GND    |   GND     |
         +--------+----+----+----+-----------+----------+-----------+
         |   4    | 1  | 0  | 0  |   GND     |   OPEN   |   OPEN    |
         +--------+----+----+----+-----------+----------+-----------+
         |   5    | 1  | 0  | 1  |   GND     |   OPEN   |   GND     |
         +--------+----+----+----+-----------+----------+-----------+
         |   6    | 1  | 1  | 0  |   GND     |   GND    |   GND     |
         +--------+----+----+----+-----------+----------+-----------+
         |   7    | 1  | 1  | 1  |   GND     |   GND    |   GND     |
         +--------+----+----+----+-----------+----------+-----------+
         *1  When using the ID Address setting switch
             (Connector: "OPEN").

         *2  When using the ID Address setting connector
             (Switch: set to "0").

 The SCSI address is factory-set to "0". When using it on the system,
 change it to the setting suitable for the system.


 J2   Spindle Synchronous Operation
 ----------------------------------
 The disk drive has the spindle synchronous operation function. The
 synchronous operation is performed automatically by accepting the
 clock for spindle synchronization. The clock for synchronization is
 output to Connector J2-05, and input to J2-06. When performing the
 synchronous operation, connect J2-05 of the master disk drive with
 J2-06 of the slave disk drive, and J2-11 of the master disk drive
 with J2-12 of the slave disk drive with a cable. Set the cable length
 to 0.5 m or less.

 J9 LED LED assembly connector.
 JP1 Test mode.


 Terminating Resistor Setting
 ----------------------------
 The SCSI interface needs the terminating resistor only at both ends
 of the interface cable. The terminating resistor of the disk drive is
 packaged in the socket of Single In Line. If the terminating resistor
 of the disk drive is to be used at a location other than both ends of
 the interface cable, remove it.



**********************************************************************
                      I   N   S   T   A   L   L
**********************************************************************
NEC      D3872/D3881  PRODUCT DESCRIPTION 806-521359-0 REV. 1

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

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

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

 D3872/D3881 magnetic disk drives can be installed both horizontally
 and vertically. When installing the disk drive horizontally, be sure
 to install it with the main printed wiring assembly faced down.
 (Do not face the front panel upward or downward.)

 The disk drive has fourteen mounting tap holes. Use four or more tap
 holes suitable to install the disk drive. The frame and the disk en-
 closure assembly of the disk drive are insulated from each other by
 the shock absorber for absorbing the vibration and impact, and the
 disk enclosure assembly is connected with the signal ground of the
 printed wiring assembly by the system itself. Make sure not to
 connect the frame of the system with the disk enclosure assembly to
 improve the vibration resistance, impact resistance and lead margin.
 When installing the disk drive, also make sure to provide at least
 2.54 mm spacing around the disk enclosure part resistance and lead
 margin.


 Delivery and Handling Notes
 ---------------------------
 Handle or deliver the disk drive with care so as not subject it to
 strong shocks, vibrations, or impacts. The package case of the disk
 drive is recommended for storing or transporting the dik drive.
 Ensure that the temperature of the disk drive is the same as the
 ambient temperature before opening the package to avoid the
 possibility of condensation. Never try to open the disk enclosure
 containing magnetic disk media and heads, thus letting the magnetic
 disk media, etc. contact the outside air.


 Frame
 -----
 The disk drive has a frame which has 14 mounting holes. This frame is
 insulated from the disk enclosure assembly by the shock absorber for
 absorbing vibration and impact. When installing the system, make sure
 that the disk enclosure assembly does not contact the system frame.


 Interface
 ---------
 The disk drive has Connector J1 for logical connection to the SCSI
 bus, and Connector J3 for power supply. On this SCSI interface, the
 disk drive at each furthest end of the cable must have a terminating
 resistor installed. As the single-ended interface is employed for the
 disk drive, the maximum cable length is 6 m. If the initiator and the
 target use different power supplies, it is recommended that the
 power for terminating resistor (TERMPWR) be supplied from the
 initiator through Pin 26 of the SCSI bus.

                   Single Initiator/Single Target
        +----------------+                    +---------------+
        |   Initiator    +--------------------+    Target     |
        |                |                    |               |
        +----------------+                    +---------------+


                   Single Initiator/Multi Target
        +----------------+                    +---------------+
        |   Initiator    +-----------+--------+    Target     |
        |                |           |        |               |
        +----------------+           |        +---------------+
                                     |                |
                                     |        +---------------+
                                     +--------+    Target     |
                                              |               |
                                              +---------------+



                   Multi Initiator/Multi Target
        +----------------+                    +---------------+
        |   Initiator    +-------+---+--------+    Target     |
        |                |       |   |        |               |
        +----------------+       |   |        +---------------+
               |                 |   |                |
        +----------------+       |   |        +---------------+
        |   Initiator    +-------+   +--------+    Target     |
        |                |                    |               |
        +----------------+                    +---------------+


 Connector J1
 ------------
 A 50-pin non-shielded connector based on the SCSI standard is used as
 Connector J1 for interface to the SCSI bus. 50-Conductor Flat cable
 and 25-Single Twisted Pair cable can be used for the SCSI bus.
 Special cables of impedance 90  to 140  and conductor diameter 28 AWG
 or more should be used to match the impedance of the drive.

 Example of recommended connector on the J1 cable side:

     Du Pont 66900-250 (Monolithic housing and pin)


 Connector J3
 ------------
 Connector J3 for power supply is Burg's 8620-002 or equivalent. The
 connector housing AMP P/N 1-480424-0, which has conventionally been
 used as a connector for power supply of the small-size magnetic disk
 drive suits this connector. Select a power cable taking the disk
 drive current consumption and cable length into consideration. The
 connector pins must fit the wire.

    +---------+
    | 4 3 2 1 |
    +-+-+-+-+-+
      | | | +--------  +12 VDC
      | | +----------  +12 VDC Return
      | +------------  + 5 VDC Return
      +--------------  + 5 VDC



**********************************************************************
                      F   E   A   T   U   R   E  S
**********************************************************************
NEC      D3872/D3881  PRODUCT DESCRIPTION 806-521359-0 REV. 1

 Outline and Features
 --------------------
 The D3872/D3881 Magnetic Disk Drive has an unformatted storage
 capacity of 406/522 megabytes with a 3.75-inch magnetic disk media
 and thin-film magnetic heads incorporated, employing a Small Computer
 System Interface (SCSI).

 The magnetic head drive mechanism achieves a high-speed seek by
 employing a rotary type voice coil motor, which is controlled by the
 specialized servo-surface information. It also achieves highly
 reliable read/write operations by using the data surface servo in
 parallel. A large capacity is also achieved with a 1-7 RLL modulation
 method adopted for write operation.


 Seek Times
 ----------
    +----------------------------------+-----+
    |Track-to-Track         msec.      |   4 |
    +----------------------------------+-----+
    |               Average msec. typ. |  14 |
    +----------------------------------+-----+
    |Latency                msec. avg. | 8.33|
    +----------------------------------+-----+



 D3872 Magnetic Disk Drive
 -------------------------

    +------+-------+----------------------------+--------+
    | ITEM |Bytes/ | Format Capacity            |Sector/ |
    | No.  |Block  +---------+----------+-------+Track   |
    |      |       |MB/Drive |B/Cylinder|B/Track|        |
    +------+-------+---------+----------+-------+--------+
    |  1   |  512  | 331.463 | 225,792  | 32,256|  63+1  |
    +------+-------+---------+----------+-------+--------+
    |  2   | 1024  | 326.208 | 222,208  | 31,774|  31+1  |
    +------+-------+---------+----------+-------+--------+
    |  3   | 2048  | 315.679 | 215,040  | 30,720|  15+1  |
    +------+-------+---------+----------+-------+--------+
    "1" for the sectors/track column indicates the spare sectors per
    track.


 D3881 Magnetic Disk Drive
 -------------------------

    +------+-------+----------------------------+--------+
    | ITEM |Bytes/ | Format Capacity            |Sector/ |
    | No.  |Block  +---------+----------+-------+Track   |
    |      |       |MB/Drive |B/Cylinder|B/Track|        |
    +------+-------+---------+----------+-------+--------+
    |  1   |  512  | 426.168 | 290,304  | 32,256|  63+1  |
    +------+-------+---------+----------+-------+--------+
    |  2   | 1024  | 419.402 | 285,696  | 31,774|  31+1  |
    +------+-------+---------+----------+-------+--------+
    |  3   | 2048  | 405.873 | 276,480  | 30,720|  15+1  |
    +------+-------+---------+----------+-------+--------+
    "1" for the sectors/track column indicates the spare sectors per
    track.


 Disk Enclosure Assembly
 -----------------------
 The disk enclosure (DE) assembly contains a magnetic disk media,
 magnetic heads, a head carriage mechanism, a voice coil motor and an
 air filter. An inside-hub type DC brushless motor is used as a
 spindle motor o rotate magnetic disk media. Air can go into or come
 out of the disk enclosure assembly only through the air filter, thus
 keeping the air in the assembly highly clean.


 Printed Wiring Assembly
 -----------------------
 The printed wiring assembly includes a SCSI interface circuit, read/
 write control circuit, voice coil motor control drive circuit and
 apindle motor control drive circuit, etc. to control all disk drive
 operations and interfaces. The Busy LED, which indicates the disk
 drive operation status ba means of the front panel. (The connector
 for LED, convenient for externally installing the Busy LED, is also
 packaged on behalf of Busy LED.)


 Front Panel Option
 ------------------
 The disk drive has two type - one that has the front panel option
 which is convenient when the disk drive can be seen from the system
 outer package; another that does not have the front panel option,
 thus convenient for system integration. Choose the type that is suit-
 able for the system.


 SCSI Interface Circuit
 ----------------------
 The disk drive uses Cirrus Logic's SH-350 as the IC for SCSI inter-
 face. The interface terminating resistor of the disk drive is
 packaged in the single-in-line socket, thus making it removable.


 SCSI Interface Signals
 ----------------------
 The disk drive employs a SCSI single-ended interface. The interface
 employs 220  /330  as the terminating resistor. As the interface
 cable for the system, ensure to use those that satisfy the SCSI
 standard specification (special impedance and conductor diameter,
 etc.). The logical and electrical specifications of the signals in
 the section are described below.

     OUTPUT
     Signal Assertion = 0.0 VDC to 0.4 VDC (@ 48 mA Sink)
     Signal Negation  = 2.5 VDC to 5.25 VDC or Open Circuit

     INPUT
     Signal True      = 0.0 VDC to 0.8 VDC
     Signal False     = 2.0 VDC to 5.25 VDC



 Logical Connection SCSI Initiator
 ---------------------------------
 The disk drive operates as a SCSI target and has no initiator
 function. Logical connection to the SCSI initiator is executed
 according to the SCSI logical specifications shown in ANSI SCSI-2.
 The disk drive has an arbitration function for disconnection/re-
 connection. The disk drive automatically decides based on presense/
 absense of ID of the initiator in the Selection phase or the value
 of Bit 6 in the Identify Message whether or not to use the
 disconnect/reconnect funcion. The disk drive also has the two
 functions of Synchronous and Asynchronous transfers. The Synchronous
 transfer is decided upon by the presence/absence and contents of the
 Synchronous Data Transfer Request Message. (If the above message is
 not available, the Asynchronous transfer is supported.) In the non-
 arbitration system, SCSI logical connection is executed in the
 Information Transfer Phase through the Arbitration Phase and
 Selection Phase and completed in the Bus Free Phase. The disk drive
 also supports the Linked command. In the case of the Linked command,
 the normal termination is made by terminating the command with the
 intermediate Good at Status-Linked command complete. The Command
 Phase is this moved to receive the next command.


 Read Look Ahead Cache
 ---------------------
 The disk drive is capable of the Read Look Ahead Cache function.
 However, before the product is shipped out, it is set to mode which
 does not support Cache, by the RCD (Read Caching Disable) = 1. There-
 fore, change this by means of the Mode Select Command when using the
 Look Ahead Cache function.


 Arbitration System
 ------------------
 This system consists of the SCSI devices that have an arbitration
 funcion and makes it a precondition for them to use the disconnect/
 reconnect function. On this system, the phase is transited from the
 bus free phase to the arbitration phase, and then to the selection/
 reselection phase by a winner. Then, this is followd by the shift
 from the selection/reselection phase to various data transfer phases
 and returns to the bus free phase. As this system makes it a pre-
 condition to use the Disconnect/Reconnect function, the following
 conditions are necessary to use this system on the disk drive.

    1.   The initiator shall apply OR to its own SCSI ID in the
         Selection phase.

    2.   Transmit the Identify message that indicates that the disk
         drive is supporting the Disconnect/Reconnect by letting the
         Attention condition occur before the Command phase.



 Reliablity
 ----------
 Mean time between failures (MTBF)  50,000 POH
 Mean time to repair (MTTR)         Within 30 minutes
 Periodical maintenance             Not necessary
 Service life                       5 years or 30,000 POH whichever
                                    occurs first. Contact start/stop:
                                    up to 10,000 times.


