
D 3 8 6 1    NEC
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 5.25"/HH              Cylinders     915|     |     |
Capacity form/unform   114/  134 MB        Heads           7|     |     |
Seek time   / track  20.0/ 5.0 ms          Sector/track   35|     |     |
Controller           SCSI1 SINGLE-ENDED    Precompensation
Cache/Buffer               KB              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         5 50    |    -40 60
Power: sleep              W     Humidity     %         8 80    |
       standby            W     Altitude    km            3.000|        12.000
       idle               W     Shock        g        10       |     40
       seek               W     Rotation   RPM      3573
       read/write         W     Acoustic   dBA
       spin-up            W     ECC        Bit
                                MTBF         h     300000
                                Warranty Month
Lift/Lock/Park     YES          Certificates                                  

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                        L   A   Y   O   U   T
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NEC      D3861  PRODUCT DESCRIPTION 806-520918-0 REV. A 1989

  +---------------------------------------------------------+
  |                                                         |XX
  |                                                    +-+  |XX
  |                                   Terminator ON/OFF| |  |XX
  |                                   and mode SCSI ID +-+  |XX
  |+-+                                setting switch   +-+  |XX
  || |                                Parity check ON/ | |  |XX J1
  || |                                OFF Auto Start/  +-+  |XX
  |+-+                                Inhibit          +-+  |XX
  |                                                    | |  |XX
  |                                                    +-+  |XX
  |                                                         |XX
  |                                                         |XX
  |                                                         |  1
  |                                                         |
  |                                                  XXXXXXX|Power
  +---------------------------------------------------------+J3




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                      J   U   M   P   E   R   S
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NEC      D3861  PRODUCT DESCRIPTION 806-520918-0 REV. A 1989

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

 SCSI Address Setting
 --------------------
 The SCSI address is factory-set to "0". If two or more SCSI devices
 are connected to the same SCSI bus, alter the SCSI address with the
 switch shown in the following figure.


 Optional Function Setting
 -------------------------
 This magnetic disk drive is provided with optional functions that can
 specify use or non-use of a Start/Stop Unit command, one of the SCSI
 commands, and ON/OFF of SCSI BUS parity check. This function is
 factory set so that the spindle motor starts regardless of a Start/
 Stop Unit command and the parity check is set to ON automatically
 when the power is turned on. To start the spindle motors of two or
 more drivers sequentially with a Start/Stop Unit command, alter the
 switch setting beforehand as shown in following figure.

                   + Parity
                   | +------------- START CMD
                   | | ADDR
                   | | +-+-+
   -------++-----------0-1-2--+0
    x x x || x x x x x x x x  |
   -------++---------------ON-+1
   ||
   \/
   J1 connection side

   Auto Start = 0
   Auto Start inhibit = 1

   Parity check OFF = 0
   Parity check ON = 1


 SCSI Address Option Function Setting
 ------------------------------------
 Setting of Use or Non-use of a Start/Stop Unit Command and ON/OFF of
 SCSI Parity Check.

 NOTE
 Setting of the SCSI ADDRESS switch is read during resetting or when
 power is turned on.

 NOTE
 Setting of the AUTO MOTOR START and PARITY CHECK ON/OFF switches
 becomes valid immediately after setting.

   +----------+-----------------------+
   | SCSI ID  |        ADDR.          |
   |          |   2   |   1   |   0   |
   +----------+-------+-------+-------+
   |    0     |   0   |   0   |   0   |
   +----------+-------+-------+-------+
   |    1     |   0   |   0   |   1   |
   +----------+-------+-------+-------+
   |    2     |   0   |   1   |   0   |
   +----------+-------+-------+-------+
   |    3     |   0   |   1   |   1   |
   +----------+-------+-------+-------+
   |    4     |   1   |   0   |   0   |
   +----------+-------+-------+-------+
   |    5     |   1   |   0   |   1   |
   +----------+-------+-------+-------+
   |    6     |   1   |   1   |   0   |
   +----------+-------+-------+-------+
   |    7     |   1   |   1   |   1   |
   +----------+-------+-------+-------+

   J1 connection side
    /\
    ||                         + The shaded portions denote projected
    ||                         | portions.
  +----------------+  +--------|-------+  +----------------+ ON
  |        x x x x |  |x x x x x x x x |  |x x x x x x x x |
  |x x x x         |  |                |  |                |
  +----------------+  +----------------+  +----------------+
             +------TERM. ON/OFF SWITCH------------------+



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                      I   N   S   T   A   L   L
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NEC      D3861  PRODUCT DESCRIPTION 806-520918-0 REV. A 1989

 Notes On Installation
 =====================

 The D3861 magnetic disk drive can be installed both horizontally and
 vertically. When installing the drive horizontally, be sure to
 install it with the main pronted wiring assembly faced down. (Do NOT
 face the front panel upward or downward.)

 The drive has eight mounting tap holes.

 An SCSI bus cable and power cable are required to operate the drive.
 If two or more SCSI devices are connected to the same SCSI bus cable,
 SCSI address setting and terminating resistor ON/OFF switch must be
 altered properly. The drive has a switch for accepting or rejecting
 and Auto Motor Start at power on and that for setting of ON/OFF of
 SCSI BUS parity check. These switches must be set depending on the
 operation conditions.


 Drive Configuration
 -------------------
 This magnetic disk drive consists of a disk enclosure assembly that
 contains recording disks, magnetic heads, and a magnetic head drive
 mechanism; one printed wiring assemblies; a frame; and a front panel.


 Disk Enclosure Assembly
 -----------------------
 The disk enclosure assembly contains recording disks, magnetic heads,
 a head carriage mechanism, a DC motor with encoder, and an air
 filter. An inside-hub type DC brushless motor is used as a spindle
 motor to rotate recording disks. Air can go into or come out of the
 disk enclosure assembly only through the air filter provided on the
 top cover off the assembly. The air in the assembly is therefore kept
 highly clean.


 Printed Wiring Assembly
 -----------------------
 The printed wiring assembly includes an SCSI interface circuit,
 buffer RAM, data manager, read/write control circuit, servo control
 circuit, and DC motor drive circuit to control all drive operations
 and interfaces.


 Power Supply
 ------------
 The D3861 magnetic disk drive requires +5 VDC and +12 VDC power for
 operation.


 Dimensions
 ----------
 Height     41.3 mm
 Width     101.6 mm
 Depth     157   mm
 Weight     1.0  kg or less

 NOTE
 Front plate excluded


 Interface
 ---------
 This drive has connector J1 for connection to SCSI bus and connector
 J3 for power supply. The device connected at each furthest end of the
 cable must have a terminating resistor installed. If the initiator
 and targets use different power supplies, power for terminating
 resistor of the target should be supplied through pin 26 of the SCSI
 bus.

            Single Initiator, Single Target
            -------------------------------
     Initiator                           Target
     XXXXXXX <*****SCSI*Bus************> XXXXXX



             Single Initiator, Multi Target
             ------------------------------
     Initiator                           Target
     XXXXXXX <*****SCSI*Bus************> XXXXXX
                                   :
                                   :     Target
                                   :***> XXXXXX



             Multi Initiator, Multi Target
             -----------------------------
     Initiator                           Target
     XXXXXXX <*****SCSI*Bus************> XXXXXX
                     :             :
     XXXXXXX <*******:             :     Target
     Initiator                     :***> XXXXXX


 Connetcor J1
 ------------
 A 50-pin non-shielded connector used for interface to the SCSI bus.

 Fifty-conductor flat cables and 25-signal twisted-pair cables can be
 used for the SCSI bus. Cables of impedance 100 ohms   10% 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:

    DuPont 66900-250 or equivalent (monolithic housing and pin)


 Connector J3
 ------------
 Connector J3 for power supply is an AMP P/N 350211-1 or equivalent.

 The connector housing AMP P/N 1-480424-0 of the cable suits this
 connector. Select a power cable, considering the current consumption
 and cable length into consideration. The connector pins must fit
 here.

  |+-----J3-----+   pin 1    +12 VDC
  || 4  3  2  1 |   pin 2    +12 Volts Return
  |+------------+   pin 3    + 5 Volts Return
  +---------------- pin 4    + 5 VDC



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                      F   E   A   T   U   R   E  S
**********************************************************************
NEC      D3861  PRODUCT DESCRIPTION 806-520918-0 REV. A, 1989


 Outline and Features
 --------------------
 The D3861 Magnetic Disk Drive has an unformatted storage capacity of
 134.45 megabytes with 3.75-inch magnetic disk media and mini
 Winchester magnetic heads incorporated, employing a Small Computer
 System Interface (SCSI).

 The magnetic head drive mechanism employs a DC motor with encoder,
 achieving high-speed seek and highly reliable read/write operations.
 A large capacity is also achieved with a 2-7 RLL modulation method
 adopted  for read/write operation.


 Logical Connection to SCSI Initiator
 ------------------------------------
 This drive operates as an SCSI target and has no initiator function.
 Logical connection to the SCSI initiator is executed according to the
 SCSI logical specifications.

 This drive has an arbitration function for disconnection/
 reconnection. It operates on the basis that the initiator has a
 disconnect/reconnect function, an SCSI Message Identify signal must
 be sent for a Disconnect message from the drive to indicate that the
 initiator does not have that function.

 In the non-arbitrating system, SCSI logical connection is executed
 in the information transfer phase through the selection phase, one of
 the SCSI bus phases, as a starting phase. In the arbitrating system,
 SCSI logical connection is executed in the information transfer phase
 through the arbitration phase and selection phase.


 Detecting Drive Errors
 ----------------------
 This drive has various self-diagnostic functions. It can read
 extebded sense data with a Request Sense command of the SCSI inter-
 face. You should execute a Request Sense command if an error occurs.

 Diagnoses other than for errors can be executed with a Send
 Diagnostic command. This drive supports the selftest specified with
 a Send Diagnostic command. If an error is detected, the check
 condition bit is set to "1". The detailed diagnosis result can be
 received by executing a Request Sense command.


 SCSI Interface Signals
 ----------------------
 The Unit employs a SCSI Single-Ended type interface.

 The Single-Ended type interface uses a terminal resistance of 220 /
 330 .

 The logical specification and the electrical specification of the
 signals dealt with in this section are as follows:

 1. Output Characteristics

    Signal assertion
    =0.0   0.4 VDC @ I=-48 mA
    Signal negation
    =2.5   5.25 VDC

 2. Input charateristics
    Signal true : "1"
    =0.0   0.8 VDC @ I=500  A
    Signal false : "0"
    =2.0   5.25 VDC

 3. Terminator power
    VTerm = 4.0  5.25 VDC @ I=800 mA


