
D 3 1 2 6    NEC
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 3.5"/HH               Cylinders     615|     |     |
Capacity form/unform    20/   25 MB        Heads           4|     |     |
Seek time   / track  85.0/18.0 ms          Sector/track   17|     |     |
Controller           MFM / ST506           Precompensation   128
Cache/Buffer               KB              Landing Zone      664
Data transfer rate    0.625 MB/S int       Bytes/Sector      512
                      0.625 MB/S ext
Recording method     MFM                            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| -0.300  3.600
       idle               W     Shock        g         5       |     40
       seek               W     Rotation   RPM      3564
       read/write         W     Acoustic   dBA
       spin-up            W     ECC        Bit
                                MTBF         h      20000
                                Warranty Month
Lift/Lock/Park     NO           Certificates     FCC                          

**********************************************************************
                        L   A   Y   O   U   T
**********************************************************************
NEC      D3126  PRODUCT DESCRIPTION REV. 1 806-520467  11/1986

  +---------------------------------------------------------+
  |                                                         |XX
  |                                                         |XX
  |                                                         |XX
  |                                                         |XX J2
  |                                               +-+Drive  |XX
  |                                               | |Address|
  |                                               +-+       |XX
  |                                          +-+Terminator  |XX
  |     PWB                                  | |Resistor    |XX J1
  |                                          | |ON/OFF      |XX
  |                                          | |            |XX
  |                                          +-+            |XX
  |                                                         |XX
  |                                                         |XX
  |                                          +-+            |
  |                                          +-+SG-FG    XXXXXXPower
  +---------------------------------------------------------+



**********************************************************************
                      J   U   M   P   E   R   S
**********************************************************************
NEC      D3126  PRODUCT DESCRIPTION REV. 1 11/86 806-520467

 Jumper Settings
 ===============

 Drive Address
 -------------
  +---------+
  | x . . . | ON
  | . x x x | OFF
 DS-1-2-3-4-+
    +-+-+-+
      |
      +-------- Drive Select (set only one bit to ON)

 The -Drive Select 1,2,3,4 signals are control signals used for
 logical connection between the disk controller and the disk drive to
 be accessed.

 With any one of the -DRIVE SELECT signals set to be "true", the
 interface signal of connector J1 on the disk drive that has been
 given the same number by the drive address switch is effective.

 At the time of shipment the drive address is preset to allow
 selection only when -DRIVE SELECT 1 is "true". If only one disk drive
 is connected, -DRIVE SELECT 1 can be used without change.

 If two or more disk drives are connected to a disk controller, change
 the drive address.

 +--------------+------+------+------+------+
 |Drive Address |  DS1 |  DS2 |  DS3 |  DS4 |
 +--------------+------+------+------+------+
 |      1       |  ON  |  OFF |  OFF |  OFF |
 +--------------+------+------+------+------+
 |      2       |  OFF |  ON  |  OFF |  OFF |
 +--------------+------+------+------+------+
 |      3       |  OFF |  OFF |  ON  |  OFF |
 +--------------+------+------+------+------+
 |      4       |  OFF |  OFF |  OFF |  ON  |
 +--------------+------+------+------+------+

 The front-panel LED illuminates when the disk drive is selected by
 the corresponding -DRIVE SELECT signal and is in the READY state.

 This disk drive allows functional change of control signal (connector
 J1 signal) to the Radial system.

 Changing to the Radial system is available by setting the terminator
 resistor ON/OFF switch contact "1" to ON.

 In this condition all input and output signals are effective
 independently of thge -DRIVE SELECT signal. There is no change in the
 turn-on conditions of the front-panel LED.

  SW1  Terminator Res.
  +-----------------+
  | . x x x x x x x |ON
  | x . . . . . . . |OFF  Terminator ON, means active
  +-R---------------+
    +------------------ Radial Bit, always set to OFF!


 Only the last drive on the cable must be terminated.


 J1 Connector for control signal interface
 J2  Connector for data signal interface


 Ground Interface Physical Specification
 ---------------------------------------
 At the time of shipment, Frame (FG) is connected to signal Ground
 (SG) by the SG-FG Jumper on the PWA.

 If the isolation between them is required, remove SG-FG Jumper.



**********************************************************************
                      I   N   S   T   A   L   L
**********************************************************************
NEC      D3126  PRODUCT DESCRIPTION 806-520467  11/86  REV. 1

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

 Drive mounting
 --------------

     horizontally             vertically
   +-----------------+   +--+             +--+ +------------------+
   |                 |   |  +-----+ +-----+  | |                  | x
   |                 |   |  |     | |     |  | x+----------------+x
 +-+-----------------+-+ |  |     | |     |  | ||x              x||
 +---------------------+ |  |     | |     |  | ||  x          x  ||
                         |  |     | |     |  | ||    x      x    ||
      x           x      |  |     | |     |  | ||      x  x      ||
 +------x------x-------+ |  +-----+ +-----+  | ||       xx       ||
 +-+------x--x-------+-+ +--+             +--+ ||     x    x     ||
   |       xx        |                         ||   x        x   ||
   |     x    x      |                         || x            x ||
   +---x--------x----+                         |x                x|
     x            x                           x++----------------++x
      UNACCEPTABLE!                                UNACCEPTABLE!
      Never install PC board on the Top!

 There are eight screw holes for #6-32 UNC screws.

 Terminator
 ----------
 Disk Controller land far-end D3126 requires Terminator.


 Radial Type
 -----------

     +-------------------------------------------------+----------+
     |                                                 |Data      |
     |    DISK CONTROLLER                              |Separator |
     |                                                 |          |
     +-+--------------+-------------+-------------+----+-+-+-+-+--+
       |     +--------+-------------+-------------+------+ | | |
       |     |        |      +------+-------------+--------+ | |
       |     |        |      |      |      +------+----------+ |
       |     |        |      |      |      |      |      +-----+
       |     |        |      |      |      |      |      |
       |     |        |      |      |      |      |      |
       |     |        |      |      |      |      |      |
       |     |        |      |      |      |      |      |
       |     |        |      |      |      |      |      |
     +-+-----+---+  +-+------+-+  +-+------+-+  +-+------+-+
     |J1     J2  |  |J1      J2|  |J1      J2|  |J1      J2|
     |           |  |          |  |          |  |          |
     |  D3126    |  |  D3126   |  |  D3126   |  |  D3126   |
     +----+------+  +----+-----+  +----+-----+  +----+-----+
          *--------------*-------------*-------------+
                DC POWER

 Each cable must be less than 6 m (20 feet)!


 Daisy Chain Type
 ----------------

     +-------------------------------------------------+----------+
     |                                                 |Data      |
     |    DISK CONTROLLER                              |Separator |
     |                                                 |          |
     +-+-----------------------------------------------+-+-+-+-+--+
       |     +-------------------------------------------+ | | |
       |     |               +-----------------------------+ | |
       |     |               |             +-----------------+ |
       |     |               |             |             +-----+
       |     |               |             |             |
       *-----+--------*------+------*------+------+      |
       |     |        |      |      |      |      |      |
       |     |        |      |      |      |      |      |
     +-+-----+---+  +-+------+-+  +-+------+-+  +-+------+-+
     |J1     J2  |  |J1      J2|  |J1      J2|  |J1      J2|
     |           |  |          |  |          |  |          |
     |  D3126    |  |  D3126   |  |  D3126   |  |  D3126   |
     +----+------+  +----+-----+  +----+-----+  +----+-----+
          *--------------*-------------*-------------+
                DC POWER

 Each cable must be less than 6m (20 feet)!

 Terminator resistor switch contact "2"   "8" of far-end drive must be
 ON, and any other drives must be OFF.

 Switch contact "1" is prepared for radial connection.


 Interface Cable Connector
 -------------------------
 J1 34 Pin   AMP ribbon connector P/N 88373-3
 J2 20 Pin   AMP ribbon connector P/N 88373-6
 J3 Power    AMP Mate-N-Lock P/N 350211-1
    Mate     AMP Mate-N-Lock P/N 1-480424-0


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



**********************************************************************
                      F   E   A   T   U   R   E  S
**********************************************************************
NEC      D3126  PRODUCT DESCRIPTION 806-520467 REV. 1  11/86


 Installation Procedure
 ----------------------
 Set the correct setup type and perform a low level format, in the
 most cases can the media defect list be entered in this step. If you
 cannot find a correct Setup Type use either a lower cylinder count or
 special disk installation programms like DISK MANAGER from ONTRACK or
 SPEEDSTOR from STORAGE DIMENSIONS.

 Run under DOS FDISK and DOS FORMAT, the drive becomes bootable with
 the command: FORMAT C:/s.


 General Outline and Features
 ----------------------------
 The D3126 magnetic Winchester disk drive is a random acces storage
 device with 3.75" media and mini-Winchester type magnetic heads.

 The formatted storage capacity is 20MB.


 Media Defects
 -------------
 The D3126 magnetic disk drive is checked for presense of media
 defects before shipped from the factory.

 Maximum defects allowed are 48 locations per drive, and cylinder 0
 is error free.

 Media defects are indicated by the presence of a "1" bit in bit
 position 7 of the HD byte in the ID field.


