
WESTERN DIGITAL CORPORATION

WD286-WDM20

Processor               80286
Processor Speed         12.5MHz
Chip Set                Faraday
Max. Onboard DRAM       4MB
Cache                   None
BIOS                    AMI
Dimensions              330mm x 218mm
I/O Options             Parallel port, serial ports (2), bus mouse port,
                        floppy drive interface, ST506/412 interface, video
                        interface, IDE interface
NPU Options             80287

[Image]

                                CONNECTIONS

  Purpose                   Location    Purpose                 Location

  IDE interface                J5       Floppy drive               J16
  (optional)                            interface

  Hard drive access LED       J10       ST506/412 drive            J17
                                        control

  Reset switch                J11       Serial port 1              J19

  ST506/412 data (Drive       J12       Serial port 2              J20
  0)

  ST506/412 data (Drive       J13       Video interface            J21
  1)

  Power LED & keylock         J14       PS/2 mouse port            J22

  Parallel port (LPT1)        J15       Speaker                    J24

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Factory configured - do not alter      W4 & W6           Open

     Factory configured - do not alter        W7             Closed

     Floppy drive interrupt enabled           W8             Closed
      (IRQ6)

      Floppy drive interrupt disabled          W8              Open
      (IRQ6)

     Keyboard select AT compatible            W12             Open
      (101 key)

      Keyboard select XT compatible (83        W12            Closed
      key)

     Video port interrupt enabled             W13            Closed
      (IRQ9)

      Video port interrupt disabled            W13             Open
      (IRQ9)

     Mouse port interrupt enabled             W17            Closed
      (IRQ12)

      Mouse port interrupt disabled            W17             Open
      (IRQ12)

     Parallel port interrupt enabled          W19            Closed
      (IRQ7)

      Parallel port interrupt disabled         W19             Open
      (IRQ7)

     Serial port 2 interrupt enabled          W20            Closed
      (IRQ3)

      Serial port 2 interrupt disabled         W20             Open
      (IRQ3)

     Serial port 1 interrupt enabled          W21            Closed
      (IRQ4)

      Serial port 1 interrupt disabled         W21             Open
      (IRQ4)

     Video port NMI enabled                   W23            Closed

      Video port NMI disabled                  W23             Open

     Video port data buffering enabled        W24           pins 1 & 2
                                                              closed

      Video port data buffering                W24           pins 2 & 3
      disabled                                                closed

     Video port enabled                       W25            Closed

      Video port disabled                      W25             Open

              DRAM CONFIGURATION

      Size          Bank 0          Bank 1

      1MB         (2) 256K x 9   (2) 256K x 9

      2MB         (2) 1M x 9         NONE

      4MB         (2) 1M x 9      (2) 1M x 9

      8MB         (2) 4M x 9         NONE

      10MB        (2) 1M x 9      (2) 4M x 9

      16MB        (2) 4M x 9      (2) 4M x 9

                            VIDEO CONFIGURATION

       Type         S1/1      S1/2     S1/3     S1/4      S1/5      W18

    Monochrome       Off      Off       On       Off      Off      1 & 2

  CGA-40 columns     On       Off       Off      On       Off      2 & 3

  CGA-80 columns     Off      Off       Off      On       Off      2 & 3

  EGA-200 lines      On        On       On       Off      Off      2 & 3

    EGA-350/480      Off       On       On       Off      Off      2 & 3
      lines

  Note: Pins designated should be in the closed position.

                         HARD DRIVE CONFIGURATION

      Type             W3            W5            W10           W22

    ST506/412        Closed        Closed         Open           Open

       IDE            Open          Open         Closed         Closed

  Expansion card      Open          Open          Open           Open

  Note:An expansion card hard drive controller may be used in addition to
  the ST506/412 with the ST506/412 Settings.

