WESTERN DIGITAL CORPORATION

WD1002A-WX1 (VER.1)

Data Bus                8-bit
Card Size               Proprietary
Hard Drives supported   Two ST-506/412(MFM) drives
Floppy drives supported None

[Image]

                                CONNECTIONS

         Function            Location         Function         Location

  34-pin control cable          J1        5-pin                   J4
  connector-hard drive                    connector-DC
                                          power

  20-pin data cable             J2
  connector-drive 0

                        USER CONFIGURABLE SETTINGS

                  Function                      Label        Position

  »   BIOS enabled                               W3           Closed

      BIOS disabled                              W3            Open

  »   I/O port address 320h                      W4          pins 2 & 3
                                                              closed

      I/O port address 324h                      W4          pins 1 & 2
                                                              closed

  »   BIOS ROM size 32K or 64K (hard-wired)      W5          pins 1 & 2
                                                              closed

      BIOS ROM size 16K                          W5          pins 2 & 3
                                                              closed

  »   8 head hard drive with RWC supported       W6          pins 2 & 3
                                                              closed

      16 head hard drive supported (head         W6          pins 1 & 2
      select 3)                                               closed

  »   Hard drive Interrupt is IRQ5               W7          pins 1 & 2
      (hard-wired)                                            closed

      Hard drive Interrupt is IRQ2               W7          pins 2 & 3
                                                              closed

  »   Single controller setting, primary         W8          pins 2 & 3
      controller                                              closed

      Dual controller setting, secondary         W8          pins 1 & 2
      controller                                              closed

  »   Factory configured - Do not alter         S1/5           Open

  »   Factory configured - Do not alter         S1/6           Open

  »   Factory configured - Do not alter         S1/7           Open

  »   Factory configured - Do not alter         S1/8           Open

                       BIOS REVISION DRIVE TYPE TABLE

  Drive1   Drive
             0

      #    S1/1     S1/2     S1/3     S1/4    Cap.   Hds   Cyls.   WP    RWC

      0    Closed  Closed   Closed   Closed    20    4     612     613   613
                                               MB

      1    Open    Closed    Open    Closed    10    2     612     128   128
                                               MB

      2    Closed   Open    Closed    Open     20    4     612     128   613
                                               MB

  »   3    Open     Open     Open     Open     10    4     306     0     306
                                               MB

  Note: S1/1 and S1/2 select the setting for drive1 & S1/3 and S1/4 select
  the setting for drive 0

                       MISCELLANEOUS TECHNICAL NOTES

            Note: This controller has a built-in low-level format
            program. To enter the program, run the DEBUG utility supplied
            with DOS and at the prompt enter: G=C800:5. Two additional
            jumpers may be present, W1 & W2, and are reserved for factory
            use and may not be changed.