
WESTERN DIGITAL CORPORATION

WD1002A-WX1

Replaced by the WD1004A-WX1

Data bus: 8-bit, PC/XT

Size: Full-length, full-height card

Hard drives supported: Two MFM ST506/412 drives

Floppy drives supported: None

Maximum heads/cyl.: 16 heads and 1024 cylinders

[Image]

                           CONNECTIONS

                  Function                        Location

  34-pin control cable connector-hard drive          J1

  20-pin data cable connector-drive 0                J2

  20-pin data cable connector-drive 1                J3

  5-pin connector-DC power                           J4

                        USER CONFIGURABLE SETTINGS

               Function                    Location           Setting

     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                W5             pins 1 & 2
      (hard-wired)                                             closed

      BIOS ROM size 16K                       W5             pins 2 & 3
                                                               closed

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

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

     x 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,              W8             pins 2 & 3
      primary controller                                       closed

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

     Not used                            S1/jumper 5           open

     Not used                            S1/jumper 6           open

     *Hard Drive Interrupt is IRQ5       S1/jumper 7           open

      *Hard Drive Interrupt is IRQ2       S1/jumper 7          closed

      *XT mode enabled                    S1/jumper 8           open

      *AT mode enabled                    S1/jumper 8          closed

  Note:* This controller can be purchased with several different BIOS
  revisions.

  These jumpers are not applicable when used with some BIOS revisions.

                BIOS REVISION "SUPER BIOS" DRIVE TYPE TABLE

      Drive     Drive
        0        1

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

  0   closed   closed    closed   closed   21MB   4     612     450   450

  1   open     closed    open     closed   10MB   4     306     0     153

  2   closed    open     closed   open     10MB   2     615     450   450

  3   open      open     open     open     21MB   4     615     450   450

                    BIOS REVISION "G" DRIVE TYPE TABLE

  #   Drive    Drive
        0        1

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

  0   closed   closed   closed  closed   20MB    4     612    none   none

  1   open     closed   open    closed   10MB    2     612    128    128

  2   closed   open     closed   open    20MB    4     612    128    none

  3   open     open     open     open    10MB    4     306     0     none

                  BIOS REVISION "H" DRIVE TYPE TABLE - S1

                    JUMPERS 3, 4, & 8 CONFIGURE DRIVE 0

                    JUMPERS 1, 2 & 7 CONFIGURE DRIVE 1

  #    S1/1 &    S1/2 &    S1/7 &    Cap.    Hds    Cyl.     WP     RWC
         3         4         8

  0   closed     closed    closed    42MB     5     977     none    none

  1    open      closed    closed    31MB     5     733     300     none

  2   closed      open     closed    33MB     6     640     none    none

  3    open       open     closed    62MB     8     1024    1024    1024

  4   closed     closed     open     42MB     6     820     none    none

  5    open      closed     open     10MB     2     612     128     128

  6   closed      open      open     20MB     4     612     128     none

  7    open       open      open     10MB     4     306      0      none

                       MISCELLANEOUS TECHNICAL NOTES

    The Super BIOS revision includes the following features not found in
       other revisions: ability to format bad tracks, dual controller
   operation, automatic configuration, virtual drive operation, and PC/AT
  compatibility. 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 must not be changed.

