WESTERN DIGITAL CORPORATION
===========================

   WD1002S-WX2A

   +------------------------------------------------------------+
   +------------------------------------------------------------+

   Data bus: 8-bit, PC/XT

   Size: Full-length, full-height card

   Hard drives supported:  Two MFM ST506/412 drives

   Floppy drives supported: None

<gopher://bitreich.org/I/th99/c/U-Z/20219-1.png>
   

   +------------------------------------------------------------+
   |                        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      |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |            Function            |   Location   |  Setting   |
   |--------------------------------+--------------+------------|
   |>> | Not used                   |   W1 & W2    |    N/A     |
   |---+----------------------------+--------------+------------|
   |>> | 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 size 32K or 64K       |      W5      | pins 1 & 2 |
   |   |                            |              |   closed   |
   |---+----------------------------+--------------+------------|
   |   | BIOS size 16K              |      W5      | pins 2 & 3 |
   |   |                            |              |   closed   |
   |---+----------------------------+--------------+------------|
   |>> | 16 head hard drive         |      W6      | pins 1 & 2 |
   |   | supported (Head Select 3)  |              |   closed   |
   |---+----------------------------+--------------+------------|
   |   | 8 Head hard drive with RWC |      W6      | pins 2 & 3 |
   |   | supported                  |              |   closed   |
   |---+----------------------------+--------------+------------|
   |>> | Hard Drive Interrupt is    |      W7      | pins 1 & 2 |
   |   | IRQ5                       |              |   closed   |
   |---+----------------------------+--------------+------------|
   |   | Hard Drive Interrupt is    |      W7      | pins 2 & 3 |
   |   | IRQ2                       |              |   closed   |
   |---+----------------------------+--------------+------------|
   |>> | Factory setting            |      W8      | pins 2 & 3 |
   |   |                            |              |   closed   |
   |---+----------------------------+--------------+------------|
   |   | CO23 setting               |      W9      | pins 1 & 2 |
   |   |                            |              |   closed   |
   |---+----------------------------+--------------+------------|
   |>> | Standard Configuration     |     W10      | pins 2 & 3 |
   |   |                            |              |   closed   |
   |---+----------------------------+--------------+------------|
   |   | Special feature            |     W10      | pins 1 & 2 |
   |   |                            |              |   closed   |
   |---+----------------------------+--------------+------------|
   |>> | Factory configured - do    | SW1/jumper 5 |    open    |
   |   | not alter                  |              |            |
   |---+----------------------------+--------------+------------|
   |>> | Factory configured - do    | SW1/jumper 6 |    open    |
   |   | not alter                  |              |            |
   |---+----------------------------+--------------+------------|
   |>> | Hard Drive Interrupt is    | SW1/jumper 7 |    open    |
   |   | IRQ5                       |              |            |
   |---+----------------------------+--------------+------------|
   |   | Hard Drive Interrupt is    | SW1/jumper 7 |   closed   |
   |   | IRQ2 (JP7/pins 2-3 must be |              |            |
   |   | closed and a custom BIOS   |              |            |
   |   | must be install)           |              |            |
   |---+----------------------------+--------------+------------|
   |>> | AT mode enabled            | SW1/jumper 8 |   closed   |
   |---+----------------------------+--------------+------------|
   |   | XT mode enabled            | SW1/jumper 8 |    open    |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |        BIOS REVISION "SUPER BIOS" DRIVE TYPE TABLE         |
   |------------------------------------------------------------|
   |   |Drive 1|Drive 0|      |      |     |    |     |         |
   |---+-------+-------+------+------+-----+----+-----+---------|
   | # | SW1/1 | SW1/2 |SW1/3 |SW1/4 |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 1|Drive 0|      |      |     |     |     |         |
   |--+-------+-------+------+------+-----+-----+-----+---------|
   |# | SW1/1 | SW1/2 |SW1/3 |SW1/4 |Cap. |Hds. |Cyl. | WP |RWC |
   |--+-------+-------+------+------+-----+-----+-----+----+----|
   |0 |closed |closed |closed|closed|20MB |  4  | 612 | 0  |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             |
   |                                                            |
   |          JUMPERS 3, 4, &AMP; 8 CONFIGURE DRIVE 0           |
   |                                                            |
   |           JUMPERS 1, 2 &AMP; 7 CONFIGURE DRIVE 1           |
   |------------------------------------------------------------|
   |# |SW1/1 & 3|SW1/2 & 4|SW1/7 & 8|Cap. |Hds |Cyl. | WP  |RWC |
   |--+---------+---------+---------+-----+----+-----+-----+----|
   |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                |
   |------------------------------------------------------------|
   |  This controller can be purchased with several different   |
   |    BIOS revisions. 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.           |
   +------------------------------------------------------------+