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

   WD1007A-WA4

   Data Bus                16-bit                                 
   Card Size               Full-length, full-height card          
   Hard Drives supported   Two ESDI drives                        
   Sector Interleave       1:1                                    
   Floppy drives supported Two 360KB or 720KB drives              

<gopher://bitreich.org/I/th99/c/U-Z/21201-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   |        Function         | Function |                       |
   |-------------------------+----------+-----------------------|
   | 4-pin connector-drive   |    J1    | 34-pin data      | J5 |
   | active LED              |          | cable            |    |
   |                         |          | connector-floppy |    |
   |                         |          | drive            |    |
   |-------------------------+----------+------------------+----|
   | 20-pin data cable       |    J2    | 9-pin serial     | J6 |
   | connector-drive 1       |          | port - external  |    |
   |-------------------------+----------+------------------+----|
   | 20-pin data cable       |    J3    | 25-pin parallel  | J7 |
   | connector-drive 0       |          | port - external  |    |
   |-------------------------+----------+------------------+----|
   | 34-pin data cable       |    J4    |                  |    |
   | connector-controller    |          |                  |    |
   | board                   |          |                  |    |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                USER CONFIGURABLE SETTINGS                  |
   |------------------------------------------------------------|
   |              Function               |   Label   | Position |
   |-------------------------------------+-----------+----------|
   |>> | Primary floppy address 3FX      | W1/pins 1 |  closed  |
   |   |                                 |    & 2    |          |
   |---+---------------------------------+-----------+----------|
   |   | Floppy controller disabled      | W1/pins 2 |  closed  |
   |   |                                 |    & 3    |          |
   |---+---------------------------------+-----------+----------|
   |   | Secondary floppy address 37X    | W1/pins 3 |  closed  |
   |   |                                 |    & 4    |          |
   |---+---------------------------------+-----------+----------|
   |>> | Primary hard disk address 1FX   | W2/pins 1 |  closed  |
   |   |                                 |    & 2    |          |
   |---+---------------------------------+-----------+----------|
   |   | Secondary hard disk address 17X | W2/pins 2 |  closed  |
   |   |                                 |    & 3    |          |
   |---+---------------------------------+-----------+----------|
   |>> | Primary parallel port address   | W3/pins 1 |  closed  |
   |   | 37X                             |    & 2    |          |
   |---+---------------------------------+-----------+----------|
   |   | Parallel port disabled          | W3/pins 2 |  closed  |
   |   |                                 |    & 3    |          |
   |---+---------------------------------+-----------+----------|
   |   | Secondary port address 27X      | W3/pins 3 |  closed  |
   |   |                                 |    & 4    |          |
   |---+---------------------------------+-----------+----------|
   |>> | Primary serial port address 3FX | W4/pins 1 |  closed  |
   |   |                                 |    & 2    |          |
   |---+---------------------------------+-----------+----------|
   |   | Serial port disabled            | W4/pins 2 |  closed  |
   |   |                                 |    & 3    |          |
   |---+---------------------------------+-----------+----------|
   |   | Secondary serial port address   | W4/pins 3 |  closed  |
   |   | 2FX                             |    & 4    |          |
   |---+---------------------------------+-----------+----------|
   |>> | Digital input register,         |    W9     |   open   |
   |   | non-latched                     |           |          |
   |---+---------------------------------+-----------+----------|
   |   | Digital input register, latched |    W9     |  closed  |
   |---+---------------------------------+-----------+----------|
   |>> | WD 1007 mode                    | W16/pins  |   open   |
   |   |                                 |   1 & 2   |          |
   |---+---------------------------------+-----------+----------|
   |   | WD 1005 mode                    | W16/pins  |  closed  |
   |   |                                 |   1 & 2   |          |
   |---+---------------------------------+-----------+----------|
   |>> | Translation enabled             | W16/pins  |   open   |
   |   |                                 |   3 & 4   |          |
   |---+---------------------------------+-----------+----------|
   |   | Translation disabled            | W16/pins  |  closed  |
   |   |                                 |   3 & 4   |          |
   |---+---------------------------------+-----------+----------|
   |>> | ECC correction, 4 bytes         | W16/pins  |   open   |
   |   |                                 |   5 & 6   |          |
   |---+---------------------------------+-----------+----------|
   |   | ECC correction, 7 bytes         | W16/pins  |  closed  |
   |   |                                 |   5 & 6   |          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                  BIOS ADDRESS SELECTION                    |
   |------------------------------------------------------------|
   |      Address      |  W13   |       W14        |    W15     |
   |-------------------+--------+------------------+------------|
   |>> | C8000h-C9FFFh |  N/A   |    Pins 2 & 3    | Pins 2 & 3 |
   |   |               |        |      closed      |   closed   |
   |---+---------------+--------+------------------+------------|
   |   | CA000-CBFFFh  |  N/A   |    Pins 2 & 3    | Pins 1 & 2 |
   |   |               |        |      closed      |   closed   |
   |---+---------------+--------+------------------+------------|
   |   | CC000-CDFFFh  |  N/A   |    Pins 1 & 2    | Pins 2 & 3 |
   |   |               |        |      closed      |   closed   |
   |---+---------------+--------+------------------+------------|
   |   |  CE00-CFFFh   | Closed |    Pins 1 & 2    | Pins 1 & 2 |
   |   |               |        |      closed      |   closed   |
   |---+---------------+--------+------------------+------------|
   |   | BIOS disabled |  Open  |       N/A        |    N/A     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |               MISCELLANEOUS TECHNICAL NOTES                |
   |------------------------------------------------------------|
   |      Note: This controller has a built-in low-level format |
   |      program. To enter the program, run the BIOS routine   |
   |      through the DOS DEBUG utility and at the prompt       |
   |      enter: G=C800:5.                                      |
   +------------------------------------------------------------+