AUVA COMPUTER, INC.
===================

   HFDC-II

   +------------------------------------------------------------+
   |------------------------------------------------------------|
   | Data bus:         | 16-bit ISA                             |
   |-------------------+----------------------------------------|
   | Size:             | Three-quarter length, full-height card |
   |-------------------+----------------------------------------|
   | Hard drive        | Two MFM ST-506/412 drives              |
   | supported:        |                                        |
   |-------------------+----------------------------------------|
   | Floppy drives     | Two 360KB, 720KB, 1.2MB, or 1.44MB     |
   | supported:        | drives                                 |
   +------------------------------------------------------------+

<gopher://bitreich.org/I/th99/c/A-B/20902-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   |                   Function                    |  Location  |
   |-----------------------------------------------+------------|
   | 4-pin connector - drive active LED            |     J1     |
   |-----------------------------------------------+------------|
   | 20-pin data cable connector - drive 1         |     J2     |
   |-----------------------------------------------+------------|
   | 20-pin data cable connector - drive 0         |     J3     |
   |-----------------------------------------------+------------|
   | 34-pin control cable connector - hard drive   |     J4     |
   |-----------------------------------------------+------------|
   | 34-pin control cable connector - floppy drive |     J5     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |              Function               | Location  | Setting  |
   |-------------------------------------+-----------+----------|
   |   | LED always "on" when system on  |   W1/1    |   open   |
   |---+---------------------------------+-----------+----------|
   |   | LED "on" only when drive is     |   W1/1    |  closed  |
   |   | being accessed                  |           |          |
   |---+---------------------------------+-----------+----------|
   |>> | Four byte ECC enabled           |   W1/2    |   open   |
   |---+---------------------------------+-----------+----------|
   |   | Reserved - do not use           |   W1/2    |  closed  |
   |---+---------------------------------+-----------+----------|
   |   | Cache enabled                   |   W1/3    |   open   |
   |---+---------------------------------+-----------+----------|
   |   | Cache disabled                  |   W1/3    |  closed  |
   |---+---------------------------------+-----------+----------|
   |   | Interleave ratio is 1:1         |   W1/4    |   open   |
   |---+---------------------------------+-----------+----------|
   |   | Maximum interleave ratio is 1:3 |   W1/4    |  closed  |
   |---+---------------------------------+-----------+----------|
   |   | Floppy drive primary address is |    W2     |   open   |
   |   | 3F2-3F7h                        |           |          |
   |---+---------------------------------+-----------+----------|
   |   | Floppy drive secondary address  |    W2     |  closed  |
   |   | is 372-377h                     |           |          |
   |------------------------------------------------------------|
   | Note: Close W1/4 when using disks formatted under the      |
   | WD1003-WAH controller.                                     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |            USER CONFIGURABLE SETTINGS CONTINUED            |
   |------------------------------------------------------------|
   |               Function                | Location | Setting |
   |---------------------------------------+----------+---------|
   | Hard drive primary address is         |    W3    |  open   |
   | 1F0-1F7h                              |          |         |
   |---------------------------------------+----------+---------|
   | Hard drive secondary address is       |    W3    | closed  |
   | 170-177h                              |          |         |
   |---------------------------------------+----------+---------|
   | Floppy drive single speed enabled     |    W4    |  open   |
   |---------------------------------------+----------+---------|
   | Floppy drive dual speed enabled       |    W4    | closed  |
   +------------------------------------------------------------+