ADAPTEC, INC.
=============

   ACB-4525S4000, ACB-4525Z

   +------------------------------------------------------------+
   |------------------------------------------------------------|
   | Data bus:                | None (SCSI to ESDI interface)   |
   |--------------------------+---------------------------------|
   | Size:                    | Drive card                      |
   |--------------------------+---------------------------------|
   | Hard drives supported:   | SCSI to two RLL ESDI drives     |
   |--------------------------+---------------------------------|
   | Floppy drives supported: | None                            |
   +------------------------------------------------------------+

<gopher://bitreich.org/I/th99/c/A-B/20023-1.png>
   

   A diagram for these Models was not available, the ACB-4000A is
   pictured above.

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   |                   Function                   |  Location   |
   |----------------------------------------------+-------------|
   | 20-pin data cable connector-drive 0          |     CN0     |
   |----------------------------------------------+-------------|
   | 20-pin data cable connector-drive 1          |     CN1     |
   |----------------------------------------------+-------------|
   | 34-pin control cable connector-hard drive(s) |     CN2     |
   |----------------------------------------------+-------------|
   | 4-pin connector-DC power                     |     CN3     |
   |----------------------------------------------+-------------|
   | 50-pin SCSI connector-to host adapter        |     CN4     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                        SCSI ADDRESS                        |
   |------------------------------------------------------------|
   |  SCSI ID   | JP5/Jumper 1  | JP5/Jumper 2  | JP5/Jumper 3  |
   |------------+---------------+---------------+---------------|
   |    |   0   |     open      |     open      |     open      |
   |----+-------+---------------+---------------+---------------|
   |    |   1   |    closed     |     open      |     open      |
   |----+-------+---------------+---------------+---------------|
   |    |   2   |     open      |    closed     |     open      |
   |----+-------+---------------+---------------+---------------|
   |    |   3   |    closed     |    closed     |     open      |
   |----+-------+---------------+---------------+---------------|
   |    |   4   |     open      |     open      |    closed     |
   |----+-------+---------------+---------------+---------------|
   |    |   5   |    closed     |     open      |    closed     |
   |----+-------+---------------+---------------+---------------|
   |    |   6   |     open      |    closed     |    closed     |
   |----+-------+---------------+---------------+---------------|
   |>>  |   7   |    closed     |    closed     |    closed     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |             Function              |   Location   | Setting |
   |-----------------------------------+--------------+---------|
   |>> | Not used                      |     JP2      |   N/A   |
   |---+-------------------------------+--------------+---------|
   |>> | Provides a protocol           | JP5/jumper 4 | closed  |
   |   | compatible with ACB-5500 and  |              |         |
   |   | ACB-4000 families of          |              |         |
   |   | controllers (4525S4000 only)  |              |         |
   |---+-------------------------------+--------------+---------|
   |   | Does not allow for            | JP5/jumper 4 |  open   |
   |   | compatibility with ACB-5500   |              |         |
   |   |                               |              |         |
   |   | and ACB-4000 controllers      |              |         |
   |   | (4525S4000 only)              |              |         |
   |---+-------------------------------+--------------+---------|
   |>> | Zero latency default enabled  | JP5/jumper 4 | closed  |
   |   | (4525Z only)                  |              |         |
   |---+-------------------------------+--------------+---------|
   |   | Zero latency default disabled | JP5/jumper 4 |  open   |
   |   | (4525Z only)                  |              |         |
   |---+-------------------------------+--------------+---------|
   |>> | Spindle motor starts on       | JP5/jumper 5 | closed  |
   |   | command                       |              |         |
   |---+-------------------------------+--------------+---------|
   |   | Spindle motor starts on       | JP5/jumper 5 |  open   |
   |   | power-up                      |              |         |
   |---+-------------------------------+--------------+---------|
   |>> | SCSI unit attention disabled  | JP5/jumper 6 | closed  |
   |---+-------------------------------+--------------+---------|
   |   | SCSI unit attention enabled   | JP5/jumper 6 |  open   |
   |---+-------------------------------+--------------+---------|
   |>> | SCSI parity check enabled     | JP5/jumper 7 | closed  |
   |---+-------------------------------+--------------+---------|
   |   | SCSI parity check disabled    | JP5/jumper 7 |  open   |
   |---+-------------------------------+--------------+---------|
   |>> | Normal operation              | JP5/jumper 8 |  open   |
   |---+-------------------------------+--------------+---------|
   |   | Self-diagnostic enabled       | JP5/jumper 8 | closed  |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |               MISCELLANEOUS TECHNICAL NOTES                |
   |------------------------------------------------------------|
   |  The function of JP1 is to determine the select technique  |
   |            used to interface the host adapter.             |
   |                                                            |
   |  Soldering Pin-2 to Pin "P" allows for the "pulse" select  |
   |   that is used by controllers designed to work with SCSI   |
   |  hosts. Soldering Pin-2 to Pin "H" or "L" allows for the   |
   |  "handshake" or "level" select signal used in accordance   |
   |                    with SCSI standards.                    |
   |                                                            |
   |    Unit attention (JP5/6) is not supported if the JP5/4    |
   |         jumper is installed on the ACB-4525S4000.          |
   +------------------------------------------------------------+