SCIENTIFIC MICRO SYSTEMS, INC.
==============================

   OMTI 3120A, OMTI 3127A

   +------------------------------------------------------------+
   |------------------------------------------------------------|
   | Data bus:     | 50-pin SCSI interface                      |
   |---------------+--------------------------------------------|
   | Size:         | 4" x 5.75"                                 |
   |---------------+--------------------------------------------|
   | Hard drive    | Up to two ST506/412 MFM drives in 3120A,   |
   | supported:    | and up to two                              |
   |               |                                            |
   |               | ST506/412 RLL 2,7 drives in 3127A          |
   |---------------+--------------------------------------------|
   | Floppy drives | None                                       |
   | supported:    |                                            |
   +------------------------------------------------------------+

<gopher://bitreich.org/I/th99/c/S-T/20640-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   |                 Function                 |    Location     |
   |------------------------------------------+-----------------|
   | 50-pin SCSI interface                    |       J1        |
   |------------------------------------------+-----------------|
   | 34-pin MFM disk control connector        |       J2        |
   |------------------------------------------+-----------------|
   | 20-pin data cable connector              |       J3        |
   |------------------------------------------+-----------------|
   | 20-pin data cable connector              |       J4        |
   |------------------------------------------+-----------------|
   | DC power connector                       |       J10       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                        SCSI ADDRESS                        |
   |------------------------------------------------------------|
   |    SCSI ID    |      W1      |      W2      |      W3      |
   |---------------+--------------+--------------+--------------|
   |>>  |    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 |
   |-----------------------------------+--------------+---------|
   |>> | SCSI parity enabled           |      W4      | closed  |
   |---+-------------------------------+--------------+---------|
   |>> | SCSI parity disabled          |      W4      |  open   |
   |---+-------------------------------+--------------+---------|
   |>> | Factory configured - do not   |   W12/1-3    |   N/A   |
   |   | alter                         |              |         |
   |---+-------------------------------+--------------+---------|
   |>> | Factory configured - do not   |   W13/1-3    |   N/A   |
   |   | alter                         |              |         |
   |---+-------------------------------+--------------+---------|
   |>> | Factory configured - do not   |   W14/1-2    |   N/A   |
   |   | alter                         |              |         |
   |---+-------------------------------+--------------+---------|
   |>> | TRMPWR supplied by board      | W15/pins 1 & | closed  |
   |   | (3127A)                       |      2       |         |
   |---+-------------------------------+--------------+---------|
   |>> | TRMPWR supplied by SCSI bus   | W15/pins 2 & | closed  |
   |   | (3127A)                       |      3       |         |
   |---+-------------------------------+--------------+---------|
   |>> | Factory configured - do not   |   W17/1-3    |   N/A   |
   |   | alter                         |              |         |
   |------------------------------------------------------------|
   | Note: Location of W15 pin 1 is unidentified.               |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                    SECTOR CONFIGURATION                    |
   |------------------------------------------------------------|
   |    Bytes/Sector    | Sector/Track  |    W5     |    W6     |
   |--------------------+---------------+-----------+-----------|
   |>>  |      512      |      17       |   open    |  closed   |
   |----+---------------+---------------+-----------+-----------|
   |>>  |      256      |      32       |  closed   |   open    |
   |----+---------------+---------------+-----------+-----------|
   |    |  512 (3120A)  |      18       |   open    |   open    |
   |----+---------------+---------------+-----------+-----------|
   |    |  532 (3127A)  |      17       |   open    |   open    |
   |----+---------------+---------------+-----------+-----------|
   |>>  |     1024      |       9       |  closed   |  closed   |
   |------------------------------------------------------------|
   | Note: Location of W6 is unidentified.                      |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 TERMINATION POWER - 3120A                  |
   |------------------------------------------------------------|
   |            Function             | W11/1  | W11/2  | W11/3  |
   |---------------------------------+--------+--------+--------|
   |>> |  TRMPWR supplied by board   |  open  | closed | closed |
   |---+-----------------------------+--------+--------+--------|
   |>> | TRMPWR supplied by SCSI bus | closed | closed |  open  |
   +------------------------------------------------------------+