SEAGATE TECHNOLOGY INC.
=======================

   ST21M, ST21R

   Data bus: 16-bit, ISA

   Size: Half-length, full-height card

   Hard drives supported:  Two MFM ST506/ST412 drives (ST21M)

   Two RLL ST412 drives (ST21R)

   Floppy drives supported: None

<gopher://bitreich.org/I/th99/c/S-T/20197-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   |                 Function                  |    Location    |
   |-------------------------------------------+----------------|
   | 34-pin control cable connector-hard drive |       J2       |
   |-------------------------------------------+----------------|
   | 20-pin data cable connector-drive 1       |       J3       |
   |-------------------------------------------+----------------|
   | 20-pin data cable connector-drive 0       |       J4       |
   |-------------------------------------------+----------------|
   | 4-pin connector-drive active LED          |       J5       |
   |-------------------------------------------+----------------|
   | 5-pin connector-DC power                  |       J6       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                        BIOS ENABLE                         |
   |------------------------------------------------------------|
   |           Function           |   Location   |   Setting    |
   |------------------------------+--------------+--------------|
   |>> | BIOS enabled             |     JP3      |     open     |
   |---+--------------------------+--------------+--------------|
   |   | BIOS disabled            |     JP3      |    closed    |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                    I/O AND BIOS ADDRESS                    |
   |------------------------------------------------------------|
   |    Hard/Floppy Drive     | BIOS Addresss |  JP1   |  JP2   |
   |         Address          |               |        |        |
   |--------------------------+---------------+--------+--------|
   |     1F0-1F7/3F6-3F7h     | C8000-CBFFFh  |  open  |  open  |
   |--------------------------+---------------+--------+--------|
   |     1F0-1F7/3F6-3F7h     | CC000-CFFFFh  |  open  | closed |
   |--------------------------+---------------+--------+--------|
   |     170-177/376-377h     | D8000-DBFFFh  | closed |  open  |
   |--------------------------+---------------+--------+--------|
   |     170-177/376-377h     | DC000-DFFFFh  | closed | closed |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |          DRIVE PARAMETERS SUPPORTED BY THE ST21M           |
   |------------------------------------------------------------|
   |   Capacity    |     Heads     |   Cylinder    |    SPT     |
   |---------------+---------------+---------------+------------|
   |     21.4      |       4       |      615      |     17     |
   |---------------+---------------+---------------+------------|
   |     32.1      |       6       |      615      |     17     |
   |---------------+---------------+---------------+------------|
   |     42.5      |       5       |      977      |     17     |
   |---------------+---------------+---------------+------------|
   |     42.8      |       6       |      820      |     17     |
   |---------------+---------------+---------------+------------|
   |     44.5      |       5       |     1024      |     17     |
   |---------------+---------------+---------------+------------|
   |     80.2      |       9       |     1024      |     17     |
   |---------------+---------------+---------------+------------|
   |     83.9      |       9       |     1072      |     17     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |          DRIVE PARAMETERS SUPPORTED BY THE ST21R           |
   |------------------------------------------------------------|
   |   Capacity    |     Heads     |   Cylinder    |    SPT     |
   |---------------+---------------+---------------+------------|
   |     21.17     |       2       |      667      |     31     |
   |---------------+---------------+---------------+------------|
   |     32.7      |       4       |      615      |     26     |
   |---------------+---------------+---------------+------------|
   |     42.9      |       4       |      667      |     31     |
   |---------------+---------------+---------------+------------|
   |     49.1      |       6       |      615      |     26     |
   |---------------+---------------+---------------+------------|
   |     65.5      |       6       |      820      |     26     |
   |---------------+---------------+---------------+------------|
   |     122.7     |       9       |     1024      |     26     |
   |---------------+---------------+---------------+------------|
   |     128.4     |       9       |     1072      |     26     |
   +------------------------------------------------------------+