(TXT) View Source
# SCIENTIFIC MICRO SYSTEMS
OMTI 8150C, 8250, 8250C, 8157, 8257
Data bus: 16-bit, ISA
Size: Full-length, full-height card
Hard drives supported: OMTI 8150C/8250/8250C:Two MFM
ST506/ST412 drives
OMTI 8157/8257:Two RLL ST506/ST412 drives
Floppy drives supported: OMTI 8150C/8157:None
OMTI 8250/8250C/8257:Two 360KB, 720KB, 1.2MB,
Sector interleave: 1:1
Maximum heads/cyl.: 16 heads and 2048 cylinders
(IMG) IMG 1
+------------------------------------------------------------+
| CABLE CONNECTIONS |
|------------------------------------------------------------|
| 34-pin data cable connector-floppy drive (OMTI | J1 |
| 8250/C/8257 only) | |
|-------------------------------------------------------+----|
| 20-pin data cable connector-drive 0 | J3 |
|-------------------------------------------------------+----|
| 20-pin data cable connector-drive 1 | J4 |
|-------------------------------------------------------+----|
| 34-pin control cable connector-hard drive | J5 |
|-------------------------------------------------------+----|
| 4-pin connector-drive active LED | J6 |
+------------------------------------------------------------+
+------------------------------------------------------------+
| USER CONFIGURABLE SETTINGS |
|------------------------------------------------------------|
| Function | Location | Setting |
|------------------------------------+----------+------------|
| » | Sysclk signal from AT bus | W7 | pins 1 & 2 |
| | input to 5098C chip | | closed |
|---+--------------------------------+----------+------------|
| | No sysclk signal from bus, | W7 | pins 2 & 3 |
| | input tied low | | closed |
|---+--------------------------------+----------+------------|
| » | Single speed floppy drives | W8 | pins 1 & 2 |
| | (OMTI 8250/8250C/8257 only) | | closed |
|---+--------------------------------+----------+------------|
| | Dual speed floppy drives (OMTI | W8 | pins 2 & 3 |
| | 8250/8250C/8257 only) | | closed |
|---+--------------------------------+----------+------------|
| » | Floppy precomp. values normal | W9 | pins 2 & 3 |
| | (8250/8250C/8257 only) | | closed |
|---+--------------------------------+----------+------------|
| | Alt. floppy precomp. values | W9 | pins 1 & 2 |
| | (OMTI 8250/8250C/8257 only) | | closed |
|---+--------------------------------+----------+------------|
| » | Factory configured - do not | W10 | N/A |
| | alter | | |
|---+--------------------------------+----------+------------|
| » | Hard drive port address is | W11 | open |
| | 1F0-1F7h | | |
|---+--------------------------------+----------+------------|
| | Hard drive port address is | W11 | closed |
| | 170-177h | | |
|---+--------------------------------+----------+------------|
| » | Floppy drive port address | W12 | pins 2 & 3 |
| | 3F0-3F7h (8250/8250C/8257 | | closed |
| | only) | | |
|---+--------------------------------+----------+------------|
| | Floppy drive port address | W12 | pins 1 & 2 |
| | 370-377h (8250/8250C/8257 | | closed |
| | only) | | |
|---+--------------------------------+----------+------------|
| » | Power-ground and | W13 | open |
| | chassis-ground separate | | |
|---+--------------------------------+----------+------------|
| | Power-ground and | W13 | closed |
| | chassis-ground connected | | |
+------------------------------------------------------------+