SCIENTIFIC MICRO SYSTEMS

OMTI 8640

Data bus: 16-bit, ISA

Size: Full-length, full-height card

Hard drives supported: Two ESDI RLL drives

Floppy drives supported: Four 360KB, 720KB, 1.2MB,or 1.44MB

Sector interleave: 1:1

Maximum heads/cyl.: 16 heads and 2048 cylinders

CONNECTIONS

Function

Location

34-pin data cable connector-floppy drive 1 & 2

J1

34-pin data cable connector-floppy drive 3 & 4

J2

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

»

Floppy drive port address is 3F0-3F7h

W2

open

 

Floppy drive port address is 370-377h

W2

closed

»

Hard drive port address is 1F0-1F7h

W3

open

 

Hard drive port address is 170-177h

W3

closed

»

Floppy enabled

W5

open

 

Floppy drive disabled

W5

closed

»

SPT-read from drive

W16

open

 

SPT-calculate and set

W16

closed

»

Cache disabled

W17

open

 

Cache enabled

W17

closed

»

Track Offset Cmd. and Data Strobe Offset disabled

W18

open

 

Track Offset Cmd. and Data Strobe Offset enabled

W18

closed

»

Single speed floppy drive supported

W19

open

 

Dual speed floppy drive Supported

W19

closed

»

Floppy connector (CN1) polarity active high

W20

pins 1 & 2 closed

 

Floppy connector (CN1) polarity active low

W20

pins 2 & 3 closed

»

Floppy connector (CN1) polarity active high

W21

pins 1 & 2 closed

 

Floppy connector (CN1) polarity active low

W21

pins 2 & 3 closed

»

BIOS enabled

W25

closed

 

BIOS disabled

W25

open

»

Chassis not grounded

W28

open

 

Chassis grounded

W28

closed

Note:W22, & W11-15 are not documented

BIOS ADDRESS

Address

Jumper W23

Jumper W24

»

C8000h

closed

closed

 

CA000h

closed

open

 

CC000h

open

closed

 

CE000h

open

open