
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

[Image]

                              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            W2               open
      3F0-3F7h

      Floppy drive port address is            W2              closed
      370-377h

     Hard drive port address is              W3               open
      1F0-1F7h

      Hard drive port address is              W3              closed
      170-177h

     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              W18              open
      Strobe Offset disabled

      Track Offset Cmd. and Data              W18             closed
      Strobe Offset enabled

     Single speed floppy drive               W19              open
      supported

      Dual speed floppy drive                 W19             closed
      Supported

     Floppy connector (CN1) polarity         W20            pins 1 & 2
      active high                                             closed

      Floppy connector (CN1) polarity         W20            pins 2 & 3
      active low                                              closed

     Floppy connector (CN1) polarity         W21            pins 1 & 2
      active high                                             closed

      Floppy connector (CN1) polarity         W21            pins 2 & 3
      active low                                              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

