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