
SCIENTIFIC MICRO SYSTEMS

OMTI 8620, OMTI 8627

Data bus:                16-bit, ISA
Size:                    Full-length, full-height card
Hard drives supported:   OMTI 8620:Two MFM ST506/ST412 drives or ESDI
                         drives

                         OMTI 8627:Two RLL ST506/ST412 or ESDI drives
Floppy drives supported: Two 360KB, 720KB, 1.2MB, 1.44MB drives
Sector interleave:       1:1
Maximum heads/cyl.:      16 heads and 2048 cylinders

[Image]

                            CONNECTIONS

                   Function                          Location

  34-pin control cable connecter-floppy drive           J1

  34-pin control cable connecter-hard drive             J2

  20-pin data cable connecter-drive 0                   J3

  20-pin data cable connecter-drive 1                   J4

  4-pin connecter-drive active LED                      J5

                        USER CONFIGURABLE SETTINGS

                Function                    Location          Setting

      Drive 1 set for fixed media drive       W4              open

       Drive 1 set for removable media         W4             closed
       drive

      Drive 1 set for ST506 drive             W5              open

       Drive 1 set for ESDI drive              W5             closed

      Drive 1 soft sectored                   W6              open

       Drive 1 hard sectored                   W6             closed

      Drive 0 set for fixed media drive       W7              open

       Drive 0 set for removable media         W7             closed
       drive

      Drive 0 set for ST506 drive             W8              open

       Drive 0 set for ESDI drive              W8             closed

      Drive 0 soft sectored                   W9              open

       Drive 0 hard sectored                   W9             closed

       If the drive on CN3 is a ESDI           W12             open
       drive this trace must be cut

       If the drive on CN4 is a ESDI           W13             open
       drive this trace must be cut

      Floppy drive port address is            W14             open
       3F0-3F7

       Floppy drive port address is            W14            closed
       370-377

      BIOS base address is C8000h             W15             open

       BIOS base address is CA000h             W15            closed

      BIOS enabled                            W16             open

       BIOS disabled                           W16            closed

      Factory configured - do not alter       W20              N/A

      I/O speed set to high performance       W21             open
       string mode

       I/O speed set to loop                   W21            closed

      If BIOS is #1002661, then drive 0       W22             open
       parameters are set to 4 hds. and
       612 cyl. If BIOS is #1002662,
       then drive 0 parameter are set to
       4 hds. and 615 cyl.

      Factory configured - do not alter       W22            closed

      If BIOS is #1002661, then drive 1       W23             open
       parameters are set to 4 hds. and
       612 cyl.If BIOS is #1002662, then
       drive 1 parameter are set to 4
       hds. and 615 cyl.

      Factory configured - do not alter       W23            closed

                           SECTOR CONFIGURATION

  Jumper W10     Jumper W11      BPS (ST506     SPT- 8620      SPT- 8627
                                   only)

     open           open            512             17            26

     open          closed           512             17            26

    closed          open           1024             18            26

    closed         closed          1056             9             13

                   I/O PORT ADDRESS

   Address     Jumper W17    Jumper W18    Jumper W19

     320h         open          open          open

     324h         open          open         closed

     328h         open         closed         open

     32Ch         open         closed        closed

     1A0h        closed         open          open

     1A4h        closed         open         closed

     1A8h        closed        closed         open

     1ACh        closed        closed        closed

                    DRIVE TYPE CONFIGURATION - #1002579

    DRIVE 0         DRIVE 2

      W20             W21            W22         W23       Cyl.     Hds.

     closed         closed         closed       closed     ESDI     ESDI

      open          closed          open        closed     987       7

     closed          open          closed        open      918       15

      open           open           open         open      612       4

                    DRIVE TYPE CONFIGURATION - #1002578

    DRIVE 0         DRIVE 2

      W20             W21            W22         W23       Cyl.     Hds.

     closed         closed         closed       closed     ESDI     ESDI

      open          closed          open        closed     820       6

     closed          open          closed        open      1024      9

      open           open           open         open      615       4

