SCIENTIFIC MICRO SYSTEMS, INC.

OMTI 3120A, OMTI 3127A

  Data bus:                  50-pin SCSI interface

  Size:                      4" x 5.75"

  Hard drive supported:      Up to two ST506/412 MFM drives in 3120A, and
                             up to two

                             ST506/412 RLL 2,7 drives in 3127A

  Floppy drives supported:   None

[Image]

                     CONNECTIONS

              Function                   Location

  50-pin SCSI interface                     J1

  34-pin MFM disk control connector         J2

  20-pin data cable connector               J3

  20-pin data cable connector               J4

  DC power connector                       J10

                               SCSI ADDRESS

     SCSI ID              W1                 W2                 W3

  »        0             open               open               open

  »        1            closed              open               open

  »        2             open              closed              open

  »        3            closed             closed              open

  »        4             open               open              closed

  »        5            closed              open              closed

  »        6             open              closed             closed

  »        7            closed             closed             closed

                        USER CONFIGURABLE SETTINGS

               Function                    Location           Setting

  »   SCSI parity enabled                     W4               closed

  »   SCSI parity disabled                    W4                open

  »   Factory configured - do not           W12/1-3             N/A
      alter

  »   Factory configured - do not           W13/1-3             N/A
      alter

  »   Factory configured - do not           W14/1-2             N/A
      alter

  »   TRMPWR supplied by board          W15/pins 1 & 2         closed
      (3127A)

  »   TRMPWR supplied by SCSI bus       W15/pins 2 & 3         closed
      (3127A)

  »   Factory configured - do not           W17/1-3             N/A
      alter

  Note: Location of W15 pin 1 is unidentified.

                           SECTOR CONFIGURATION

     Bytes/Sector         Sector/Track            W5             W6

  »         512                17                open          closed

  »         256                32               closed          open

        512 (3120A)            18                open           open

        532 (3127A)            17                open           open

  »        1024                 9               closed         closed

  Note: Location of W6 is unidentified.

                         TERMINATION POWER - 3120A

         Function               W11/1           W11/2           W11/3

  »    TRMPWR supplied by        open           closed         closed
             board

  »    TRMPWR supplied by       closed          closed          open
            SCSI bus