SCIENTIFIC MICRO SYSTEMS

OMTI 5520A, OMTI 5527A

Data bus: 8-bit, ISA

Size: Half-length, full-height card

Hard drives supported: OMTI 5520A:Two MFM ST506/ST412 drives

OMTI 5527A:Two RLL ST506/ST412 drives

Floppy drives supported None

Maximum heads/cyl.: 16 heads and 2048 cylinders

[Image]

                           CONNECTIONS

                  Function                        Location

  34-pin control cable connector-hard drive          J1

  20-pin data cable connector-drive 0                J2

  20-pin data cable connector-drive 1                J3

  6-pin DC power connector                           J4

                        USER CONFIGURABLE SETTINGS

               Function                    Location           Setting

  »   BIOS enabled                            W7               open

      BIOS disabled                           W7              closed

  »   BIOS base address is C8000h             W8               open

      BIOS base address is CA000h             W8              closed

  »   Factory configured - do not             W9                N/A
      alter

  »   Factory configured - do not             W10               N/A
      alter

  »   Factory configured - do not             W11               N/A
      alter

  »   Drive 0 soft sectored                   W11              open

      Drive 0 hard sectored                   W11             closed

  »   Factory configured - do not             W12               all
      alter

  »   Drive 1 soft sectored                   W14              open

      Drive 1 hard sectored                   W14             closed

  »   Not documented                       W17 to 19            N/A

                             I/O PORT ADDRESS

          Address                 Jumper W5               Jumper W6

  »          320h                   open                    open

             324h                  closed                   open

             328h                   open                   closed

             32Ch                  closed                  closed

                       MISCELLANEOUS TECHNICAL NOTES

   W1 through W4 are used to configure the drive type. To support most of
     the drives on the market, there have been several different BIOS's
  offered. The different BIOS drive type tables are listed with the 5510;
       The jumper settings are the same for the 5520A and the 5527A.