
TANDY/RADIO SHACK

250-4161/250-4161A

Card type               Hard drive controller
Hard Drives supported   Up to 7 SCSI devices
Floppy drives supported None
Data Bus                16-bit ISA
Card Size               Half-length, full-height card

[Image]

                                CONNECTIONS

         Function           Location         Function           Location

  50-pin SCSI connector -     CN1      Drive active LED           LED
  internal

                        USER CONFIGURABLE SETTINGS

                   Function                     Label        Position

     TERMPWR supplied from host adapter to       F1          Closed
      SCSI interface

      TERMPWR not supplied to SCSI interface      F1           Open

     Synchronous Negotiation disabled           J1/1          Open

      Synchronous Negotiation enabled            J1/1         Closed

     Factory configured - do not alter          J1/2          Open

     SCSI parity check enabled                  J1/3          Open

      SCSI parity check disabled                 J1/3         Closed

     Zero wait states enabled                    J4           Open

      One wait state enabled                      J4          Closed

     System computer is Tandy 4000               J5           Open

      System computer is Tandy 3000               J5          Closed

                           DMA CHANNEL SELECTION

    Channel       J1/7        J1/8        J6/1        J6/2        J6/3

         0       Closed      Closed      Closed       Open        Open

        5        Open       Closed       Open       Closed       Open

         6       Closed       Open        Open        Open       Closed

         7        Open        Open        Open        Open        Open

                     DMA CHANNEL SELECTION (CONTINUED)

    Channel       J6/4        J7/1        J7/2        J7/3        J7/4

         0        Open       Closed       Open        Open        Open

        5        Open        Open       Closed       Open        Open

         6        Open        Open        Open       Closed       Open

         7       Closed       Open        Open        Open       Closed

                            INTERRUPT SELECTION

    Setting        J1/9       J1/10       J1/11       J8/1        J8/2

         9         Open       Open        Open       Closed       Open

         10       Closed      Open        Open        Open       Closed

        11        Open      Closed       Open        Open        Open

         13       Closed     Closed       Open        Open        Open

         14        Open       Open       Closed       Open        Open

         15       Closed      Open       Closed       Open        Open

                      INTERRUPT SELECTION (CONTINUED)

     Setting          J8/3          J8/4           J8/5          J8/6

          9           Open          Open           Open          Open

          10          Open          Open           Open          Open

         11         Closed         Open           Open          Open

          13          Open         Closed          Open          Open

          14          Open          Open          Closed         Open

          15          Open          Open           Open         Closed

                          BIOS ADDRESS SELECTION

         Address              J10/1            J10/2           J10/3

            C0000h            Closed          Closed           Closed

            C4000h            Closed          Closed            Open

            C8000h            Closed           Open            Closed

            CC000h            Closed           Open             Open

            D0000h             Open           Closed           Closed

            D4000h             Open           Closed            Open

            D8000h             Open            Open            Closed

           DC000h             Open            Open             Open

                            BASE I/O ADDRESS SELECTION

  Setting    J9/1     J9/2     J9/3     J9/4    J9/5     J9/6     J9/7     J9/8

      004h  Closed    Open     Open     Open    Open     Open     Open     Open

      008h   Open    Closed    Open     Open    Open     Open     Open     Open

      00Ch  Closed   Closed    Open     Open    Open     Open     Open     Open

      010h   Open     Open    Closed    Open    Open     Open     Open     Open

      014h  Closed    Open    Closed    Open    Open     Open     Open     Open

     330h   Open     Open    Closed   Closed   Open     Open     Closed   Closed

      3F0h   Open     Open    Closed   Closed   Closed   Closed   Closed   Closed

      3F4h  Closed    Open     Open     Open    Open     Open     Closed   Closed

      3F8h   Open     Open     Open     Open    Open     Open     Closed   Closed

      3FCh   Open    Closed   Closed   Closed   Closed   Closed   Closed   Closed

      3FFh  Closed   Closed   Closed   Closed   Closed   Closed   Closed   Closed

                                      Note:

  The switches are a binary representation of the decimal memory addresses. SW1/8
  is the Most Significant Bit and switch SW1/1 is the Least Significant Bit. The
  switches have the following decimal values: SW1/8=512, SW1/7=256, SW1/6=128,
  SW1/5=64, SW1/4=32, SW1/3=16, SW1/2=8, SW1/1=4. Add the values of the closed
  jumpers to obtain the correct memory address. (Closed=1, Open=0)

                               ID SELECTION

      SCSI ID              J1/4              J1/5              J1/6

           0              Closed            Closed            Closed

          1               Open             Closed            Closed

           2              Closed             Open             Closed

           3               Open              Open             Closed

           4              Closed            Closed             Open

           5               Open             Closed             Open

           6              Closed             Open              Open

           7               Open              Open              Open

                           TERMINATION SELECTION

           Setting                      RN6                   RN7

       Termination enabled          Installed             Installed

       Termination disabled           Removed               Removed

            Note: Terminators should be removed if inline terminators are
            used or the host adapter is not at the end of the SCSI bus.

