Multi-User Board  (250-4031)      Installation         Faxback Doc. # 14556

1.  Caution should be exercised in low humidity environments to prevent
    damage to electronic parts by static electricity being discharged
    through them.  Discharge any built-up static electricity by touching a
    grounded metal object before proceeding further.

2.  WARNING:  Turn off all equipment.  Turn the power off and disconnect
    the power cord from the computer.  If the computer is on, you could
    damage the central processing unit, as well as the Multi-User Board.

3.  Before proceeding with the installation of the Multi-User Board kit be 
    sure it contains the Multi-User Board, 4 short cables, a cable clamp, 2
    screws for the clamp, a mounting bracket and 2 screws for the bracket.

4.  Remove the screws from the back panel of the main unit.  Remove the
    cover by sliding it toward the front of the unit, parallel to the
    computer.  Your computer Owner's Manual contains illustrations on
    removing the cover.

5.  Be sure the jumper options are set to the desired positions.  The
    Multi-User Board is shipped with the jumpers for each channel set for
    DCE as shown in Faxback Doc. # 14331.

6.  To obtain the correct Base I/O address for the Multi-User Board set dip
    switch S1 as follows:
                                S1 Switch
                                Positions      Base I/O
                                 1 to 4        Address

    1st Multi-User Board          0001         100 Hex
    2nd Multi-User Board          0010         104 Hex
    3rd Multi-User Board          0100         108 Hex

              0 = Switch in off or open position.
              1 = Switch in on or closed position.

7.  To obtain the correct host Interrupt Request Line set dip switch S2 as
    follows:
                                S2 Switch      Interrupt
                                Positions    Request Line
                                 1 to 8        Selected

    1st Multi-User Board        00001000        IRQ10
    2nd Multi-User Board        00000100        IRQ11
    3rd Multi-User Board        00000010        IRQ12

              0 = Switch in off or open position.
              1 = Switch in on or closed position.

8.  Select any empty double card edge connector slot and with a screw
    driver remove the slot cover.  Tilt the slot cover away from you and
    lift the cover so that the tab clears the bottom of the slot.  Store
    the cover in a safe place for possible future use.

9.  Attach the Multi-User Board mounting bracket to the board using the two
    screws enclosed in the kit.

10. Insert the small end of each cable through the opening in the rear of
    the chassis.  Push the connector onto the Multi-User Board pins nearest
    the opening.  Install all four cables for each Multi-User Board in this
    fashion.

11. Carefully install the Multi-User Board by inserting the board edge onto
    the connector.

12. Install the clamp over the cables just outside of the chassis, using
    the 2 screws provided in the kit.

13. Install and tighten the screw that holds the Multi-User board to the 
    chassis.  Do not overtighten the screw.

14. Before replacing the main unit's cover, check all connections to be
    sure all screws are tightened.

NOTES:  See your computer owner's manual for particular steps in replacing
        the main unit cover.

        If a particular user needs to send and receive at different baud
        rates that user must be plugged-in to the cable attached to
        connector J3 (Channel 1) or to the cable attached to connector J5
        (Channel 3).

        This board is designed for use in a Xenix operating system 
        environment.  It will not function in MS-DOS.


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