    AST RESEARCH, INC.            TECHNICAL BULLETIN # 0963               8-24-94

                                  ASCENTIA 900N PCMCIA USAGE

    PROBLEM:        User is unable to use both PCMCIA slots without using the
                    supplied Cardsoft drivers on the Ascentia 900N.

    CAUSE:          Not using the Cardsoft utility provided with the system.

    SYSTEMS
    AFFECTED:           AST                                              REVISION
                    PART NUMBER            DESCRIPTION                     LEVEL

                    501299-2XX      ASCENTIA 900N 4/50 CS10                 All
                    501300-3XX      ASCENTIA 900N 4/50 CT9                  All
                    501302-2XX      ASCENTIA 900N 4/75 CS10                 All
                    501304-3XX      ASCENTIA 900N 4/75 CT10                 All

    SOLUTION:       If the user wishes to use both PCMCIA slots without using the
                    supplied Cardsoft drivers on the Ascentia system, the user
                    will be required to contact the vendor to get the independent
                    "point enablers" to communicate with both PCMCIA slots.  If
                    the user does not use the supplied Cardsoft drivers for the
                    PCMCIA usage, the user will not be able to use both slots
                    concurrently. the user will only be able to use slot "0".
                    The following are technical details about the point enablers in
                    slot 1 of the Ascentia 900N system.

                             Intel 82365SL PCMCIA controller
                                       __________
                                      |          |
                                      |          |------- slot 0
                                      |          |
                                      |          |------- slot 1
                                      |__________|

                    This chip controls two slots using ports 3F0h and 3F1h. The
                    access to control registers in each PCMCIA card is indexed
                    through these ports.
                    Slot 0 occupies indices 0 through 3Fh. Slot 1 occupies indices
                    40h through 7Fh. The Ascentia 900N was implemented using this
                    architecture.

                                       VLSI 82C146
                                       __________
                                      |          |
                                      |          |------- slot 0
                                      |          |
                                      |          |
                                      |__________|

                                       VLSI 82C146
                                       __________
                                      |          |
                                      |          |------- slot 1
                                      |          |
                                      |          |
                                      |__________|

                    With the VLSI’s 82C146 PCMCIA controller, each chip controls
                    one slot only.  There are two chips in the Ascentia 900N
                    system to implement two slots.
                    For slot 0, the control registers in the PCMCIA card are
                    accessed the same way as the Intel slot 0 implementation.
                    That is, through ports 3F0h and 3F1h with indices 0 through
                    3Fh.  However, a PCMCIA card in slot 1 will be accessed
                    through ports 3F4h and 3F5h with indices 0 through 3Fh.

                    With socket services and card services installed, the VLSI
                    implementation is supported properly because socket services
                    communicates and understands the VLSI implementation.  But the
                    point enablers that PCMCIA card vendors provide may not have
                    been upgraded to support the VLSI implementation of slot 1.
                    When this type of point enablers try to access slot 1 directly
                    without socket service, they will not be able to access the
                    card properly.
                    A PCMCIA card running with such a point enabler in slot 0 will
                    still function.