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AST RESEARCH, INC.        FIELD CHANGE NOTICE #0071                  07-15-92

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                  BRAVO 486-25 AND BOUNDS CHECKER SOFTWARE


PURPOSE:            To allow proper operation of the application "Bounds
                    Checker" from Nu-Mega Technologies, Inc.  When the driver
                    BC.SYS is loaded via the CONFIG.SYS file, the system will
                    not "warm boot" using the CTL-ALT-DEL key sequence.

CAUTION:            This modification should be performed by a qualified
                    service technician.  It is strongly recommended that this
                    FCN be completed by an AST Authorized Service Center.  In
                    no case will AST Research, Inc. be liable for damage to
                    the system and its components or loss of data caused by
                    improper modification.

PREREQUISITES:      None

TIME REQUIRED:      30 Minutes

ASSEMBLIES
AFFECTED:
                    This FCN should be installed in the Bravo 486-25 if the
                    keyboard controller is at the revision level described in
                    the table below:

                        AST                             REVISION
                    PART NUMBER     DESCRIPTION          LEVEL

                    237002-001      Keyboard             1.01 or
                                    Controller           below


STATUS
VERIFICATION:       The revision level of the keyboard controller can be
                    identified by

                    1) Observing the revision letter at the end of the nine
                       digit part number located on the label of the keyboard
                       controller, which is at position U70 on the system
                       board.

                    2) Observing the revision level returned by the "SYSTEM
                       CONFIGURATION" option of the AST Advanced Diagnostics
                       program (AST part number 500881-001).

PARTS
REQUIRED:           The proper revision of the keyboard controller is
                    available either as a separate item or as part of the
                    BIOS upgrade kit listed below:

                        AST                             REVISION
                    PART NUMBER     DESCRIPTION          LEVEL

                    237002-002      Keyboard             1.02 or
                                    controller           above

                    500890-003      BIOS Upgrade         1.22 E
                                                         or above


TOOLS
REQUIRED:           Standard computer tools

DIAGNOSTICS
REQUIRED:           None

INSTALLATION
PROCEDURE:          Removal and replacement of system "Field Replaceable
                    Units" (F.R.U.s) should only be performed according to
                    the installation procedures approved and prescribed by
                    AST Research, Inc.

CHECK-OUT
PROCEDURE:          To verify proper operation of the system upon completion
                    of this FCN, follow the setup and test procedures
                    described in the AST User's Manual.

NOTE:               Warranty reimbursement for installation of this FCN
                    requires prior approval of AST Research, Inc.