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    AST RESEARCH, INC.          TECHNICAL BULLETIN # 1190              5-19-95

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    BRAVO LC 4/66D PS/2 MOUSE NOT RECOGNIZED BY SCO ODT LITE 3.0

    PROBLEM

    The Bravo LC 4/66D system mouse may not be recognized by SCO ODT Lite 3.0.

    CAUSE

    The problem is detected when SCO, upon testing for the available hardware
    in the system, issues a "Test Mouse Port" command to the mouse controller.
    The rise time in the Data line is too slow.
    The hardware/software can not detect the correct state of the mouse data
    signal causing the error.

    A correction was made to the system board P/N  202688- XXX.  The pull-up
    resistor on the AUX DATA (mouse data) line was changed to a lower value.

    SYSTEMS AFFECTED
    AST PART NUMBER AND DESCRIPTION

    501498-XXX          BRAVO LC 4/66D
    501548-XXX          BRAVO LC 4-50D
    501433-XXX          BRAVO LC 4-50S
    501378-XXX          BRAVO LC 4-33S
    501379-XXX          BRAVO LC 4-33
    501654-XXX          BRAVO LC 4-50D
    501380-XXX          BRAVO LC 4-66D

    SOLUTION

    Take the system to an AST Authorized Service Center for a system board
    replacement.  Request AST part number 202688- XXX, revision B or higher.