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    AST RESEARCH, INC.         TECHNICAL BULLETIN # 1261                7-26-95

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    DSP DIGISPEACH FUNCTIONS ERRATICALLY ON ASCENTIA XXXN NOTEBOOKS

    PROBLEM

    When the DSP Digispeach device is attached to the parallel port of an
    Ascentia 900N notebook, the sound device will fail at random intervals.

    CAUSE

    The "Functional Specification" for the device that controls the parallel port
    in the Ascentia XXXN notebook computer states that the "PACK" signal from the
    external device should be at least 2.5 usec. in width.  This signal
    specification complies with IEEE std. 1284-1994.  Any device that provides
    a pulse whose width is less than specified is likely to experience random
    failures.

    SYSTEMS AFFECTED

    All AST Ascentia XXXN notebook computers, or any system that uses the VLSI
    Technologies VL82C144 peripheral controller chip.

    SOLUTION

    At present there is no solution to this issue and this bulletin is provided
    for informational purposes only.  We suggest you contact the manufacturer of
    the incompatible device to see if there is currently a fix or if a fix is
    planned to alleviate the problem.

    The parallel port on the Ascentia XXXN complies with the IEEE, ECP, and EPP
    specifications.  AST has made the VLSI chip's timing requirements available to
    the manufacturers of any incompatible hardware that have been reported to us.