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    AST RESEARCH, INC.          TECHNICAL BULLETIN # 1140               4-18-95

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    				   BRAVO MS P/90 VIDEO SHADOW EFFECT

    PROBLEM

    The Bravo MS P/90 system may have a strong video "shadow effect".

    CAUSE

    The problem is caused by noise sensitivity of the feature connector from the
    Cirrus Logic 543x video chipset.

    SYSTEMS AFFECTED
    AST PART NUMBER AND DESCRIPTION

    501651-XXX          BRAVO MS P/90
    501533-XXX          BRAVO MS P/60

    SOLUTION

    There are two solutions to the video "shadow effect":

    1. Download the file 5434.ZIP from AST's BBS and unzip it.
       At the DOS prompt, run 5434.COM to disable the driver circuits.
       Type

    	5434.COM

       anywhere in AUTOEXEC.BAT.  This will disable the feature connector.
       For those user who need to use the feature connector, do not run this
       program.

    File 5434.ZIP can be found on AST's BBS (817) 230-6850, in the "Systems"
    file area.  AST's BBS supports modem speeds up to 28.8k bps.
    The above file will also be posted on:

    CompuServe
    Go ASTSUPPORT

    AST Worldwide Web Site
    http://www.ast.com

    2. Run the program (5434.COM) with debug script at DOS prompt as follow:

    Debug
    A
    MOV DX, 3C4
    MOV AL, 18
    OUT DX, AL
    INC DX
    MOV AL, C0
    OUT DX, AL
    MOV AH, 4C
    INT 21

    N 5434.COM
    R CX
    E
    W
    Q