    AST RESEARCH, INC.        TECHNICAL BULLETIN # 1713          05/06/97

    TITLE:  Video Galaxy MPEG, Video Distortion

    ISSUE

       When attemptimg to play an AVI or MPG file, the video will either
       become distorted or shift to green.

       This issue affects all systems using the ATI mach64 internal or
       add on video adapter.

    BACKGROUND

       The Video Galaxy Oscar Pro MPEG playback board only supports a
       refresh rate of 60Hz.

    ACTION

       Configure the ATI mach64, 64VT,and CT video as follows:

       Instructions for the Windows 3.x operating system:

         1. Go to Program Manager and click on the ATI desktop
            icon.

         2. When the ATI screen appears, configure your
            monitor's Refresh Rate to 60Hz.

         3. Select Screen Adjustment and then Preview
            Adjustment.

         4. Under Synchronization, click the Horizontal and
            Vertical Sync buttons until the Negative sign
            appears on each button.

         5. Close the ATI Desktop Applet.

       Instructions for the Windows 95 operating system:

         1. Go to Display under Control Panel.

         2. Click the Adjustments tab under Display Properties.

         3. Under Synchronization, click the Horizontal and
            Vertical Sync buttons until the Negative sign
            appears on each button.

         4. Close the ATI Desktop Applet.

    NOTES

       N/A

    TAN 003200AO

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