    AST RESEARCH, INC.        TECHNICAL BULLETIN # 1533           7-19-96

    TITLE:  AST Vision 4i Monitors and ATI Mach64

    SUMMARY

       AST Vision 4i monitors will lose horizontal synchronization.

       This issue applies to all systems using the ATI Mach64 video
       subsystem regardless of the manufacturer.

    ISSUE

       When connecting an AST Vision 4i monitor to any system that uses
       the ATI Mach64 video subsystem, the monitor may lose horizontal
       synchronization (sync) under Windows 95.

    BACKGROUND

       The monitor will lose horizontal sync when attempting to use a
       resolution higher than 800x600.  The ATI Mach64 video drivers
       v2.1x or lower are incompatible with interlaced monitors that
       use resolution above 800x600.

    ACTION

       Download version 2.22 (AST part number 911374-317 through -322)
       or later of the ATI Mach64 video drivers and follow the README
       onscreen instructions.

       Files 11374317.EXE, 11374318.EXE, 11374319.EXE, 11374320.EXE,
       11374321.EXE, and 11374322.EXE are available from one of AST's
       On-Line! services as follows:

       AST WWW Site:  http://www.ast.com
       AST On-Line! BBS*:  See IB0001.TXT
       CompuServe:  GO: ASTFORUM
       Prodigy: Jump: astsupport

    NOTES

       Caution: If you exceed the rate parameters, you risk damage to the
       monitor.

    TAN 002100SW

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