AST RESEARCH, INC.         TECHNICAL BULLETIN #0848               07-29-93




                   POWER EXEC SIMULTANEOUS DISPLAY DROP OUT


PROBLEM:       The customer experiences a problem on their PowerExec 3/25SL
               and 4/25SL notebooks, when attempting to run simultaneous
               video (FN + F5) with an external monitor.  When they used the
               ALT-TAB keys to switch form a Windows application to a DOS
               window, one of the displays would drop out.

CAUSE:         When Windows is started with both the external CRT and the LCD
               screens active (Both displays are on), both screens will
               operate properly.

               When the simultaneous display is initiated after Windows has
               been loaded, the original video configuration will be present
               when you ALT-TAB between Windows and DOS applications.

SYSTEMS
AFFECTED:      AST PowerExec Notebook family.

SOLUTION:      Configure the system for simultaneous display prior to loading
               Windows.