                                                             Last Revised
    AST RESEARCH, INC.        TECHNICAL BULLETIN # 1742          07/22/97

    TITLE:  Simultaneous Display Functionality

    ISSUE

       When using external desktop projectors, the Ascentia P notebook
       may exhibit the following problems:

       1. With the Xerox DP2810 projector in either Liquid
          Crystal Display (LCD) or CRT display mode, the
          display on the internal LCD and external projector
          work well respectively. However, in simultaneous
          (LCD+CRT) display mode, both the LCD and the projector
          display shows flickering.

       2. In simultaneous display mode, only the internal LCD
          display works on the Sharp XG5800E projector.
          There is no display on the external projector.

       This issue affects all Ascentia P systems.

    BACKGROUND

       These problems are most commonly encountered when the high
       resolution (800x600 or even 1024x768) notebooks used with
       monitors, video projectors, or LCD display panels that,
       typically, only support a resolution of 640x480. Either the panel
       displays nothing, or it displays a scrambled or skewed picture.

       Due to current technology limitations in portable graphic
       controllers, and the timing requirements of various display
       devices, AST cannot guarantee nor support full simultaneous
       display functionality in all environments.

       This issue may also affect all portable systems on the market
       today.

    ACTION

       In order to make use of simultaneous display mode with Ascentia P
       notebooks that come with high resolution screens, your external
       display device must support the native resolution of your
       notebook's screen. In other words, to have simultaneous display
       on Ascentia P systems with a native resolution of 800x600, an
       external display device with a resolution up to 800x600 must be
       used.

    NOTES

       N/A

    TAN PRJ 3615AN

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