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    AST RESEARCH, INC.         TECHNICAL BULLETIN # 1443B                3-8-96

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    	      Advantage! Adventure 60xx Torisan CD-ROM and Windows 95
    		   Configuration/Mindmaze in MS Encarta GPF Error

    PROBLEM

    1. Windows 95 may report that an illegal operation has occurred on an
       Advantage! Adventure 60xx system, when using Microsoft Encarta 95.

    2. After running Mindmaze in Encarta for 10 minutes or longer in
       Windows 95, a Multimedia system may crash with a general protection
       fault (GPF) error and a stack dump.

    CAUSE

    The CD-ROM is configured for single-speed operation within MS Windows 95.

    SOLUTION

    Configure the CD-ROM for quad-speed operation. To configure the CD-ROM,
    follow the steps below:

    1.  Boot into Windows 95 (start) and click on the following:

    		      Settings
    		      Control Panel
    		      System
    		      Performance (under System Properties)
    		      File System (under Advanced Settings)
    		      CD-ROM

    2.  Under "Optimize Access Pattern", select Quad speed or higher.

    NOTE:  On Supplemental cache size, AST recommends the user select "Large"
           (by moving the arrow to the extreme right).

    3.  Select "OK" and "Close".

    4.  Choose "yes" to restart the computer.

    BACKGROUND INFORMATION

    A CD-ROM requires a software driver to work with the MS Windows 95
    operating system.  Two different types of software drivers are available.
    They are called "protected-mode" and  "real-mode".  The following
    paragraphs describe a key difference between the two types of drivers.

    Protected-mode Driver:

    When a CD-ROM drive is installed in the computer system, MS Windows 95
    will detect the speed of the CD-ROM and automatically configure itself to
    match the speed of the CD-ROM.

    Real-mode Driver:

    When a CD-ROM is installed in the computer system, MS Windows 95 does not
    detect the speed of the CD-ROM drive and the default speed parameter is used.
    The default speed is "single-speed".

    The Torisan CD-ROM is a quad-speed CD-ROM and uses a real-mode driver.
    This means it can experience anomalies during system operation because it has
    been configured to operate as a single-speed CD-ROM.

    SYSTEMS AFFECTED
    AST PART NUMBER AND DESCRIPTION

    501766-XXX       Advantage! Adventure 60xx

    234167-410       Torisan CD-ROM Drive Model CDR-S1G

    Note:  The Torisan CD-ROM mentioned in this Technical Bulletin is
    manufactured by Sanyo.  Sometimes this Torisan CD-ROM is referred to as a
    Sanyo CD-ROM.