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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.