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                    DISABLING WRITE CACHING

        To avoid potential write caching problems, you may want to
        disable the DOS 6 SmartDrive write caching feature. 
        However, first you will need to know about the DOS 6
        AUTOEXEC.BAT file.
        
        Below is a typical DOS 6 AUTOEXEC.BAT file for an 80286, an
        80386, or an 80486 machine. 
        
        @ECHO OFF
        PATH C:\DOS;C:\WINDOWS;C:\UTILS
        PROMPT $P$G
        SET TEMP=C:\DOS
        SMARTDRV
        
        You can use EDIT, the built-in DOS editor, to make or modify the
        AUTOEXEC.BAT file or the CONFIG.SYS file.  Both of these
        files reside on the root directory of your start-up disk.  Remember,
        the changes you make when you modify an existing
        AUTOEXEC.BAT or CONFIG.SYS file will not take effect until
        you restart your computer.  Never make a modification to either
        the AUTOEXEC.BAT file or the CONFIG.SYS file without first
        making a backup of these important files on diskette.  If your
        start-up disk is drive C, you can load the AUTOEXEC.BAT file into
        EDIT by typing:
        
                       edit c:\autoexec.bat <ENTER>
        
        When you are in EDIT, you can press <F1> for more help.  If
        you make changes, don't forget to save the file by pressing:

                       <ALT>
                       f
                       s

        Note that the last line in the sample AUTOEXEC.BAT file is
        SMARTDRV.  SMARTDRV is a disk cache that works with
        computers that have extended memory.  If you have an 80286 or
        greater machine with at least 1 megabyte of memory, then you can
        probably use SMARTDRV.  A disk cache uses a portion of memory
        to store information that DOS reads from disk.  DOS can read
        information from the disk cache much faster than it can read
        information from a drive.  The result is that you will get a big
        performance boost if you use a disk cache.
        
        The DOS 6 SMARTDRV will cache both floppy and hard drives
        and is faster than the DOS 5 SMARTDRV.  The DOS 6
        SMARTDRV is very similar to the one that is included with
        WINDOWS 3.1 and can be loaded in the AUTOEXEC.BAT file. 
        The DOS 6 version of SMARTDRV will automatically calculate
        values by determining how much upper memory exists in your
        machine.  It will also automatically load itself into high
        memory if it is available.
        
        The DOS 6 SMARTDRV will do read caching and write caching
        for hard drives and read caching for floppies.  With write
        caching, you could lose data if you turn your computer off
        immediately after quitting a program.

        IT IS BEST TO WAIT AT LEAST FIVE SECONDS AFTER YOU QUIT AN
        APPLICATION BEFORE YOU TURN THE MACHINE OFF.

        On drives that are write cached, SMARTDRV waits until the
        cache is about full, or until there has been about 5 seconds of
        idle time, before writing the data to your hard drive.  If you
        want to force the write cache to immediately write the data to
        the hard drive, type:
        
                       smartdrv /c <ENTER>

        ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ

        To avoid potential write caching problems, you may want to
        disable the DOS 6 SmartDrive write caching feature.

        ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ

        You can disable write caching by following the SMARTDRV
        command with the letters of your hard drives.  Suppose you had
        hard drives C, D, E, and you wanted to disable write caching on
        these drives.  Use the DOS EDIT program to change the
        SMARTDRV line in the AUTOEXEC.BAT file to read the
        following:
        
        SMARTDRV C D E 
        
        The above line tells DOS to allow read caching while disabling
        write caching for drives C, D, and E.  Don't try to cache a
        DoubleSpaced drive.  SmartDrive will not cache compressed
        drives (DoubleSpaced drives), CD-ROM drives, network drives,
        or RAM drives.  If you are running DoubleSpace, you can get
        information on all your drives by typing:
        
                       dblspace /info <ENTER>
                  
        If you want to see which drives SMARTDRV is caching, at the
        system prompt type:
        
                       smartdrv <ENTER>
        
        For more information on the DOS 6 SMARTDRV command, type:
        
                        help smartdrv <ENTER>

   This section is finished.  It is an excerpt from LEARNING DOS FOR
   THE COMPLETE NOVICE, by Steven Woas, copyright 1993.  When you register
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