DOCUMENT:Q77219  22-NOV-1999  [msdos]
TITLE   :XMS Memory Is Not Reported Until Accessed
PRODUCT :Microsoft Disk Operating System
PROD/VER:MS-DOS:5.0
OPER/SYS:
KEYWORDS:msdos

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The information in this article applies to:

 - Microsoft MS-DOS operating system version 5.0 
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SUMMARY
=======

XMS (extended memory specification) memory may not be reported by the MEM
command, even if HIMEM.SYS is properly loaded and extended memory is available.
XMS memory will not be reported until it has been accessed.

MORE INFORMATION
================

To reproduce this result, create a CONFIG.SYS file as follows:

      device=c:\dos\himem.sys
      files=30
      buffers=10
      shell=c:\dos\command.com c:\dos\ /p

and AUTOEXEC.BAT as follows:

      echo off
      prompt $p$g
      path=c:\dos;c:\ 

If you boot your computer with 2 MB of extended memory and the above
configuration and immediately run the MEM.EXE command, note that MEM will report
the following:

   2097152 bytes total contiguous extended memory
   2097152 bytes available contiguous extended memory

Because no program has yet accessed XMS memory, no XMS memory will be reported.
As soon as an XMS "user" (for example, DOS=HIGH, SMARTDRV.SYS) is loaded, all of
the contiguous extended memory will be reported as available XMS memory, less
the 64K high memory area (HMA) controlled by HIMEM.SYS itself.

Additional query words: 5.00 noupd

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Keywords          : msdos 
Technology        : kbMSDOSSearch kbMSDOS500
Version           : MS-DOS:5.0

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