Microsoft KB Archive/77219

= XMS Memory Is Not Reported Until Accessed =

Article ID: 77219

Article Last Modified on 11/22/1999

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APPLIES TO


 * Microsoft MS-DOS 5.0 Standard Edition

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This article was previously published under Q77219



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 &quot;user&quot; (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

Keywords: KB77219

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