Debug: xm (map expanded memory pages)

Maps a logical page of expanded memory, belonging to the specified handle, to a physical page of expanded memory. Used without parameters, xm checks for the presence or absence of extended memory support (EMS).


xm [lpage] [ppage] [handle]


lpage : Specifies the number of the logical page of expanded memory that you want to map to the physical page ppage.

ppage : Specifies the number of the physical page to which lpage is to be mapped.

handle : Specifies the handle.

?: Displays a list of debug subcommands.


Windows XP does not use this command. It is accepted only for compatibility with MS-DOS files. 

Windows XP does not support EMS. To use expanded memory, you must install an expanded memory device driver that conforms to version 4.0 of the Lotus/Intel/Microsoft Expanded Memory Specification (LIM EMS).


To map logical page 5 of handle 0003 to physical page 2, type:

xm 5 2 0003

If the command is successful, Debug.exe displays the following message:

Logical page 05 mapped to physical page 02

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Elements that the user must type exactly as shown

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Parameter that can be repeated several times in a command line

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Optional items

Between braces ({}); choices separated by pipe (|). Example: {even|odd}

Set of choices from which the user must choose only one

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Code or program output

Debug subcommands

Debug: xa (allocate expanded memory)

Debug: xd (deallocate expanded memory)

Debug: xs (display expanded memory status)

Command-line reference A-Z

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