Debug: n (name)

Specifies the name of an executable file for a debug l (load) or w (write) subcommand, or specifies parameters for the executable file that you are debugging. Used without parameters, n clears the current specifications.


n [Path][executable]

n [FileParameters]


[Path][executable] : Specifies the location and name of the executable file you want to test.

[FileParameters] : Specifies parameters and command-line options for the executable file you are testing.

?: Displays a list of debug subcommands.


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

Using the n subcommand

You can use the n subcommand in two ways. First, you can use it to specify a file to be used by a later l (load) or w (write) subcommands. If you start Debug.exe without naming a file to be debugged, you must use the command n FileName before you can use l to load the file. The file name is correctly formatted for a file control block (FCB) at CS:5C. Second, you can use n to specify command-line parameters and command-line options for the file that you are debugging.

Memory areas

The following table lists the four areas of memory that can be affected by the n command.

Memory locationContents


File control block (FCB) for file 1


File control block (FCB) for file 2


Length of n command line (in characters)


Beginning of n command-line characters

The first file name you specify for the n command is placed in an FCB at CS:5C. If you specify a second file name, this name is placed in an FCB at CS:6C. The number of characters typed on the n command line (exclusive of the first character, n) is stored at location CS:80. The actual characters on the n command line (again, exclusive of the letter n) are stored beginning at CS:81. Note that these characters can be any command-line options and delimiters that would be valid in a command typed at the command prompt.

For information about loading the contents of a file or of specific disk sectors into memory by using the l (load) subcommand, see Related Topics.

For information about writing the file that you want to debug to a disk by using the w (write) subcommand, see Related Topics.


In this example, run debug and load the program for debugging. To specify two parameters for and run the program, type:

nparam1 param2

In this case, the g (go) subcommand runs the program as if you typed the following command at the command prompt:

prog param1 param2

Testing and debugging reflect a typical run-time environment for

In the following sequence of commands, the first n subcommand specifies File1.exe as the file for the subsequent l (load) subcommand, which loads File1.exe into memory. The second n subcommand specifies the parameters to be used by File1.exe. Finally, the g (go) subcommand runs File1.exe as if you typed File1 File2.dat File2.dat at the command prompt.

nfile2.dat file3.dat

Do not use the l subcommand after the second instance of the n subcommand. If you use the w (write) subcommand after the second instance of the n subcommand, File1.exe (that is, the file you are debugging) will be saved with the name File2.dat. To avoid this result, always use the first form of the n subcommand immediately before either an l or w subcommand.

Formatting legend



Information that the user must supply


Elements that the user must type exactly as shown

Ellipsis (...)

Parameter that can be repeated several times in a command line

Between brackets ([])

Optional items

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

Set of choices from which the user must choose only one

Courier font

Code or program output

Debug subcommands


Debug: l (load)

Debug: w (write)

Command-line reference A-Z

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