Microsoft DOS debug command

Updated: 06/22/2018 by Computer Hope

About debug

Debug is a method of looking at portions of your computer and writing assembly code to perform certain tasks on your computer.


The debug command is an external command and is available in the below Microsoft operating systems. MS-DOS 2.x - 4.x use as the external file. MS-DOS 5.x and later and all versions of Windows that support this command above uses debug.exe as the external file.

Debug syntax

DEBUG [[drive:][path]filename [testfile-parameters]]

[drive:][path]filename Specifies the file you want to test.
testfile-parameters Specifies command line information required by the file you want to test.

After debug starts, type ? to display a list of debugging commands.

To get out of debug, you need to type "Q" and press Enter.
To execute the debug routine, you need to type "G" and press Enter.

Debug examples

debug      <press Enter>
-D40:00 <TypeD40:00, and press Enter>

Information about your computer ports is displayed.

-Q        <Type Q, and press enter>

Additional information

  • Help with the debug command is on our debug routine page.
  • See our debug definition for further information and related links.