BUG: /N1 Switch Does Not Function Properly in CodeView

The information in this article applies to:

• Microsoft CodeView for MS-DOS, versions 4.0, 4.01, and 4.1

SYMPTOMS

CodeView, versions 4.0, 4.01, and 4.1, always traps non-maskable interrupts (NMI) in programs being debugged, regardless of whether you use the /N0 or /N1 CodeView options, which are supposed to trap NMIs.

STATUS

Microsoft has confirmed this to be a bug in CodeView for MS-DOS. We are researching this problem and will post more information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

You can use the sample code below to demonstrate this problem. Build the application for debug mode and load it into CodeView, version 4.10, using the /N1 switch. When the program is run by pressing F5, the NMI breakpoint is reported and the program breaks.

Sample Code

/* Compile options needed:  /Zi
*/

   #include <stdio.h>

   void main( void )
   (
       _asm int 2;
       printf( "Hello World.\n" );
   }