FIX: CodeView Cannot Display Data in a Huge Array Beyond 64k

MS-DOS                        | OS/2           | WINDOWS

The information in this article applies to:

• Microsoft CodeView for MS-DOS, versions 3.0, 3.11, 3.14, 4.0, 4.01, 4.05, and 4.1
• Microsoft CodeView for OS/2, versions 3.0, 3.11, 3.12, and 3.5
• Microsoft CodeView for Windows, versions 3.0, 3.05, 3.06, 3.07, 4.0, 4.01, and 4.1

SYMPTOMS

A huge array that contains more than 64K (65535) bytes of data cannot be fully expanded in Microsoft CodeView. Both the Watch and Quick Watch windows only allow the display of the first 64K of data in a huge data structure.

STATUS

Microsoft has confirmed this to be a problem in the versions of CodeView listed above. This problem was corrected in CodeView version 4.1.

MORE INFORMATION

The example code below demonstrates this limitation. Compile and link the program for huge memory model (/AH) and specify CodeView debugging information (/Zi). Bring the program up in CodeView and set a watch on big_array, which is a huge array of 10000 doubles (80000 bytes). Expand the array by clicking on it in the Watch window with the mouse or by moving the cursor to it and pressing ENTER.

At this point, you can scroll down through the array, but the only visible array elements will be 0 through 8191 (65536 bytes).

Sample Code

/* Compile options needed: /AH /Zi /Od
*/

#include <stdio.h>

void main( void)

   int i;
   double d;
   for( i = 0, d = 0.0f ; i < 10000 ; i++, d += 0.01)
      big_array[i] = d;

   for( i = 0 ; i < 10000 ; i++)
      printf( "big_array[%d] = %2.2f\n", i, big_array[i]);