The C Graphics Library Supports Only One Video Page

MS-DOS                 | WINDOWS

The information in this article applies to:

• Microsoft C for MS-DOS, versions 6.0, 6.0a, and 6.0ax
• Microsoft C/C++ for MS-DOS, version 7.0
• Microsoft Visual C++ for Windows, versions 1.0 and 1.5

SUMMARY

Only one video page is allowed in VGA modes with the Microsoft C graphics functions. This is by program design and may change to allow for more video pages in a future version of the compiler.

The sample code below uses the _getvideoconfig() function to determine the number of video pages available.

Sample Code

#include <graph.h>
#include <stdio.h>
#include <stdlib.h>

void main(void)

   struct videoconfig vc;

   if (!_setvideomode(_VRES16COLOR)) {
      puts("Unable to set video mode to VRES16COLOR.");
      exit(-1);
   }
   _getvideoconfig( &vc );
   _setvideomode(_DEFAULTMODE);
   printf("Number of video pages: %d\n", vc.numvideopages);