#include <graphics.h>
void setgraphmode(int mode);
 

setgraphmode selects a graphics mode different than the default one set
by initgraph. mode must be a valid mode for the current device driver.
setgraphmode clears the screen and resets all graphics settings to their
defaults (current position, palette, color, viewport, and so on).
You can use setgraphmode in conjunction with restorecrtmode to switch
back and forth between text and graphics modes.

/* setgraphmode example */
 
#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
 
int main(void)
{
   /* request autodetection */
   int gdriver = DETECT, gmode, errorcode;
   int x, y;
 
   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, "");
 
   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk) {  /* an error occurred */
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
 
getch();
exit(1);   /* terminate with an error code */
   }
 
   x = getmaxx() / 2;
   y = getmaxy() / 2;
 
   /* output a message */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(x, y, "Press any key to exit graphics:");
   getch();
 
   /* restore system to text mode */
   restorecrtmode();
   printf("We're now in text mode.\n");
   printf("Press any key to return to graphics mode:");
   getch();
 
   /* return to graphics mode */
 
   setgraphmode(getgraphmode());
 
   /* output a message */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(x, y, "We're back in graphics mode.");
   outtextxy(x, y+textheight("W"), "Press any key to halt:");
 
 
   /* clean up */
   getch();
   closegraph();
   return 0;
}

getgraphmode getmoderange graphresult initgraph restorecrtmode

  no output of example at the moment
  do not hesitate and add it...