/************************************************************************/
/* Draw a set of radial lines from center of the screen to the outside  */
/************************************************************************/

radial_lines()
        {
        int     i;
        clear_screen();
        for (i = 0; i < 640; i += 20) line(320,100,i,  0,i/20);
        for (i = 0; i < 640; i += 20) line(320,100,i,199,i/20);
        for (i = 0; i < 200; i += 10) line(320,100,0,  i,i/10);
        for (i = 0; i < 200; i += 10) line(320,100,639,i,i/10);
        }