create_system_bitmap - Creates a system memory bitmap. Allegro game programming library.

       Allocates  a  system  memory  bitmap  of  the specified size. Read the introduction of this chapter for a
       comparison with other types of bitmaps and other specific details.

       create_system_bitmap - Creates a system memory bitmap. Allegro game programming library.

       Returns a pointer to the bitmap on success, NULL otherwise. Remember to destroy this  bitmap  before  any
       subsequent call to set_gfx_mode().

create_bitmap(3alleg4),              create_bitmap_ex(3alleg4),             create_video_bitmap(3alleg4),
       create_sub_bitmap(3alleg4),  destroy_bitmap(3alleg4),  is_system_bitmap(3alleg4),  clear_bitmap(3alleg4),
       clear_to_color(3alleg4), exupdate(3alleg4)

Allegro                                           version 4.4.3                    create_system_bitmap(3alleg4)

#include<allegro.h>BITMAP*create_system_bitmap(intwidth,intheight);