Same principle, as I see it, whether it's writing 1 byte, calling gotoxy/putch, or copying a whole bunch of bytes. Dirty rects! The insight is the same: you dra

Same principle, as I see it, whether it's writing 1 byte, calling gotoxy/putch, or copying a whole bunch of bytes. Dirty rects! The insight is the same: you draw the things that have changed, and leave alone the things that stay the same.