The 4014 made a change to the way graphics points were entered by adding an "execution character" which denoted that a particular coordinate was complete. This allowed, for instance, the X or Y coordinate to be changed without changing the previously stored location for the other. This was useful for drawing boxes or especially a series of lines like an axis, or drawing a point on the screen by sending in the same address as the one last stored or moved to using dark mode. Since the X and Y coordinates used separate characters, the terminal would still notice a sequence of coordinates being sent in the older 4010 format, and draw them as they arrived, providing backward compatibility.