A primary power supply and a secondary power supply are operable to supply power to at least one electrical device. The display apparatus also has an image control unit that controls a position of the virtual image to circle around the obstacle in a view of a driver when the obstacle is determined to be unsafe by the safety determination unit. The needle cover protects the user from being hurt by broken needle. In addition, level one and level two cache memory misses result in loading and recording of the requested data into both level one and level two cache memories.