A spread illuminating apparatus comprises a plurality of LED’s as light sources, a light conductive plate, and a light controlling means disposed between the LED’s and the light conductive plate. Temporal and locality caching hints and prefetching hints are provided to improve system wide caching and prefetching. Next, a second mask process is performed to form a patterned insulating layer and a patterned semiconductor layer over the gate, wherein the patterned insulating layer is disposed on the patterned first metal layer, and the patterned semiconductor layer is disposed on the patterned insulating layer. Since four functions are performed simultaneously during one stroke, every stroke becomes a power stroke. A diagnostic message may be sent from the vehicle via a communications path, and, if the battery requires charging, an alert message sent to a receiving point accessible to vehicle operator. A motor current sensor senses an actual current of the electric motor and generates a signal indicative of the actual motor current.