A display device including a thin film transistor having a semiconductor layer comprising an i-type semiconductor and an impurity doped semiconductor laminated over a first insulating film, a first electrode formed over the semiconductor layer, and a second electrode formed by a part of a data line. The method can effectively improve the accuracy of the route change and alleviate the delay due to the route change. Though the first move has not actually taken place, the library replies to the host computer that the first tape drive has been loaded with the first tape cartridge, at least to an acceptable level of engagement, at which point, the first move instruction is queued. The system can be used for fixed or mobile applications in water, wind and manually induced air flow.