A shift control device for a motorcycle includes a transmission that allows switching between a neutral state and a number of engaged shift positions, a shift control section that controls a shift state of the transmission, and an ND changeover switch that switches between the neutral state and a drive mode for executing automatic shift among the plural shift positions. A simplifying unit comprises an automatic transformer which compares an elapsed time to a time limit at each stage of decoding the image and switches the decoding process to a simplified process if necessary. Detachment of the two scanners from one another eliminates crosstalk. The at least two conductive layers are at substantially a same electrical potential when operational and form a single gate electrode. The magnetic field generating conductor and the magnetoresistive effect elements are formed in the same stacked body.