Abstract: A tractor includes an engine, a vehicle body, a rear PTO shaft, a central PTO shaft, a permission switch, and a control unit. The engine is configured to generate power. The vehicle body includes an operator's seat. The rear PTO shaft is configured to supply power generated by the engine to a rear work machine attached to a rear part of the vehicle body. The central PTO shaft is configured to supply power generated by the engine to a central work machine attached to a central part of the vehicle body. The permission switch is operable by an operator. The control unit indicates that the permission switch is operated as one of permission conditions for rotation of the rear PTO shaft after disembarkation, and indicates that the permission switch is operated as one of permission conditions for rotation of the central PTO shaft when moving backward.

Abstract: A method and apparatus for independently and dynamically performing smooth-scrolling a display line at a time is disclosed herein. An offset value for smooth-scrolling for each display line, is provided which shifts the image information of each display line by pixel. Rewriting of the screen according to the offset value is performed in synchronization with refreshing of the display screen. Selective smooth-scrolling can be performed for a displayed image in each display line, and complicated and various image display can be shifted by controlling the existence or nonexistence and speed of smooth-scrolling for each display line.

Abstract: A method and apparatus for displaying an image in each of plural display areas that are adjacently defined in a row direction on a display screen having a plurality of display rows, by defining boundary data for determining a boundary in a row direction between each adjacent display areas for each display row, and switching the image display between each adjacent display area for each display row based on the corresponding boundary data for each row, thereby enabling definition of the boundary freely and simply.