Safety structure for a roof and more particularly a flat roof. The initialization operation controlled by the peripheral circuit proceeds in parallel with the initialization operation of the CPU. A fixation pin can be brought into a desired position by means of the fixation pin applicator. The surface of the developing sleeve is configured such that a transportation capacity of the developer in end portions of the developing sleeve which correspond to a vicinity of ends of the magnet roller is smaller than the transportation capacity of the developer in a central portion of the developing sleeve which corresponds to a central portion of the magnet roller. Thus, utilizing the platform software stored in the memory of the CRASH REPAIR BOX, the local host computer will be able to properly and fully BOOT.