The present invention relates to engines having multiple hydraulic devices. A pair of support arms pivotably connect the platform to the side members, and a lift arm is pivotably connected between the platform and the side members. In a step part where the steps are formed, a distance between a periphery of the lower drain electrode and a periphery of the upper drain electrode is more than 0. The first through fourth steps are repeated for each data region, until completion, to transform the physically contiguous data in-place on the disk.