Abstract: A data carrier drive apparatus (1) comprises data carrier loading means (3) for supporting a data carrier, which data carrier loading means (3) is movable between an open and a closed end position along a traveling path by means of a loading means motor (4); and detection means (23, 25) being arranged to monitor an electric driving current (IM) or a driving voltage (UM) impressed to the loading means motor (4), wherein the detection means (23, 25) is adapted to detect a predefined signal pattern of the driving current (IM) or voltage (UM), which signal pattern is representative for the traveling of the loading means along its traveling path at a specific position or section of the path.

Abstract: The present invention relates to a method of performing a writing power calibration for optical recording on an optical storage medium having a spiral track structure, comprising the steps of: selecting a first partition (10) on the track structure having a first track (12) and an adjacent second track (14) that do both not contain written information on track portions (16, 18) within the first partition (10), wherein the second track (14) may be neighboured by a third track (20) that may have a track portion (22) within the first partition (10) containing written information, writing to the track portion (16) of the first track (12) within the first partition (10) using a predetermined writing power profile of a laser beam, reading information written to the first track (12) within the first partition (10), and determining a relation between an asymmetry value and laser power on the basis of the writing power profile and the information read from the first track (12).