Abstract: A method and device for recording information blocks on a record carrier is described. The device has control means 20 for recording and retrieving position data indicative of the position of the recorded information blocks. The control means include a mapping unit 31 for determining in which region the information block is recorded and a detection unit 32. The region is one of a number of consecutive regions constituting the recordable area. The mapping unit records a random signal unit in a unit location in a mapping area. The unit location indicates said region, and the unit length of the random signal unit is smaller then the length of said information block. The detection unit 32 detects the presence of the recorded random signal units in said mapping area and so determines if a region contains at least one information block. The highest written address is found by detecting the highest written unit location in the mapping area, and subsequently searching said region for the presence of recorded marks.

Abstract: A method and device for recording information signals on a partly recorded writable record carrier (11), e.g. an optical disc. An information signal represents at least one information unit. The record carrier has a recording track which comprises preformed track position information indicative of locations for recording the information units. From the information signal a modulated signal is generated, and the recording track is scanned for recording the modulated signal. If recording is after and adjacent an existing recorded unit, linking information is read from an end boundary area of the existing recorded unit and used for logically generating the modulated signal. If recording is before and adjacent to an existing unit, linking information is read from a begin boundary area of the existing unit and thereafter used for logically generating the modulated signal.

Abstract: The rewritable data storage medium (1) has a rewritable recording layer (9) provided with a tracking structure (8). Said layer (9) has a data recording area (5). An erasable identification mark is present in an identification mark area (4, 4′) other than the data recording area (5). The data recording area (5) has a first tracking structure (8′), whereas the identification mark area (4, 4′) is substantially free from a tracking structure or has a second tracking structure (8″) substantially different from the first tracking structure (8′).