An optical disc recording/reproducing apparatus detects last position information of already recorded data and information of initial data recordable capacity of an optical disc that is in a state of no further writing by a recording completion process, a calculating device that calculates data recordable capacity of a free space in accordance with the last position information of already recorded data and the information of initial data recordable capacity of the optical disc and records data in the free space after the last position of already recorded data. The optical disc recording/reproducing apparatus scans the area after the last position of the already recorded data, and when the recorded data is found in the area, the data recorded after the last position is read. Data can be recorded to or reproduced from a free space of the optical disc to which the finalizing process has been executed.

To provide a recording control device able to control a data recording so as not to use a defective sector free from a sector test before a shipment thereof, which controls a data recording with respect to a plurality of sectors in a recording region of a recording medium and has: a verification unit writing data to be written to a first sector in the recording medium when receiving a write request to the recording medium, then reading out the data from the first sector, and performing a verification processing comparing the data to be written with the read out data; and a processing unit writing the data to be written to a second sector on condition that the verification unit decides that the comparison result is disagreement, and determining attribute data as a management data.

A method of recording digital information signals on a removable rewritable disc like recording medium, the method including recording user data on a logical area of the disc and, prior to removal of the disc out of a recording/reproducing apparatus, finalizing the disc with a lead-in and lead-out area comprising predefined medium format data. A general purpose area within the logical area for other use than recording of user data, is being reserved. Such a use may be, for example, defect management. Further, the method involves interrupting recording a lead-in area or a lead-out area at predefined splice points whenever a request for user data is made.

A recording medium for storing start position information for each zone and a method of managing data using the information. In a disc having a plurality of zones which form a group, and a spare area which is allocated at the start portion or the end portion of the group for replacing defects, when start logical sector numbers of each zone are changed by slipping replacement during initialization or reinitialization, the information is stored in the defect management area to thereby increase the compatibility of the medium. In particular, by the method of managing data using information stored in a defect management area, generation of errors is prevented in reading or writing due to the change of a physical position of a real-recorded file which are caused by wrong calculation of the start logical sector numbers for each zone.

A method for accessing data in an optical disk with a drive. The drive has a memory. The optical disk has data blocks for recording data, and spare blocks for replacing defect data blocks. The method includes reading a predetermined number of spare blocks into the memory, and while reading a defect data block, checking whether a corresponding replacing spare block is stored in the memory. If so, suspending further reading of the spare block. Otherwise, reading the spare block with a predetermined number of other spare blocks into the memory to reduce further reading of spare blocks.