| 摘要 |
An information recording and retrieval system used for recording and playing back programs on and from a rewritable recording medium which includes absolute addresses; an information recording area for storing programs input from outside the system; and a TOC area for storing supplemental data on the programs recorded in the information recording area. This system comprises: (1) a magnetic coil and an optical head which function in combination (a) to successively record the items of supplemental data in the TOC area in such a way that each item of supplemental data is repeatedly recorded a plurality of times, each item of supplemental data at least comprising an identification number corresponding to a program recorded in the information recording area and the storage location of the program which corresponds to the absolute addresses thereof, and (b) to store supplemental data on an additionally recorded program at the end of the sequence of supplemental data items in the TOC area; (2) a TOC memory for storing each item of supplemental data in the TOC area when the item is read without an error, such an item being read at least once at the time the recording medium is mounted in the system; (3) edit control means for (a) performing an edit control consisting of the steps of i) judging from the items of supplemental data stored in the TOC memory whether a program is recorded over another program in the information recording area, ii) selecting one as effective data from the items of supplemental data corresponding to the overlapped programs by a specified rule if it is judged that a program is recorded over another and iii) assigning new identification numbers to the new group of supplemental data items which includes thus selected data item, and for (b) permitting the TOC memory to store the new group of supplemental data after the editing operation; and (4) restoring means for repeating a recording cycle a plurality of times, the recording cycle being a process in which each item of supplemental data stored in the TOC memory is repeatedly recorded in the TOC area a plurality of times. This arrangement makes it possible to minimize the amount of data to be renewed in the TOC area when a new program is additionally recorded in the information recording area of a disk in which different programs have been already stored, and allows the system to read supplemental data recorded in the TOC area without an error in a short time.
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