representation of the linking of banks 2 a the linking between the video banks which is a separate concept from bank link list in the bank management information for the three ports indicated as ports 1 to 3 of all of the sdi input output ports 1 by the program vdc in fig1 an example is shown where data a is recorded by port 1 other data c is subjected to forward playback using the banks 2 a with the indices 0 to 2 before chasing playback starts for video data a by port 2 and other video data b is recorded by port 3 the program vdc manages a plurality of banks 2 a being used by the corresponding sdi input output port 1 by linking the banks 2 a for a predetermined number of bytes centered on the position of the bank 2 a for which a read or write is presently being carried out the program vdc links a bank 2 a with the index 6 and a bank 2 a with the index 7 as the banks 2 a being used by port 1 when chasing playback of the data a starts the program vdc links the bank 2 a with the index 1 the bank 2 a with the index 2 and the bank 2 a with the index 6 as the banks 2 a being used by port 2 although not shown in the drawings the banks 2 a with the indices 0 to 2 are linked during forward playback of data c and when chasing playback of the data a starts the bank 2 a with the.