A recording medium cartridge includes a memory circuit for storing information
concerning signals recorded on the recording medium within the cartridge. The information
is stored in the memory circuit in the form of a hierarchic data structure which
includes a plurality of data packets having a predetermined form and length. Each
data packet includes a code indicative of a level in the data structure to which
the data packet belongs. At least some of the data packets include data indicative
of starting and ending positions on the recording medium of recorded signals which
the data packet represents. The hierarchic (or "tree") data structure facilitates
rapid retrieval and reproduction of the signals recorded on the recording medium,
particularly when the recording medium is a magnetic tape. The tree structure also
facilitates storage of information in connection with recording of additional signals
on the recording medium.
