A MCAV optical disc read/write system with a postscript type of recording medium is disclosed, which uses a pit edge method of recording information in spiral physical tracks of the medium. The spiral physical tracks are grouped into logical tracks in which a single track address is assigned to each logical track. The logical tracks in turn are grouped into circumferential zones. The number of physical tracks constituting a logical track in adjacent circumferential zones, and the number of track sectors per logical track are set such that the increment in the number of sectors per physical track in proceeding from an inner one to an outer one of such zones is controlled to minimize rate changes in the read/write clock frequency at zone boundaries. Sector addresses thereby may be read even when a read/write head is positioned in a wrong one of adjacent zones.