Method for Con-trolling a Data Storage System

A system comprises a data management system, a media transport unit with a plurality of bins, each bin having a bin specific capacity for storing storage media units, at least one data processing unit and at least one loader mechanism for selectively moving a media unit from its actual location to another location within the media transport unit, a number of storage media units loaded in particular ones of the bins, and a control unit functionally interconnecting as programming interface said data management system and said media transport unit. The control unit is configured to emulate functionalities of a media changer with elective media access by generating, updating and managing a table, the table having a number of rows, wherein each storage media unit is assigned to exactly one of those rows which are identified as unique virtual slots. Each row of said table comprises fields that are continuously updated to provide actual position information about the assigned storage media unit, so that in case of a requested access to a specific one of the number of storage media units the control unit can unambiguously determine the actual position of the specific storage media unit for that access can be achieved, if required, by an appropriate stock transfer of the storage media units amongst the bins.