The convenience input/output station (Figure 1, item  4 ) is an optional feature on the 3494 that is used for inserting cartridges into or ejecting cartridges from the ATLDS, without interrupting normal automated operations. For more detailed information on the convenience input/output features of the IBM TotalStorage Enterprise Automated Tape Library (3494), see IBM TotalStorage Enterprise Automated Tape Library (3494) Introduction and Planning Guide.