In an automatic tape loader mechanism, for example for a digital tape storage system, the forces of registration springs intended to engage notches in a tape cartridge are de-rated prior to andor during insertion of a tape cartridge into the loader. The dual evaporator air conditioning system includes primary and auxiliary HVAC units having primary and auxiliary evaporators, respectively, to cool the air in the front and rear portions of the cabin. One illustrative disclosed system includes an optical velocity sensor and a detector where a light beam produced by the velocity sensor and a reference beam interfere at the detector, and the detector produces a signal indicative of a velocity experienced by the velocity sensor. According to embodiments, a method and devices for mobility control of a terminal are provided wherein a mobility policy parameter defines the mobility control of the terminal.