Disclosed herein are a processing method and a processing apparatus for processing a plurality of files stored on a storage medium. According to the invention the spacer layer is formed by a printed layer having dispersion particles with monomodal or oligomodal size distribution. The delay of the adjustable-delay buffer is controlled by bias voltages that determine the charging and discharging current to the adjustable buffer. When the cable is pulled out or pushed in, it can move freely inside the corridor compartment. The PL is used to search the construct database to determine a construct type. Related apparatus and methods are also described.