A method of multiplexing in a multiplexer a plurality of data streams to a single channel each of the data streams containing a plurality of fixed length data packets being serially transmitted from a source to a destination by way of the data stream and the channel. In steady state operation, that is when no object is entering or within the area of interest, only those portions of the incoming images that correspond to the border of the area of interest are analyzed. The second conductor defines a generally spiral-shaped signal path having at least one turn. The shaping tip is moved in parallel with a surface of the slider pad toward the side of the lead pad to soften the solder mass. The circuit also includes an interpolation circuit with a first input coupled to the first output of the pre-filter and a second input coupled to the second output of the pre-filter.