A semiconductor package including top-surface terminals for mounting another semiconductor package provides a three-dimensional circuit configuration that can provide removable connection of existing grid-array packages having a standard design. The main difference is the unique construction of the frame, which has space between its two levels under the seat, enable the chair to carry different kind of mechanical-, electronic- and digital devices or equipment. The image processing section is operable by the processor to control processing of two dimensional images. The second networking device includes an output port connected to a port of the first networking device and to an output port of the multiplexer, and operational up to a second throughput greater than the first throughput.