A video display device comprising a display to display a primary image, originating from a first input signal, and a picture-in-picture overlaying the primary image and originating from a second input signal. In one embodiment, the method creates and maintains a persistent modem connection by searching for an unconnected modem, detecting an unconnected modem; and initiating a dial-up to a computer network. Given node records contain coordinate information about neighboring nodes which define connections of roads between its unit and a neighboring unit. The asynchronous unpacker includes a read buffer commonly used for an asynchronous bridge and for upsizing and for buffering a read channel data; and first and second asynchronous unpacking controllers controlling channel compaction according to the first and second clocks, respectively, regarding the read channel data inputtedoutputted tofrom the read buffer during a burst read operation.