Abstract: A data compression interface is characterized by a memory system having an architecture configured from a first and a second serial memory connected in parallel. One memory serves during alternate frames as a data collection memory while the other serves during that same frame as an output memory.

Abstract: A motional bridge circuit for generating feedback signals proportional to the vibration of an ultrasonic transducer is modified by means of an active filter in the feedback circuit which is coupled to a starting circuit that raises the Q of the active filter when a signal is not present in the feedback loop to change the active filter from a mode suppressant to a self-oscillating state.

Abstract: A method for reading bar-coded labels by taking ratios of successive bars and spaces, then discriminating and categorizing the ratios of one of four possibilities. This output is combined and decoded into characters using a read-only-memory. The characters along with information on spacing between the characters is then passed to a microprocessor. The microprocessor decides which of the characters are valid and assembles a complete scans worth of information by making use of the data relating to the separation between characters. Handling the data in this fashion provides a means to assemble data from partial scans of the label into one complete scan.