Abstract: A novel high speed unidirectional bus system is provided for receiving a plurality of novel circuit card assemblies in receptacles on the bus. Adjacent receptacles are connected by lines on the bus which interconnect output pins to input pins. The circuit between output pins and input pins are formed by connecting the plugs on circuit card assemblies into the receptacles on said bus. The system comprises a plurality of function circuit card assemblies connected in a daisy chain when inserted into adjacent receptacles on said bus between a source circuit card assembly and a destination circuit card assembly and the address portion of the information supplied by the source circuit card assembly is programmed to identify the function circuit card assembly to first receive the source data whereby the unidirectional bus system may be operated in a time division random access mode at data rates in excess of the data rates of individual functional circuit card assemblies.

Abstract: The present invention shows a cleaning system for dislodging the collected dust from filter media in a low pressure high capacity gas stream filter. In the preferred embodiment, pressurized gas from an external tank is ducted through a revolving arm which stretches radially across a pie-shaped segment of a tube sheet separating a clean gas plenum from a dirty gas plenum in a bag collection gas filtration system. The ducted gas is intermittently discharged from the rotating arm through multiple orifices into a venturi contained within the openings in the tube sheet as these orifices are above the individual filter elements.

Abstract: An improved interface unit for receiving a stream of parallel bit words from a source bus comprising an address field, a data field and a clock field. The parallel bit words are first phase adjusted and stored in an input register where the address field is compared in enable logic to determine whether to store the data field in a sink buffer register for processing. The word in the input register is coupled to the buffer storage register. The address field is further compared in pass through disable logic to determine whether to pass the address and data field to an output register or to generate a null code address in the address field of the word being outputted from the buffer storage register. The word in the buffer storage register is coupled through a word selector to an output register.

Abstract: A quantizer, which converts an input group of data samples into one of N quantized groups of data samples, does so by performing several dot products and compares. Each dot product is between the input group of data samples and a reference group of data samples u.sub.x, and each compare is with the dot product result and a constant k.sub.y. All of the reference groups of data samples and all of the constants are stored in a memory. This memory holds only N-1 constants and less then N/2 reference groups of data samples. A memory saving of several thousand percent is achieved by limiting the memory to hold no more then 2r reference groups of data samples where r is the number of samples in the input group, or no more then 2 log.sub.2 N reference groups of data samples.

Abstract: Apparatus is provided for performing two stages of high-speed compression of vector data inputs. Two input channels of vector data are compressed and encoded through a vector quantizer encoder to provide a first stage of data compression. The output of the first encoder is further decoded then compressed and encoded in a novel high-speed computing mapping means which may be implemented in the form of a look-up table. Vector quantized encoded output is double the previous data compression of a single stage. The second stage of data compression causes very little degradation of the data from the first stage of data compression.

Abstract: A binary encoder for vector quantization is provided which comprises a plurality of identical two-level branch selectors connected in a turnaround cascade pipeline array. The upper levels of the two-level selectors are connected in series and the first selector receives a formatted digital data vector input. The upper level of last selector has its output connected to its own lower level input and the outputs of the lower level selectors are connected in series so that the last lower level selector in the turnaround cascade resides in the first two level selector. The output of the last lower level selector provides a desired compressed data vector output.

Abstract: A system and apparatus for encoding a set of input vector components by initiating a sequential search through a codebook memory to put out a series of associated error code vectors which can be compared in sequence over a period of time in order to select the minimum error code vector (best fit). A clocking-sequencing means enables an output latch to hold (after termination of the sequence period) the index number which represents the particular error code vector presently having the minimum distortion. Each new set of input vector components will be sequenced to search for the minimum error code vector (and index) for that particular set of input vector components.

Abstract: An intercom arrangement in a key telephone system is disclosed that permits the answering of intercom calls "hands-free" at a called station. Intercom calls are originated in the standard manner, with the calling party lifting the handset at a station and selecting an idle intercom line. After the calling party depresses a direct station selection button that corresponds to the called station, a hands-free answer unit located in the called station automatically connects to the proper intercom line and provides an alerting tone to both the calling and called station. The calling party is then able to converse with the called party by alternately activating a loudspeaker and a microphone contained in the called station.

Abstract: This invention relates to a portable seat cushion which unfolds to form a seat section and a back section. Both the seat and back sections include therein a frozen coolant package covered by a thermally transparent pad or cushion. The coolant package contains a liquid which may be frozen in the freezer section of an ordinary refrigerator and then placed within a recess in the seat and back sections of the seat cushion for absorbing heat, and thereby cooling the occupant of the seat cushion.