Abstract: A binary gas analyzer instrument and analysis method for determining percent composition of a cooling gas within a turbine generator is disclosed. The instrument includes a measurement block having a plurality of cells therein, some of which comprise sealed cells containing a known reference gas. One of the cells comprises a measurement cell and contains the binary gas mixture to be evaluated. Each of the cells contains a thermistor and a heater is provided for keeping the cells at a substantially constant temperature. An electric current supply provides a constant current to each thermistor for selfheating, and the gas within each cell conducts heat away from the thermistor at a distinctive rate.

Abstract: A device for visually presenting communications information, communicated over the telephone network by a pair of sequential dual-tone-matrix-frequency (DTMF) signals to a hearing-impaired person's location, includes an integrated circuit filter for separating the dual tones into one high-frequency-group tone and one low-frequency-group tones for concurrent presentation to a decoder. The decoder presents a four-bit signal to a microprocessor programmed to recognize the pair of sequentially-decoded DTMF signals as one of a set of alphanumeric symbols and to the parallel-format this character information. the character information is coupled to display drivers and associated displays, to present a plurality of sequential alphanumeric characters upon a visible display, in scrolled fashion, whereby the hearing-impaired person views visible information converted from audible tones.

Abstract: A reference generator, providing a plurality of precisely-phased output signals, utilizes a microprocessor having a table of values for the output waveforms stored in a read-only memory thereof. The table entries include a multiplicity of values for providing a stepwise representation of each of the desired waveforms, which may have constant angular increments therebetween. The incremental tabular values are consecutively read responsive to the count in a timer, integral in the microcomputer, which is sequentially advanced by the pulse output of a voltage-to-frequency converter receiving a rate signal. The tabular values are converted to analog polyphase reference signals by a like number, equal to the number of phases, of digital-to-analog converters and associated low-pass filters. The output waveform peak amplitude is established by a dual-polarity reference voltage generator, responsive to a variable level signal.

Abstract: A microcomputer controller for a printer, and apparatus for facilitating direct memory access to the microcomputer, includes a central processing unit (CPU) with a known set-up time at the beginning of each machine cycle. A memory, associated with the CPU, has an access time less than the CPU set-up time. A pair of three-state buffers are utilized on the address bus to, and the data bus to and from, the memory from each of the CPU and a direct memory access (DMA) port. A DMA control circuit is coupled to the three-state buffers to facilitate direct access to the memory, from the DMA port, during CPU set-up time intervals and also returns control of memory access to the CPU when the set-up, or synchronization, time interval ends.