Abstract: A method and apparatus for seismically retrofitting pre-existing household brick chimneys is described to meet current building codes. Vertical steel rebar and horizontal chimney anchors are inserted into the chimney and a polymer concrete is poured between the liner and the brick masonry thereby bonding to the chimney, the vertical steel rebar, and the horizontal chimney anchors. The horizontal chimney anchors are coupled at one end to the external face of the chimney and at another end to the interior frame of the house. Holes are vertically drilled into the masonry of the chimney base in order to anchor the steel rebar at one end. Holes are drilled through the chimney and into the interior of the house at an appropriate point to properly anchor the pre-existing chimney to the house. A polymer concrete that has similar heat properties to other fireplace components is poured into the chimney around a chimney liner in order to reinforce and provide resiliency.

Abstract: A method and apparatus for seismically retrofitting pre-existing household brick chimneys is described to meet current building codes. Vertical steel rebar and horizontal chimney anchors are inserted into the chimney and a polymer concrete is poured between the liner and the brick masonry thereby bonding to the chimney, the vertical steel rebar, and the horizontal chimney anchors. The horizontal chimney anchors are coupled at one end to the external face of the chimney and at another end to the interior frame of the house. Holes are vertically drilled into the masonry of the chimney base in order to anchor the steel rebar at one end. Holes are drilled through the chimney and into the interior of the house at an appropriate point to properly anchor the pre-existing chimney to the house. A polymer concrete that has similar heat properties to other fireplace components is poured into the chimney around a chimney liner in order to reinforce and provide resiliency.

Abstract: The invention doubles the bit rate for a given media bandwidth as compared to, for example, Manchester encoding. It is applicable to serial transmission or storage of digital data. An arbitrary NRZ data stream is first encoded by a pre-encoding method, such as Manchester, that combines clock and data to represent a single NRZ bit in one clock cycle. A toggle flip flop then re-encodes the pre-encoded waveform, thus generating a double toggle (DT) encoded waveform, which spreads the spectral energy over a larger bandwidth and encodes two NRZ data bits within one transmission clock cycle. In the case of Manchester pre-encoding, data is decoded by determining if there are transitions nearly synchronous with an edge of the recovered clock. For other pre-encoding methods, decoded data is determined by the length of the transition period and the edge polarity of the recovered clock at the leading edge of the transition within the DT encoded waveform.

Abstract: Interrupts are prioritized such that selected interrupts use shadow registers to save the current state of the machine, whereas other interrupts use a software implemented interrupt service routine (ISR) to save and restore the current machine state. Hence, the number of nested interrupts that can be serviced will not be limited to the depth of register shadowing.

Abstract: Motion video may be imported into a personal or portable computer through an I/O port having a limited data bandwidth, such as a PCMCIA interface. Motion video data is compressed by sub-sampling both luminance and chrominance difference data for different sized groups of pixels. The compression apparatus may be formed on a PCMCIA card which interfaces with a personal or portable computer. Motion video data, compressed by as much as 5:1 or 6:1, is transferred through the PCMCIA card to a host computer. The host computer may serialize the compressed data and store the data in serialized compressed format in a video memory of a video controller. The video controller is provided with decompression circuitry to decompress the motion video data into luminance and chrominance difference data. The luminance and chrominance difference data is converted into RGB data and displayed in a video display.

Abstract: A multimedia system including an audio/video decoder/decompresser for decoding/decompressing a compressed encoded audio/video data stream to generate video images for display and audio signals for audible reproduction. The multimedia system includes an integrated system and video decoder with an audio/video synchronization circuit for substancially synchronizing the display of video images with audio playback. A method is described for detecting when the playback of audio and the display of video images are out of synchronization. The circuitry includes three programmable registers, a finite state machine and one full adder using an audio presentation time stamp and the video presentation time stamp. The method uses a rounded programmable bias value which is compared with the difference between the video presentation time stamp and the audio presentation time stamps.

Abstract: The invention doubles the bit rate for a given media bandwidth as compared to, for example, Manchester encoding. It is applicable to serial transmission or storage of digital data. An arbitrary NRZ data stream is first encoded by a pre-encoding method, such as Manchester, that combines clock and data to represent a single NRZ bit in one clock cycle. A toggle flip flop then re-encodes the pre-encoded waveform, thus generating a double toggle (DT) encoded waveform, which spreads the spectral energy over a larger bandwidth and encodes two NRZ data bits within one transmission clock cycle. In the case of Manchester pre-encoding, data is decoded by determining if there are transitions nearly synchronous with an edge of the recovered clock. For other pre-encoding methods, decoded data is determined by the length of the transition period and the edge polarity of the recovered clock at the leading edge of the transition within the DT encoded waveform.

Abstract: A general-purpose, single-pass, adaptive, and lossless data compression invention implements an LZ1-like method using a hash-based architecture. It is suitable for use in data storage and data communications applications. Implementation efficiency, in terms of required memory and logic gates relative to the typical compression ratio achieved, is highly optimized. An easy-to-implement and quick-to-verify hash function is used. Differential copy lengths may be used to reduce the number of bits required to encode the copy-length field within copy tokens. That is, if multiple matches to a sequence of input bytes are found in the current window, then the length of the copy may be encoded as the difference between the lengths of the longest and the second-longest match, which results in a smaller copy length which likely has a shorter encoded representation.