Abstract: An interlocking three-dimensional solid puzzle having component pieces that can be interlocked into an assembled configuration without any significant internal voids. The component pieces include sliding control mechanisms to control movement of the pieces and are preferably structured such that specific movement of one or more pieces is required before any piece can be removed. The sliding control mechanism preferably includes an array of mating projecting studs and channels on the individual puzzle pieces that cooperate to selectively limit movement of the pieces, and or provide false moves that do not advance assembly and/or disassembly. The present invention provides a new class of interlocking solid puzzles characterized as being challenging to assemble and disassemble while having a lower piece count than comparable existing puzzles.

Abstract: Disclosed is a frame processing engine for receiving and processing a data frame having a header and a payload, comprising a first memory for receiving at least a portion of the header of the data frame; a second memory for receiving the payload of the data frame; and a controller, upon receipt of the data frame, for storing the header (at least most of it) in the first memory and the remainder of the data frame (including the payload) in the second memory, with the first memory having a shorter access time than the second memory.

Abstract: A switched digital circuit is used to restore a failed dedicated digital circuit to a remote station in conjunction with reconfiguration of the network's multipoint junction units (MJU). A circuit is established over the public switched digital network from the customer's central location to a remote station requiring restoral. The remote station is then connected back to the dedicated multipoint circuit, at the telephone company central office facilities, by way of digital cross connects and MJUs that perform the digital bridging. The switched digital access line, from the customer central location to the telephone company facilities is then available for use in establishing switched connections to the other remote stations. The process is sequentially repeated for each dedicated digital circuit to a remote station to be restored, thus conserving hardware required at the customer premises and minimizing the number of dial up switched digital access lines needed at the customers central location.

Abstract: In a Digital Data System (DDS) a method and apparatus for providing multipoint multiport service. Differences in time delays through the network are compensated by an alignment training wherein the delays from each remote station are measured at a Central station. The Central station determines how much delay to insert at each remote station and then instructs the remote stations to insert the delays. This allows all inbound data to be aligned in time so that when the data are combined within the network by the Multipoint Junction Units (MJU) data errors are not produced. Aligned frames are combined in the MJU operating in data mode in a logical AND operation so that marks transmitted by inactive ports are combined with data from active ports to produce a composite signal which is passed to the Central DSU.

Abstract: A method and apparatus for disabling an echo canceller in a digital telephone network. An originating DSU transmits a sequence of synchronization codes which are shifted by the various delays in the network. The answering DSU receives the shifted codes and determines how much adjustment is required by the originating modem in order to have byte boundaries aligned with those of the network. The answering DSU then transmits this information back to the originating DSU so that the originating DSU can adjust its transmit time to align with the byte boundaries of the network. The originating DSU then transmits byte aligned 2100 Hz tone samples in order to disable the network's echo canceller.