Abstract: Method and apparatus for providing multiple connection modes in a CAD tool or other computer program for integrated circuit design. The apparatus includes a graphical editor for entering and modifying, in memory, circuit elements of an integrated circuit layout. Within the apparatus is an implicit connection generator for automatically extracting electrical connections between the circuit elements in the layout, the generator representing the connections by connectivity data stored in a design database contained within memory. Also within the apparatus is an explicit wiring generator for creating and preserving electrical connections between the circuit elements in response to user commands from the editor. The explicit wiring generator represents the connections by connectivity data stored in the design database.

Abstract: Method and apparatus for design integrated circuit layouts with extensible elements. The elements are generated by extensible element programs the first time the element is selected for a design, with the results stored in a run time cache. Element entries in the cache are accessible through a hash table, with each element reference hashed to provide a hash handle to the table. Subsequent hashes of an element reference provide access to the cache so that the same extensible element need not be regenerated by the element program each time the element is selected. To reduce the cache size, only the attributes of an element derived from the defining attributes of an element are cached. Other attributes such as location and orientation are stored with the element reference as part of a circuit design in a design database. In this way, related but different elements may use the same cache entry, with the differences then added once the cache entry is retrieved.

Abstract: A system, method and station interface arrangement which permits video games to be played over a telephone network is disclosed. Communications delay between the games can be mitigated by transmitting local player position data to a remote game, the position data being detected at a local game during a current "generation" but the position data not being used by the local and remote games until the next generation and the transmission occurring during the time interval in which the current generation is being run at the local game. The position data can be encoded so that errors, e.g. transmission errors, may be detected. Detected errors may be corrected by retransmitting the priorly transmitted local position data. In addition, the games may be synchronized or resynchronized by transmitting a frame count along with the position data. The frame count may identify by order of succession the respective local and remote position data so that the games obtain and remain synchronized.