Abstract: A faster method of generating a mask stroke for a given trajectory. The first step is to determine if parallel lines can be developed for the entire trajectory. If not, the trajectory is divided into segments for each of which a set of parallel lines can be generated. The second step is to generate the parallel lines.

Abstract: A system for maintaining data consistency among distributed processors, each having its associated cache memory. A processor addresses data in its cache by specifying the virtual address. The cache will search its cells for the data associatively. Each cell has a virtual address, a real address, flags and a plurality of associated data words. If there is no hit on the virtual address supplied by the processor, a map processor supplies the equivalent real address which the cache uses to access the data from another cache if one has it, or else from real memory. When a processor writes into a data word in the cache, the cache will update all other caches that share the data before allowing the write to the local cache.