A symbol string collating apparatus includes a memory unit, a shift register, a collating unit, and an encoder. The memory unit includes memory circuits arranged in a matrix, stores a series of variable-length reference data with reference to a lower bit position of each column of the memory circuits,...http://www.google.com/patents/US5175860?utm_source=gb-gplus-sharePatent US5175860 - System string search system using matrix memory?comparator with columns simultaneously comparing with symbols of string supplied in parallel from a column of input shift registers
