7. Structure as in claim 5 wherein said means for comparing comprises a plurality of logical gates, each said logical gate corresponding to one character string to be decoded and wherein each said logical gate comprises: a plurality of K input leads corresponding to an equal plurality of K characters comprising a desired character string, said input lead corresponding to the kth character (where kth is an integer given by 1.ltoreq./.ltoreq.K) from the end of said desired character string being connected to the kth least significant bit of said shift register associated with said kth character.
7. Structure as in claim 5 wherein said means for comparing comprises a plurality of logical gates, each said logical gate corresponding to one character string to be decoded and wherein each said logical gate comprises: a plurality of K input leads corresponding to an equal plurality of K characters comprising a desired character string, said input lead corresponding to the kth character (where kth is an integer given by 1.ltoreq./.ltoreq.K) from the end of said desired character string being connected to the kth least significant bit of said shift register associated with said kth character. 10. Structure as in claim 7 which further includes a plurality of J (where J is a positive integer less than or equal to K) latches for storing information as to whether an associated one of J character strings has been located.