1. A textual comparison system for locating a desired character string within textual material formed from a predefined sequence of characters comprising: means for sequentially receiving a plurality of stored textual characters; means for sequentially decoding said plurality of stored textual characters as they are received, thereby providing a sequence of decoded characters, said means for decoding including means for being programmed to detect only characters forming a part of said desired character string; means for storing said decoded characters and information as to the relative positioning of said decoded characters within said predefined sequence of characters; means for comparing said decoded characters and said information as to the relative positioning of said decoded characters with information defining said desired character string, whereby the presence of said desired character string is determined; and means responsive to said means for comparing for providing a signal indicating that said desired character string has been located.