14. Apparatus of claim 13 further including means responsive to the value of the byte in the stored group preceeding the byte being compared for selecting one of said plurality of character tables, each character having an associated table of characters arranged in the two portions of the table according to the frequency in which each character in the table follows the associated preceeding character in standard English words.
13. Apparatus of claim 12 further including means for storing a plurality of tables of characters coded as bytes, each table having a portion of the characters addressable by a single nibble and a portion of the character addressable by two nibbles, the characters stored respectively in the two portions being different for each table, means for selecting one of the tables to operate with said means for comparing each byte with characters stored in a character table.