Digital computer having a high speed table look-up operation

Claim 1

APPARATUS FOR SEARCHING FOR A SELECTED WORD IN A DIGITAL STORAGE UNIT IN WHICH WORDS ARE STORED IN ADDRESSABLE STORAGE POSITIONS, SAID APPARATUS COMPRISING A FIRST REGISTER FOR STORING DIGITALLY CODED INSTRUMENTS, A SECOND REGISTER FOR STORING A WORD, A DIGIT COMPARATOR FOR GENERATING SIGNALS, INDICATING EQUALITY OR INEQUALITY BETWEEN TWO ELECTRICALLY CODED DIGITS COUPLED THERETO, MEANS RESPONSIVE TO A CODED INSTRUMENT IN THE FIRST REGISTER FOR READING OUT A SELECTED WORD FROM THE STORAGE UNIT AND APPLYING A FIRST DIGIT OF THE SELECTED WORD TO THE COMPARATOR, MEANS RESPONSIVE TO SAID CODED INSTRUCTION FOR APPLYING A FIRST DIGIT OF THE WORD IN THE SECOND REGISTER TO THE COMPARATOR, MEANS RESPONSIVE TO A SIGNAL FROM THE COMPARATOR INDICATING THE DIGITS ARE UNEQUAL FOR READING OUT THE NEXT WORD IN SEQUENCE FROM THE STORAGE UNIT AND APPLYING THE FIRST DIGIT TO THE COMPARATOR, MEANS RESPONSIVE TO A SIGNAL FROM THE COMPARATOR INDICATING THE DIGITS ARE EQUAL FOR APPLYING A SECOND DIGIT FROM THE WORD IN THE SECOND REGISTER TO THE COMPARATOR TOGETHER WITH THE NEXT LOWER ORDER DIGIT OF THE SAME SELECTED WORD FROM THE MEMORY UNIT, MEANS ACTUATED BY THE GENERATION OF A COMPARATOR SIGNAL INDICATING EQUALITY FOR COUNTING THE NUMBER OF PAIRS OF DIGITS ON WHICH AN EQUAL INDICATION IS GENERATED BY THE COMPARATOR, AND MEANS RESPONSSIVE TO THE COUNTING MEANS FOR GENERATING A SIGNAL INDICATING WHEN A PREDETERMINED NUMBER OF DIGITS IN THE WORD IN THE SECOND REGISTER ARE EQUAL TO A CORRESPONDING NUMBER OF DIGITS IN A WORD READ OUT OF THE MEMORY UNIT.