Electronic calculating apparatus

Claim 1

ELECTRONIC APPRATUS FOR FORMING THE ALGEBRAIC SUM OF TWO MULTIDENOMINATIONAL VALUES EACH COMPRISING A SUCCESSION OF INPUT DIGITS IN ORDER OF INCREASING DENOMINATIONAL SIGNIFICANCE ENCODED ACCORDING TO BINARY CODE NOTATION, CORRESPONDING DENOMINATIONAL DIGITS OF BOTH VALUES OCCURRING CONCURRENTLY AND BEING REPRESENTED BY SUBSTANTIALLY SIMULTANEOUSLY OCCURRING ELECTRICAL SIGNALS REPRESENTING THE BINARY CODE ELEMENTS OF THE APPLIED DIGITS, INCLUDING MEANS FOR REGISTERING A PAIR OF CONCURRENTLY OCCURRING INPUT DIGITS; A FIRST BINARY ADDER; GATING MEANS CONNECTED BETWEEN SAID REGISTERING MEANS FOR BOTH DIGITS AND SAID FIRST ADDER FOR TRANSFERRING THE PAIR OF INPUT DIGITS TO THE FIRST ADDER, THE FIRST ADDER BEING RESPONSIVE ONLY TO THE APPLICATION OF THE PAIR OF DIGITS TO PRODUCE A BINARY CODED SUM VALUE HAVING ONE MORE CODE ELEMENT THAN THE INPUT DIGITS, SAID ONE MORE CODE ELEMENT BEING OF GREATEST BINARY CODE SIGNIFICANCE; MEANS FOR EXAMINING SAID BINARY CODED SUM VALUE TO PRODUCE CONCURRENTLY WITH SAID SUM VALUE A SINGLE CARRY INDICATING SIGNAL; MEANS FOR DERIVING FROM, AND DELAYED RELATIVE TO, SAID CARRY INDICATING SIGNAL A CARRY-IN SIGNAL OCCURRING CONCURRENTLY WITH THE BINARY CODED SUM VALUE ASSOCIATED WITH THE INPUT DIGITS OF NEXT SUCCEEDING DENOMINATIONAL SIGNIFICANCE, SAID EXAMINING MEANS PRODUCING SAID CARRY INDICATING SIGNAL IN RESPONSE ONLY TO THE OCCURRENCE OF A BINARY CODED SUM VALUE REPRESENTATION AT LEAST EQUAL TO A PREDETERMINED VALUE AND THE CONCURRENT OCCURRENCE OF THE CARRY-IN SIGNAL RESULTING FROM THE PRECEDING PAIR OF INPUT DIGITS AND A BINARY CODED SUM VALUE EQUAL TO ONE LESS THAN SAID PREDETERMINED VALUE; CORRECTION DIGIT GENERATING MEANS OPERABLE UNDER CONTROL OF SAID CARRY INDICATING SIGNAL RESULTING FROM THE CURRENT PAIR OF DIGITS AND THE CARRY-IN SIGNALS RESULTING FROM THE PRECEDING PAIR OF INPUT DIGITS FOR PRODUCING A BINARY CODED CORRECTION DIGIT INCLUDING FILLER AND CARRY COMPONENTS; A SECOND ADDER; AND MEANS FOR APPLYING SAID CORRECTION DIGIT AND ALL THE BINARY CODE ELEMENTS EXCEPT THAT OF GREATEST SIGNIFICANCE OF SAID BINARY CODED SUM VALUE TO SAID SECOND ADDER, THE SECOND ADDER BEING RESPONSIVE THERETO TO PRODUCE A FINAL CORRECTED SUM DIGIT HAVING THE SAME NUMBER OF CODE ELEMENTS AS THE INPUT DIGITS.