ADDER AND COMPARATOR: (a) Using two keypad inputs (under Input and Output) and one 4-bit adder circuit, construct a circuit to build a simple calculator. (b) Determine how you can modify the above circuit to perform both addition and subtraction using only one circuit. You can use a simple switch to specify whether the operation is addition or subtraction. Hint: Use the 2's complement concept of A-B= A + (-B). (c) Using a comparator in Cedar Logic (under Add & Compare), explore how this unit can be added to the adder circuit to detect for carry and overflow. Explain how the circuit will work for unsigned and 2's complement numbers. ADDER AND COMPARATOR: (a) Using two keypad inputs (under Input and Output) and one 4-bit adder circuit, construct a circuit to build a simple calculator. (b) Determine how you can modify the above circuit to perform both addition and subtraction using only one circuit. You can use a simple switch to specify whether the operation is addition or subtraction. Hint: Use the 2's complement concept of A-B= A + (-B). (c) Using a comparator in Cedar Logic (under Add & Compare), explore how this unit can be added to the adder circuit to detect for carry and overflow. Explain how the circuit will work for unsigned and 2's complement numbers