Build Calculator with lOGISIM

Build a calculator that can add and subtract decimal unsigned [login to view URL] calculator should have a display of 5 decimal digits. • There should be a number pad with digits: o 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 • and 3 possible operators: o + (addition) o - (subtraction) o = (equals) The flow of the operations should be as follows (as in a regular calculator): 1. While typing the number it should be displayed right aligned, extending to the left. 2. After pressing "+" or "-" display should be reset to empty, and the next number should be typed. 3. After typing the second number, "=" should be pressed and the display should contain the final result. Specifications for input-output size and structure of the circuit (Important!): For addition and subtraction modules the circuit should work directly on BCD numbers. For addition and subtraction operations each entered number can be at most 4 digits. Entered numbers are positive (no negative numbers as inputs). However, for subtraction the result can be negative. Therefore, the leftmost display (5th) should show minus sign for negative results and a number for positive results.