Once you've started Logisim, it's very easy to create a circuit. To learn how, just click on "Help" and then "Tutorial" to run the tutorial. It takes only a few minutes to get through the tutorial. As practice, be sure to build the XOR device described in the tutorial.
6. Build a 4-bit adder from AND, OR, and NOT gates as follows.
a. Write out the truth table for a 1-bit adder, which has three 1-bit inputs: a, b, and carry_in, and two 1-bit outputs: result and carry_out.
b. Implement, in Logisim, the circuit for the 1-bit adder corresponding to the above truth table.
c. In Logisim, create the four-bit adder by making three more copies of the above 1-bit adder, and then connecting them together. The resulting four-bit adder should have the following inputs: a0, a1, a2, a3, b0, b1, b2, b3 and carry_in. It should have the following outputs: result0, result1, result2, result3, and carry_out. (Note: To copy and paste the 1-bit adder, select the entire 1-bit adder by dragging the mouse over the adder, copy by typing either control-C or command-C, and then paste by typing control-V or command-V. You'll need to drag each new copy into the right position).
d. Be sure to test the adder to make sure it is getting the right outputs. Once you have it working, save the circuit (by clicking "File" and "Save") to a file named "adder.circ".
7. In Logisim, create a 2-input 1
