In the next few sets of lab exercises you will use Logg-0 to build increasingly sophisticated, and increasingly useful, circuits. You'll start by designing some circuits to implement gates¹ that we already have available. This way, you'll be able to verify the performance of your circuit directly.

1. Build you own version of a NOR circuit, without using the NOR gate provided by Logg-O. Your circuit should have two input switches (call them A and B) and one output light. The light should turn on when A OR B is FALSE; the light should remain off when A OR B is TRUE. That is, your NOR circuit should perform the logical negation of an OR circuit. Here is a "truth table" for NOR:

   A	B	(A NOR B)
   OFF	OFF	ON
   OFF	ON	OFF
   ON	OFF	OFF
   ON	ON	OFF

2. Now, place one of Logg-O's built in NOR gates on the board, leaving your NOR circuit in place. Use the same input switches as input to this new NOR gate, and add a new light bulb to serve as its output.
   
   Run the circuits now. If your implementation of NOR is correct, both lights on the board should perform identically for all combinations of switch values.
   
   
3. Repeat exercise 1 and 2, but this time build your own XOR circuit. The truth table for XOR is provided below. Notice, in building your circuit that A XOR B is equivalent to:

   (A OR B) AND (NOT (A) OR NOT (B)).
   

   A	B	(A XOR B)
   OFF	OFF	OFF
   OFF	ON	ON
   ON	OFF	ON
   ON	ON	OFF

   Test your circuit by comparing its performance (using the same switches as input) to one of Logg-O's built-in XOR gates.
   
   
4. The circuits described below are not provided directly by Logg-0. The only way to "test" these circuits is to compare their performance for all possible combinations of inputs to their truth tables.
   1. Build and test a three-way AND circuit, which accepts three inputs from switches (call them A, B, and C) and turns its one output light ON only when all three switches are ON. Otherwise, its output light should be OFF. Use the truth table below to verify your circuit.

      A	B	C	3 AND
      OFF	OFF	OFF	OFF
      OFF	OFF	ON	OFF
      OFF	ON	OFF	OFF
      OFF	ON	ON	OFF
      ON	OFF	OFF	OFF
      ON	OFF	ON	OFF
      ON	ON	OFF	OFF
      ON	ON	ON	ON

   2. Build and test a three-way OR circuit, which accepts three inputs from switches (A, B, and C), and turns on its one output light whenever at least one of the switches is ON. Use the truth table below to verify your circuit.

      A	B	C	3OR
      OFF	OFF	OFF	OFF
      OFF	OFF	ON	ON
      OFF	ON	OFF	ON
      OFF	ON	ON	ON
      ON	OFF	OFF	ON
      ON	OFF	ON	ON
      ON	ON	OFF	ON
      ON	ON	ON	ON