Transistor implementation

After computer simulation of ALU, we’re going to make an implementation of our ALU using transistors and integrated circuits. This is our first labratory implementation of logic gates (using transistors) :

Also, at the first step, we made a 2x4 decoder using these gates:

But, as soon as possible, we’ll switch to use 74 Series integrated circuits for labratory implementation, because they’re cheaper and better than transistor circuits.