Professor Smith computes grades as follows: He uses only the first digit (that is, 9 for averages between 90 and 99). He never has an average of 100. He gives a P (pass) to anyone with an average of 60 or above and an F to anyone with an average below 60. The inputs are w, x, y, and z.

Design a circuit using up to two of the decoders with active high outputs and an active low enable, one NOT gate, and one OR gate to produce an output of 1 if the student pass.

Pre-Lab:

1. Write the truth table and draw the chip layout for the 74LS138D IC.