1. Construct a BCD to Excess-3 code converter

2. Draw a logic diagram of a 2-to-4-line decoder using only NOR gates. Include an ENABLE input.

3. Construct a clocked "D" type flip-flop using only NOR gates. The clock must be active high.

4. A logic circuit contains 2 JK flip-flops, A and B, and has two inputs x and y and an output z.

The flip-flop input functions and the circuit's output function are given below

JA = Bx + B'y'       KA = B'xy'
JB = A'x       KB = A + xy'
z = Axy + Bx'y'

where JA is the J input to flip-flop A and also A and A' are the Q and Q' output of flip-flop A and likewise for flip-flop B

you are required to draw the logic diagram for the circuit but you may use block symbols for the flip-flops.

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