A spacecraft uses two ground-based computers and one on-board computer to control the thrusters used to make course corrections. There is also a manual override control that will switch control of the thrusters directly to the onboard computer in case the spacecraft id unable to contact the ground station. If the manual overrride is off (logic 0), then the thrusters will fire iff at least two of the three computers output a logic 1. If the manual override is on (logic 1), then the thrusters will fire iff the on-board computer outputs a logic 1.
Let A represent the manual override switch, B represent the output of the on-board computers, and C and D represent the outputs of the two ground computers.
a) Derive a truth table for the output function Z which is 1 iff the thrusters fire.
b) Write the minterm expansion for Z and simplify algebraically to a minimum sum-of-products form.
c) Write the maxterm expansion for Z and simplify algebraically to a minimum product-of-form.
d) Check to see that your answer to (c) is equivalent to the answer for (b).
e) Design a minimum AND-OR gate network to realize Z.