
Logical Gates
Hi, I'm struggling with the topic of logical gates so I hope someone can help me out.
I'm having trouble with the following:
 boolean expressions, De Morgan Law and expressing terms in NOR/NAND only.
 designing circuits
 implementing circuits with given inputs/outputs (4 bit adder?)
An example of the question I'm struggling on would be:
'Write boolean expressions and design a ciruit with three inputs and one output such that the output is 1 if and only if two or more inpurs are 1.'
Help appreciated, I'm finding this topic so confusing.

little sample:
Code:
public static boolean andGate(boolean in1, boolean in2){
if(in1 && in2)
return true;
return false;
}
public static boolean orGate(boolean in1, boolean in2){
if(in1  in2)
return true;
return false;
}
the int version would be:
Code:
public static int andGate(int in1, int in2){
if(in1==1 && in2==1)
return 1;
return 0;
}
public static int orGate(int in1, int in2){
if(in1==1  in2==1)
return 1;
return 0;
}
Now you would do something similar for NOR/NAND using three inputs.
check out wikipedia for the truth table, it'll help you out.