[sdiy] an XOR question

[Schierl, Dan]

Hi list--
I have an application I'm working on in which I need to perform an exclusive OR on 4 inputs. Since I don't think anyone makes a 4-input XOR, I tried to rig something up using some CMOS chips. My first attempt was a little too simplistic (i.e. wrong), which I didn't realize until I'd already wired it into my application. I think my second attempt works (haven't tried it yet, tho) but i think it might be overkill. 
 
Go here: http://people.msoe.edu/~schierld/temp/xor.html to see my two ideas.
 
My question is: the second idea is pretty much a literal definition of an XOR gate, but I wonder if there are any trick ways to make one of these with fewer chips. Any thoughts you might have would be appreciated. thanks!
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