How do you spell "Nerd?"

By 1960, the word Nerd had a meaning very close to its current one (perhaps a little more antagonistic in those days), but it also had an alternate spelling that, I think, has pretty much disappeared: knurd. I remember very inconclusive discussions in 1960 about the correct way to spell this word, but I suspect knurd lost out due to the utter lack of correlation between nerds and drunks.