Saving in version 0.30

I've been playing a lot of the older versions recently, due to nostalgia and simplicity (sorry, I'm just not that in to the newer versions, to me 1.2.5 and before is the best), but I have been trying to save a world in 0.30 that has some nice stuff I built in it, but when I try to, it doesn't create a new file for the world. I know you will probably not do anything about this because it is outdated and almost nobody plays it anymore, and I think you have said you will not fix the old versions, but I need to know a way to save it, or atleast get a reply, or anything.

Long time player and fan, SCZealot.

P.S. Don't listen to the affects version tag. I wanted it to say 0.30, but it won't permit me to