Beginner's questions about Electric

   Excuse my stupid questions, but I'm struggling with some basics
here.

   How can I change the technology of a cell? Up to now, I have edited
its text file!

   Is it true that a cell can only exist inside a library? I can't seem
to save a cell to the working directory.

   Are libraries all writable? I am struggling to stop corrupting one
of the reference libraries copied from the web site.

Thanks for the advice, Graham Petley