Can I save source files in Clisp?

Question

I'm a beginner programmer and am going through the book "Land of Lisp".

I have been typing in the examples from the book with the REPL. Is it possible to save my current program as a .lisp file so I can load it and continue working on it later? I know I can just create the .lisp files in a text editor and load them in, but I am enjoying using the REPL in full screen mode to do the examples.