Best I can tell from the instructions, when you type (edit 'b) it should display b. You should also be able to navigate through your code and hit enter to see the current form. When I use it, I only see my code when I type q to exit the editor.
Is this a bug or just a misunderstanding on my part?
(defun b (x) (pinmode 13 t) (digitalwrite 13 x) (delay 500) (b (not x)))
[shouldn't I see the definition of b here?]
?q [Ok I'll quit]
(lambda (x) (pinmode 13 t) (digitalwrite 13 x) (delay 500) (b (not x)))
[Ah there is what I expected to see, but now I've closed the editor]