undo continually vi

Question

Hi, I am using vi(not Vim) and I would like to continually undo the changes made. u works for a single command undo and Ufor a single line undo. But Is there a way to undo continuously like vim(I recall a command in vim can even undo changes by time!) in vi? Thanks in Advance.

Edit: I am using vi version 3.10

Answer 1

Repeat the undo, with the . key.

Answer 2

If this is nvi, AFAIK you simply can't.