Doing undo in Vi editor

I generally use 'u' to do undo in vi editor. The problem is that it only does one level of undo.

Is it possible to recursively undo all the changes in vi editor till we reach the original stage.

Hi

:e!

Guru

Just for info, If you use vim, the command "u" will do exactly what you want.
to redo the change in vim,

:redo

In vi, "u" is like a toggle between undo and redo.