c-x Altmode

[Moon at MIT-AI (David A. Moon)]

In the version of zwei on system 30.1, with microcode 671, on LISP Machine One:

It doesn't remember numeric arguments; this is a screw with m-x List Callers for 
example.

Typing c-m-Y (I think that's what it is in Emacs, you have to type it a funny
way due to brain damage) at any minibuffer should start over with the previous
thing in the ring of saved commands.  This is in ^U m-alt rather than c-x alt
in Emacs, but you get the idea.