Don Hopkins wrote:
> emacs /usr/ucb/sendmail (or whatever directory you keep all your
> stinky hippie software in), ^S DEBUG ESC M-b ^D ^Q ^@ ^X ^S (that is,
> null out the first character of the “DEBUG” command).

This piqued my interest, because exiting incremental search with ESC
doesn't look familiar to me (unless in ITS).  I tried it in a recent
Emacs, and just got "ESC M-b is undefined".  Emacs 18 was contemporary
with the Morris Worm.  Would it allow ESC?