Helen Keller mode

Helen Keller mode n.  1. State of a hardware or software
   system that is deaf, dumb, and blind, i.e., accepting no input and
   generating no output, usually due to an infinite loop or some other
   excursion into {deep space}.  (Unfair to the real Helen Keller,
   whose success at learning speech was triumphant.)  See also {go
   flatline}, {catatonic}.  2. On IBM PCs under DOS, refers to a
   specific failure mode in which a screen saver has kicked in over an
   {ill-behaved} application which bypasses the very interrupts the
   screen saver watches for activity.  Your choices are to try to get
   from the program's current state through a successful save-and-exit
   without being able to see what you're doing, or to re-boot the
   machine.  This isn't (strictly speaking) a crash.