The stty command sets the terminal in non-echoing mode, it is not a
shell builtin and such it doesn't matter what shell you use. It might
work on ksh since the (original) ksh is using some clever combination of
raw and cooked mode and thus can have the terminal echoing (or not
echoing) things. I don't know if ksh93 still does this, though. Tcsh is
doing character-by-character reads and echoes back on its own, so stty
-echo doesn't have an effect on it. You can however try to disable
tcsh's editor with "unset edit", in which case, tcsh will revert to
reading full lines from the terminal (in raw mode). This should achieve
what you want.

F'up-to comp.unix.shell, since it doesn't belong in this newsgroup.