[plt-scheme] Parse-tracing

Hello, all,

Is there an easy way, in DrScheme v. 103, to disable the visual "parse
tracing" that occurs when the (read) procedure is invoked?  On some of
my students' machines, this turns out to be painfully slow, and I'd
have assumed there would be a parameter controlling it -- but I
haven't been able to find it.

I apologize if this turns out to be an FAQ -- I couldn't find it among
the PLT documentation, nor in DrScheme's Help Desk.  I'll be happy to
look it up myself, if you can point me in the right direction.

Thanks!
-M

-- 
Michael J. Fromberger             | Lecturer, Department of Computer Science
http://www.dartmouth.edu/~sting/  | Dartmouth College, Hanover, NH, USA

"Our enemies shall talk themselves to death, and we will bury them
 with their own confusion.  We shall prevail."