There were a number of emails on exception handling to the
Squeak list from about 8/4/97 to 8/7/97 or so that should be of
interest also. You can see them at the CREATE site:

http://www.create.ucsb.edu/squeak/

There were two threads: "VisualSmalltalk-like Exceptions and insured
execution" and "Implementing unwind-protect without virtual machine
modification"

-- Dwight