MACL2.0b deftraps commented as "Not in ROM" - how to access?

[cdj@tc.pw.com (Cris Johnson)]

Some of the traps mentioned in the interface files included with MACL2.0
are commented out with the remark "Not in ROM" and coded with a
(:stack-trap #x0) specification.  Is there some officially blessed way
to access these things?

I have access to MPW3.1 and have found in the past that I could include
LISP access to MPW functions via the foreign function interface and one
or more of the object files included with MPW.  While I was happy to get
the access I wanted, it seemed like I was doing a lot of groping in the
dark with one object file causing others to be needed in ways I couldn't
predict, and it seemed that I ended up loading far more things than I
truely needed or wanted despite my best efforts at specifying options
to the foreign function interface calls.  Is a procedure such as this
implied by the "Not in ROM" comment?  Do I have to acquire MPW3.2 to get
functions new to MAC-OS 2.0?  If so, are (deftrap ) and the foreign
function interface related? - deftrap isn't documented.

Thanks,
Cris Johnson 
Price Waterhouse Technology Centre 
68 Willow Road, Menlo Park, CA 94025 
(415) 322-0606