[comp.sys.mac] MDEF 0 on System 4.1

tomc@mntgfx.MENTOR.COM (Tom Carstensen) (10/13/87)

I'd really like to avoid having to write my own MDEF
when is practically done for me in System 4.1, but
it seems to depend on perhaps some other patches.

What else, if possible do I need to include in my resource
file (beside the MDEF) to make the MDEF work on all 
systems/machines (the HFS menus)?

In looking at the MDEF assembly language, I noticed that it
checks in a few places for a new trap (calling NGetTrapAddress).
with the HEX value 9F.  What trap is this?

:------------------------------------------------------------:
: Tom Carstensen              Usenet: tomc@mntgfx.MENTOR.COM :
: Mentor Graphics             GEnie:                         :
:------------------------------------------------------------:

jww@sdcsvax.UCSD.EDU (Joel West) (10/14/87)

In article <970@mntgfx.MENTOR.COM>, tomc@mntgfx.MENTOR.COM (Tom Carstensen) writes:
> In looking at the MDEF assembly language, I noticed that it
> checks in a few places for a new trap (calling NGetTrapAddress).
> with the HEX value 9F.  What trap is this?

The next thing it does is call NGetTrapAddress with some other trap
and then compare the two returned addresses (he predicted, not
having looked at the code).  Trap A89F is the standard unimplemented
trap, so if the address of any trap is the same as that for A89F,
there is no such trap.  For example, _PopUpMenuSelect ($A80B) is
only implemented in System 4.1 or later, as is _InitProcMenu ($A808).

This is all covered in the August 1987 MacTutor.
-- 
	Joel West  (c/o UCSD)
	Palomar Software, Inc., P.O. Box 2635, Vista, CA  92083
	{ucbvax,ihnp4}!sdcsvax!jww 	jww@sdcsvax.ucsd.edu