Path: utzoo!attcan!uunet!seismo!sundc!pitstop!sun!amdcad!ames!mailrus!cornell!rochester!pt.cs.cmu.edu!sei!ajpo!eberard
From: eberard@ajpo.sei.cmu.edu (Edward Berard)
Newsgroups: comp.sys.mac.programmer
Subject: Segment Loader and Related Questions
Keywords: Segment loader, language interfaces, 32K limit
Message-ID: <369@ajpo.sei.cmu.edu>
Date: 15 Sep 88 15:27:01 GMT
Lines: 35

I have a number of remotely related questions. They all center around,
or are inspired by the segment loader.

   1. There is a program (Sample.p) which comes with MPW. Near the
      begining of this program there is a line that reads:

                        PROCEDURE _DataInit; EXTERNAL;

      Where is _DataInit documented?

   2. Later in the same program, there is a procedure call:

                        UnLoadSeg(@_DataInit);

      This is, of course, documented in Inside Maintosh (II-59). What
      are the C and the assembly language equivalents of this Pascal
      call?

   3. A number of the segment loader routines are clearly labeled:
      [Not in ROM]. In terms of upward compatibility, and portability,
      should a programmer be concerned about these routines? Are there
      any other considerations?

   4. Some people have informed me that they are not happy with the
      upper bound of 32K. They have said that they might want to write
      their own segment loader which did not have the fixed upper
      limit of 32K. Assuming such a thing is possible, what problems
      should they anticipate? Is Apple doing anything in Version 7.0
      of the System which would mitigate, or otherwise impact such an
      effort? Are there accptable alternative approaches? Is the 32K
      limit still practical given the every expanding memory
      capabilities of the Macintosh product line?

				-- Ed Berard
				   (301) 695-6960