changes to support MacMiNT

[brad@tazboy.Jpl.Nasa.Gov (Brad Pickering)]

Hi MiNT people -
  I have ported MiNT 0.95 to the Macintosh, and I'm starting to port version
1.04.  For my 0.95 port I basically hacked around until it worked.  For
the 1.04 port I would like to be a little more systematic.  It turns out that
the major changes to MiNT have to do with low memory addresses.  MiNT wants
to find certain system globals in low memory but the Mac stores its own
stuff there, so the the Mac version of MiNT needs to look somewhere else for
these values.  What I would like to suggest, so that my port will be cleaner,
is that access to low memory globals not be hard coded.  I have started
two files: one to be included in assembler files and one to be included by
C files.  The following is what I have in 'locore.i', the assembler include:

%ifndef MAC
%define LC_TERM ($408).w
%define LC_FRAME ($59e).w
%define LC_FLOPLCK ($43e).w

%define GEMDOS 1
%define AES 2
%define BIOS 13
%define XBIOS 14
%else
	XDEF	_mac_term
	XDEF	_mac_frame
	XDEF	_mac_floplck

%define LC_TERM _mac_term
%define LC_FRAME _mac_frame
%define LC_FLOPLCK _mac_floplck

%define GEMDOS 1
%define AES 15
%define BIOS 2
%define XBIOS 3
%endif

The other header would do the same sort of thing for C files. This would make
it easier to port and not much more complicated.

What do you think?

Brad