Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uwm.edu!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu!m.cs.uiuc.edu!p.cs.uiuc.edu!gillies
From: gillies@p.cs.uiuc.edu
Newsgroups: comp.sys.mac.programmer
Subject: Re: Finding the size of the screen unde
Message-ID: <104700069@p.cs.uiuc.edu>
Date: 15 Jan 90 17:38:42 GMT
References: <10139@saturn.ucsc.edu>
Lines: 20
Nf-ID: #R:saturn.ucsc.edu:10139:p.cs.uiuc.edu:104700069:000:590
Nf-From: p.cs.uiuc.edu!gillies    Jan 13 11:28:00 1990


/* Written  2:51 pm  Jan 12, 1990 by beard@ux1.lbl.gov */
#To access low-memory globals from C, you would say
#
##define CurrentA5 (*(long *)0x904)

A cleaner way to do low memory globals from THINK C is the ':' notation.

extern Ptr CurrentA5 : 0x904;

This method gives you do type checking if you want.
/*****/

Actually, I can't see the benefit of the THINK C notation, except to
make your code non-portable (to other Mac C compilers).  It seems like

#define CurrentA5 (*(Ptr)0x904)

Would give you the type-checking you need.  I'm not sure this
extension is an asset in Lightspeed C.