Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!usc!apple!bionet!agate!shelby!rutgers!njin!uupsi!cci632!ph
From: ph@cci632.UUCP (Pete Hoch)
Newsgroups: comp.sys.mac.programmer
Subject: Re: SwapMMUMode? or GetPixBaseAddr?
Summary: GetPixBaseAddr and 32 bit addresses.
Message-ID: <43514@cci632.UUCP>
Date: 28 Nov 90 18:10:13 GMT
References: <77758@ipl.jpl.nasa.gov>
Organization: Computer Consoles Inc. an STC Company, Rochester, NY
Lines: 21

In article <77758@ipl.jpl.nasa.gov>, mkt059@ipl.jpl.nasa.gov (Mike Tschudi (Cartographic Applic.)) writes:
> Has anyone had experience with SwapMMUMode or 32-bit QuickDraw's
> GetPixBaseAddr?
 
> I'd like to alter the values of pixels in an offscreen GWorld, but
> GetPixBaseAddr says that it returns a 32-bit pointer that is the
> only way to get to the offscreen GWorld's PixMap, and SwapMMUMode
> crashes my Mac (IIcx using Think C 4).
 
I think you will find that the documentation for GetPixBaseAddr said
that you may get a 32 bit address back.  There is another call to
find out if it really is a 32 bit address.  Now ask yourself, "Where
would a 32 bit address come from, since my Mac runs in 24 bit mode?"
The answer my friend is ridding on the NuBus.  If you want to support
the 8/24 GC graphics card from Apple then you may get a 32 bit address.
If you don't care about this card, then do not worry.

If you want to do the right thing and supprot it, then I suggest you
get a real development system where you can call SwapMMUMode. ;=]

Pete Hoch