Bonjor Ian,

I have compiled the 64-bit VM per your instructions with this :
../config/configure --prefix=/opt/local/Squeak64 --enable-shared=yes  
--with-quartz --with-gnu-awk  LDFLAGS='-L/opt/local/lib -L/sw/lib -L/ 
usr/lib' CPPFLAGS='-I/opt/local/include -I/sw/include -I/usr/include'  
--with-src=src64 CFLAGS='-g -O3 -mtune=G5 -mcpu=G5 -mpowerpc64 - 
maltivec -mabi=altivec -mpowerpc-gpopt -mpowerpc-gfxopt -pipe' -- 
without-x --enable-mpg-pthreads

and my environment variables are:
CXXFLAGS=-g -O3 -mtune=G5 -mcpu=G5 -mpowerpc64 -maltivec - 
mabi=altivec -mpowerpc-gpopt -pipe
CFLAGS=-g -O3 -mtune=G5 -mcpu=G5 -mpowerpc64 -maltivec -mabi=altivec - 
mpowerpc-gpopt -pipe
CPPFLAGS=-g -O3 -mtune=G5 -mcpu=G5 -mpowerpc64 -maltivec - 
mabi=altivec -mpowerpc-gpopt -pipe

I did compile with success, however, I am a newbie :) I do not know  
what to do next and how to generate a 64 bit version of the .image file.
when I run

/opt/local/Squeak64/squeak
with 'open' dialog, I chose the latest image file, but I get this  
error in the command line:

allume:~/Desktop/WorkSpace/squeak/merge64/platforms/unix/ppc64 fatih 
$ ./squeak
This interpreter (vers. 68000) cannot read image file (vers. 64).
Press CR to quit...

Any help or any referral to certain material will very much appreciated.

Merci de votre bonne assistance!

Fatih

P.S. Can't we use the -m64 or -arch ppc64 switches with gcc-4 when we  
compile --with-src=src64? I also get this error that ld64 complains  
about some CoreFoundation unknown calls.. I know that the Cocoa parts  
cannot be 64-bit but is it possible to bypass this and build a real  
64-bit VM on Tiger.3?