In order for the Chapter 6 examples to run, you must have the QuickDraw GX extension in the Extensions folder of your Mac's System Folder. QuickDraw GX is a part of System 7.5. If you installed System 7.5, but didn't install QuickDraw GX, use your install disks to add it to your system.
QuickDraw GX examples compile and run "as is" when using a Metrowerks compiler. Symantec doesn't fully support GX as of this writing. When the Apple Universal Interfaces (Universal Headers) version 2.1 are available (soon, or now as you read this), GX examples should compile properly using a Symantec compiler. The latest versions of the Apple header files are available on the Internet at ftp.info.apple.com: