It is a well known fact that 9.2.1 and 9.2.2 can be installed unsupported on older machines using some install tricks. This is for the installer to do it's job. It is also a known fact that most everything that is upgraded from 9.1 that Apple is preventing Older machine owners from directly installing can be obtained from the OS updates and a Tomb viewer / expander. Does anyone know what parts of OS 9.2.1 an 9.2.2. will work as replacements to 9.1? Primarily Open Transport? USB support? Firewire support? Could you replace System Suitcase and essentially everything Classic piece by piece? I have already replaced Open GL and Firewire on my 9600 but hesitate to do USB and Open transport? Anyone done it all, or is everyone just afraid of Apple's warning? The force over to a new machine shouldn't be because your next upgrade won't work without that new OS, it should be because you can't live without it.