Please read this document in its entirety before using LeopardAssist.
What's New?
Version 3.0 introduces several new additions to LeopardAssist, and is a complete rewrite from previous versions.
- Complete Rewrite with extensive under-the-hood improvements and optimisations.
- Redesigned interface and icon.
- Limited customisation of startup options now available on G5 systems.
- Users can now choose to start in Single User Mode and Safe Boot after restart.
- Added automatic detection of Single and Dual processor systems.
- Added the ability for users to specify a custom processor clock frequency.
- Added detection for unsupported architectures and insufficient memory.
- Added option to boot from USB where supported.
- Reset Firmware Defaults now performs a complete Open Firmware reset on restart.
- Improved security when handling passwords at Authentication stage.
What does LeopardAssist do?
LeopardAssist assists in the process of installing OS X Leopard on PowerPC based Macs, including machines that did not meet the minimum system requirement of an 867MHz or faster processor. It achieves this by temporarily writing a script into the NVRAM of your G4-based Mac. Executed at startup, this script will temporarily force the system to report that a faster processor is installed, allowing the Leopard installer to successfully complete its minimum system requirements check.
This allows Leopard to be installed from unmodified installation media or another bootable device. LeopardAssist handles the interaction with Open Firmware, specifying the target processor speed, the number of physical processors in the system, the desired boot device and any additional startup flags to simplify the installation and configuration process.
Some aspects of LeopardAssist are derived from the article "Faking Out the Leopard Installer with Open Firmware", written by Dylan McDermond for LowEndMac (www.lowendmac.com).
How do I use it?
LeopardAssist will run on any G4 or G5 based Mac with a previous installation of OS X Panther 10.3 or OS X Tiger 10.4. Insert or connect your OS X Leopard installation media, ensure you are logged in as an Administrator and follow the prompts in LeopardAssist to prepare the system for installation.
Known Risks & Issues
LeopardAssist has been tested across many different systems and hardware configurations, however it is impossible to accurately test every different possible combination of hardware and software. While all changes made by LeopardAssist are designed to be reversible, the software can not be guaranteed to function correctly across all configurations and is provided on an as-is basis.
- Installing an Operating System requires a minimal amount of preparation and post-install configuration. Anyone that does not possess a basic knowledge of Macs or the process of installing an operating system may wish to consult with someone more knowledgeable on the subject before attempting to use LeopardAssist.
- OS X Leopard may not function correctly on all unsupported hardware configurations. While Leopard can generally operate on most G4-based Macs, some issues may be experienced, such as reduced functionality as a result of missing or incomplete kernel extensions, or an inability for a machine to successfully enter sleep mode or take advantage of other power saving features.
- After the system is restarted or installation completes, some users may experience undesired behaviour of their machine. To clear any changes made by LeopardAssist, users should power off their Mac, hold down the Command (Apple) + Option + P + R keys and power on the system. Continue holding the keys down until you hear the startup chime a second time. Once Leopard is installed, LeopardAssist is no longer required.
- After installing OS X Leopard, some users may experience an issue that causes the machine to shut off during startup. Starting up from the Leopard install disc and performing a Disk Repair and Permissions Repair from within Disk Utility usually resolves this problem.
- Some machines may Kernel Panic (crash) while attempting to start up into OS X Leopard, displaying an "Unable to find driver for this platform" error in the crash output. If this occurs, your computer may require a Firmware Update. You can find information on what firmware updates are available for your computer in Apple support article HT1395 - "Mac OS X: Available firmware updates" ( http://support.apple.com/kb/ht1395 ).
- LeopardAssist makes use of the sudo command and as such may require that a password be set. Attempting to provide a blank password may result in the authentication attempt being rejected.
- WARNING! Users of Third-Party processor upgrade cards that supply their own custom firmware should not use LeopardAssist. Incompatibilities between the changes made by LeopardAssist and the modified firmware may result in consequences such as instability, reduced performance or damage to the firmware, rendering the system unusable.
Technical Support
LeopardAssist is widely used and supported across many specialist Mac communities, such as the MacRumors PowerPC Macs Forum (forums.macrumors.com). Any questions related to the use, care and maintenance of your PowerPC based Mac and the installation of OS X Leopard can be directed to one of these communities.
In addition, further information about LeopardAssist can be found on the LeopardAssist SourceForge site (leopardassist.sourceforge.net).