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LeopardAssist can help in the process of installing OS X 10.5 Leopard on 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, more...

What's New

Version 3.0:
  • Complete rewrite with numerous 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 more...


OS X 10.3 or later

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LeopardAssist User Discussion

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DanieleFox8970 Member IconReview+0

Please Help!

After executing leopardassist witch checked "Verbose" the OS 10.4 on my HD don't starts anymore! On Boot there is the Apple Icon and i can hear the HD loading, but after 1 Minute the Powermac shuts down. What can i do? please help!

Reply1 reply
Version 2.3.3

Sorry, the HD bocomes Broken. But the Installation application says, that the installation isn't possible.

Charneca36 Member IconReview+1

Obrigada! Funcionou. Consegui instalar o Leopard no meu iBook G4 800. Thanks!

Reply0 replies
Version 2.3.3
Take3 Software (Developer) Member IconDev+4
Take3 Software (Developer)

The server was revoked some time ago, after I decided to back down from maintaining the project. I'm surprised this listing is even still here, but because it's lasted for so long i'll turn a copy of 2.3.3 over to MacUpdate for hosting.

LeopardAssist doesn't normally have a problem with CPU upgrades, but since most of the CPU upgrades available on the market push the system past the required 867MHz barrier anyway, there's simply no need for this tool on those systems.

The software was and still is only a frontend to compile and execute a shell script to be deployed into the system NVRAM at boot time, and considering just how little there is to work with in the way of faking a CPU clock speed, it's been developed to the best of my abilities. Now with the release of Snow Leopard, there's not much more that can be done to push LeopardAssist into the future.

Reply0 replies
Version 2.3.3
Micg Member IconReview+37

Poor documentation, the Server's been down for an age.
No support for CPU upgrades that is cleared out in any documentation and it did not work after many attempts.
Luckily I had a Leopard compatible eMac and installed it on a FW 400 PATA drive and booted up on my G4 DA 800MHz and it runs super fast too even on the FW 400 Drive that I still use.

I'm disappointed that Mac utilities for Mac OS X like LeopardAssist can be so cheesy. o_O

Reply0 replies
Version 2.3.3
MacFenton Member IconComment+12

Will LeopartAssist work for an older Mac using a processor upgrade card, such as a Sonnet Crescendo PCI 1GHz?

I seem to recall that it might, but am not 100% on this.

I'd gladly buy a new Mac with Leopard on it IF I had the extra cash laying around, but it seems the wife AND I want to continue to eat and live indoors, for some strange inexplicable reason.

Hopefully LA will fill the void.


Reply1 reply
Version 2.3.3
Anonymous Member Icon

LeopardAssist probably won't be able to correct limitations on this system due to the lack of support for the hardware in Leopard itself. As far as I know, Leopard can be forced onto machines as early as the Beige Power Macintosh G3 (using kernel extensions from the Leopard Developer Preview) but considering it's using a Crescendo PCI, the highest this Mac would be is a 9600 series.

Bob_Vicktor Member IconComment+0

Obviously OSX supports multiple processors, and obviously have more processors helps things run faster, but I was wondering if anybody had any first hand experiences they could share? I have a Dual 533 Mhz G4 (digital audio) and was planning on installing 10.5 and was wondering if it would be worth it.

Reply1 reply
Version 2.3.2
Take3 Software (Developer)

Leopard seems to respond well to multi-processor systems. The key to remember is that Leopard benefits from decent amounts of RAM (768mb-1GB) and will also run quite a bit faster with a 32mb graphics card that supports Quartz Extreme at the very least. Turning off the 3D dock also helps performance.

It should run quite well on your Digital Audio 533, but it's not about to set the world of fire with its performance. If you need it to work at peak performance then Tiger 10.4 is still the champion, but if your main concern is running the very latest browsers or other software, then 10.5 should work well enough to handle thst.

astrodude18 Member IconComment-3

Would this work on installing Leopard on a non-supported computer not built by apple?

Reply1 reply
Version 2.3.1
Take3 Software (Developer)

LeopardAssist only supports Apple manufactured hardware with a G4 processor.

Bonbons Member IconReview+10

Used the previous version to install 10.5 on a Powerbook G4 800/1GB RAM, installation went fine, 10.5 was usable but compared to 10.4 very slow, I think that's a main problem with Leopard. And the 10.5.4 update made it slower once again.
To my surprise new software from Apple needs new hardware from Apple... ;-)

I saw tests were Leopard was called "much faster" than Tiger, well maybe, maybe on Intels, but on my G5 the Tiger runs faster, not to speak from the many G4s around.

If youl think you can't survive without 10.5, this is the way to install it on older Macs, but if you see your Computer as a tool to get your work done or to have some fun, I think Tiger is just fine.

Reply1 reply
Version 2.2

I agree, Tiger seems to be better for older macs, so I wouldn't install it on my quicksilver 800.

Even on a supported powerbook 1,25, 1,5 GB RAM, leopard is slow. It could be an illusion, but even slower from update to update.
Actually under 10.5.5 I'm considering downgrade. It's a pain every time when I'm changing from last generation iMac to my powerbook.

Take3 Software (Developer) Member IconDev+4
Take3 Software (Developer)

I picked up an eMac G4 and decided to do a bit of extra work on LeopardAssist. Did away with boot.txt as requested by beta testers, now writing the 867mhz script directly into the Parameter RAM. This should correct problems on many systems which previously had issues finding boot.txt on restart (a majority of cases).

Reply0 replies
Version 2.0
Justingraziano Member IconComment+0

A great app. Works excellent, it would be nice if there was an option to mod the OS X install DVD so that it doesn't have to be installed everytime you reinstall OS X but it's still nice.

Reply0 replies
Version 1.2
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Current Version (3.x)


Downloads 79,716
Version Downloads 6,615
Type Utilities / System
License Free
Date 06 Feb 2014
Platform OS X / PPC 32
Price Free
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