Leopard- Install on unsupported hardware

Uh, no!

No personal experience with this type of setup, but I have to ask you... if the minimum requirements are twice the speed of your CPU, why would you want to run leopard? People with 1GB of ram on new Intel machines, like myself, have upgraded to 2GB simply because 1GB was waaaaaay too slow, even with Tiger and now you want to run it on a 400mhz system?

There has to be a cutoff point, which is why G3's are no longer supported under leopard, so why would you want to force feed leopard to an old G4?

Its crying out to you and wants to be put in that big electronic retirement home in the sky. Let it go man... let it go

 

I honestly don't think you will get a good user experience with that setup but I am interested in how it will turn out...
if you succeed I'd very much like to hear how it is.

 

What do you see when you do a Option-V reboot? What does the log say?

 

It won't say anything. Command-V may help though

See here for cool instructions on making a Leopard install DVD that removes/changes the processor speed check

An alternative method is to install Leopard on a supported faster Mac, then image the hard drive. You can then restore the image to your "unsupported" Mac (note: G3s are not invited to the party). There are reports this even works between Intel and PPC Macs, but I haven't confirmed this myself.