Installing 10.5 on iBook G4 = Fail. Help with booting?

[z11111]

So I have my Leopard DVD installer that I want to put on my iBook, but I can't, for many reasons.
1. My built in Combo Drive won't recognize the installer DVD, so I can't install that way.
2. The only drive I have that will recognize the DVD is a external USB DVDRW drive, and after lots of research, I am already well aware that you cannot boot a G4 (let alone any PPC) from USB.

So what can I do? Can I burn some sort of image to a CDR that will let me boot from my USB drive? I read about modifying firmware so a G5 will boot from USB, but I'm not sure if this will work. I mean, in a worse case scenario I can go out and buy a firewire cable and boot in Firewire Target Disk off a friend's Mac, but I'd like a simpler solution if possible.

Thanks

[Giaguara]

Which iBook? Specs? CPU speed, RAM amount, HD size, model or at least year?
Does it meet system requirements?
Is it a black or a gray Mac OS X install disc? If it's gray forgettdaboutit, those are CPU specific just like the discs that shipped with your iBook...

[z11111]

One year later I am back with no success.
I will be upgrading to a Macbook relatively soon, I think/hope, but for now, I would still like to get my Leopard disc working on my iBook G4.

It's the 933 Mhz iBook G4 14". It meets the system requirements for Leopard (1.12gb ram, enough disk space, etc), but the problem I run into is that my Combo Drive (not superdrive) will not recognize the Leopard DVD (which is definitely Dual Layer, when I check the info). My Leopard DVD is the retail disk, not machine specific.
I know it won't boot from my Combo Drive for whatever reason and apparently I'm not the only one who experiences this, but I would like to get it working from USB DVD writer drive. I am also aware that a G4 cannot boot from USB, but I have found many references that tweaking Open Firmware can make this work. However, the only even slight resource I can find explaining how to do this is how to boot OS X from a USB drive...I don't want to do that, I just want to boot and install my Leopard disk!

Thanks

[DeltaMac]

Prior to Leopard (OS X 10.5), you are correct about USB booting, which is fairly challenging to do. That changed with Leopard, however, and you can boot your G4 from the Leopard installer through a USB external optical drive.
The difference with Leopard? Older system will reset the USB bus during boot, which makes it impossible to boot from USB without somehow preventing that USB reset. That's where the open-firmware commands are used.
The Leopard installer does not reset the USB bus during boot. SO, if you tried it, you should find that it will work, at least with Leopard....

[redghost]

YOu could also try a remote install using another mac running Leopard. It allows you to use the DVD drive of the other computer to install to your iBook. I tried it and it worked great on both a 1.33 and 1.42 that had faulty optical drives that were later replaced.