10.6 install ATI card crashing install

[vr00m]

I've been trying for the better part of two days to get Snow Leopard installed on my system. Not getting it to work. If there's some noob friendly instructions, would be appreciated. I'm comfortable enough using Nix but I don't know where to start - EFI string, kext, DSDT, bootup string.......

 

Specs as follows: Gigabyte EP45-UD3R, Core2Quad, XFX ATI 4850 512 MB.

 

Now, I realise I'd probably have a heck of a lot less problems if I chose the Sapphire or NV card. I like the ATI cards and hadn't researched enough at the time to know the XFX as opposed to the Sapphire would be more difficult. That said, I have a working, bootable 10.5.5 iDeneb system which I was using to burn the .dmgs, create the bootable USB key. The USB key boots. Ditto boot-132/Chameleon but I always get a crash with bad video - gabled and black background, black screen.

 

Verbose output always shows stuck at message similar to:"Client task not privileged to open IOHIDSystem for mapping memory".

 

I've tried the Chameleon 2.0 RC3. No luck. I've tried Lifehacker USB method (I know they used NV card).

 

I also found Empire EFI bootloader. Tried the ATI and "Normal" builds - both the default and legacy builds. No luck.

 

I'm also aware there's an ATI thread on this form w/instructions on the 48xx series incl 4850. I don't know if these are intended for post-install instructions. Seems most of the posts there are from people who have booting systems with 10.6 already installed.

 

So .....

 

How can I make a CD or USB drive I can boot into and start the installer. No matter what I've tried, it always crashes before I can get to the installer. I noticed iDeneb uses a Vesa 16 MB ATI Bios at startup. Anyway I can get this to work?