G5 Woes

[Stephen Donahue]

I recently acquired a dual 2.7ghz G5 and have since been attempting to
install YDL version 6.0 (with little success). My plan is to dual boot
linux / osx.

My problem, I cannot begin the install process. The machine will boot
to the optical drive and load the bootloader. From there, everything
goes downhill.
I arrive at the "check media" screen (it verifies the disk integrity
successfully). Once I proceed to the actual installer the computer
suffers horrific graphical issues
The screen image becomes distorted, warped etc. At this point I am
unable to proceed. I found a tip online which stated that I should
lower the monitor resolution to 800x600.
However, as soon as I get to the check media screen the monitor
reverts to its native resolution (see below)

My Hardware:

dual 2.7ghz G5 PPC
2 GB DDR SDRAM (two 1 GB PC3200U-30330 sticks)
ATI Radeon 9650 (AGP with 256 megs vram)
20 inch apple cinema display