When you boot off of the LinuxPPC 2000 Q4 CD-ROM or CD image , you should see a splash screen with a count down timer set for 10 seconds. At that screen, hit the space bar and it should take you to the configuration screen . The first three icons have different video settings.
Many machines require special video arguements to be passed to the kernel at boot time.
The 266Mhz Apple PowerBook G3 can have strange video artifacts unless you use a modified version of the Ultra Safe Video setting. Contact the webmaster .