I am trying to install Debian 10.9 on the old iMac G5. I burned the 'debian-10.9.0-ppc64el-netinst.iso’ image to CD on a newer iMac (2017). When I boot the iMac G5 holding the ‘Option’ key down with the CD inserted, the G5 doesn’t recognise the CD as a bootable CD. I then did the same with the 'debian-bullseye-DI-rc1-ppc64el-DVD-1.iso’. Till the same problem. I was able to install Ubuntu Mate 16.04 for powerpc without any problem.
Can you please help me to solve this problem? Kind regards Pat
