I finally managed to install the following image on my iMac G5 :
https://cdimage.debian.org/cdimage/ports/current/
The installation went fine. When I start the system, the grub menu loads allowing me to select Debian Linux to boot. On selecting the option it goes through the startup process and the last thing was 'Starting Gnome manager' (or something to that effect). It then hangs with a black screen and a small blinking cursor on the top left corner.
It took many attempts to get here. Still no luck. Any suggestions?
Pat