hey paul...
visit the thread:
http://macos9lives.com/smforum/index.php?topic=305.0i installed 9 on my mdd using this os9general.dmg
u should be able to install 10.5 no problem from a retail disc
and then restore this os9general.dmg
to the os9 drive u want to boot from.
or u can use this freshdraginstall file
which has even more recent versions of driver files for video etc
i have an mdd dual 867mhz with an 8500 that dual boots between osx panther + os9.2.2
and i installed using these files... i had tried many times previous to that to install with retail discs and it drove me bananas;)
what did u do with the os9general.dmg? u have to use disk utility and restore it to a physical drive from the image file
https://support.apple.com/kb/PH5848 <-- read this re: single partition dmg's
also:
make sure u partition the os9 drive in 2.. with no partition size being larger then 190gb
and then restore the dmg to the first partition on the drive (id reccomend two 128gb partitions)
i personally would name the first of the os9 drive partitions "os9" and then the 2nd i would name "data"
and restore the dmg to the first os9 partition so it can be selected as the startup disk
u can review the info here:
http://macos9lives.com/smforum/index.php?topic=397.0aswell for clarity re: partition sizes