PowerMac 6500?
You can upgrade to OS 9.1 if you want to do that. Also, if you can find a PCI USB card then OS9 has USB drivers you can install. Would give your Mac USB 1 ports.
Generally, for showing off our PowerPC Macs it's here:
https://forums.macrumors.com/threads/post-your-powerpc-setup.1399769/
Second sticky post at the top of the subforum.