Before you continue reading, consider two caveats. First, I know the Power Computing PowerTower Pro is not actually a mac, and so maybe doesn't have any business being discussed here. Second, I don't have access to the machine (it's now in my parents' basement thousands of miles away) and I haven't attempted to do what I'm going to ask about for several months, so some details will be lacking and I can't test any suggestions anytime soon. If neither of these bother you, then please read on.
Basically, I've tried numerous times over the years to install various iterations of Panther on my old PT Pro and have never been fully successful. It's got a 300 MHz Sonnet Crescendo G3 card.
I've tried numerous versions of XPostFacto, including the latest one as of about 4 months ago. I've tried swapping out display cards I wasn't sure were compatible (namely a couple of 3dfx Voodoo's and an ATI Rage128,) tried different install discs and different opticals to eliminate the possibility of corrupt installations, and I've manipulated many other factors. I even tried rearranging the SCSI chain and trying to install on drives on different buses.
XPostFacto will install the necessary files to the target volume and the machine will reboot. The installer will run (ostensibly) successfully. Then, after the installation is complete, the machine reboots aaaannnnd....dead. Sometimes infinitely scrolling kernel panic text and sometimes just lockup at the initial Apple Logo screen. I know nothing about the code so the scrolling text is meaningless to me. Also, sadly, I can't provide it right now.
This is perplexing. Basically my question is this: is there anything about the PTP's architecture that precludes Panther's running on it? IIRC I had similar problems with Jaguar. Is there something I'm missing?
I did some more looking around and found a thread on OWC's forum started by a guy with a _very_ similar configuration having similar problems. The thread died 5 years ago when the OP apparently got frustrated and gave up. Here's a link:
http://forum.macsales.com/viewtopic.php?t=1057&postdays=0&postorder=asc&start=0