@Jim,

Interesting! It appears that the previous owner had taken the hard drive cage that was vertical in the back of the case behind the optical drive bays, and placed it under the optical drive bays. It is the exact same cage that works in both locations, so if you like it vertical, behind the optical drive bays, you can easily unhook it from where it currently is sitting, and move it to the other hard drive cage location. IIRC, the faster IDE100 controller is the one that feeds the IDE cable that goes to the hard drive cage behind the optical drive bays, not to the one under the optical drive bays. You might want to check to make sure which one goes where, as I am sure you would rather use the IDE100MHz controller, instead of the IDE66MHz controller for your boot drive(s) and only use the IDE66MHz controller if you are going to use more than two hard drives in your FW800 PowerMac. I need to confirm which controller is the faster one in my MDD PowerMac, so I will have my MacOSX & MorphOS hard drives on this faster IDE controller too.