Drive listed as unknown device by mac os 10.5 Terabyte drive connected to iMac 2.8 GHz dual core

Question

Terabyte drive connected to iMac 2.8 GHz dual core Intel by an 800 to 800 firewire hums but does not light up and is listed by the computer running Leopard 10.5.0 as unknown device, model and manufacturer.Computer does say max speed is 800mb/sec but connection speed is unknown. I think my connections are good and proper and I powered up as the last step. Apparently the startup software WD states is on the disc did not install the drive so I assumed I needed an upgrade for compatibility. I tried WD button manager software to no avail. I need help to find the proper software if indeed that is the problem. Thanks Martin