SGI Indigo2 Hard Drive Problem

A couple of months ago I was lucky enough to find a SGI Power Indigo2, with a R8000 CPU. Naturally it came with no HDD sled but it had a DAT drive on a sled which I figured would work. Only problem is that when I put a HDD on the DAT sled, using an 80 pin to 50 pin adapter (known good), I never see a HDD in the firmware (serial console). Googling didn't produce a lot of answers so I figured I'd ask the list. Can the DAT sled be used like this? The SCSI ID selection seems to depend, a little too cleverly, on what bay the sled is plugged into, but the sled has a small cable which is supposed to plug into ID selection pins on the drive. I have nowhere to put that. Maybe the cable needs some of its pins bridged? The drive itself is jumpered to the ID that the machine expects for a boot drive. Is a 9 GB drive too big for the firmware? I am a SGI novice, and my reading of the docs says the firmware should "just see" a correctly configured drive without entering any commands to rescan, but am I wrong about that? Thanks, John