Ok, so more information (sorry).

The drive was set to scsi id 1, with the original internal hard drive at id 0 and the cd drive at id 3.

It is jumpered to force narrow ("no-wide"), and also jumpered to force single-ended (though in reading through the documentation for this drive, it should automatically set to SE if the drive determines it's needed).

The drive does not have termination, but shouldn't need it as it's in the middle of the chain.

I also tried booting from 8.6 and it still wasn't seen by any of the formatting tools.

And yes, the drive is spinning.