Originally posted by Phil Of Mac
Every SCSI bus needs to be terminated at both sides so that the SCSI signals know when to stop and turn around, otherwise they just go out the end of the SCSI bus and disappear.
That's a good way of putting it. It's kind of like a loop. If there's nothing at the end of one set of wire to send the signal back down the other side the loop is broken. Is the disk still potentially readable without a terminator? Yes. Will it be reliable? Probably not.
If you don't know what a terminator is then I recommend reading up on it and you probably need to get one so that you can terminate that drive you have. It's the most likely reason it's not being recognized at startup.