Yeah, I misunderstood it. I should have specified that the drive I was using is an NP model of Fujitsu U160 SCA drive, that does have the jumper for Narrow mode. Am I correct to assume that my SCA U320 drives that aren't recognized in the same setup, and don't have the narrow mode jumper setting, would work in a narrow bus Mac with the upper bits properly terminated? @max1zzz's thread on terminating the adapters does have an example on terminating the upper bits on one of these adapters, if I recall correctly, so I might need to try that and see if my 72GB drives would work on Macs then.