SCSI SCA connectors

OT, sorry - but are there any SCSI fans on the list who know anything about the SCSI SCA standard? If so can you dro me an email off-list if you know the answer to the following... I've got a couple of drives with SCA connectors and adapters plugged into them to bring them out to the more normal 68-pin connectors. There's a bunch of inline resistors on each adaptor which I'd like to know whether they are terminators or just something that's needed when connecting an SCA device to a normal SCSI bus. Both drives work together happily despite the resistors (have been doing for the last 2 years anyway) which surprises me if those are terminators, but nothing works if I try to chain anything else onto the same bus which makes me wonder... ps. one of the drives is 6 years old, but not ten - so take notice of 60% of this email or something :-) cheers Jules