SCSI CD burner

I've been going crazy here trying to get a burner working. One flat-out won't see a disc, even though I bought that one brand new (though that was a while ago and I made the mistake of continually using it for a CDROM drive as well), another one has mechanical problems, and then there's this external unit... It's a Yamaha CRW4260tx. I don't have a cable to connect from it to the Adaptec 2940 card that's installed in the machine. I currently have a 50-pin cable running from the inside connector on the Adaptec card to the internal connector on the drive (with its cover off). I'd like to put the drive in the box. Right now for both device number and termination these functions are handled by the external drive's box, on the rear panel. Can any of you guys help me with whether jumpers need to be _on_ or _off_ a pair of pins to make termination happen and to assign a device number? I'd measure it with a meter but don't have any handy means to get into those connectors at the moment... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin