Need help with DSSI/SCSI and an ext CD-ROM

Hi, I need some help with a Vax 4000-200. I picked up an RRD43 CD-ROM drive and installed it into an external SCSI-1 enclosure. On the 4000-200 on the far left side of the QBus slots is a slot with 2 connectors, one appears to be a standard SCSI-1 connector and the other is an inverse SCSI-2 connector (labels Bus 0) with a terminator on it that lights up on power up. I attempted to hook up the RRD43 to the SCSI-1 connector and after power up at the >>> prompt I do a show device and show dssi and the internal DSSI drives and the TF85 show up, then it shows the ethernet AUI port and Mac address, but nothing on the SCSI devices (CD-ROM set to device #6, then I tried device #4, no change) Show SCSI shows nothing. So, what am I doing incorrectly??? Is that port usable as an external SCSI-1 connector??? I have a terminator installed on the Drive enclosure. I picked up a spare dual SCSI Qbus board, but before going down that road and having to set it up and such I just want to make sure that I can use the built in SCSI bus first (or not) Any and All help is greatly appreciated, I would really like to get OpenVMS installed on this unit and get it up and running, thanks. Curt