Thanks to all who replied.  The solution is (original query included 
below):
> Beware that only the internal or only the external plug may be
> usable. 
So, options are - plug the external disk into the internal bus, or
purchase a new SCSI card.
original query:
> We have a personal workstation alpha 433 running tru64 4.0D.  It has a 
> qlogic SCSI card from which the internal disks are attached.  The card 
> also has an external wide port (68 pin).  When trying to add an
> external disk the following scenario occurs.
> 
> Before external disk added show dev reveals the internal disks:
> 
>        dkc0.0.0.1008.0	   DKC0
>        dkc500.5.0.1008.0   DKC500
> 
> upon adding the external disk, and doing a reset, using show dev the
> system returns the polling error:
> 
> 	waiting for pkc0.7.0.1008.0 to poll?
> 
> 
> If I don't do a rest after adding the external disk, then all the
> disks disappear from a show dev.
> 
> The external disk is a standard 9GB IBM, the cable is a 68pin to
> 50pin microD.
> 
> Does anyone know what is happening, and how to attach an external disk 
> correctly to this system?
~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~
Andrew Gillies                     
Institute for Adaptive & Neural Computation        
Division of Informatics              EMAIL A.Gillies_at_anc.ed.ac.uk
2 Buccleuch Place                    PHONE    +44 (0)131 650 4408 
Edinburgh EH8 9LW                    FAX      +44 (0)131 650 4406
Scotland                             WEB     
http://anc.ed.ac.uk/
Received on Mon Aug 02 1999 - 10:35:42 NZST