DSSI != SCSI.  even though the same chip is used in DECstation 3100,
the wiring is completely different than SCSI.  

The SII chip is a difficult chip to program.  (or so the persons who
did the support for under ULTRIX told me).

I wish you luck.
-- 
Matt Thomas               Internet:   matt@3am-software.com
3am Software Foundry      WWW URL:    http://www.3am-software.com/bio/matt.html
Westford, MA              Disclaimer: I disavow all knowledge of this message