Reads are now working (a RZ23L gets about 730KB/s).  
Writes seems to never complete.

I had to add a vmapbuf/vunmapbuf routines but hopefully
they won't effect the other disk drivers too much.
-- 
Matt Thomas               Internet:   matt@3am-software.com
3am Software Foundry      WWW URL:    http://www.3am-software.com/bio/matt/
Cupertino, CA             Disclaimer: I avow all knowledge of this message