Total accident I found this site.  It's more VMS oriented buy under   
Hardware Documentation is some stuff on the 3100 and 4000 that might be   
of interest to some.

http://vstlnr.irb.hr/htbin/webbook/$2$DKB200:[PUBLIC.DECW$BOOK]/

John A. Maier
Kemper Military School and College
Director of MIS
Voice: 660-882-5623
Fax: 660-882-3778
Email: johnam@kemper.org
Web: www.kemper.org