BI & CI in Ultrix land

[George Robbins]

Well, as a capacity planning excercise, I'm looking at either a 6X00
or one of these newfangled 58XX systems and trying to come up with
a realistic configuration.

A few questions:

1) Are there any real problems with the BI serial controllers, either
   the DMB32 or DHB32?  For example two of the current unibus controllers
   are seriously compromised: the DMF32 has hard-wired modem control that
   makes it all but useless with smart modems, and the DHU11 output speed
   is really limited to 9600 baud, with obvious consequences.

2) Are there thruput/performance limitations that would favor multiple
   DMB32's vs a DHB32 or the opposite?  How large are the input fifos
   and are they shared between all lines? 

3) Is anybody out there using CI attached disks on an Ultrix system?
   How does performance compare to Massbuss or BI attached drives?
   Does Ultrix really get any benefit from the rather expensive CI
   hardware? 

4) How about CI attached tape drives?  The lack of direct attachment
   for TU78 class drives is a real bummer.  I don't particularly want
   to downgrade to a TU81+.  Does anyone actually use TK70's for
   backup on mid-range systems?
-- 
George Robbins - now working for,	uucp: {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr at uunet.uu.net
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)