BI & CI in Ultrix land

[Leeland Heins]

In article <7373 at cbmvax.UUCP> grr at cbmvax.UUCP (George Robbins) writes:
>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?

   We were running Ultrix for a short time on our VAX 8250 which has a BI
bus.  The DMB32 looks pretty much like a BI version of the DMF32.  Since there
is as yet no driver for the DMB32 for 4.3BSD-Tahoe (which we upgraded to) we
are no longer using the DMB32, its just sitting around gathering dust.

>  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,

   Only the first two ports on a DMF-32 have modem control.  We are using
DMF32's with Hayes-clone modems on the first two ports, and they work fine.
We are also using Emulex CS21/F, which is a DMF32 look alike (two DMF32's
on one hex Unibus card).  The Emulex card has modem control on all 16 lines.
Of course, you have to set the flags in your config file when you build your
UNIX kernel to turn on modem control.

> and the DHU11 output speed
>   is really limited to 9600 baud, with obvious consequences.

   Hmmm...  is the DHU11 really limited to only 9600bps?  TMF says it will
do 19,200, but not 38,400.  I haven't used one so I can't say if that is
really right or not.

>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?

   I don't know about CI tapes.  If you can hang a Unibus on the machine your
cheapest route to tape drives may be 3rd party.  We have a TU81+ that we aren't
using because DEC won't give us enough technical info to write a device driver
for the BI bus KLESI-B card.  It works fine under Ultrix, but the TU81+ as you
implied, is no speed-demon.  We probably could have gotten the Unibus KLESI-U
controller, but we couldn't find anyone who is actually using one with a TU81+,
and althought most of the people I talked to "assumed it should work", that
wasn't good enough for me.  We are replacing the TU81+ & KLESI-B with a
Ciper M990 and an Emulex TC13 (TS11 emulating) Unibus controller.  Its a
combination we know works, and the M990 seems to be about 3x faster than the
TU81+, not to mention less expensive.  We've had some old 1600bpi Cipher drives
with Emulex controllers and they've been trouble free for years.

>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)

  //|||\\   "Attack of the killer 	Lee Heins, EXNET Programmer
 //-O-O-\\   mutant techno-hippies	Iowa State U. Extension
 ||  v  ||   from Hell"			heins at atanasoff.cs.iastate.edu
 || === ||				...!hplabs!hp-lsd!atanasoff!heins
 || --- ||
/// `|' \\\	Disclaimer: I am not an official spokesman of ISU.