Subject: RE: Still need DHV11 (M7940) docs
To: None <>
From: Jim Bender <>
List: port-vax
Date: 09/30/1998 14:00:37
>Dear Vax Gurus,
>I am trying to connect a VT220 to a VAX 11/785.  The 11/785 has a frontend
>processor which is a pdp 11/03.  The 11/03 has a Serial Line Unit (SLU, aka
>DHV11/M7940) card in it that is the point of connection for the mainframe

You mean DLV11, right?   DHV11 is a multi port async mux that someone
else here was trying to get working with PPP....

>console.  The problem I am having is getting any kind of documentation on
>the DHV11 (M7940). Several people have posted that they will at some time
>post this information but haven't yet. Also some have suggested that the pin

I have posted the pertinent pages from the DHV11 manual (rest of it to
come if anyone is interested) and the full DL11 manual.   The DL11 is
the unibus version and the 40 pin berg is the same pinout.

>outs of the M7940 are the same as the unibuss DHV11 but it appears that this
>is not the case although this is somewhat hard to verify because I may not
>have the jumpers on the M7940 in the correct position.  The cable coming off
>of the DHV11 (M7940) is a DEC part number BC03L-05, which has a 40 pin berg
>connection on one end (M7940 end) and a 25 pin male connector on the other
>end.  It would be my guess that this would imply the use of a null modem
>(both VT220 and console port being DTE's) cable between the console and the
>VT220 but this does not work regardless of the baud rate set or other
>configurations set at the VT220.  I have several of the DHV11's (M7940's)
>and a M8017AA, a complete spare of the front end processor and cable, so I
>have swaped everything at some point to verify that a bad card or card
>cage/power supply is not the problem.  This of course points me back to the
>configuration of the DHV11 both jumbers on the board and cable.
>Can anyone give me a hand on this one?

Please see for the info.   Page 2-10 has
the complete pinout of the 40 pin berg.

I have the actual DLV11 manual and printset floating about and will
post that as well if anyone has any interest.

>Thanks in advance.
>Rick Copeland
>Information Systems Manager
>InterMag, Inc.   

Hope this helps...