Need pinouts for MDB Systems DLV11J serial line interface

From: Pete Turnbull <>
Date: Sun Oct 31 03:51:49 2004

On Oct 30 2004, 17:02, Vintage Computer Festival wrote:
> I've got a serial line interface in this LSI 11/23 system I've got
> It's made by MDB Systems and is model DLV11J. I've got the manual
for the
> DLV11 but it gives the digram for one big 40 pin Berg style
> whereas the DLV11J has 4 10-pin Berg style connectors.
> Does anyone have the documentation for this?

Not for that make/model, but for a DEC DLV11-J, yes. The DLV11 is a
single RS232 interface, by the way, and the DLV11-J has 4 serial lines.

Looking into each 10-pin socket, the pinout is:

        | |
        | 9 7 5 3 1 |
        | |
        | 10 8 6 4 2 |

         1 UART clock in or out (not normally connected)
         2 Signal ground
         3 Tx +
         4 Tx -
         5 Signal ground
         6 Index position - no pin
         7 Rx -
         8 Rx +
         9 Signal ground
        10 +12V via fuse F1 (if fitted)

The receivers are differential. If you're using them for an RS-232
device, connect a link between pin 7 and one of 2, 5, or 9, to make the
RX- line ground-referenced, then use 3 for TxD and 8 for RxD.

Loopback connectors for testing usually jumper 3 to 8 and 4 to 7
(RS-422 mode) but sometimes jumper 3 to 8 and 7 to 9 (RS-232 mode).

On a DEC DLV11-J, there are several wirewrap jumpers to set baud rate,
word length, address, etc, and also two to set channel 3 to the console
address, if required. Channel 3 is the connector nearest the left as
you look into the back of a machine, with the board fitted
component-side up. The jumpers are labelled C1 and C2; link X to 1 if
you do want the console on channel 3, or X to 0 if you don't. There's
also a set of three labelled B/X/H which determine what happens if you
send a break if Ch.3 is the console. Jumpering X to B makes the system
boot (it grounds the BINIT line), jumpering to H makes it halt (grounds
the BHALT line). Leave it disconnected if you don't want either

> And now for a really stupid question:
> Can the 11/23 run RT-11?

It will run it very well. Several of my 11/23s came with RT-11 of one
flavour or another.

Pete						Peter Turnbull
						Network Manager
						University of York
Received on Sun Oct 31 2004 - 03:51:49 GMT

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