Subject: Re: slightly-off-topic: serial ports?
To: Jacob H. Suter <jsuter@intrastar.NET>
From: Tim Shoppa <shoppa@alph01.triumf.ca>
List: port-vax
Date: 08/05/1997 11:10:05
> Ok.. I've gotta make myself some serial cables. I've got some VS3100's
> and some VT320-C2 (vt320 dumb terminals made by digital). Anyone got the
> pin-outs for these ports (whats tx/rx/dts/dsr/ground/etc)...
If you can't find any MMJ plugs locally, you can either just get a
regular RJ11 and file the jack until it fits (it won't latch in)
or you can buy the plugs mail order, from places like Digi-Key
(1-800-DIGI-KEY). I also sell complete cables.
>From the comp.unix.ultrix FAQ:
26. What are the pinouts of the MMJ jacks on the back of various DECstations
and VAXstations?
This describes the 6-pin modified modular jack (MMJ) used for serial ports
on various DECstations and VAXstations, as well as on other DEC equipment.
DEC carries four DB-to-MMJ adaptors. They are internally wired as follows
Rdy Out TX+ TX- RX- RX+ Rdy In
Adaptor Gender 1 2 3 4 5 6 Use with:
--------------------------------------------------------------------------
H8575-A F 20 2 7 7 3 6&8 VTxxx terminal
H8571-C M 6 3 7 7 2 20 DEC printer
H8571-D M 6 3 7 7 2 20 Modem
H8571-E M 20 2 7 7 3 6&8 Female terminal
or LaserWriter
--------------------------------------------------------------------------
RS-232 using DB-25 connectors:
DTE DCE
Terminal Modem
or computer
Pin Number Signal Name
2 TD Transmit Data -->
3 RD Receive Data <--
7 GND Ground ---
6 DSR Data Set Ready <--
8 DCD Data Carrier Detect <--
20 DTR Data Terminal Ready -->
Tim. (shoppa@triumf.ca)