Re: Serial console on second port?

[Johnny Billquist <bqt%softjar.se@localhost>]

It should perhaps be pointed out that all such cables should in fact be 
"null"-modem cables, since we're talking about connecting two DTEs.
Too bad that almost no one except DEC actually read the RS-232 specs.
Now, MMJ isn't exactly RS-232, but it's close enough to be discussed in 
the same sentence here. (Lots of companies seem to have been confused 
about DTE and DCE, as well as which gender the connection should be 
depending on this.)

One nice property of MMJ is also that for a null-modem cable, you should 
connect 1-6, 2-5, 3-4. So it's symmetrical. So the easy way to see if a 
cable is a null-modem cable is just to inspect the connectors. If they 
are turned the same way at both ends, it's a null-modem cable, and if 
they are the opposite ways, it's a straight cable.

        Johnny

Steve Davidson wrote:
> The actual DEC cable part number is BC16E-XX where XX is the length in
> feet.  The most common were 10 and 25 foot lengths.  They appear to be
> null-modem cables (I'm looking at one now).  One other supplier (in the
> US, anyway) is:
>
> http://www.callcct.com/Shop/On-Sale-Now/BC16E-10
>
> -Steve
>
>
> -----Original Message-----
> From: port-vax-owner%NetBSD.org@localhost 
> [mailto:port-vax-owner%NetBSD.org@localhost] On
> Behalf Of Martin Husemann
> Sent: Monday, March 30, 2009 04:42
> To: port-vax%NetBSD.org@localhost
> Subject: Serial console on second port?
>
> I have a Vax Station 4000 M96 and would like to use it with serial
> console.
> It apparently has two serial ports, one MMJ and another one for the
> printer
> with a DB25 connector.
>
> Since MMJ adapters (or even connectors) are pretty hard to get hold of
> here
> (or unreasonable expensive) - is there an easy way to just use the DB25
> connector instead?
>
> Thanks,
>
> Martin
> P.S.: there seems to be no "console mode switch" to select keyboard or
> console
> on this machine (like on the M60) - is it hidden somewhere or should I
> expect
> it to just work?
>
> P.P.S.: I have a SFX graphics, but lacking a video cable for that
> (working
> on solving that too), so I'm basically blind - please excuse the stupid
> newbie questions.


--
Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt%softjar.se@localhost             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol