cool! that was a not so common expansion card for those machines! 
the db25 is not the console, its (i think) the third of the three mmj 
ports. 
wrt the expansion cable for the 36 pin centronix, this sounds a lot like
the same thing thats on a CXA16.. theyre going to be mmjs, not db25s. i have
one or two of those _somewhere_ that i know im not using all of at the 
moment.. if you cant find one anywhere else, one of mine oculd serve. 
do you know if the serial mux it connects to is supported? 
happy hacking,
isildur

On Mon, 21 Oct 2002, Brian Chase wrote:

> I've got an early MicroVAX 3100; one of the ones that just reads
> "MicroVAX 3100" across the front.  On the back of the system there are
> three MMJ serial ports identified as 1-3, there's an DB-25M port which
> I'd imagine is serial port 0 (the console), and beneath that is a
> 36-pin Centronics style connector labelled 4-11 with the DEC serial
> port pictograph beneath it.  I'd gather this is for some sort of serial
> port cable "octopus."
> 
> Does anyone have a spare one of these cables or a part number for
> this cable?  Thanks.
> 
> -brian.
> 
>