[plug] Easymail

[david.buddrige at mitswa.com.au]

I've a brother who could 99.9% certainty, build one/more of these... will
ask him about it on weekend... 8-)

regards

Dave... 8-)

> -----Original Message-----
> From:	Denis Brown [SMTP:dsbrown at cyllene.uwa.edu.au]
> Sent:	Friday, March 19, 1999 2:27 PM
> To:	plug at linux.org.au
> Subject:	Re: [plug] Easymail
> 
> Mike Holland wrote in part...
> >Anyway, reverse engineering the protocol sounds like fun.
> >Is there any existing software to log two rs-232 streams in parallel, so
> >you can see the sequence afterwards?
> >
> 
> Too much of a newbie to know about such software on Linux but here's an
> old-timer's trick which worked reliably bL (before Linux).
> 
> Take two silicon signal diodes (1N914, 1N4148 or similar) and connect
> their
> anodes together (un-banded ends).  To this common anode connection, add
> one
> end of a 10 kilohm resistor.  That forms the "output" signal which you
> wire
> to the Rx line of your snooper port.  Then take one cathode (banded end)
> to
> each of pins 2 and 3 on the RS232 connector carrying the data stream.  The
> unused end of the resistor goes to a 9 to 12-ish volt positive supply
> (positive wrt ground); a 9-volt transistor radio battery works well.  In
> some cases the resistor and positive supply isn't needed -- just depends
> on
> how critical your snooper Rx interface chip is about otherwise floating Rx
> lines :-)  There's no magic in teh choice of 10 kilohm, either; anything
> from 7.5 kilohm through to 33 kilohm should work okay, it's just a bleed
> after all.
> 
> As long as the snooper is able to swallow incoming data without dropping
> bits, you'll capture both streams.  That technique was a Godsend in
> earlier
> days.  No reason for it not to work just as well now.  Yes, you'll
> probably
> have to eyeball at least some of the data stream but with any luck the eol
> character(s) will be obvious so the streams should be easy to seperate.
> 
> HTH
> 
> Cheers,
> Denis
> 
>