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From: Andrew Stesin <stesin@gu.kiev.ua>
Message-Id: <199607291639.TAA17631@creator.gu.kiev.ua>
Subject: Re: Problems connection a terminal!!
To: Lars_Koeller@odie.physik2.uni-rostock.de (Lars Koeller)
Date: Mon, 29 Jul 1996 19:39:13 +0300 (EET DST)
Cc: hardware@freebsd.org
Reply-To: stesin@gu.kiev.ua
In-Reply-To: <199607291551.RAA07802@odie.physik2.uni-rostock.de> from "Lars Koeller" at Jul 29, 96 05:51:12 pm
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Hello,

| > 	I've seen such a caveat.  Terminal we used to play with had a DCE-style (!)
| > 	DB25 connector, just like a modem; but it was wired as plain DTE,
| > 	so none of our ready-to-use null-modem cables worked, and
| > 	a "normal" straight DTE-DCE cable didn't work either.
| > 
| > 	So we were forced to solder a "crazy" nullmodem ourselves.
| 
|       Yes, that could be the solution, can you  send me the wire scheme for
|    such a 'crazy cable' please? 

	Just a plain vanilla "full null modem" cable,
	you should probably find a scheme in any RTFM.
	TD/RD and RTS/CTS are crossed, GND is straight (of course :).
	(Sorry, my right arm is still broken, so it's difficult
	for me to perform ASCII art exercises just now).

	BUT you need a null-modem with one male
	and one female connector (usually null-modem cables
	have 2 female connectors, because DTE be it a PC or a terminal
	or whatever _usually_ is male connector).

	The easiest way to do this is to get a cheap miniature device
	from Patton Electronics, look at http://www.patton.com
	which allows you to create just any RS232 wiring scheme
	with a mini plugs and nit also has LEDs to monitor what's
	going on. I think you might find a null-modem wiring schema on their
	site, too -- their printed catalog have some.
	And I've seen this kind of mini devices from other vendors, too.

	OR you may take a plain modem cable, cut it in the middle
	and cross-solder appropriate signal wires (that's what we did).

	Hope this helps.  (BTW -- our terminal was an Esprit one).

-- 

	nic-hdl: ST73-RIPE