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From: jc58+@andrew.cmu.edu (Johnny J. Chin)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: null modem cable
Message-ID: <0bdHwzC00W45Q_qfZ1@andrew.cmu.edu>
Date: 29 Jan 91 09:24:15 GMT
References: <2582@s5.Morgan.COM> <8Fy4V2w163w@cybrspc>,
	<3439@nosc.NOSC.MIL>
Organization: Carnegie Mellon, Pittsburgh, PA
Lines: 52
In-Reply-To: <3439@nosc.NOSC.MIL>

Excerpts From Captions of netnews.comp.sys.ibm.pc.hardware:
26-Jan-91  Re: null modem cable           Walter A. Koziarz@halibu (1215)   
>It's never a good move to try to 'fake-out' hardware handshaking!!!!!  Don't 
>do
>it!!  Presented below is *the RIGHT way* to make a null modem cable --
> 
>[1]------chassis GND--------[1]
> 
>[2]-------------------------[3]
> 
>[3]-------------------------[2]
> 
>[4]-------------------------[5]
> 
>[5]-------------------------[4]
> 
>[6]------------------------[20]
> 
>[7]-----signal GND----------[7]
> 
>[8]-------------------------[8]
> 
>[20]------------------------[6] 
> 
> 
>This is the correct wat to make a FULL-HANDSHAKING null modem; throw away
>ANYTHING that tells you to use the 'other', fake-out connection.

What about this cable then?  I've been told by many many product 
manufacturers (including big cable companies ... ie. Black Box) that this is 
a "FULL HANDSHAKING null-modem cable":

    1 ---- 1  (shielding ground)
    2 ---- 3
    3 ---- 2
    4 ---- 5
    5 ---- 4
    6 -+-- 20
    8 -+
    7 ---- 7  (signal ground)
    20 --+ 6
         + 8  (6 and 8 tied on each side to 20 on the other side)

Any suggestions?  What is pin-8 anyway?  Thanks.

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