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[TRLog] Multi-Operation

Subject: [TRLog] Multi-Operation
From: (Kenneth E. Harker)
Date: Mon, 1 Apr 2002 07:30:03 -0600
On Sun, Mar 31, 2002 at 04:12:31PM -0500, Ralph T. Stetson III wrote:
> Mike another option that I did not see in Guy's note is an "Null Modem
> Adaptor/Dongle" that plugs in at either end of the standard serial cable
> they come in 9 and 25 pin flavors as well as many gender combinations.
> This way down the road you wont have to worry about the internal wiring of
> any given cable.  I have been using these Adaptor/Dongles for years now and
> really does help in the sanity maintenance department for this fuzzy ol
> operator
> Good luck and look forward to working you during FD as well

What I do is different.

At each computer, I have wired a serial port connector with two RG-174 
(you could use any small diameter coax) pigtails.  The pigtail that has 
TX on the center pin and GND on the shield is terminated in an RCA male
connector.  The pigtail that has RX on the center pin and GND on the shield 
is terminated in an RCA female connector.

When two PCs are sitting next to each other, just plug the RCA connectors
together in the only way they can go.  If the computers are spread out,
all you need is regular RCA M-F extension cables, and it's impossible 
to get TX going to TX or RX going to RX because of the connector genders.

> Ralph Stetson KD1R
> ----- Original Message -----
> From: "Guy Olinger, K2AV" <>
> To: "Mike D." <>; <>
> Sent: Sunday, March 31, 2002 1:28 PM
> Subject: Re: [TRLog] Multi-Operation
> > If you are connecting a pair of laptops with a straight serial cable,
> > they will never be able, has zilch to do with the program.
> >
> > If you want to directly connect two serial ports, you have to use a
> > "null modem" cable which flips the send pins on one end to the receive
> > pins on the other. You can sometimes buy a null modem cable at a local
> > computer store or radio shack.
> >
> > If not and you have to make your own, search the TR archives for "null
> > modem" and you will find some prior posts that give the pin
> > connections that you need to wire one up.
> >
> > If you are already using a null modem cable, then it is most likely
> > related to having the baud rates in the two, unequal, or too fast, or
> > with different settings.
> >
> > 73, Guy.
> _______________________________________________
> TRLog mailing list

Kenneth E. Harker      "Vox Clamantis in Deserto"
University of Texas at Austin                   Amateur Radio Callsign: WM5R
Department of the Computer Sciences      VP, Central Texas DX & Contest Club
Taylor Hall TAY 2.124                         Maintainer of Linux on Laptops
Austin, TX 78712-1188 USA  

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