Path: utzoo!attcan!uunet!husc6!bloom-beacon!mit-eddie!killer!vector!nobody
From: jbn@glacier.stanford.edu (John B. Nagle)
Newsgroups: comp.dcom.telecom
Subject: Re: Tip and Ring reversal
Message-ID: <telecom-v08i0209m07@vector.UUCP>
Date: 25 Dec 88 17:59:36 GMT
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X-TELECOM-Digest: volume 8, issue 209, message 7


      A "classical" Touch-Tone phone (WE 2500) won't work with tip and ring
reversed.  Talk and ring work, but the keypad is dead.  Newer phones have
diode bridges so that polarity is irrelevant.

      Older coin telephones use polarity reversals to control the coin
mechanism, incidentally.

						John Nagle