From: utzoo!decvax!harpo!duke!unc!mcnc!jcw Newsgroups: net.dcom Title: Re: question on 2-wire phone connections Article-I.D.: mcnc.1300 Posted: Thu Sep 2 07:04:17 1982 Received: Sun Sep 5 03:15:38 1982 References: mh3bs.185 Your old (or new, for that matter) dial phones will work fine with red and green (tip and ring in telco parlance) swapped. However, the oscillator in the tone pad requires power to operate, and the power must be of the correct polarity. The power is obtained from the phone line, which has a nominal 48 volts DC across it with nothing connected, and about 24 volts when 'off hook'. Nothing else in a standard phone requires a particular polarity, so you can still receive calls on your touch-tone phone wit the wires reversed.