Thompson.PA@XEROX.COM (06/02/88)
Re: ---------------------------------------------------------------- >Subject: Three wire lines (was 2 line wiring) >Date: 27 May 88 23:48:21 GMT >Reply-To: mdf@tut.cis.osu-state.edu (Mark D. Freeman) >My house was built in the 1920's and was wired for telephone with 3 >wires. I can understand two or four, but three? Why? The three wire are TIP, RING and GROUND (or SLEEVE in the CO). In a residence phone with multi-party service it was used to split the ringing circuit. For two party service they would ring from either TIP or RING to GROUND. The conversation took place across TIP and RING. Geoff Geoffrey O. Thompson Xerox Corporation 475 Oakmead Parkway Sunnyvale, CA 94086 U.S.A Telephone: (408) 737-4690 ARPA Mail: Thompson.OSBUNorth@Xerox.COM
dave@westmark.UUCP (Dave Levenson) (06/04/88)
In article <880601-154524-5927@Xerox>, Thompson.PA@XEROX.COM writes: > >Subject: Three wire lines (was 2 line wiring) ... > The three wire are TIP, RING and GROUND (or SLEEVE in the CO)... Ground and Sleeve are not equivalent. Sleeve is used to mark a line as being busy. It is grounded sometimes. Ground, on the other hand, is always grounded, and (as the original poster reported) is used to selectively ring the parties on a two-party line. -- Dave Levenson Westmark, Inc. The Man in the Mooney Warren, NJ USA {rutgers | clyde | mtune | ihnp4}!westmark!dave