Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!dimacs.rutgers.edu!dpz From: dpz@dimacs.rutgers.edu (David Paul Zimmerman) Newsgroups: comp.dcom.lans Subject: 10BaseT && serial - don't try this at home kids Keywords: what a hack Message-ID: Date: 26 Jul 90 02:03:10 GMT Distribution: comp Organization: Rutgers University DIMACS Lines: 38 I've got a floor that is AT&T wired for 4 twisted pair to each office. That includes my office. I needed to get two connections to my office, one serial connection for my PC and one 10baseT for my Sun. It almost looked like I had to do a new 4 pair run for the second connection, but decided to try a hack: In the closet, I punched down 2 pair serial in my now-standard pattern: 1 (jack pin 5) cisco RxD 2 (jack pin 4) cisco TxD 5 (jack pin 3) cisco ring (I don't use it on the DTE but punch anyway) 6 (jack pin 6) cisco ground Then I punched in the Cabletron 10baseT stuff non-standardly: 3 (jack pin 1) normal 4 (jack pin 2) normal 7 (jack pin 7) shifted from 5 (jack pin 3) 8 (jack pin 8) shifted from 6 (jack pin 6) In the room, I took a 4 cubit length of flat 8 conductor (my standard wall-to-computer cabling) and stripped off half the length of outside gray plastic. On the intact end, I crimped a 8 conductor modular normally. On the other end, I crimped 4 of the now-flailing wires normally for serial (3->3, 4->4, 5->5, 6->6). I then crimped the other four to reverse my 10baseT closet hack (1->1, 2->2, 7->3, 8->6). It actually works, if you don't mind looking at it, just don't tug very hard on those modular connectors :-). It certainly saved me the work and cost of another wire run. BTW - yes, if I had thought out my wiring plan a little better four months ago when I started forming my wiring plan, I wouldn't have had to do the shifting. In fact I probably could have also instead just gotten a modular adapter to duplicate the 8 conductor wall socket into two 8 conductor connectors. David -- David Paul Zimmerman dpz@dimacs.rutgers.edu Systems Programmer rutgers!dpz Rutgers Univ Center for Discrete Math and Theoretical Computer Science (DIMACS)