Xref: utzoo comp.unix.questions:15734 comp.unix.xenix:7164 Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.csd.uwm.edu!cs.utexas.edu!uunet!portal!cup.portal.com!compata From: compata@cup.portal.com (David H Close) Newsgroups: comp.unix.questions,comp.unix.xenix Subject: Re: Using the DigiComm multi-port board with SCO Xenix Message-ID: <21364@cup.portal.com> Date: 17 Aug 89 03:30:58 GMT References: <963@lakesys.UUCP> <170@hrtix.UUCP> Distribution: usa Organization: The Portal System (TM) Lines: 36 David Raines recently comments: > I believe they [Digiboard] also have an adaptor for RJ-45 connectors, > which would be nice, but I have other machines with other IO boards > and every manufacturer seems to have their own idea of what RJ45 > pin configurations should be. (ARE YOU READING THIS Digiboard, > Bell, Arnet, Anvil, etc. etc....). > Actually, Digiboard has the closest setup of all boards that > I,m aware of, to what I,d like to see. If the pins were symmetrical, then > the same adaptors could be used for either modems, computers, terminals,etc. > by simply flipping the wire. > Example: 1 DTR --------- > 2 GND ------ | > 3 RTS --- | | > 4 XMT | | | > 5 RCV | | | > 6 CTS --- | | > 7 GND ------ | > 8 DSR/DCD ----- > Any thoughts? Yes. Many terminals operate just fine on three wires. It's a shame to require a 6-or 8-wire cable to support these devices. 4-wire IW cable is cheap and widely available. Tools to crimp the connectors are cheaper than RJ45 also. It seems to me that, if RJ45 is to be used, the TxD, RxD, and SG pins should be grouped in the center so that RJ11 connectors and cables can be used when appropriate. The example shown for Digiboard (which I cannot independently confirm) almost makes it but SG is too far out. I've the same complaint on the Bell Tech boards I've used. Surely, the crosstalk problem isn't so bad that these three signals must be so widely separated? Dave Close, Compata, Arlington, Texas compata@cup.portal.com