dlw@ucbopal.CC.Berkeley.ARPA (03/28/84)
We had some trouble with DEC transceivers, which look visually identical to Interlan I've seen. Our technical people ordered a cable a fraction larger diameter then what DEC specifies. It worked fine with 3Com screw-on transceivers but when we first spiked in a DEC transceiver the cable shorted. Our DEC FE thought it was a bad transceiver, or that we should use a special drill (a la Interlan) to make the "hole". In a moment of inspiration one of us noted that the "larger" cable was slightly oval on the transceiver channel. Forcing the pin in a little farther (with a small ball bearing under the spike screw) caused it to come to life. No short; everything worked fine. We now have the "right" cable but I thought the experience might be useful to some of you out there. David Wasley dlw@Berkeley
Jeff@decwrl.UUCP (03/29/84)
Here's my experience with transceiver/interface compatability: Interface: DEUNA 3Com Interlan Xcvr ================================================================ H4000 works not tried not tried 3Com doesn't works works TCL works not tried works We think the DEUNA/3com combination fails because the 3com xcvr eats a few bits of the "preamble", which is apparently legal, but the DEUNA self-test microcode can't deal with that. As to crashing a system by plugging in the xvcr: yes, the Interlan board draws a large surge and causes a DC LO. The DEUNA's cable attachment panel apparently cures this, because we don't have that problem with DEUNAs. -Jeff (...decwrl!Shasta!mogul, mogul@shasta.ARPA)
fred@mot.UUCP (Fred Christiansen) (10/29/84)
[ what is this line for? ]
This site is a fairly recent addition to Usenet news, and this is
my first posting. Kindly forgive me if this has been discussed in the past.
We just "discovered" that there are TWO styles of Ethernet Transceivers,
and that depending on the "type" of Ethernet being used, you must use one or
the other type of Transceiver.
There is "Ethernet 1" and "Ethernet 2" (Ethernet 2 is "compatible" with the
802.3 standard, Ethernet 1 is not).
The LAN software we just received is Ethernet 2, and must use the latter
type of transceivers. The correct ones from TCL have model numbers which are
suffixed with "I" or "IS". Previously we (and our vendor) have been using
ones with a "E" or "EB" suffix. For the new LAN software release, the "E" and
"EB" ones are WRONG!
How well known is this problem? Anything else we need to be aware of?sunny@sun.uucp (Sunny Kirsten) (11/06/84)
> [ what is this line for? ] > This site is a fairly recent addition to Usenet news, and this is > my first posting. Kindly forgive me if this has been discussed in the past. > We just "discovered" that there are TWO styles of Ethernet Transceivers, > and that depending on the "type" of Ethernet being used, you must use one or > the other type of Transceiver. > There is "Ethernet 1" and "Ethernet 2" (Ethernet 2 is "compatible" with the > 802.3 standard, Ethernet 1 is not). > The LAN software we just received is Ethernet 2, and must use the latter > type of transceivers. The correct ones from TCL have model numbers which are > suffixed with "I" or "IS". Previously we (and our vendor) have been using > ones with a "E" or "EB" suffix. For the new LAN software release, the "E" and > "EB" ones are WRONG! > How well known is this problem? Anything else we need to be aware of? It is well known that the 802.3 Standards Committed is well influenced by manufacturers who are entering the LAN market well after the emergence of Ethernet 1 as a standard, and they went out of their way to make Ethernet 2 (802.3) incompatible with Ethernet 1, to negate the market-place lead-time that the existing Ethernet 1 manufacturers had gained. -- exit {ucbvax,decvax,ihnp4}!sun!sunny (Sunny Kirsten of Sun Microsystems Inc.)