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From: forys@boulder.UUCP (Jeff Forys)
Newsgroups: comp.dcom.lans
Subject: Re: talk problems between SUN and uVAX - (nf)
Message-ID: <300@boulder.UUCP>
Date: Sat, 10-Jan-87 03:42:08 EST
Article-I.D.: boulder.300
Posted: Sat Jan 10 03:42:08 1987
Date-Received: Sat, 10-Jan-87 09:35:43 EST
References: <6300001@iaoobelix.UUCP> <16784@ucbvax.BERKELEY.EDU>
Reply-To: forys@boulder.UUCP (Jeff Forys)
Organization: University of Colorado, Boulder
Lines: 25
Summary: 4.2 and 4.3 talk not really compatible

In article <16784@ucbvax.BERKELEY.EDU> Erik E. Fair writes:
> "talk" as distributed with 4.2 BSD UNIX is a badly written program.

I dont know, certainly by todays standards it's poorly written, but
it was probably the first of its kind and it did work pretty well in
an all-vax environment...

> I am given to understand that the new version which is distributed with
> 4.3 BSD UNIX is much better behaved (and among other things, it is also
> backward compatible).

True, 4.3final `talk' finally speaks in network byte order, but it's not
backward compatible -- in fact, it even uses a different port.  It just
*looks* backward compatible because the old talk daemon (well, actually
inetd) hangs out on the old port (517) but tells you to respond using
`/usr/old/talk' (same old 4.2 talk speaking VAX-ese).

The new talkd sits on a different port (518), and says to use `talk'
when responding.  Of course, all this is hidden from the user and
everything looks compatible.  Clever idea.  In my opinion, this *had*
to be done... everyone remember hacking 4.2 talk (oh yeah, with that
UDP checksum fix) to speak in a mixed machine environment.  Whew!
---
Jeff Forys @ UC/Boulder Engineering Research Comp Cntr (303-492-6096)
Forys@Boulder.Colorado.Edu  -or-  ..!{hao|nbires}!boulder!forys