Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!amdahl!nsc!voder!apple!korn
From: korn@apple.UUCP (Peter "Arrgh" Korn)
Newsgroups: comp.sys.mac
Subject: Re: EtherTalk vs. LocalTalk on Mac II
Message-ID: <7364@apple.UUCP>
Date: 9 Feb 88 18:40:28 GMT
References: <9414@steinmetz.steinmetz.UUCP> <11540122@hpsmtc1.HP.COM> <5193@well.UUCP>
Reply-To: korn@apple.UUCP (Peter "Arrgh" Korn)
Organization: Apple Computer Inc., Cupertino, USA
Lines: 44
Disclaimer:  I wasn't hired to give Apple's opinions


In article <5193@well.UUCP> mz@well.UUCP (Michael Zentner) writes:
>
> [LocalTalk,] what is it ?

In the beginning, there was AppleTalk.  It consisted of some circutry
inside a Macintosh CPU, some code to talk over that circutry, and some
cables.  As time went on, more protocalls were added to it, and the
code portion of AppleTalk expanded; but even so, it was still all 'AppleTalk'.
The cables were called 'AppleTalk' cables, talking 'AppleTalk' protocalls
to devices that understood AppleTalk.

Then the picture got more complex.  The transport and physical layers of
the network model started to change.  No longer were all the protocalls 
strictly 'AppleTalk'.  No longer were all of the possible cabling systems 
thin, twisted pair wiring.  Ethernet cards and cabling came along, and
started adding confusion (as well as speed) to the picture.  And to
differentiate things, Apple renamed some of the individual players that 
together make up Apple's networking picture.

The card and circutry inside a machine that allows a Macintosh to send
AppleTalk protocalls over Ethernet wiring is called "EtherTalk" (as in,
"putting an Ethertalk card into your Mac II").  The cabling is called
"Ethernet" (as in, "connect those two Mac II's together with an 
Ethernet cable").  What used to be known as "AppleTalk cabling" (the old
twisted pair stuff that connected Mac Plus-type machines to LaserWriters
in a network [not direct connect]) has been renamed "LocalTalk" (as in,
"connect these Mac Plus machines together with LocalTalk").

The term "AppleTalk" now refers to only the protocalls (the medium level
ones, like NBP, ATP, etc.), and the entire 'networking system' itself
(as in, "does that xyz PostScript printer speak AppleTalk?"; or "I've
got all the office machines talking to eachother via the AppleTalk 
networking system").

Another addition that may have not gotten the press that the LocalTalk 
name change has gotten is "AppleTalk services".  A service is something
provided over AppleTalk, above and beyond  the network itself.  For
instance, AppleShare is an AppleTalk service.  LaserShare is also an
AppleTalk service.  As are Intermail and In Box.  These services also
fall under the umbrella of "AppleTalk networking system".


Hope this clears things up...

Peter