Xref: utzoo comp.sys.mac:10955 sci.electronics:1889
Path: utzoo!utgpu!water!watmath!clyde!rutgers!husc6!think!ephraim
From: ephraim@think.COM (ephraim vishniac)
Newsgroups: comp.sys.mac,sci.electronics
Subject: Re: Appletalk Connectors
Keywords: What's inside that little box?????
Message-ID: <15128@think.UUCP>
Date: 20 Jan 88 17:58:44 GMT
References: <1498@bgsuvax.UUCP>
Sender: usenet@think.UUCP
Reply-To: ephraim@vidar.think.com.UUCP (ephraim vishniac)
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Organization: Thinking Machines Corporation, Cambridge, MA
Lines: 20

In article <1498@bgsuvax.UUCP> hovan@bgsuvax.UUCP (John Hovan) writes:
>	Does anyone know what makes appletalk connectors special?  A few 
>readings with an ohmmeter showed that the connectors are not merely a straight
>though cable.  One possible explanation is that the box supplied with 
>appletalk has an optically isolated circuit inside its 2" x 1" mysterious
>box. Has anyuone been brave enough to open one of these boxes and solve the
>mystery???  If you have, please let me know!  They cannot be complex since 
>the appletalk hardware only uses 3 wires from the computers subminature
>din-8 jack.

I opened up an AppleTalk connector last year, and found an isolation
transformer and a trivial amount of wiring.  The connector box is
glued shut, but it's possible to open it without damaging the contents
by prying carefully all the way around the seam.  You'll undoubtedly
inflict some cosmetic damage, but not very much if you're careful.

BTW, bgsuvax complains that "hovan" is an unknown user!

Ephraim Vishniac					  ephraim@think.com
Thinking Machines Corporation / 245 First Street / Cambridge, MA 02142-1214