12 Sep
2002
12 Sep
'02
8:51 a.m.
On Sep 12, 9:51, Ethan Dicks wrote:
That won't work. The LocalTalk/PhoneNet adapters are not passthrus.
Apple LocalTalk adapters contain self-terminating connectors (the
plastic pip in the end of the cable pushes on a switch that disengages
the internal terminator; PhoneNet adapters use RJ-11s with
external terminators), and both adapters contain at least a transformer,
IIRC to couple the Mac to the network. There might also be a resistor
or two in the adapter. I haven't opened up one in over 10 years.
All the commercial LocalTalk and Phonenet adaptors contain an isolating
transformer, which is carefully designed to preserve nice clean square
waves from one side of the interface to the other. Note that you can't
just use any old small transformer! There's a web page describing the
innards at
http://ground.ecn.uiowa.edu/apple2/MiscInfo/Hardware/appletalk.phonenet
It's also commonly believed that the Farallon Phonenet system using
unsheilded cable works better than Apple's own grounded shielded cable
system.
However, I have seen one DIY design that didn't use an isolating
transformer. Called CapNet, it was intended for small networks, and used
capacitors to acheive some degree of isolation. A slightly updated version
was claimed to work with printers and the like.
http://hyperarchive.lcs.mit.edu/HyperArchive/Abstracts/info/hdwr/at-connect…
http://www.loten-am-mac.yucom.be/cap1.htm
--
Pete Peter Turnbull
Network Manager
University of York
--- Carlos Murillo <carlos_murillo(a)epm.net.co>
wrote:
> >> Now I have another question: How do you
connect the Fastpath 4's
> >> DE-9 Localtalk connector to a phonenet network?
With a standard (ancient) DE-9<->PhoneNet
adapter. Barring that, I
have made DIN-8 to DE-9 LocalTalk adapters
You would need a female DIN-8 connector to go the
other way.
That would be the trickiest part... I think that I should
try wiring the DE9 directly to a 4wire phone cable; it is easier
to find a phone cable than a female DIN8. 
12 Sep
12 Sep
1:24 p.m.
--- Pete Turnbull <pete(a)dunnington.u-net.com> wrote:
On Sep 12, 9:51, Ethan Dicks wrote:
Perfect! Just the sort of page I knew existed somewhere... here's
a helpful table from it:
And here are the serial connections from page A-4 of "Inside Appletalk"
Second Edition:
Wire Sig MiniDIN-8 DE-9
-------------------------------------
Red TxD- pin 3 pin 5
Blu RxD- pin 5 pin 9
Wht RxD+ pin 8 pin 8
Grn TxD+ pin 6 pin 4
GND Case Shield Shield
That's the information you need to make a MiniDIN-8 to DE-9
adapter like the one sitting next to me (I really didn't want
to have to pull it and whip out the continuity tester; I *knew*
this was not hard-to-get information).
The comment that page makes about hooking Apple's cable scheme to
Farallon's is absolutely true. My mother's network had a satin
cable with an Apple connector on one end, and an RJ-11 on the other
to bridge the two wiring schemes. I did not make it. She did not
make it. AFAIK, she bought it from Farallon.
Thanks for the excellent link, Pete.
-ethan
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--- Carlos Murillo
<carlos_murillo(a)epm.net.co> wrote:
> >> Now I have another question: How do
you connect the Fastpath 4's
> >> DE-9 Localtalk connector to a phonenet network?
> >With a standard (ancient)
DE-9<->PhoneNet adapter. Barring that, I
> >have made DIN-8 to DE-9 LocalTalk adapters
All the commercial LocalTalk and Phonenet adaptors contain an isolating
transformer, which is carefully designed to preserve nice clean square
waves from one side of the interface to the other. Note that you can't
just use any old small transformer! There's a web page describing the
innards at
http://ground.ecn.uiowa.edu/apple2/MiscInfo/Hardware/appletalk.phonenet 
4:59 p.m.
I thought I should post the url of a good resource for older Macs
that I found:
http://home.earthlink.net/~gamba2/
carlos.
--------------------------------------------------------------
Carlos E. Murillo-Sanchez carlos_murillo(a)nospammers.ieee.org
13 Sep
13 Sep
2:40 a.m.
And here are the serial connections from page A-4 of
"Inside Appletalk"
Second Edition:
Wire Sig MiniDIN-8 DE-9
-------------------------------------
Red TxD- pin 3 pin 5
Blu RxD- pin 5 pin 9
Wht RxD+ pin 8 pin 8
Grn TxD+ pin 6 pin 4
GND Case Shield Shield
Progress report: I made the adapter and turned on the shiva fastpath.
After a few seconds, all of the machines connected to phonenet
flashed a message: "Your appletalk network is now available".
Not that they could not see each other before; but now, the
fastpath box seems to have "zoned" the appletalk network;
the Appletalk control panel in all machines now has different
info in the "current-zone" field, the "Network" field and
the "Network Range" field. Wow. Talk about self-configuration.
The "network" application in the Powermac 8100 shows the named
appletalk zone under a tab, containing all of the machines currently turned
on. There is another tab, named "etalk" (probably by the previous
owner of the fastpath box); I guess that's the ethertalk side
of the network. I haven't connected that side to the enet hub yet;
I need to do some reconfiguration first. But things look good.
Carlos.
--------------------------------------------------------------
Carlos E. Murillo-Sanchez carlos_murillo(a)nospammers.ieee.org
12 Sep
12 Sep
4:55 p.m.
At 08:53 PM 9/12/02 GMT, you wrote:
All the commercial LocalTalk and Phonenet adaptors
contain an isolating
transformer, which is carefully designed to preserve nice clean square
waves from one side of the interface to the other. Note that you can't
just use any old small transformer! There's a web page describing the
innards at
http://ground.ecn.uiowa.edu/apple2/MiscInfo/Hardware/appletalk.phonenet
-snip-
Thanks Pete! Excellent links. By the way, I had found an apple
PDF file documenting most ports, but the serial mini DIN8 connector
shown in page 2 seems to be have the wrong pin numbering; according
to my own measurements, pin 4 is actually closer to pin 3 than
to pin 5; if the pins were numbered in right to left, bottom-up
order the picture would be right:
http://www.apple.com.pl/infotech/varia/Ports/Ports_Pinouts.pdf
(2MB download)
The document that you referenced shows a numbering that is in accord with
my own measurements. A case of an official document being wrong and a
hobbyist-produced document being right.
--------------------------------------------------------------
Carlos E. Murillo-Sanchez carlos_murillo(a)nospammers.ieee.org
8137
days inactive
8138
days old
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