TELECOM@Usc-Eclb (09/04/82)
TELECOM AM Digest Saturday, 4 September 1982 Volume 2 : Issue 114
Today's Topics: Public Touch Tone Polarity Sensitivity
Stewartstown - PA or MD
Collect Local Calls When Problems Arise
Reprogramming ESS For Touch Tone
202, 212A, 3400 - 1200 Baud Protocols & Tone Detection
Sprint Charges For Ringing Signal Time
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Date: 3 Sep 1982 04:16:58-PDT
From: whuxlb!mag at Berkeley
Note on coin phone polarity. I know the guys at the labs who designed
those pay phones. I have spent the last year designing testing
methods for them. The polarity sensitivity of the Touch-Tone pad IS,
repeat IS, a security measure. The person who authored the article
saying it is not is all wet. Believe me, I know. With normal
battery, the totalizer will home after any coins are deposited greater
than initial rate. With reversed battery, or in ANY toll situation,
the totalizer will home after EVERY coin, whether or not it equals
initial rate. If its accumulating coins, then the phone is BROKEN.
MAG.
P.S. Perhaps the author was confusing the totalizer with the hopper,
which will accumulate coins untilthe coin relay collects or returns
them.
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Date: 3 Sep 82 7:47:46-EDT (Fri)
From: Carl Moore (VLD/VMB) <cmoore@BRL>
Subject: Stewartstown; NXX
It would be interesting to learn what it says on pay phones in the
Stewartstown (Pa.) exchange. I would guess that it says 717-993
instead of 301-996, and that the (rural?) area served by this exchange
in Md. might not have a pay phone in it.
What "step-by-step" areas are likely to get N0X and N1X prefixes?
(I.e., areas that already have 1+ dialing.) I don't think LA area
(213) had 1+ before N0X and N1X; NYC (212) did not, and Chicago area
(312) does not have it now.
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Date: 3 September 1982 08:29-EDT
From: Jeffrey Krauss <KRAUSS at MIT-MC>
Subject: Collect Local calling
I received a collect LOCAL call last night!! It was in the middle of
a thunderstorm, and my wife was trying to call home from a pay
station, and she was getting no ringing (high-and-dry) after dialing.
The operator refused to assist with the diaaling--that's what they
will do on toll calls--but offered to put through a clooect call.
Cost is 15 cents for the call plus 30 cents for operator handling. I
am interested to see how it will appear on my bill
---Jeff Krauss---
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Date: 3 Sep 1982 0812-PDT
From: Lynn Gold <FIGMO at KESTREL>
Address: Kestrel Institute, 1801 Page Mill Rd., Palo Alto, CA 94304
Phone: (415) 494-2233
Subject: "Reprogramming the line"
A friend of mine in New York City was given a similar line, so he
complained to the PUC (Public Utilities Commission).
It is, in fact, CHEAPER for most phone companies to install and
maintain touch-tone lines than pulse! The reason they still charge
more for the former is that it is "unfair to those customers who live
in areas where touch-tone is not available (i.e., where there are
mountains in the way, etc.), so to be fair, we HAVE to charge more."
There is no "conversion" that takes place on your line unless you
actually have to change your phone number.
--Lynn
[In the case of older switching, it may require central office work to
enable your line for touch tone, until we are all on Electronic
Switching, we will continue to class, and pay for, similar services
based on obsolete switching restrictions. The same argument applies to
Calling Card Calls which can be "dialed direct" (without an operator).
--JSol]
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Date: 2 Sep 82 09:17:33 EDT (Thu)
From: Steve Bellovin <smb.unc@UDel-Relay>
Subject: TELECOM Digest V2 #112 -- 202 modems, tone encoders
Cc: AWalker at Rutgers
Via: UNC; 3 Sep 82 1:59-EDT
The 202 modem is an old half-duplex 1200 baud modem; when you're done
sending, you drop RTS and the carrier goes away. That in turn will
free the remote modem to send its carrier, and present CTS to its machine
(after the machine requests it via RTS). The advantage of the Vadic 3400
and the Bell 212 protocols is that they are full duplex.
About tone detection -- there was a pretty good article on it in BYTE
a few months back that describes some nifty ICs for the purpose. If
anyone wants, I can dig up more specific information on it.
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Date: 3 Sep 1982 1119-PDT
From: Ted Shapin <BEC.SHAPIN at USC-ECL>
Subject: Sprint Gotcha
Mail-Address: 2500 Harbor Blvd., Fullerton, CA 92634
Phone: (714) 970-3393
I am in the habit of using SPRINT at home for long distant calls. I
used it to call a talk-show radio station on their long distance line
(mistake!). They don't answer this line until they are ready to take
the call on the air. I let it ring for 1-1/2 hours.
Surprise - Sprint billed me for a 1-1/2 hour call!
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End of TELECOM Digest
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