403 lines
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403 lines
25 KiB
Plaintext
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# <Tolmes News Service> #
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# ''''''''''''''''''''' #
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# > Written by Dr. Hugo P. Tolmes < #
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Issue Number: 12
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Release Date: November 19, 1987
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This entire issue is an article about blue boxing.
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Notice: This article is full of errors that most phreaks will catch.
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$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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TITLE: The Blue Box an Ma Bell
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FROM: Radio Electronics
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DATE: November 1987
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-WHEN BLUE AND READ MEANT THE TRASHING OF MA BELL............
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Before the Breakup of AT&T, Ma Bell was everyone's favorite enemy. So
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it was not suprising that so many people worked so hard and so
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successfully at perfecting various means of making free and untraceable
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telephone calls. Whether it ws a Red box used by Joe and Jane College to
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call home, or a blue box used by organized crime to lay off untraceable
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bets, the technology that provided the finest telephone system in the world
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contained the seeds of its own destruction. The fact of the matter is that the
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blue box was so effective at making untraceable calls that there is no
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estimate how many calls were made or who made them. No one knows for certain
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whether Ma Bell los revenues of $100,$100-million, or $1 billion on the
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Blue Box.
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Blue Boxes were so effective at making free, untraceable calls that Ma
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Bell didn't want anyone to know about them, and for many years denied their
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existence. They even went as far as strong-arming a major consumer-science
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magazine into killing an article that had been prepared on the Blue and Red
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boxes. Further, the police records of a major city contain a report concerning
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a break-in at the residence of the author of the article. The only item
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missing following the break-in was the folder containing copies of one of the
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earliest Blue-Box designs and a Bell-system booklet that described how
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subscriber billing was done by the AMA machine-a boklet that Ma Bell denied
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ever existed; Fig. 1 proves otherwise.
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Since the AMA (Automatic Message Accounting) machine was th means whereby
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Ma Bell eventually tracked down both the Blue and Red boxes, we'll take time
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out to explain it. Besides, knowing how the AMA machine works will help you to
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better understand Blue and Red Box "phone phreaking."
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WHO MADE THE CALL?
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Back in the early days of the telephone, a customer's billing
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originated in a mechanical counting device, which was usually called a
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"register" or a "meter." Each subscriber's line was connected to a
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meter that was part of a wall of meters. the meter clicked off the message
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units, and once a month someone simply wrote down the meter's reading, which
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was later interpolated into message-unit billing for the subscriber's who
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wunit. (Flat-rate subscriber's could make
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unlimited calls only within a designated geographic area. The meter clicked
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off message units for the calls outside the area.) Because eventually there
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were too many meters to read individually, and because more subscribers
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started questioning their monthly bills, the local telephone companies
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turned to photography.
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A photograph of a large number of meters served as an inconstestable
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record of their reading at a given date and time, and was much easier to
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convert to customer billing by the accounting department. As you might
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imagine, even with photographs billing was cumbersome and did not reflect the
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latest technical developments. a meter didn't provide any indication of what
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the subscriber was doing with the telephone, nor did it indicate how the
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average subscriber made calls or efficiency of the information service (how
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fast the operators could handle requests). So meters were replaced by
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the AMA machine. One machine handled up to 20,000 subscribers. It produced a
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punched tape for a 24-hour period that showed, among other things, the time
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the phone was picked up for (went off-hook).
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One other point, which will answer some questions that you're certain to
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think of as we discuss the Red and Blue boxes: Ma Bell did not want person
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outside their system to know about the AMA machine. The reason? Almost
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everyone had complaints-usually unjustified-about their billing. Had
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the public been aware of the AMA machine they would have asked for a
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monthly list of their telephone calls. It wasn@t that Ma Bell feared errors in
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billing; rather, they were fearful of being buried under an avalanche of
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paperwork and customer complaints. also, the public believed their
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telephone calls were personal and untraceable, and Ma Bell didn't want to
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admit that they knew about the who,
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what, and where of every call. and so Ma Bell always insisted that billing
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was based on a meter that simply "clicked" for each message unit; that
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thee was no record, other than for the long-distance calls, as to who called
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whom.
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Long distance was handled by, and the billing information ws done by and
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operator, so ther was a written record Ma Bell could not deny. The secrecy
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surrounding the AMA machine was so pervasive that local, state, and even
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federal police were told that local calls made by criminals were
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untraceable, and that people who made obscene telephone calls could not be
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tracked down unless the person receiving the call could keep the caller
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on the line for some 30 to 50 minutes so the connections could be physically
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traced by technicians. Imagine asking woman or child to put up with almost an
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hour's worth of the most horrendous obscentities in the hope someone could
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trace the line.
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Yet in areas where the AMA machine had replaced the meters, it would have
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been a simple, though perhaps time-consuming task, to track down the numbers
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called by any telephone during a 24-hour period. but MaBell wanted the AMA
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machine kept as secret as possible, and so many a criminal was not caught, and
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many a w by obscene calls of a potential rapist, because
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existance of the AMA machine was denied. As a sidelight as to the
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secrecy surrounding the AMA machine, someone at Ma Bell or the local
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operating company decided to put the squeeze on the author of the article on
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Blue Boxes, and reported to the Treasury Department that he was, in
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fact, manufacturing them for organized crime- the going rate in the mid 1960's
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was supposedly $20,000 a box. (Perhaps Ma Bell figured the author would get
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the obvious message: Forget about the Blue Box and the AMA machine or you'll
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spend lots of time, and much money on lawyer's fees to get out of the hassles
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it will cause.)
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The author was suddenly visited at his place of employment by a Treasury
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agent. Fortunately, it took just a few minutes to convince the agent that the
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author was really just that, and not a technical wizard working for the mob.
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but one conversation led to another, and the Treasury agent was astounded to
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learned about the AMA machine. (Wow! Can and author whose story is squelched
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spill his guts.) According to the Treasury agent, his department had been told
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that it was impossible to get a record of local calls made by gangsters; the
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Treasury department had never been informed of the existance of automatic
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message accounting. Needless to say,
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the agent left with his own copy of the Bell System publication about the AMA
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machine, and the author had an appointment with the local Treasury-Bureau
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director to fill him in on the AMA machine.
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That information eventually ended up with Senator Dodd, who was conducting
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a congressional investigation into, among other things, telephone company
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surveillance of subscriber lines- which was a common practice for which there
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was detailed instructions, Ma Bell's own switching equipment ("crossbar")
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manual.
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THE BLUE BOX
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The Blue Box permitted free telephone calls because it used Ma Bell's
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own internal frequency-sensitive circuits. When direct long-distance
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dialing ws intorduced, the crossbar equipment knew a long-distance call was
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being dialed by the three-digit area code. The crossbar then converted the
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dial pulses to the CCITT tone groups, shown in Taple 1, that are used for
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international and trunkline signaling. (Note that those do not correspond to
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Touch-Tone frequencies.) As you can see in that table, the tone groups
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represent more than just numbers; among other things there are tone groups
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identified as KP (prime) and ST (start)- keep them in mind.
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When a subscriber dialed an area code and a telephone number on a
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rotary-dial telephone, the crossbar automatically connected the subscriber's
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line to a long-distance trunk, converted the dial pulses to CCITT tones,
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set up electronic cross-country signaling equipment, and recorded the
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originating number and the called number on the AMA machine. the CCITT
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tones sent out on the long-distance trunk lines activated special equipment
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that set up or selected the routing, and caused electro-mechanical equipment
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in the target city to dial the called telephone. Operator-assisted
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lls worked the same way. The operator simply logged into a
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long-distance trunk and pushed the appropriate buttons, which generated
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the same tones as direct-dial equipment.
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The button sequence was KP (which activated the long-distance equipment),
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then the complete area code and telephone number. At the target city,
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the connection was made to the called number but ringing did not occur until
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the operator there pressed the ST button. The sequence of events of
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early blue Boxes went like this; The caller dialed information in a distant
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city, which caused his AMA machine to record a free call to information. When
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the information operator answered, he pressed the KP key on the Blue Box,
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which disconnected the operator and gave him access to a long-distance
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trunk. He then dialed the desired number and ended with an ST, which
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cuased the target phone to ring. For as long as the conversation took place,
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the AMA machine indicated a free call to an information operator.
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The technique required a long-distance information operator because
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the local operator, not being on a long distance trunk, was accessed through
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local wire switching, not the CCITT tones.
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CALL ANYWHERE
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Now imagine the possibilities. Assume the Blue Box user was in
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Philadelphia. He would call Chicago information, disconnect from the
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operator with a KP tone, and then dial anywhere that was on direct-dial
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service: Los Angeles, Dallas, or anywhere in the world if the Blue Box
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could get the international codes. The legend is often told of one blue Boxer
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who, in the 1960's, lived in New York and ahd a girl friend at college near
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Boston. Now back in the 1960's, making a telephone call to a college town on
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the weekend was even more difficult that it is today to make a call from
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New York to Florida on a reduced-rate holiday using one of the cut-rate
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long-distance carriers. So our Blue Boxer got on an international
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operator's circuit to Rome, Blue Boxed through to a Hamburg operator, and
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asked Hamburg to patch through to Boston. The Hamburg operator thought
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the call originated in Rome and inquired as to the "operator's" good
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english, to which the Blue boxer replied that he was an expatriate hired
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to handle calls by American routists back to their homeland. Every weekend,
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while the Northeast was stranged by reduced-rate long-distance calls, our
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Blue Boxer had no trouble sending his voice almost 7,000 miles for free.
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VACUUM TUBES
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Assembly plans for blue boxers were sold through calssified
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advertisements in the electronic-hobbyist magazines. One of
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the earliest designs was a two-tube portable model that used a 1.5 volt "A"
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battery for the filaments and a 125-volt "B" battery for the high
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voltage (B+) power supply. The portable blue box's functional circuit is shown
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in Fig. 2. It consisted of two pase-shift oscillators sharing a common speaker
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that mixed the tones from both oscillators. Switches s1 and s2 each
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represent 12 switching circuits used to generate the tones. (No, we will not
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supply a working circuit, so please don't write in and ask- e user placed
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the speaker over the telephone handset's transmitter and
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simply pressed the buttons that corresponed to the desired CCITT tones. It was
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just that simple. Actually, it was even easier than it reads because Blue
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Boxers discovered they did not need the operator. If they dialed an active
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telephone located in certain nearby, but different, area codes, they could
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Blue Box just as if they had Blue Boxed trhough an information operator's
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circuit. The subscriber whose line was Blue Boxed simply found his phone was
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dead when it was picked up. But if the Blue box conversation ws short, the
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"dead" phone suddenly came to life the next time it ws picked up.
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Using a list of "distant" numbers, a Blue Boxer would never hassle anyone
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enough time to make them complain to the telephone company. The difference
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between Blue Boxing off of a subscriber rather than an information operator was
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the the Blue Boxer's AMA tape indicated a real long-distance telephone call-
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perhaps costing 15 or 25 cents- insted of a freebie. Of course, that is the
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reason why when Ma Bell finally decided to go public with the "assisted"
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newspaper articles about the Blue Box usuers they had apprehened, it was
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usually some college kid or "phone phreak". One never read of a mobster
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being caught. Greed and stupidity were the reasons why the kids were caught.
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It was the transistor that led Ma Bell going public with the Blue Box. By
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using transistors with RC phase-shift networks for the oscillators, a portable
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blue Box could be made inexpensively, and small enough to be used
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unobtrusively from a public telephone. The college crowd in many technical
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schools went crazy with the portable Blue Box; they could call the folks
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back home, their friends, or get a free network (the Alberta and Carolina
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connections- which could be a topic for a whole separate article) and never pay
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a dime to Ma Bell. Unlike the mobsters who were willing to pay a small
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long-distance charge when Blue Boxing, the kids wanted it, wanted ti all free,
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and as they used the information operator routing, and would often talk
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"free-of-charge" for hours on end.
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Ma Bell finally realized that Blue Boxing was costing them Big Bucks, and
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decided a few articles on the criminal penalties might scare the Blue Boxers
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enough to cease and desist. But who did Ma Bell catch? The college kids and the
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greedies. When Ma Bell decided to catch Blue Boxers she simply examined the AMA
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tapes for calls to an information operator that were excessively long. No one
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talked to an operator for 5, 10, 30 minutes, or several hours. Once a long
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call to an operator appeared several times on an AMA tape, Ma Bell simply
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monitored the line and the Blue Boxer was caught. (Now do you understand why
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we opened with the explanation of the AMA machine?)
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If the Blue Boxer worked from a telephone booth, Ma Bell simply
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monitored the booth. Ma Bell might not have known who originated the call, but
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she did know who got the call, and getting that party to spill their guts
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was not problem. The mob and a few Blue Box h even
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thousands) knew of the AMA machine, and so they used a real telephone number
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for the KP skip. Their AMA tapes looked perfectly legitimate. Even if Ma Bell
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had told the authorities they could provide a list of direct-dialed calls
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made by local mobsters, the AMA tapes would never show who was called through
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a Blue Box. For example, if a bookmaker in New York wanted to lay off some
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action in Chicago, he would make a legitimate call to New Jersey. Nowhere
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would there be a record of the call to Chicago. Of course, automatic tone
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monitoring, computerized billing, and ESS (Electronic Switching Systems) now
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makes that all vitually impossible, but that7s the way it was. You might wonder
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how Ma Bell discovered the tricks of the Blue Boxers. Simple, they hired the
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perpetrators as consultants.
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While the initial newspaper articles detailed the potential jail
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penalties for apprehended Blue Boxers, except for Ma Bell employees who
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assisted a Blue Boxer, it is almost impossible to find an article on the
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resolution of the cases because most hobbyist Blue boxers got suspened
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sentences and/or probation if they assisted Ma Bell in developing
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anit-Blue Box techniques. It is asserted, although it can't be easily
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proven, that cooperating ex-Blue Boxers were paid as consultants. (If you can't
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beat them, hire them to work for you.) Should you get any ideas about Blue
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Boxing, keep in mind that modern switching equipment has the capacity to
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recognize unauthorized tones. It's the reason why a local office can leave
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their subscriber Touch-Tone circuits active, almost inviting you to use the
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Touch-Tone service. A few days after you use an unauthorized Touch-Tone
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service, the business office will call and inquire whether you'd like to pay
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for the service or have it disconnected. The very same central-office
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equipment that knows you're using Touch-Tone frequencies knows if you
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line is originating CCITT signals.
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THE RED BOX
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The Red Box was primarily used by the college crowd to avoid charges when
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many calls were made between two particular locations, say the college
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and a student's home. Unlike the somewhat complex cicuitry of a Blue Box,
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a Red Box was nothing more than a modified telephone; in some cases nothing
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more than a capacitator,a momentary switch, and a battery.
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As you recall from our discussion of the Blue Box, a telephone circuit is
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really established before the target phone ever rings, and the circuit is
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capable of carrying an AC signal in either direction. When the caller hears
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the ringing in his or her handset, nothing is happening at the receiving
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end because the ringing signal he hears is really a tone generator at his local
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telephone office. The targe (called) telephone actually gets 20
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pulses-per-second ringing voltage when the person who dials hears nothing- in
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the "dead" spaces between hearing nothing and the ringing tone. When the
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called phone is answered and taken off the hook, the telephone compleats a
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local-office DC loop that is the signal to stop the ringing voltage. About
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three seconds later the Din a signal being sent all the way back
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to the caller's AMA machine that the called the telephone was answered. Keep
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that the three-second AMA delay in mind. (By now you should have a pretty
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good idea of what's coming!) Figure 3 shows the simplified functonal
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schematic of the telephone. Switch S1 is the hook switch. When S1 is open
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(on-hook) only the ringer circuit consisting of C1 and BELLI is connected
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across the line. Capacitator C1 really has no purpose in the ringing ciruit;
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it only serves to keep the DC from flowing through BELLI. When the local
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telephone office feeds a 20-pps ringing signal into the line it flows though c1
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and a ringer coil in BELLI. A vibrating device attached to BELLI strikes a
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small ball- the ringing device. When the phone is answered by lifting the
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handset across from its cradle, switch s1 closes (goes off-hook) and connects
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the handset across the telephone line. since the handset's receiver and
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transmitter (microphone) are connected in series, a DC path is established fro
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one side of the line to the other- what is called completing a DC loop with the
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central office.
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The DC current flowing in the loop causes the central office to instantly
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stop the ringin signal. When the handset is replaced in its cradle, s1 is
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opened, the DC loop is broken, the circuit is clear, and a signal is sent
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to the originating telephon's AMA machine that the called party has
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disconnected. Now as we said earlier, the ciruit can actually carry AC before
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the DC loop is closed. The Red Box is simply a device that provides a
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telephone with a local battery so that the phone can generat and AC signal
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without having a DC connection to the phone line. The earliest of the Red
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Boxes was the surplus military field telephone, of which there were
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thousands upon thousands in the marketplace during the 1950's and
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1960's. The field telephone was a portable telephone unit having a manual
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ringer worked by crank- just like the telephone Grandpa used on the farm -and
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two D-cells. A selector switch set up the unit so that it functioned as a
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standard telephone that could be connected to a combat switchboard, with
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the DC power supplied by the switchboard. but if a combat unit wasn't
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connected to a switchboard, and the Lieutenant yelled "Take a wire," the
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signalman threw a switch on his field telephone that switched in the local
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battaries.
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To prevent the possibility of having both ends of the circuit feeding
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battery current into the line in opposit polarity- therby resulting in
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silence -the output from the field telephone was running from its internal
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batters ws only the AC representing voice input, not modulated DC. Figure 4
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is the functional simplified schematic for a field telephone (do not attempt
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fo build that ciruit). Momentary switch s4 is not part of the field
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telephone, it is added when the phone is converted to a Red Box; so for now,
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consider that S4 does not exist. Once again, S1 is the hook switch. When S2
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is set to N (NORMAL) and S1 is closed, DC flows from line A through T1's
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secondary (S), through S2-a to S2-b,rimary (P), through the
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handset, through S2-c, to line B.
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There is a complete DC path across the line, and if the unit is connected
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across a conventional subscriber telephone line it will close the Dc loop
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from the local office. to use the field telephone as a Red Box, switch S2 is
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set to L (LOCAL). Switches S2-b and S2-c connect batteries B1 and B2 in
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series with the handset and the transformer's primary, which constitute
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an active, working telephone ciruit.
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Switch S2-a connects T2's secondary to one side of the telephone line through
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a non-polarized capacitator (C1), so that when hook-switch S1 is closed,
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T1's secondary cannot close the Dc loop.
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PRESS ONCE TO TALK
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The Red Box was used at the receiving end; let's assume it's the
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oldhomestead. The call was originated by Junior (or Sis) at their college
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1000 miles from home. Joe gave the family one ring and hung up, which told
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them that he's calling. Pop set up the Red Box by setting S2 to LOCAL. Then
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Junior redialed the old homestead. Pop lifted the handset when the phone rang,
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which closed S1. Then Pop closed momentary-switch S4 for about a
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half-second, which caused the local telephone office to silence the ringing
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signal. When Pop release S4, the folks can talk to Junior without Junior
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getting charged because his AMA tape did not show his call was answered- the
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DC loop must be closed for at least three-seconds for the AMA tap to show
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Junior's call was answered.
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All the AMA tape showed is that Junior let phone at the old homstead
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ring for almost 30 minutes; a length of time that no Bell Operating Company is
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likely to believe twice! A modern Red Box is simply a conventional telephone
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that's been modified to emulate the vintage 1940 military field telephone.
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Aside from the fact that the operating companies can now nail every Red Box
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user because all modern billing equipment shows the AMA information
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concerning the length of time a caller let the target phon ring, it's use has
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often put severe psychological strain on the users.
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Does getting electronics mixed up with psychology sound strange? Well it
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isn't because it's what helped Ma Bel put an end to indiscriminate use of the
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Red Box. The heyday of the Red Box was the 1950's and 1960's. Mom and Pop were
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lucky to have finished high school, and almost without exception, both
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elementry and high schools taught honesty and ethics. Mom and Pop didn't have
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the chance to take college courses like Stealing 101 that masqueraded under
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quaint names such as Business Management, Marketing, o Arbitrage.
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When Junior tried to get the old folkes to use his "free telephone" they
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just wouldn't go along. So Junior installed the Red Box on his end. He gave
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one ring to notify the family to call him back. When Pop called Junior, it
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was Junior who was using the Red Box. Problem was, Junior didn't know that
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the AMA tapes for Mom and Pop's phone showed a 20- or 30-minute ringing. When
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Ma Bell's investigators showed up it was only then that the folks discovered
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their pride and joy had been taught to steal. There are nncering how many Red
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Boxes were in use, or how much money Ma Bell lost, but one thing is known:
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she had little difficulty in closing down Red Boxes in virtually all instances
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where the old folks were involved because Mom and Pop usually would not
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tolerate what to them was stealing. If you as a reader have any ideas about
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using a Red Box, bear in mind that the AMA (or its equivalent) will get you
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every time, even if you use a phone booth, because the record will show the
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number being called, and as with the Blue Box, the people will spill their
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guts to the cops.
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