Elenco Electronics MO-1251 Manual do Utilizador descarregar pdf (Página 31)

nect

from the

operator

with a KP

tone,

and then

dial anywhere

that

was on direct

dial

service:

Los Angeles,

Dallas,

or any-

where

in the

world if the Blue

Boxer

could

get the

international

codes.

The legend

is often

told of one

Blue

Boxer

who, in the

1960's,

lived

in New

York

and had a girl

friend

at a college

near

Boston. Now

back

in the 1960's,

making

telephone

call to a

college

town

on the

weekend

was even

more difficult

than

it is

today

to make

a call from

New

York to

Florida on a

reduced -rate

holiday

using

one

of the

cut -rate

long- distance

carriers.

So our Blue

Boxer

got on an

international

operator's

circuit

to Rome,

Blue

Boxed

through to a

Hamburg

operator,

and asked

Hamburg

patch

through to

Boston.

The

Hamburg operator

thought the

call ori-

ginated

in Rome

and

inquired

as to the

"operator's"

good

English,

which the

Blue

Boxer replied

that he

was an expatri-

ate hired to

handle

calls by American

tour-

ists back

to their

homeland.

Every

weekend,

while the

Northeast

was stran-

gled by

reduced -rate

long -distance

calls,

our

Blue Boxer

had no trouble

sending

his

voice

almost

7,000

miles

for free.

Vacuum

tubes

Assembly plans

for Blue

Boxes

were

sold

through classified

advertisements

the

electronic-

hobbyist

magazines.

One

of the earliest

designs

was a two

-tube por-

table

model that

used a

1.5

-volt

"A"

bat-

tery for the

filaments

and a 125 -volt "B"

battery

for the high

-voltage (B

+ ) power

supply.

The portable

Blue

Box's

func-

tional circuit

is shown

in Fig.

2. It con-

sisted of

two phase -shift

oscillators

sharing

a common

speaker

that mixed

the

tones

from both

oscillators. Switches

and S2 each

represent

12 switching

cir-

cuits

used fo generate

the tones.

(No,

will not supply

a working

circuit,

please don't

write in and

ask-Editor.)

The

user placed

the speaker

over the

tele-

phone

handset's

transmitter

and simply

pressed the buttons

that corresponded

the

desired CCITT

tones.

It was just

that

simple.

Actually,

it was even

easier than

it reads

because

Blue

Boxers

discovered they

did

not need the

operator. If they

dialed

active telephone

located

in certain

nearby,

but different,

area

codes, they

could Blue

Box just

as if they

had Blue

Boxed

through an

information operator's

circuit.

The subscriber

whose

line

was Blue

Boxed

simply found

his phone

was dead

when

was

picked

up.

But if the

Blue Box

conversation

was short,

the "dead"

phone

suddenly

came

to life the

next time

it was

picked up. Using

a list of

"distant"

num-

bers, a Blue

Boxer

would never

hassle

anyone enough

time to

make them

com-

plain to the telephone

company.

The difference between

Blue

Boxing

off of a subscriber

rather than

an informa-

tion operator

was that the

Blue Boxer's

AMA tape

indicated a real long-

distance

telephone

call- perhaps costing

15 or

cents

-instead of a freebie. Of

course,

that is the reason

why when

Ma Bell fi-

nally decided to go public

with "assisted"

newspaper articles about the

Blue

Box

users they had apprehended,

it was usu-

ally about

some college

kid or "phone

phreak." One never

read of a mobster

being

caught. Greed

and stupidity

were

the

reasons why the kid's

were caught.

It was the

transistor that

led to Ma Bell

going

public with the Blue Box.

By using

transistors and RC phase

-shift networks

for the oscillators,

a portable Blue

Box

could be made

inexpensively, and

small

enough

to be to be used

unobtrusively

from a public

telephone. The

college

crowd in many technical

schools

went

crazy

with the portable

Blue Box; they

could call the folks back

home, their

friends, or

get on a free network

(the Al-

berta and Carolina

connections

which

could be a topic

for a whole separate

arti-

cle) and never pay

a dime to Ma

Bell.

simply

monitored

the booth.

Bell

might

not have

known

who originated

the

call,

but she did

know

who

got

the

call,

and getting

that party

to spill

their guts

was no problem.

The

mob and a

few Blue

Box hobbyists

(maybe even

thousands)

knew

of the

AMA

machine,

and so they

used

a real

telephone

number

for the

KP skip.

Their

AMA

tapes

looked perfectly

legitimate.

Even

if Ma

Bell had told

the authorities

they

could provide

list of direct

-dialed

calls made by

local mobsters,

the

AMA

tapes

would never

show

who was called

through

a Blue Box.

For example,

if a

bookmaker

in New

York

wanted to lay off

some action

Chicago,

he could

make a

legitimate

call to a phone

New Jersey

and then Blue

Box to Chicago.

His AMA

tape

would show

a call

to New Jersey.

Nowhere

would there be

a record

of the

call

to Chicago. Of

course,

automatic

tone

monitoring,

computerized

billing,

and ESS (Electronic

Switching

Systems)

now makes

that all

virtually

impossible,

FIG. 2 -A

POPULAR BLUE

BOX DESIGN used two phase

-shift oscillators,

vacuum

tubes,

and

a simple

speaker connection that mixed both oscillators

into a single two

-tone output.

Unlike the mobsters

who were willing

pay a small long- distance charge

when

Blue Boxing, the kids wanted it,

wanted it

all free, and so they used the information

operator routing, and

would

often talk

"free

-of-

charge" for hours on end.

Ma Bell finally

realized

that

Blue Box-

ing was costing them

Big Bucks,

and de-

cided a few articles on the criminal

penalties

might scare the Blue Boxers

enough to cease and desist. But who did

Bell catch? The college kids and the

greedies. When Ma Bell decided to catch

the Blue Boxers she simply examined the

AMA tapes for calls to an information

operator that

were excessively long. No

one

talked to an operator for 5,

10,

minutes, or

several hours. Once a long

call

an operator appeared several times

on an

AMA tape, Ma Bell simply

monitored the

line and the Blue Boxer

was caught. (Now

you understand

why

opened

with

an explanation

of the

AMA machine?) If the Blue Boxer

worked from a telephone booth, Ma Bell

but

that's the

way

was.

You

might wonder how

Ma Bell dis-

covered

the tricks of the Blue

Boxers.

Simple,

they hired the perpetrators

consultants.

While the initial

newspaper

articles detailed the

potential jail

penalties

for apprehended Blue

Boxers, except

for

Ma Bell employees

who assisted

a Blue

Boxer,

it is almost impossible

to find an

article on the

resolution of the

cases be-

cause most

hobbyist Blue Boxers

got sus-

pended sentences

and

/or

probation

if they

assisted Ma

Bell in developing

anti -Blue

Box techniques. It

is asserted, although

can't be easily

proven, that

cooperating

ex -Blue Boxers

were paid as consultants.

(If

you can't beat

them,

hire

them

work

for you.)

Should

you get any ideas

about Blue

Boxing, keep

in mind that

modern

switching equipment

has the capacity

recognize unauthorized

tones. It's the

rea-

son why a local office

can leave their

subscriber Touch -Tone circuits active,

al-

most inviting you to

use the Touch -Time

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