Old TAS - How Did It Work?
Lester Hiraki
business. Calls after normal hours were taken by this answering
service. She did _not_ have to advise the TAS at the end of each day,
nor did she activate any call forwarding procedure. When someone did
call after hours, you would hear the phone ring maybe two or three
times and then stop. Presumably the answering service took the call.
I didn't try this myself, but I think you could go off-hook at this
point and listen to the answering service operator taking the message;
the TAS was like an extension phone on the same line. Also, if my
mother went out for lunch, she could call the TAS and tell them to
take her calls in her absence.
Can anyone explain to me from a technical point of view how these
answering services worked? (How did the call get to the TAS? Was
there parallel wiring or was this some 70's software? How did the TAS
activate receiving of calls for lunch? etc.)
As the TAS NXX was different from my mother's NXX, I gather that they
were served from different COs.
How did the TAS operator know to answer with "ABC Enterprises" or
whatever? She must have answered for hundreds of firms. (Was DID
sent to the TAS, etc?)
[TELECOM Digest Editor's Note: The old answering services were hooked
up to their clients with extension phones. Literally. The wire pair
which served your mother's business was bridged over to the answering
service as well. Consider it like an extension phone in your house; it
rings and you wait for the person downstairs to answer; after a few
rings you decide they are not going to answer so you take the call
instead.
At the old answering services, they had cord style switchboards just
like telephone operators. Each plug on the board was the termination
of a wire pair from a client, and little strips of paper over the plugs
told the name of the client so that the answering service operator could
use the proper answer phrase when picking up the call. In very small
answering services, instead of a switchboard there might instead be
dozens of actual telephones sitting around. For example when I had my
office downtown in the 1970's the building had an answering service for
tenants. It was a privately operated 'secretarial service', which was
a very common thing in those days. Almost all large office buildings
had an office for a public stenographer, a paid-by-the-page typist who
would do your correspondence and someone to answer 'your' phone. At
the one in my building, the woman had about a hundred wall telephones
mounted on one wall by her desk. To identify one ringing bell from
another -- and sometimes the place went crazy with half a dozen or
more ringing at one time -- each of the wall phones (none of them had
dials, they were all 'answer-only' instruments) had an associated
'bee-hive lamp', a little neon bulb in an oval plastic shell which
flashed with the ringing cadence. She'd hear a ring, look up at the
row after row of wall phones, see the one with the flashing bee-hive
lamp, pick it up with the appropriate answer phrase and take a message.
But the bigger services with hundreds of clients or even perhaps a
thousand clients used switchboards. The smaller answering services
generally only accepted clients on the same common central office
as themselves, although a central office might include many prefixes.
When you signed up with the service, the service put in an order with
telco to have your line in the CO bridged to one of (usually hundreds)
of pairs coming to their service. Your phone would ring, their phone
would ring (or your appearance on their board would illuminate or
whatever.) The bigger services accepted clients from other central
offices as well, since they had what were known as 'concentrators'
between central offices. It was the same idea with the service simply
being an 'off premise extension' to the phone at your business.
The two most common ways of regulating when the service answered and
when it did not answer (you took your own calls) were by instruction
to the service or a mechanical switch. With the former, you told the
service something like 'always answer after three rings' or 'answer
beginning at 5 PM and quit answering at 9 AM'. With the latter, a
switch in a little box was mounted usually by the front door of the
business. When you went out, you flipped the switch; when you came in
you flipped it the other way. This was a little more expensive since
it required an extra pair to your premises. Instead of your phone
being wired in parallel to the answering service at the central office
your phone came to you exclusively as always, then it went back out on
the second pair via the little switch on the wall and back to the CO
and onward to the answering service from there. When you used this 'wired
in series' method, the service never even 'saw' your calls at all when the
exclusion switch was on. Without that switch, the service always saw your
calls; it was just by mutual agreement when they would or would not
respond to them. With the exclusion key method, if they saw your call
they answered it. If the service did answer and they heard you on the
line -- having answered as well -- they would always just hang up on
their end.
In downtown Chicago in the 1940-70 era, there were three major answering
services. Rogers Telephone Answering Service was the biggest, with
several additional features such as mobile service in your car. General
Telephone Company had a big service also but I don't remember much about
them. Annex Answering Service was the other biggie; they were in the
Chicago Temple Building and I used that one since they were the first
ones to have 'pager' service. In fact the other answering services that
wanted to offer paging to their clients had to broker it from Annex; all
the other answering services had a tie-line to Annex's transmitter and
tower which at the time was on the roof of the Chicago Temple Building,
23 stories in the air. Finally General Telephone also started a paging
service about 1975 or so; their tower was on top of the Lawson YMCA
building, a 23 story building on the near north side which is also
where the police station in that district had their tower at the time.
Answering *machines* were available in limited numbers beginning in
the middle 1960's, but they were big, bulky, heavy and very expensive.
I bought one in 1967 for a mere five hundred dollars. By comparison,
most answering services in those days charged $15-30 per montn with
some small fee per message taken. The machines I used in my telephone
information service from 1972-1975 weighed about a hundred pounds each;
they belonged to telco (you either rented answering machines from telco
or you bought your own with 'protective couplers' attached). With
the increasing availability of answering machines and their decrease in
cost the answering services began to suffer financially. I remember
when, in the early 1970's if you even mentioned the phrase 'answering
machine' to the proprietor of a service, you got them very angry with
you. Add call forwarding and voicemail to the competition, and that
pretty much caused the answering services to close their doors. PAT]