While I know it’s been asked before why and when did Hollywood start using the 555 exchange, but the REAL question is…what’s the history to how it came to be that the 555 exchange was NEVER utilized by the phone company anywhere across the USA? And, while we’re on the subject, are there 666 numbers lurking out there somewhere?
The closest answer to WHY is that Ma Bell herself used the 555 in her own publications.
There’s mentions of early TV and movie usage here:
and, being wiki links, I’m sure you can spend an hour reading more than you want to about phone numbers if you keep clicking around.
I don’t know if it’s still the case but in Chicago the Pilsen neighborhood was known to have 666-#### phone numbers. I’m pretty sure it was Pilsen - it’s been almost 20 years since I lived in Chicago.
Back when the area code system for direct dialing of long distance calls was first instituted (prior to that, you had to call an operator to put through a long distance call), the number that was established for directory assistance in any given area code XXX was (XXX) 555-1212. So they did use the exchange number in a sense, but it was as a national default for information. And it pains me that I’m old enough to remember all that (including the part about having to dial the operator to call long distance).
In area code 208 (Idaho) the prefix 666 is a Coeur d’Alene number.
In area code 208 (Idaho) prefix 666 is a Coeur d’Alene number.
If I could make a slight hijack here, how did they decide upon 555-1212 for directory assistance? Why not something slightly simpler, like 555-5555, or 555-1111? Were there any other special 555-xxxx numbers in use, or was -1212 the only one?
As far as I can recall, -1212 was the only use of a 555 exchange. I have no idea how they arrived at that particular number. Maybe that would be a good question for Cecil?
I think that any 555 number actually got you the same result-- 1212 is just catchy.
I read this either in one of Cecil’s columns, or in Joel Achenbach’s “Why Things Are” a long time ago:
As I remember it, the area codes for the cities with the largest populations were chosen to have the fewest ‘clicks’ on rotary systems. “1” elicited one click; “2”, two; and so on, with “0” eliciting 10 clicks.
That’s why we started out with 212 for Manhattan, 312 for Chicago, and 213 for Los Angeles, the biggest cities at the time the system was adopted: to minimize the aggregate waiting time. (I guess starting an area code with a 1 wasn’t possible for some reason).
Similar reasoning may have been used in choosing 1212 for directory assistance. They may have wanted to minimize the number of clicks (i.e., the wait, under a rotary system) for a frequently-dialed number.
As noted above, 1212 is also easy to remember.
Presumably directory assistance is still active, so maybe you (or someone else in North America) could test that theory. Growing up, I recall there was a 50¢ charge to use the service, but I’m pretty sure it was levied only once you got the number you were asking about. If you just called and hung up or said, “Sorry, wrong number!” then you didn’t get dinged. 
Whitehall 1212 was the telephone number of Scotland Yard. Is it possible that they co-opted it?
I can remember when you had to book an overseas call. I took a friend into a London Post Office so that she could phone her parents in Australia. We had to go to the counter and pay several pounds to the cashier. Then we waited on a bench for what seemed ages before her name was called and she went to a booth for a short conversation. I then took her in tears, to a travel agent who advertised cheap flights. No internet then either.
Phone boxes had two buttons. You put some money in and pressed button ‘A’, then dialed. If it was answered, it swallowed the cash, if it wasn’t press ‘B’ to get your money back. As kids we always nipped in to empty phone boxes and pressed the button in the usually forlorn hope of getting someone’s abandoned cash.
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As I remember it, the area codes for the cities with the largest populations were chosen to have the fewest ‘clicks’ on rotary systems. “1” elicited one click; “2”, two; and so on, with “0” eliciting 10 clicks.
That’s why we started out with 212 for Manhattan, 312 for Chicago, and 213 for Los Angeles, the biggest cities at the time the system was adopted: to minimize the aggregate waiting time. (I guess starting an area code with a 1 wasn’t possible for some reason).
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Those used to be called “short pull” numbers, and with each pulse of a rotary-dialed number consuming .1 seconds, it was very useful for the most often-used numbers to be short. Saving a couple tenths of a second on each of however million calls per day added up to a lot of time for the switching systems to be able to handle more calls.
Area codes couldn’t start with a 1 because 1 used to be the “Hey! This is a long-distance cal that needs to be handled by a different switch!” indicator back when the switching was done in real-time as the caller dialed the number. The electromechanical systems didn’t store or buffer the entire eleven digits in order to decide how to handle the call.
Similarly, the second digit of a local prefix could not be 0 or 1 as that was reserved for area codes, again in an effort to optimize the system’s ability to identify how to handle a call.
I had forgotten the 555-1212, although I remember it now. I don’t believe that there was, originally, a charge for information. I do, though, sort of remember, that they started charging a small amount for automatically connecting you to the number you just asked them to lookup.
I only did a small amount of long distance calling in those days (too young, probably) but I do remember having to go through the operator when I called a friend in India. I wonder how much it cost me? It was in the late 60s or early 70s.
Bob
It makes sense that they would reserve a certain portion of the space for special purposes, including the 555-0100 through 555-1999, which are the “official” range that fictitious phone numbers are to fall into. As wiki puts it:
Why 555? Well, it’s the middle of the dial (when phones had them), is one possible reason. And I seem to recall that craft (field test personnel) typically had some 555 numbers that were active for test purposes. No, not all 555 numbers should behave the same. The wiki article again:
[QOUTE]In the 1970s, dialing 555, at least in the Washington, D.C. metropolitan area, would bring one to a sort of party line known as “The Pipeline” whereby one could talk with others during the several-second intervals between a repeating recorded announcement to the effect that “The number you have dialed is not a working number. Please hang up and dial again.”
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That’s another manifestation of some central office switches during the era which turned up as the “teen line” in the Denver while I was there - the kids figured out that they could chatter to each other between the beeps of the busy tone. On that generation of switches, things like prerecorded announcement and busy tone were handled by simply connecting all lines requiring it to a particular timeslot that had the recording or tone on it. As a side effect they could all talk to each other over it, essentially an n-way call. I believe the same thing happened with PBX systems I was working on for Bell labs at the time, but I’m not sure. The Denver newspaper article commenting on it noted an AT&T spokesman being unconcerned about it and explaining that when newer equiptment went in, they wouldn’t be able to do it anymore.
ETA:
And, of course, many movie makers and such don’t like they 555 numbers because we all know it’s a phony number and the want their movie to seem “realistic”, so we get things like “Bruce Almighty” triggering crank calls to God for every poor shlub who happened to have that number.
Michelle, Ma Belle
Five-five-five
Won’t bug me on my cell-
-phone, Michelle
Thanks for the info!
This is partly speculation on my part, but I think one reason 55X fell to the bottom of the list of assigned prefixes—and thus was available for internal use—was that KLondike was about the only practical exchange name. Of course, 95X and 97X were even worse, with no practical possibilities that come to mind. The Telephone Exchange Project says that in 1955 all three were reserved for radio telephones.
As an old telephone person, I’m sure this is correct. Why not 1111? Because rotary phones take so long relatively before you can dial the next digit they might have worried that people would lose track of the 1s. 1212 is almost as fast, and much easier to keep track of.
Bell Labs did lots of psychology research on things like this.
For a long time (the first widely-deployed* computer-controlled central office in the US was the 1ESS in 1965) switching was electromechanical. That meant that all of the routing and call processing was done with relays, and there was very little memory during call setup to deal with with things like “backing up and retrying” using a different path to get from A to B.
That made it much easier to allocate a whole exchange prefix (555) for directory assistance. It didn’t even need to be an actual exchange, just a known route in the system. If call got routed there, it got delivered to in an information operator.
Internally, various numbers were used in Bell System literature - the standard “example number” in many Bell documents was 555-2368.
Depending on the equipment that processed the calls, the actual implementation could be more or less “clever”. The Bell System was a master at cost savings, which could lead to some odd things like the “party line” mentioned in other replies. Similarly, many smaller exchanges had “digit absorption”, where digits at the beginning of a called number were discarded until the point where a routing decision needed to be made. Where I grew up, all of the numbers in the exchange were in the 962-4xxx, -6xxx, or -7xxx 1000’s block. You only had to dial “2-xxxx” to call anyone else in the exchange. All of the “free local calling” neighboring exchanges were dialable without the first digit. So you could call 337, 835, 839 etc. just by dialing “37-xxxx”, for example. This severely limited the number of possible local free calling exchanges, but in those days there wasn’t a number shortage.
Whole area codes could work that way - nationwide 800 service was done with call forwarding through (IIRC) St. Louis, MO. The actual destination numbers were a well-guarded secret. Sometimes they would be in exchanges that were reachable simply by dialing the number. In other cases, they would be in exchanges that you couldn’t call, due to having unusual prefixes like 212-013-xxxx. That worked because internally, by that point, the phone system used a routing system that relied on specific “this is the end of the dialed digits” tones, so it would not internally treat the 013 exchange as a call to the operator (starts with 0). The switching system would send KP 2 1 2 0 1 3 x x x x ST and the call would end up routed to the correct exchange. That came along a good bit later, though.
Even later, the signalling was moved out-of-band (SS7, mostly). Many people think this was due to losses from “phone phreaks” making free calls, but it was done primarily as an improvement in national security.
Similarly, customers could often dial numbers that were not officially “real” - the 510 through 910 area codes were reserved for teletype machines. But you could call them from some places. Note - those services were moved off the PSTN a long time ago, and area code 710 currently has only one assigned number, which you should never call.
- The Morris, IL ESS in 1960 was a trial and did not use standard telephones.