Why Did Ma Belle Avoid 555 numbers?

[gotpasswords]

[QUOTE=yabob]
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.
[/QUOTE]

[QUOTE=Terry Kennedy]
…area code 710 currently has only one assigned number, which you should never call.
[/QUOTE]

Wow, the things you forget about until someone jogs your memory…

Back in 1982 or so, I made some circuit boards for one of the local Bell companies in Illinois that were used to time out and disconnect calls to test numbers that connected to silence so the outside plant techs could evaluate line quality. Fifteen seconds was enough to tell if a line was staticky, humming or hissy, but not much fun for kids to chat on.

As for GETS, I’m eligible for a card, but don’t want it.

[Terry_Kennedy]

@yabob

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.

Announcements were on drum or tape. The annunciator equipment knew when the beginning of an announcement came around, and didn’t complete the call until then. There was even tighter timing once “the number you have reached, xxx-xxxx, has been…”, was automated (previously it went to an intercept operator) since the digits needed to be spoken in rapid succession. There was also usually a timer to drop the call if you didn’t hang up after a few cycles.

Tones (dial, busy, ring) were generated by dedicated equipment as there were a lot more calls in those states at any given time, compared to announcements.

The electromechanical exchange I referred to in my earlier post wasn’t getting a lot of love by the early 80’s - it had had various enhancements “bolted on” over the years to handle numbers outside the -4xxx, -6xxx and 7-xxx groups, and to generate accounting records itself - previously toll calls went to operators 15 miles away who asked you what number you were calling from. Kids used to make up numbers to get free calls. The first “fix” was to allow remote “test for busy” - the operator could check to make sure the number you gave was actually off the hook, but eventually the exchange got upgraded for ANI capability, but with some weird bugs*.

Anyway, by the time the 80’s rolled around, the tone generators in this CO had drifted wildly out of spec (probably due to deterioration in the capacitors) and the tones would confuse people unfamiliar with the exchange. The sound you heard when the called party’s phone was ringing was a “Blatt!” sound, and the busy signal had become truly bizarre - it sounded like “bnee-oh-witt”. As I recall, the “screamer” (you left your phone off the hook for too long) still sounded normal. Of course.

Another weird sound effect in this exchange was loud crashing static while dialing some numbers. This was a step-by-step (YouTube video) exchange and there were contacts on the steppers to mute the line while the steppers were moving. Those weren’t maintained, so you got to sometimes got to hear the wipers moving across other terminals.

One day, people woke up, picked up the phone, and were greeted with the soft ESS “hmmm” dial tone, as the exchange had been cut over. The reason this old equipment hung on until the 80’s was because the phone company had applied for a zoning variance in the mid 70’s to enlarge the central office building, and the town denied it and told them to move (showing a fundamental misunderstanding of the way central offices worked). So the phone company ignored this exchange until it was close to not having any other offices it could interoperate with. The phone company parked an “emergency restoration” trailer outside the building, cut over to it, then ripped out the electromechanical switch and put a new ESS remote in the empty space.

• If you called from xxx-962-xxxx to yyy-962-xxxx (different area code, same exchange prefix), you got dead air until the party picked up. This was due to not comparing the area code (relays, remember?) and the exchanges assuming “the other guy” was responsible for generating the tones. The upside was that these calls were free, since the equipment thought they were local.

[Peter_Morris]

@bob_2

Whitehall 1212 was the telephone number of Scotland Yard.

Still is.

[bardos]

In Spain, many cell phone numbers begin with 666… ofttimes the butt of jokes between users.

[silenus]

@Mr_Downtown

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.

You know you are really old when you remember people using the “Klondike” prefix on TV, instead of the digits. “Call Klondike 5-3972 for information.”

[bob_2]

In the UK 999 is the emergency number. 111 would have been a lot faster to dial, but the strowger relays were slow to act and if you dialed 111 fast, by pushing the dial back, it would have misdialed. They could have used 222 or 212 etc but thinking of someone calling in a smoke filled room, they decided that 999 was the best compromise because, once you find the 9, you could keep your finger on the hole. 000 was not possible because ‘0’ called the operator…

[Emtar_KronJonDerSohn]

@psychonaut

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.

I was actually a 555-1212 operator in the 90s. That’s exactly how it worked - after a result there was an option to kick the caller into the automated reader/connector which would charge, or if it was a non published number I could verify the address they already had was correct and I had a key to charge for the search.

Occasionally I’d get weird calls, such as kids calling for help with their homework (which I actually enjoyed providing) or one particular conspiracy theorist who would scream that I bugged his phone and shut off his electricity and impregnated his wife. I could choose to charge or not.

[Leo_Bloom]

@Voyager

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.

Interesting. I knew about the 1212 business (proud Manhattan possessor of one), but never thought of the all ones.

[Leo_Bloom]

@Terry_Kennedy

…

Another weird sound effect in this exchange was loud crashing static while dialing some numbers. This was a step-by-step (YouTube video) exchange and there were contacts on the steppers to mute the line while the steppers were moving. Those weren’t maintained, so you got to sometimes got to hear the wipers moving across other terminals…l.

I was just going to post that cite: the AT&T channel on YouTube has a ton of interesting stuff.

I can’t remember if in their longish instructional video introducing and explaining how to use rotary dial if, and how, they confront the delay between the fall back time of the dial from 1 as compared to 9, as subjective experience for the user.

Certainly if, as you say, they researched the hell out of it.

Because any of us old enough to remember, and certainly in many suspense movies, that mosey-on back round the circle can be agony.

[Melbourne]

@Voyager

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.

Unless you have a reverse-dial system (some countries did that) 1 - 1 - 1 - 1 is the same as jiggling the reciever, is the same as random short-circuits on the line. If you use 1111, you are guaranteed to get bad calls.

[Mr_Downtown]

@silenus

You know you are really old when you remember people using the “Klondike” prefix on TV, instead of the digits. “Call Klondike 5-3972 for information.”

If you mean KLondike in particular, I’m pretty sure that’s a back-formation to fit 555. Exchange names had been officially phased out several years before movies and TV started using 555. Exchange names were still in popular use in some cities—even listed in the phone book to avoid resetting every line of type—but were no longer being assigned to new lines.

Perhaps you just meant that you remembered the popular use of exchange names, such as commercial jingles urging you to call NAtional 2-9000. NAtional two-nine…thousand.

[Hilarity_N.Suze]

Ma Bell used 555 as a prefix internally, as kind of a code. If you were a telephone installer, and you wanted the phone to ring, you dialed a 555 code, and then the number, and it would ring for you. That way you didn’t have to call dispatch and say, “Call me so I know this phone works.”

That’s just one example. Also I think in order to get directory assistance out of your area, in the old days you put in the area code, then dialed 555-1212. (Or something like that.) Actually once you dialed the first 1-2 you could put in any number.

There was another way to get the phone to ring, if all you wanted to know was if the ringer worked. the 555 code was to make sure the number worked.

[Terry_Kennedy]

@Hilarity_N.Suze

Ma Bell used 555 as a prefix internally, as kind of a code. If you were a telephone installer, and you wanted the phone to ring, you dialed a 555 code, and then the number, and it would ring for you. That way you didn’t have to call dispatch and say, “Call me so I know this phone works.”

This was operating company specific. In NJ Bell offices (crossbar, at least) you dialed 55x-yyyy where yyyy was the last 4 digits of your phone number and x indicated which exchange in a given central office you were on (starting at 0). If you picked the wrong x, you’d get a busy signal. You got a stutter dial tone back and if you dialed 0 on a rotary phone, you’d get an indication if the dial was fast, normal, or slow. On a touch-tone phone you dialed 0-9. If you flashed the hookswitch twice and hung up, the switch would ring your line. If you answered, you could repeat any of the above.

[JKellyMap]

@Mr_Downtown

If you mean KLondike in particular, I’m pretty sure that’s a back-formation to fit 555. Exchange names had been officially phased out several years before movies and TV started using 555. Exchange names were still in popular use in some cities—even listed in the phone book to avoid resetting every line of type—but were no longer being assigned to new lines.

Perhaps you just meant that you remembered the popular use of exchange names, such as commercial jingles urging you to call NAtional 2-9000. NAtional two-nine…thousand.

True…but silenus’ idea might still be part of the reason, if 555 was left with fewer existing in-use phone numbers than other three-number combinations, as the names system (KLondike, etc.) was discontinued.

[Me_Billy]

Technicians need numbers for testing. So something had to be designated. Also they need numbers for internal use.

[Annie-Xmas]

Straight Dope column on the subject of “555”