euatdt@euas11g.ericsson.se (Torsten Dahlkvist) (07/31/89)
Talking about which numbers to dial for operator and so on, how many different
designs of rotary-dials were there? I'm not talking about "fashion" phones
whith strange looks, I mean the encoding of "digit" to "number-of-pulses".
I know of at least three patterns and I'm curious as to whether there are
more or not and exactly where the different systems have been used. If the
subject has been handled before I would appreiciate E-mail with copies of
the relevant articles.
First of all: the "normal" - the Bell-system, used _practically_ everywhere
(n)-dialling; the digit "1" sends one pulse and so on up 'til 9. "0"=>10.
Secondly: "Swedish" dialling. Does anyone else use this?
(n+1)-dialling; "0" sends one pulse, "1" sends two... "9" sends 10 pulses.
Third: "Oslo" dialling (the Norwegian Capital is different from the rest of the
country. Historical reasons?):
(10-n)-dialling (or is it (10-(n+1))?); The dial works "backwards" and
looks quite funny to the newcomer. I'm not sure if the coding is 1=>10,
2=>9...0=>1 or 0=>10, 1=>9... 9=>1. Somebody out there to fill me in?
One possible explanation for the "Oslo" system would be that the digits could
be located like the hours on a clock face - more familiar to the user. Is this
true or just another modern myth? Has this scheme been used elsewhere? (I have
an unverified source saying it's been found somewhere in New Zeeland. Correct?)
When Sweden went automatic, starting in the 40's I think and finishing in the
60's, the (n+1) scheme was chosen. Two possible reasons have been told to me.
Since they are in no way contradictory, they _may_ both be valid and/or just
unplanned spin-offs. Or myths.
First: The zero was deemed the most "important" digit, beeing (at the
time) used to call the operator and already destined to prefix
long-distance calls. Also, the zero is (marginally) more frequent than the
nine in any set of numbers. If you have a local exchange with (for
example) a three digit numbering plan, you'd start by giving the first
subscriber number 100 (or 101). You then go on to fill the numbers, but
you (probably) never reach 999 until it's time to expand the entire
system. This way, the one through (whichever hundreds you reach) will be
most frequent followed by the zero and finally by the "remaining" digits.
There _may_ be advantages to having a more frequent digit sending a
shorter code.
Second: By having zero (a single pulse) to reach the operator, a user on
a newly converted line could use his old phone (lacking a dial) to reach
the operator by tapping the hook briefly. This is probably mythical since
phones were at this time telco property and they presumably changed them
all at the time of converting the line.
There's been a lot of talk about the different small US local admins of early
years. Did any of them go automatic or were they all manual? If any went
automatic, did they all choose the Bell dialling codes?
/Torsten
Torsten Dahlkvist ! "I am not now, nor have I ever
ELLEMTEL Telecommunication Laboratories ! been, intimately related to
P.O. Box 1505, S-125 25 ALVSJO, SWEDEN ! Dweezil Zappa!"
Tel: +46 8 727 3788 ! - "Wierd" Al Yankowitzmark@motown.altair.fr (08/02/89)
euatdt@euas11g.ericsson.se (Torsten Dahlkvist) writes of "Oslo" dialling: > (10-n)-dialling (or is it (10-(n+1))?); The dial works "backwards" and > looks quite funny to the newcomer. I'm not sure if the coding is 1=>10, > 2=>9...0=>1 or 0=>10, 1=>9... 9=>1. . . . > (I have an unverified source saying it's been found somewhere in New > Zealand. Correct?) That is correct; not only "somewhere" but all of New Zealand uses a 10-n pulse code: 9 gives 1 pulse, 8=>2 ... 0=>10. Most emergency numbers end in 999. I believe Australia uses the same system. Now, of course, most new phones use tones, but even here the tone codes are different from those used elsewhere. New Zealand Telecom did this on purpose, of course. When international pressure forced the government to abrogate Telecom's monopoly of telecommunications equipment manufacture, the bureaucrats made sure that few competitors would bother making their phones or modems work with the weird local standard. For this reason, even 300-baud modems still cost the equivalent of over $100 US. ####### Mark James ######### opinions, errors etc are my own ####### ####### mark@bdblues.inria.fr ######### +33 (1) 39 63 53 93 ########
wtho@uunet.uu.net (Tom Hofmann) (08/03/89)
From article <telecom-v09i0266m03@vector.dallas.tx.us>, by euatdt@euas11g. ericsson.se (Torsten Dahlkvist): > Third: "Oslo" dialling (the Norwegian Capital is different from the > rest of the country. Historical reasons?): > (10-n)-dialling (or is it (10-(n+1))?); The dial works "backwards" and > looks quite funny to the newcomer. I'm not sure if the coding is 1=>10, > 2=>9...0=>1 or 0=>10, 1=>9... 9=>1. Somebody out there to fill me in? I recall it is the latter: 0=>10, 1=>9... 9=>1. An other apparently not standardized feature is the keypad layout of push-button phones. In central Europe it is 1 2 3 4 5 6 7 8 9 0 It can be confusing since it is not the same layout as for calculators. I think in parts of Scandinavia (Sweden?) it is homogeneous: 7 8 9 4 5 6 1 2 3 0 Can someone confirm that? Are there any other layouts? Special keypad for Oslo? Mirror-image layout on the southern hemisphere? Tom Hofmann wtho@cgch.UUCP
wtho@cs.utexas.edu (Tom Hofmann) (08/03/89)
From article <telecom-v09i0266m03@vector.dallas.tx.us>, by euatdt@euas11g. ericsson.se (Torsten Dahlkvist): > Third: "Oslo" dialling (the Norwegian Capital is different from the > rest of the country. Historical reasons?): > (10-n)-dialling (or is it (10-(n+1))?); The dial works "backwards" and > looks quite funny to the newcomer. I'm not sure if the coding is 1=>10, > 2=>9...0=>1 or 0=>10, 1=>9... 9=>1. Somebody out there to fill me in? I recall it is the latter: 0=>10, 1=>9... 9=>1. Another apparently not standardized feature is the keypad layout of push-button phones. In central Europe it is: 1 2 3 4 5 6 7 8 9 0 It can be confusing since it is not the same layout as for calculators. I think in parts of Scandinavia (Sweden?) it is homogeneous: 7 8 9 4 5 6 1 2 3 0 Can someone confirm that? Are there any other layouts? Special keypad for Oslo? Mirror-image layout on the southern hemisphere? Tom Hofmann wtho@cgch.UUCP