Talk:Telephone number
I am not exceptionally well versed in the histroy of the telephone system, so before I go add to this with regard to discussing how area codes, exchanges and even subscriber numbers arose out of a need for automation and from increasing propogation of the telephone system throughout the country, maybe someone else could put it better?? --DigitalSorceress
I heard that in the early days (before touch tone phones) of telephone exchange, each dail pulse from the telephone set actually kicked an electro-mechanically device at the exchange one step to make a different physical connection. i.e. the device turned 9 steps before it connects to the circuit for 9. For the same reason, emergency number is 999 in the UK because random glitches would be likely to keep the number 111 ringing off the hook. I bet there are still many retired telephone technicians out there to confirm or deny this information.
Hi, you heard right, but it is not so long ago. I do not know the exact date the UK switched off the last electro-mechanical exchange, certainly after 1985. I can only speak for the UK, here the pulse dial phones still work - most phone lines are configured to accept both touch tone and pulse dialling so that old phones still work on the modern lines. I don't think it is possible to buy an new pulse dial phone anymore though. The old Strowger exchanges worked in the manner you describe. Other technologies, such as Crossbar, used a counting circuit made from relays to count the number of pulses dialled. There were also semi electronic exchanges which used an early form of computer control but still worked with pulse dialling. Examples in the UK are TXE2 and TXE4. To my knowledge, there are non of these left working. user:Perry Bebbington
112 isn't just European. 112 is the international emergency number, which is supposed to be accepted everywhere, at least on GSM mobiles. -- SJK