5 ms·

A Look at the Evolution of the Dial Telephone (2004)

34 points by spking 7y ago

pgrote 7y ago
The page was last updated in 2004 per the source. The author ends with this quote, "Today, it's unusual to see a rotary dial still in use. There is a generation growing up which has never made a phone call by turning the finger-wheel of a rotary dial telephone." 15 years later you can now make the same observation about touch tone phones. Also, from the links page (http://www.arctos.com/links.html http://www.arctos.com/links.html) only one of the external links from yesteryear still works.
- dang 7y ago
  Thanks, we've added 2004 above. I don't suppose much evolution has been missed since then.
sverige 7y ago
I have five rotary dial phones (including a rotary wall phone) that I use in my home. All but one are Model 302s or 5302s. I inherited all but one of them. One was my grandmother's that she undoubtedly paid for at least ten times over with her monthly rental fee. The sound quality is still superior to newer phones. Occasionally some younger person will use one of them out of curiosity and will be amazed by how much more sonic detail comes through the receiver compared to their cell phone. The end quote should be updated to, "Today, it's unusual to see a landline still in use. There is a generation growing up which has never made a phone call on a landline telephone."
- dbcurtis 7y ago
  Wow, can you still get rotary dial service? I thought all that CO equipment was gone, except for a few tiny independent rural telco's.
  - tyingq 7y ago
    There are VoIP ATA adapters that can handle rotary dialing.
  - jacobush 7y ago
    Even if not you can still pick up and answer with them.
  - sverige 7y ago
    Yes, the phone system is still backward-compatible where I live.
nickt 7y ago
A similar site charts the history of UK (GPO & BT) phones. http://www.telephonesuk.co.uk/phones_1960-80.htm http://www.telephonesuk.co.uk/phones_1960-80.htm
basementcat 7y ago
One vestige of rotary phones are some of the original area codes in the North American numbering plan. Highly populated areas like New York City and Los Angeles have area codes 212 and 213– both are "fast" to enter on a rotary dial. More rural area codes have digits with 9's and 0's.
- toast0 7y ago
  To add to this, the original area codes had either a 1 or a 0 as the middle digit; in the original assignment codes with 1 were issued to states which needed multiple codes, and 0 to states with single codes. Of course, as codes split, that became impossible to manage, and in the 1990s, new area codes appeared with 2-8 as the middle digit.
Stratoscope 7y ago
A rotary dial phone communicates numbers to the central office by breaking and reconnecting the circuit with a quick series of pulses: a single pulse for 1, two for 2, on up to nine for 9 and ten for 0. A longer pause separates the individual digits. So you could either use the dial or tap the hook switch repeatedly in the same sequence. I found it fun to dial numbers by tapping the hook switch. (I guess I am easily amused.) I lived in San Jose in the mid-1990s, and our phones were all touch-tone, but the lines still supported rotary dialing as all phone lines did back then. We had underground utilities that sometimes flooded in rainy weather. During one bad storm our phone was barely usable - when you picked up the phone all you could hear was click after click as the water intermittently shorted out the lines. One day there was a loud and insistent knock on the door: San Jose Police! Open up! I asked if there was a problem and the officers said there had been a 911 call placed from our number but the caller hung up. The 911 dispatcher tried to call back and no one answered, so they were required to come out and investigate. I invited them in and had them listen to the phone, and explained how rotary dial phones work and what must have happened: with all those clicks on the line, at some point there were nine clicks, then one, then one. The officers were relieved that their emergency dispatch was just a technical glitch!
- NeedMoreTea 7y ago
  Which is actually why emergency numbers were chosen to have 9's in them. 911 in the US, 999 in the UK. Slower to dial and connect, but far less likely to accidentally call via poor wiring or line noise. 0 was often already in use for connecting to the operator in the exchange, so 9 was used. During the 80s or 90s when premium rate chatlines were a new thing, there was a fairly popular urban myth going round: that you could call them free by tapping out the number on the cradle. Course all you're doing is pulse dialling the hard way. You would still be getting the very expensive phone bill. :)
  - thombat 7y ago
    Related trivia: New Zealand rotary dialers had the numbers in ascending order, that is zero was in the rest position and nine nearest to the turning stop. The pulse encoder was therefore "ten minus digit", i.e. one pulse when dialling nine, ten when dialling zero [1] - a thread with some crusty old PT&T engineers argues whether this arose to avoid patent/licensing issues or just as a mistake [2] So the emergency number was 111 rather than 999 on the same basis of reducing accidental use, not just from line noise but especially from having the finger slip out partway through the turn of the dial (even with international dialling there was no reason anyone would attempt a number starting with three zeros) [1] https://en.wikipedia.org/wiki/Rotary_dial#/media/File:New_Zealand_Rotary_Telephone.jpg https://en.wikipedia.org/wiki/Rotary_dial#/media/File:New_Ze... [2] https://www.geekzone.co.nz/forums.asp?topicid=171168 https://www.geekzone.co.nz/forums.asp?topicid=171168
benj111 7y ago
Theres at least one crossover phone that has buttons but isnt touch-tone. Actually the Trimphone seems to have come in dial and full touch-tone variants. https://en.m.wikipedia.org/wiki/Trimphone https://en.m.wikipedia.org/wiki/Trimphone
walrus01 7y ago
fun fact, if you can find one of these on ebay, it's an older model of SIP ATA that you can use to turn a rotary phone into a voip phone. It's one of the few models of ATAs that understands pulse dialing. Of course you can't use any a lot of modern things with it, since rotary phones can't sent DTMF tones to IVR menus. http://www.grandstream.com/products/gateways-and-atas/analog-telephone-adaptors/product/handytone-502 http://www.grandstream.com/products/gateways-and-atas/analog... https://famicoman.com/2018/07/29/building-a-pbx-part-4-hooking-up-a-rotary-phone/ https://famicoman.com/2018/07/29/building-a-pbx-part-4-hooki...

34 points by spking 7y ago

The page was last updated in 2004 per the source. The author ends with this quote, "Today, it's unusual to see a rotary dial still in use. There is a generation growing up which has never made a phone call by turning the finger-wheel of a rotary dial telephone." 15 years later you can now make the same observation about touch tone phones. Also, from the links page (http://www.arctos.com/links.html http://www.arctos.com/links.html) only one of the external links from yesteryear still works.

dang 7y ago
Thanks, we've added 2004 above. I don't suppose much evolution has been missed since then.

sverige 7y ago

I have five rotary dial phones (including a rotary wall phone) that I use in my home. All but one are Model 302s or 5302s. I inherited all but one of them. One was my grandmother's that she undoubtedly paid for at least ten times over with her monthly rental fee. The sound quality is still superior to newer phones. Occasionally some younger person will use one of them out of curiosity and will be amazed by how much more sonic detail comes through the receiver compared to their cell phone. The end quote should be updated to, "Today, it's unusual to see a landline still in use. There is a generation growing up which has never made a phone call on a landline telephone."

dbcurtis 7y ago
Wow, can you still get rotary dial service? I thought all that CO equipment was gone, except for a few tiny independent rural telco's.
- tyingq 7y ago
  There are VoIP ATA adapters that can handle rotary dialing.
- jacobush 7y ago
  Even if not you can still pick up and answer with them.
- sverige 7y ago
  Yes, the phone system is still backward-compatible where I live.

nickt 7y ago

A similar site charts the history of UK (GPO & BT) phones. http://www.telephonesuk.co.uk/phones_1960-80.htm http://www.telephonesuk.co.uk/phones_1960-80.htm

basementcat 7y ago

One vestige of rotary phones are some of the original area codes in the North American numbering plan. Highly populated areas like New York City and Los Angeles have area codes 212 and 213– both are "fast" to enter on a rotary dial. More rural area codes have digits with 9's and 0's.

toast0 7y ago
To add to this, the original area codes had either a 1 or a 0 as the middle digit; in the original assignment codes with 1 were issued to states which needed multiple codes, and 0 to states with single codes. Of course, as codes split, that became impossible to manage, and in the 1990s, new area codes appeared with 2-8 as the middle digit.

Stratoscope 7y ago

A rotary dial phone communicates numbers to the central office by breaking and reconnecting the circuit with a quick series of pulses: a single pulse for 1, two for 2, on up to nine for 9 and ten for 0. A longer pause separates the individual digits. So you could either use the dial or tap the hook switch repeatedly in the same sequence. I found it fun to dial numbers by tapping the hook switch. (I guess I am easily amused.) I lived in San Jose in the mid-1990s, and our phones were all touch-tone, but the lines still supported rotary dialing as all phone lines did back then. We had underground utilities that sometimes flooded in rainy weather. During one bad storm our phone was barely usable - when you picked up the phone all you could hear was click after click as the water intermittently shorted out the lines. One day there was a loud and insistent knock on the door: San Jose Police! Open up! I asked if there was a problem and the officers said there had been a 911 call placed from our number but the caller hung up. The 911 dispatcher tried to call back and no one answered, so they were required to come out and investigate. I invited them in and had them listen to the phone, and explained how rotary dial phones work and what must have happened: with all those clicks on the line, at some point there were nine clicks, then one, then one. The officers were relieved that their emergency dispatch was just a technical glitch!

NeedMoreTea 7y ago
Which is actually why emergency numbers were chosen to have 9's in them. 911 in the US, 999 in the UK. Slower to dial and connect, but far less likely to accidentally call via poor wiring or line noise. 0 was often already in use for connecting to the operator in the exchange, so 9 was used. During the 80s or 90s when premium rate chatlines were a new thing, there was a fairly popular urban myth going round: that you could call them free by tapping out the number on the cradle. Course all you're doing is pulse dialling the hard way. You would still be getting the very expensive phone bill. :)
- thombat 7y ago
  Related trivia: New Zealand rotary dialers had the numbers in ascending order, that is zero was in the rest position and nine nearest to the turning stop. The pulse encoder was therefore "ten minus digit", i.e. one pulse when dialling nine, ten when dialling zero [1] - a thread with some crusty old PT&T engineers argues whether this arose to avoid patent/licensing issues or just as a mistake [2] So the emergency number was 111 rather than 999 on the same basis of reducing accidental use, not just from line noise but especially from having the finger slip out partway through the turn of the dial (even with international dialling there was no reason anyone would attempt a number starting with three zeros) [1] https://en.wikipedia.org/wiki/Rotary_dial#/media/File:New_Zealand_Rotary_Telephone.jpg https://en.wikipedia.org/wiki/Rotary_dial#/media/File:New_Ze... [2] https://www.geekzone.co.nz/forums.asp?topicid=171168 https://www.geekzone.co.nz/forums.asp?topicid=171168

benj111 7y ago

Theres at least one crossover phone that has buttons but isnt touch-tone. Actually the Trimphone seems to have come in dial and full touch-tone variants. https://en.m.wikipedia.org/wiki/Trimphone https://en.m.wikipedia.org/wiki/Trimphone

walrus01 7y ago

fun fact, if you can find one of these on ebay, it's an older model of SIP ATA that you can use to turn a rotary phone into a voip phone. It's one of the few models of ATAs that understands pulse dialing. Of course you can't use any a lot of modern things with it, since rotary phones can't sent DTMF tones to IVR menus. http://www.grandstream.com/products/gateways-and-atas/analog-telephone-adaptors/product/handytone-502 http://www.grandstream.com/products/gateways-and-atas/analog... https://famicoman.com/2018/07/29/building-a-pbx-part-4-hooking-up-a-rotary-phone/ https://famicoman.com/2018/07/29/building-a-pbx-part-4-hooki...