5 ms·
A fun fact about pulse dial is that you can dial a digit d by quickly tapping the switch hook d times (zero is 10 taps). This is useful for dialing from a phon
by praptak 2y ago
A fun fact about pulse dial is that you can dial a digit d by quickly tapping the switch hook d times (zero is 10 taps).
This is useful for dialing from a phone with the dial intentionally disabled or removed.
- Stratoscope 2y agoI've shared this story before, but you may find it amusing: Back in 1996, I was living in Almaden Valley (South San Jose) and we had underground utilities. We also lived on top of an underground stream. After a rainstorm, water got in and intermittently shorted out the phone line. It was clicking like crazy! I was on my cool new Motorola StarTAC talking with Pacific Bell to report the problem. Then I heard a loud knock on the door: "San Jose Police. Open up!" I asked the officers what the problem was and they said "We got a 911 call with no one on the line. We tried to call you back, but no one answered. So we had to come out and investigate." I invited them in and said, "I think I know what happened." They followed me over to the landline speakerphone in the kitchen and listened to the clicking. Then I explained, "You remember the old rotary dial phones? They worked by making and breaking the circuit, just like this clicking. Even if we all have touch-tone phones these days, the phone lines are still compatible with the rotary dial. So somewhere in the midst of all this clicking, there were nine fast clicks in a row, and then one click, and one more. And that dialed 911. Sorry about that!"
- xg15 2y agoHeard a similar story about why the german emergency number is 110 and not the easier to memorize/type 111: The latter is 3 clicks on the line with generous spacing requirements, the former 12 clicks. So 111 would be much more prone to misdialing than 110. (I guess the international number 112 is a compromise. Still a low number of clicks, but I suppose the timing would be more difficult to get right?)
- exlurker 2y agoSimilar in Norway. One source of frequent misdiallings were from housewives dusting off the rotary phone, accidentally dialling 111.
- praptak 2y ago111 was also easy to butt-dial on cellphones that had physical buttons.
- grvbck 2y agoGreetings from Sweden. Before switching to European standard 112 in 1996, the emergency number was… 90 000. Three reasons for that: 1) Unlike most other countries, the Swedish dials had the number nine, and not zero, at the end. So "90 000" was considered easy to remember and easy to hit, even in the dark. 2) "90 000" was relatively easy to call by hand using the switch hook, on a telephone without a functioning number plate. (Swedish system had 1 click for zero, not 10.) 3) The statistical probability of a loose contact or some other type of electrical fault producing the sequence "90 000" is small.
- EvanAnderson 2y agoI support a PSAP (Public Safety Answering Point, aka "911 center"). We see one of these every couple of months. It used to be less frequent. The incumbent wireline carrier here is letting the cable plant rot and it's happening more often.
- lhamil64 2y agoSeems like that telco should get fined for misuse of 911...
- EvanAnderson 2y agoIt's maddening to see the wireline assets rotting and failing. In my opinion the ILECs have a ton to answer for.
- Rygian 2y agoThis wouldn't have happened if the number was 0118 999 881 999 119 725 3.
- svilen_dobrev 2y agoin 1980-90ies, playing with the switch was the way to get to "external" and dial things outside of a hotel (or office or factory, for example). And it worked because the central city-level switch-stations were replaced with much-faster-digital ones, while the local hotel/office/whatever were still old slow ones. So the old ones missed the too-fast-random-pulses series while the central ones picked it. Eh, one has to try multiple times to win that lottery..
- thaumasiotes 2y agoWhy would a phone with the dial intentionally disabled be connected to anything?
- dtgriscom 2y agoSingle-purpose phone; you pick it up and are automatically connected to somewhere (e.g. help line next to a kiosk).
- daniel_j 2y agoMy father said his parents had installed some kind of lock on the dial to prevent the use
- qingcharles 2y agoYeah, they used to look like this https://i.redd.it/vrt3vkxxfug81.jpg https://i.redd.it/vrt3vkxxfug81.jpg
- praptak 2y agoIt's an attempt to make the phone receive-only, a cost cutting measure. I know about the switchhook trick from friend's father who actually used it to bypass this measure on a phone installed at his military unit during the mandatory military service.
- lozf 2y agoThey were sometimes deployed for "incoming calls only" as used by certain service desks, but more often when directly connected to a particular end point. In this case lifting the handset would immediately signal the local Switchboard Operator (or perhaps other designated number) in a large building. These use cases have included situations where the public might have access, but not the right to call anyone e.g. behind a panel in a lift ("elevator") for emergency use. At some point the function became known as "hotline" in certain PBXs. Going back a little further it was common not to have a dial at all, with the operator being signalled immediately, literally patching your call manually through a series of other locations.