[QUOTE=Mangetout]
Interestingly, the solution implemented in UK phone boxes to prevent tap dialling was the installation of oil-damped receiver hook switches - so that they couldn’t be rapidly cycled. Seems a strange choice of solution - I suppose it must have been the easiest for retrofitting or something
[/QUOTE]
That’s hilarious. Who knows how those old state industries used to think. I’m sure the reasoning was nothing to do with logic and more to do with connections between The Post Office and the Oil Dampers’ Union or something.
(If tap dial fraud wasn’t enough, when DTMF came in my mate circumvented the entire thing by rewiring our local call box and installing his own socket round the back of the phone, so you could bring your own “trimphone” in and dial anywhere for free. He’s now a senior manager in a very well known American software company…)
[QUOTE=Lumpy]
I’ve seen a couple of movies/tv shows where someone “dials” a number by clicking the receiver in such a way as to simulate a pulse dial. Does this really work?
[/QUOTE]
It can. See this thread I linked to earler.
Mangetout, why not try out the “break the dial tone test” I suggested? Let us know what happens.
I don’t know if any phone companies in the U.S., even still offer pulse-dialing lines anymore.
[/QUOTE]
They all do. That’s the default POTS (Plain Old Telephone Service) configuration. TT is newer, and may still be an extra-cost option some backward places.
[QUOTE=Musicat] Mangetout, why not try out the “break the dial tone test” I suggested? Let us know what happens.
[/QUOTE]
As soon as my voice returns to normal, I intend to - oddly enough, this was an idea I’ve been toying with for several weeks prior to reading this thread.
[QUOTE=Mindfield]
Yep. In fact, there were products out in the 80s and early 90s that I recall were designed to allow you to dial a number on the phone without touching its keypad. Apart from not having to touch the germy keypads on public telephones or needing to dial out on a phone with a broken button or two, I couldn’t see much point.
[/QUOTE]
I used one back in that long distanct past – “bc” before cell phones, when I had to use pay phones a lot. There were several advantages:
It would store phone numbers, which I could then directly input without dialing. No big deal, I guess, but it would save a step.
I would call the States using a calling card, which required dialing about 22 digits, including several pauses. The device would allow me to put in these pauses, so I would get this all dialed easily.
[QUOTE=Musicat]
Acoustic modems/couplers have nothing to do with touch tone dialing or even the concept of. Acoustic couplers are an early version of a modem, which translates digital data to analog, sends that over the analog phone lines, then reverses the process at the other end.
They were invented because in those days, not only were phone jacks not common, but Ma Bell was paranoid about anyone connecting a wire to their circuits, claiming all their linemen would be knocked off the poles with shock if anyone did that. So the acoustic modem got around the need for a direct connect with an indirect one; a signal no more dangerous than voice or music.
The signals sent thru the phone lines of a typical modem (acoustic or otherwise) are called FSK - Frequency Shift Keying, two tones that alternate (not simultaneous). From this:This system has nothing in common with DTMF. The frequencies alone are totally different.
[/QUOTE]
I am well aware of this - but in order to dial a phone number, the computer had to generate some DTMF tones and play them on the acoustic coupler, no?
[QUOTE=Absolute]
I am well aware of this - but in order to dial a phone number, the computer had to generate some DTMF tones and play them on the acoustic coupler, no?
[/QUOTE]
I don’t think so. First of all, the DTMF system wasn’t in place world-wide when acoustic couplers were common – news teams used them most, I think. Compared to today’s electronic devices, they were primitive. They didn’t dial. You dialed for them, then put the phone handset in the cradle to transmit data. When finished, you hung up manually.
Remember, this was before the Hayes command setmade modems intelligent in 1977.
[QUOTE=Lumpy]
I’ve seen a couple of movies/tv shows where someone “dials” a number by clicking the receiver in such a way as to simulate a pulse dial. Does this really work?
[/QUOTE]
It has already been mentioned that this really works. That is one thing you *can * try at home, kids!
But to add an anecdote, in my college dorm, the phone switchbox was in the hallway and unlocked. I showed some guys how you could pick a phone line, put on a pair of headphones, and use the plug to jump the terminals. By tapping, you could dial a number. Trouble was that that there was no microphone so you couldn’t talk back when the person answered. But you could call any number on anybody else’s phone.
[QUOTE=Musicat]
I don’t think so. First of all, the DTMF system wasn’t in place world-wide when acoustic couplers were common – news teams used them most, I think. Compared to today’s electronic devices, they were primitive. They didn’t dial. You dialed for them, then put the phone handset in the cradle to transmit data. When finished, you hung up manually.
Remember, this was before the Hayes command setmade modems intelligent in 1977.
[/QUOTE]
[QUOTE=Mindfield]
Yep. In fact, there were products out in the 80s and early 90s that I recall were designed to allow you to dial a number on the phone without touching its keypad. Apart from not having to touch the germy keypads on public telephones or needing to dial out on a phone with a broken button or two, I couldn’t see much point.
[/QUOTE]
Apparently, you don’t remember the early days of long-distance calling cards where you had to punch in the card number, your phone number, your mother’s drivers license number, your brother’s date of birth, and the PIN for the account, wait for the bong tone, then punch in whatever number you were calling. Oh drat, busy. Hang up and try again later.
Of course I’m kidding about Mom’s license number, but it took a serious amount of button-pressing to get a call through with those things.
Pocket dialers also meant not worrying if a phone had a disabled dial, (such as “house” phones at hotels) or if the phone itself would simply stop accepting button presses after about the 20th number, presumably because the phone’s last-number redial had a 20-number limit.