[Corelatus] said recently that “someone” asked them to identify the phone signals in the 1982 film The Wall, based on the Pink Floyd song of the same name. We suspect that, like us, that someone might have been more just the hacker part of the brain asserting itself. Regardless, the detective work is fascinating, and you can learn a lot of gory details about phone network in-band signaling from the post.
The analysis is a bit more difficult because of the year the film was made. At that time, different countries used slightly different tone signaling standards. So after generating a spectrogram, the job was to match the tones with known standards to see which one best fit the data.
The signal was not common DTMF, as you might have guessed. Instead, it was a standard known as SS5. In addition to the tones being correct, the audio clip seemed to obey the SS5 protocol. SS5 was the technology attacked by the infamous blue box back when hacking often meant phone phreaking.
The same phone call appears on the album, and others have analyzed it with some even deeper detective work. For example, the call was made in 1979 from a recording studio by [James Guthrie], who called his own phone in the UK, where his next-door neighbor had instructions to hang up on the operator repeatedly.
If you want to see and hear the entire clip (which has several phone-related audio bits in it), watch the video below. The sequence of SS5 tones occurs at 3:13.
Usually, when we hear tones in music, we think of Morse code. As for phone phreaking, we hear it’s moved to street kiosks.
ChatGPT wouldn’t forget the link to the video, I think it’s more eggnog related.
The video was set to not embed so you have to click the link. Not much to be done for that….
Which link, out of the 4, none of which is clearly labelled to be the clip?
https://youtu.be/YiVPC8QHsQM?t=166 have fun
The SS5 encoding reminds me to the tones used at the beginning of a mobilophone call in Europe (or at least, the Netherlands with old bus/taxi companies), like in https://youtu.be/c8sikxB2FxA?
That’s CCIR Selcall.
https://en.wikipedia.org/wiki/Selcall
United States calling, are we reaching?
click
He keeps hanging up.
There must be someone else there beside your wife sir to answer.
So, the phone call wasn’t to the Dark side of the Moon?
they were just calling to say they wish you were here.
The studio was in Hollywood, California. (Producer’s Workshop 6035 Hollywood Blvd.) I was working there at the time. Maybe one of you smart guys could figure out a delay in timing due to distance from the UK.
Me? Smart?
Smart@zz maybe!
B^)
Why does the image for the article look like a DNA gel?
Haha thought the same thing
Did the operator get any royalties for their performance?
…. so, 044 1831 ? Long distance telephone call to England, but to a unused (at that time) local exchange?
hmm, not sure what you mean, but deeper in the article it is explained that many of the digits were cut out between the 1 and the 8, and that it was an actual recording of an actual call made to one of the engineer’s home, with the neighbor being instructed to pick up the phone and hang up on the operator.
Roger Waters of Pink Floyd incorporated Morse code into his 1987 solo album Radio KAOS extensively
Funny story about morse code, tones, and telephones from my childhood. When I was a kid someone thought it would be fun making obscene phone calls to my mother. My dad generally worked nights so he was usually not around, and back in those days there was not a heck of a lot the phone company could do. This went on for some time, until my dad hatched a plan. I was just old enough to get the gist of it. We had an old but not so old hallicrafters radio and that was the star of the show. Dad took a night off work and parked his car up at the Legion hall and walked back to the house, and we moved the radio from our little shack up at one end of the attic down to next to where the phone was and just ran a random wire around the kitchen, We tuned around and found a band with some action on it, code and whistles and what not, and turned the volume down. Luck was on our side as mon got a call that night, and we put our plan into action. Mom kept asking who it was like it was really bothering her, but also kind of like trying to get them to engage and stay on the phone. Dad turned the radio up a ways and I slowly moved the tuning knob and got the array of morse code and whistles, and just to seal the deal dad said in a low voice like he was talking to mom, but surely could be heard over the phoine, “We almost have him now..” and the caller hung up and never called back again.
If you listen to modern prank calls (PLA), prankcipients still often react the same, pretending to be tracing the call somehow. It’s quite amusing.
Cool
Sounded to me like they were definitely not murican phone tones the first time I watched the movie. Beyond that my interest was rather in the plot. At most sounded to me like Pink’s hearing the operator was dialing the british phone # and that was it.
Mofos of the movie theater double-billed the movie with… Grease.
But I know. People are crazy enough to dial those numbers just to hear if someone actually takes the call, that why all phone #’s in movies start with 555.
I don’t know why the author acts like this sequence originated with the movie. It’s present on the album.
I heard that they tried a number of different intercontinental operators before they found the one used in the clip. She was very interactive; the others were not chatty.
Solid State Logic E & G series audio consoles would make a very similar sound, if one entered the right (undocumented) command into the computer. There was another (equally undocumented) command to make it stop. Otherwise it would continue indefinitely, or until someone did a complete hard reset of the console.
Good times!
If you want to investigate at, check out the secret message when you play the album backwards.
It’s at the beginning of Empty $paces. It says (paraphrasing) Congratulations you have found the backward message. Send your results to…