The sound of the dialup, pictured (2012)

Re:The sound of the dialup, pictured (2012) by Jtsummers on Tuesday March 30, 2021 @09:54PM (#26642718)

https://en.wikipedia.org/wiki/Dual-tone_multi-frequency_sign...

There was a fourth column (A,B,C,D) meant for menu selection, and for the US military to indicate call precedence. Also used for various kinds of system automation and signaling but not accessible directly.

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Re:The sound of the dialup, pictured (2012) by lozf on Wednesday March 31, 2021 @05:34AM (#26645190)

Generate them all with:

      sox -n dtmf-1.wav synth 0.1 sine 697 sine 1209 channels 1
      sox -n dtmf-2.wav synth 0.1 sine 697 sine 1336 channels 1
      sox -n dtmf-3.wav synth 0.1 sine 697 sine 1477 channels 1
      sox -n dtmf-4.wav synth 0.1 sine 770 sine 1209 channels 1
      sox -n dtmf-5.wav synth 0.1 sine 770 sine 1336 channels 1
      sox -n dtmf-6.wav synth 0.1 sine 770 sine 1477 channels 1
      sox -n dtmf-7.wav synth 0.1 sine 852 sine 1209 channels 1
      sox -n dtmf-8.wav synth 0.1 sine 852 sine 1336 channels 1
      sox -n dtmf-9.wav synth 0.1 sine 852 sine 1477 channels 1
      sox -n dtmf-0.wav synth 0.1 sine 941 sine 1209 channels 1
      sox -n dtmf-star.wav synth 0.1 sine 941 sine 1336 channels 1
      sox -n dtmf-pound.wav synth 0.1 sine 941 sine 1477 channels 1
      sox -n dtmf-A.wav synth 0.1 sine 697 sine 1633 channels 1
      sox -n dtmf-B.wav synth 0.1 sine 770 sine 1633 channels 1
      sox -n dtmf-C.wav synth 0.1 sine 852 sine 1633 channels 1
      sox -n dtmf-D.wav synth 0.1 sine 941 sine 1633 channels 1

      sox -n dtmf-us-busy.wav synth 10 sine 480 sine 620 channels 1
      sox -n dtmf-rbt-US.wav synth 10 sine 440 sine 480 channels 1
      sox -n dtmf-uk-us-dialtone.wav synth 11 sine 350 sine 440 channels 1
      sox -n dtmf-uk-busy.wav synth 10 sine 400 channels 1 # needs cadence
      sox -n dtmf-uk-ringback synth 10 sine 400 sine 450 channels 1
      sox -n dtmf-eur-dialtone.wav synth 10 sine 425 channels 1
      sox -n dtmf-eur-busy.wav synth 10 sine 425 channels 1 # needs cadence
      sox -n dtmf-eur-ringback.wav synth 10 sine 425 channels 1 # needs cadence

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Re:The sound of the dialup, pictured (2012) by antiterra on Wednesday March 31, 2021 @10:23PM (#26655953)

I had forgotten about those! I had a phreaking program[1] with those on the C-64. They called the DTMF utility 'Silver Box.'

Turns out: https://en.wikipedia.org/wiki/Silver_box

[1] It was this one: https://commodore.software/images/jdownloads/screenshots/tel...

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Re:The sound of the dialup, pictured (2012) by flemhans on Wednesday March 31, 2021 @02:35AM (#26644148)

And they sounded _weird_. Almost spacey.

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