[HN Gopher] The sound of the dialup, pictured (2012)
       ___________________________________________________________________
        
       The sound of the dialup, pictured (2012)
        
       Author : zdw
       Score  : 54 points
       Date   : 2021-03-29 18:47 UTC (1 days ago)
        
 (HTM) web link (www.windytan.com)
 (TXT) w3m dump (www.windytan.com)
        
       | don-code wrote:
       | The slowest modem I ever had the pleasure of using was 9600 baud,
       | but even at that rate, it was way too fast for me to actually
       | comprehend that there was a series of high and low tones
       | representing bits.
       | 
       | Back in college, we had acoustically-coupled TDD devices at most
       | payphones on campus - you'd pick up the handset, dial a number,
       | and put it down on the coupler. Or you could just type on the
       | coupler, and hear tones come out the speaker, at a blistering 45
       | baud. 45 baud is slow enough for your brain to process the
       | different tones.
       | 
       | If you run minimodem as `minimodem --tx tdd`, you can hear the
       | same thing yourself today, without the coupler.
       | 
       | Minus some further nifty hacks above 2400 baud, it was very
       | convenient to think of modem breath as "the TDD tones, but much
       | faster".
        
       | femto wrote:
       | The best thing about this was having the infrastructure on public
       | show, a bit like having a building's water pipes visible on the
       | outside where everyone can see them. This exposure, combined with
       | natural curiosity, meant many people had an idea of how it
       | worked.
       | 
       | One takeaway from the diagram is how adaptation and channel
       | estimation can increase channel capacity. We start off simple on
       | the left hand side, with the dial tone and DTMF sending only a
       | couple of frequencies at low speeds. As we move to the right each
       | end adapts/learns and more frequencies come into play increasing
       | the information density. Eventually the adaptation has reached
       | some form of optimum and the information density (channel
       | capacity) is maximised with the spectrogram being a solid mass of
       | signals.
        
       | hpb42 wrote:
       | Is there an audio recording of "modern" handshakes somewhere?
        
       | LeoPanthera wrote:
       | I heard this sound so many times that eventually I could tell if
       | it wasn't going to negotiate properly, or negotiate at a lower
       | speed, just by listening to it. If that was happening I could
       | kill the attempt early and try again.
        
       | UI_at_80x24 wrote:
       | I've made a ring-tone out of the 56k USR modem.
       | 
       | Advantages:                 - The sound cuts through ALL
       | background noise.            - Nobody else uses it, so I don't
       | worry about false positives            - I geek a Nostalgia-
       | dopamine hit when I hear it.
       | 
       | Disadvantages:                 - Nobody ever calls me
        
         | mstade wrote:
         | Sharing is caring! :o)
        
         | toast0 wrote:
         | That's amazing. Even better than the Dubstep Nokia tone.
        
       ___________________________________________________________________
       (page generated 2021-03-30 23:01 UTC)