This beautiful Spectrogram video is instant nostalgia for any of us who used BBSes back in the 80s and 90s. The video comes from Scott H on Youtube.
Several of the videos I have made incorporate the initial connection sound (until the echo suppression is disabled.)
Enjoy this blast from the past, unless you are one of the 3 million subscribers mentioned in AOL’s 2012 Annual Report, which still use dial-up!