Besides (old) illustrations on the site of XS4ALL, there is also an old sound found. It is about the sound the handshake of a modem to the server of the IP. After the ringtone of DDS now also one of XS4ALL plus a happy birthday tune.
Text fragment: Toen digitale media nog nieuw waren - Pre-internet in de polder (1967-1997) - bit.ly/2e1T7ON. Illustration is part of the Collection Jak Boumans.