https://www.startech.com/nl-be/kabels/rj12ft
12 ft RJ11 Telephone Modem Cable
12 ft RJ11 Telephone Modem Cable
12 ftrj11 telephonemodemcable
https://makezine.com/article/craft/music/midicontrolled-circuit-be/
MIDI-controlled circuit bent telephone modem - Make:
Feb 13, 2007 - Highly liquid points to this awesome MIDI-controlled circuit bent telephone modem - what a great use for an old modem, there are millions of them just
circuit benttelephone modemmidicontrolledmake
https://www.itu.int/rec/T-REC-V.21/en
V.21 : 300 bits per second duplex modem standardized for use in the general switched telephone...