The 35-Type station dial. Source: The Beatrice Company Bell Labs conducted exhaustive research to determine the best methods for tone dialing. They settled on a DTMF system for the control tones ...

RadioShack does not sell the pocket phone dialer anymore, but they do sell a DTMF chip (an NTE1690) that can do column D (the interesting bits that make all the phreakers happy).

Bad Bunny has dropped another smash hit but what are his 'DtMF' lyrics about and why are they making people cry? Bad Bunny is no stranger to dominating the charts. From 'Mayores' to 'DÁKITI', the ...