Pulse to Tone Converter for VOIP services e.g. BT Digital Voice, Virgin Media, Sky - 'Dial-A-Tone' | Vintage Telephony
Building your own pulse to tone (DTMF) converter – Matt's Tech Pages
Amazon.co.jp: Plugable USB Audio Adapter 3.5mm with Headphone and Microphone Terminal, Black Aluminum Finish, External Stereo Sound Card Compatible with Windows, macOS, Linux No Driver Installation Required : Computers
Rotatone Pulse to Tone Converter - Oldphoneworks – oldphoneworks
Pulse Converter - Infineon Technologies
Digital or pulse to rotary dial convertor for antique telephones