Modem

modulates digital pulses into sounds, demoulates sounds into digital data. invented in 1949 for transmitting radar signals. MODulation + DEModulation. Adapted for the [[SAGE]] system in 1953; commericalized by 1958 - so you can use a regular phone line for your timesharing that dedicated lines

The modem, short for modulator-demodulator, was invented in the late 1950s as a way to transmit digital data over analog telephone lines. The first modems were large and expensive, and could only transmit a few bits of data per second. Over time, advances in technology led to faster and more affordable modems, enabling widespread access to the internet and revolutionizing the way people communicate and share information.

source: https://en.wikipedia.org/wiki/Modem