Modem- Acoustic Coupler

One of the first Modems - perhaps the first to be used at the University of Patras- in the late 1960s. It operated in the Wired Telecommunications Laboratory, in the current Department of Electrical Engineering and Computer Technology. It was connected to a computer of the time. The telephone handset of a telephone with a rotary panel was placed on the modem. The user dialed the phone number to which the corresponding system to which he wished to connect was connected. The connection was possible via a simple telephone line and it cost as much as a corresponding telephone call.

Modems began to be developed in the late 1950s, due to the need to connect printers via common telephone lines, instead of leased lines that were already in use and cost a lot.

The term Modem comes from the initials of the English words Modulator and Demodulator.

It is a hardware device that allows the transfer of digital data, through a simple analog telephone line "PSTN".