Fax machine

A fax machine is a method of transmitting document images via telephone wires. Development of the underlying technology goes as far back as 1843, predating the telephone itself, but it didn't reach mass popularity until the late 1970s, peaking in the 1980s when it was considered an essential piece of office equipment, before declining in popularity in the face of Internet-based communications technology.

Links

 * Wikipedia article
 * PN-2188, Asynchronous Facsimile DCE Control Standard