The first modems date back to the cold war and 1958, when the North American Air Defense transmitted data over telephone wires to hundreds of radar stations in the United States and Canada. A modem has one essential function, which is to translate the digital language of computers into the analog language of the telephonic system and back again.
In 1981 Dennis Hayes (b. 1950) launched the Smart modem (originally named the Hayes Stack Smart modem). This was an automatic modem that for a time led the rapidly emerging personal computer market. Earlier modems were not adaptable to a variety of computers, were expensive to produce, and also were cumbersome to operate, requiring manual connection to telephone lines,
The brilliance of the Smart modem lay in its ability to "think for itself" and program itself into the telephone networks* It did this by using its own data language to instruct itself to engage and disengage with other computers' phone lines according to the requirements of its own operator. It also opened the way to cheaper and smaller designs because, needing only data instructions from its host computer, it could be connected up to any computer by an easily accessible port.
By 1985 Hayes's company held nearly half the personal computer market and the term "Hayes compatible" had entered the language of computers as a benchmark against which to measure rival modems. The term was used to describe any modem that could claim to recognize the command sequence devised for Hayes's Smart modem.
