Who Invented the First PC Modem?

By Marques Williams

  • Overview

    PC modems are an important invention that allows for a computer to communicate with other computers. Dennis C. Hayes and Dale Heatherington invented the modem in 1977, resulting in easier data transfer all over the world.
  • History

    In 1977, Dennis C. Hayes and Dale Heatherington, who had met at National Data Corporation in Atlanta, invented the PC modem for IBM and created their company, Hayes Communications, from it. The modem was originally sold to computer hobbyists but eventually caught on to businesses.
  • Significance

    PC modems revolutionized data transfer and are now an integral part of PCs. Without modems, the Internet would not be possible, and global communication wouldn't be as prevalent and accessible as it is now.


  • Function

    Modulator-demodulators, or modems, modulate carrier signals for encoding information digitally and then demodulating a signal to decode the information. Modems achieve this through telephones and sometimes through cable lines, depending on the type of modem used.
  • Types

    There were different internal modems at the time, but their complexity is what allowed Hayes to create the Smartmodem, which was a smaller and more practical external modem. The Smartmodems also differed from the other modems due to their use of the Hayes command set.
  • Features

    Hayes and Weatherington invented the Smartmodems, which allowed modems to be easier for a wider audience to use, through the development of the Hayes command set. The Hayes command set allowed for the modems to be controlled by sending commands into the data stream. These external modems contrasted with the internal modems of the time due to a lack of the Hayes command set--as well as different hardware designs and software--making them more complex and impractical.
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