Hays Converter
A Hays Converter, also known as a Smartmodem or Hayes-compatible modem, was a type of modem that used a command set, developed by Dennis Hayes for Hayes Microcomputer Products, Inc., to control its operation. This command set, often referred to as the Hayes command set or AT command set, became a de facto standard for modem communications, allowing a wide range of software applications to control modems from different manufacturers.
The significance of the Hays Converter lay in its ability to abstract away the complexities of modem communication, providing a standardized interface for software developers. Before the Hays standard, controlling modems required specific knowledge of the individual modem's hardware and software interfaces. The AT command set provided a high-level language for tasks such as dialing, answering calls, hanging up, and setting modem parameters.
Key features of the Hays Converter and its command set included:
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AT Commands: The use of "AT" followed by a specific command sequence (e.g., ATD for dial, ATH for hang up).
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Standardized Responses: Consistent responses from the modem to indicate the success or failure of commands, as well as status information.
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Hardware Abstraction: Providing a consistent interface regardless of the underlying modem hardware.
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Software Support: Enabling a wide range of communication software, terminal emulators, and bulletin board systems (BBS) to seamlessly interact with modems.
The adoption of the Hayes standard significantly simplified modem programming and usage, contributing to the widespread adoption of dial-up networking and online services in the 1980s and 1990s. While dedicated external and internal modems are less common today due to the prevalence of broadband connections, the influence of the Hays Converter and its AT command set remains significant in the history of personal computing and telecommunications. Its legacy can be seen in modern devices that still utilize AT commands for certain modem-related functions, particularly in embedded systems and wireless communication modules.