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In 1960, a national standards committee, today known as the Electronic Industries Association (now international), developed a common interface standard for data communications equipment. At that time, data communications was thought to mean digital data exchange between any centrally located mainframe computer and any remote computer terminal. It also could be possibly between two terminals without any computer involved. These devices were linked by telephone voice lines, and consequently required a modem at each end for signal translation. While simple in concept, the many opportunities for data error that occur when transmitting data through an analog channel require a relatively complex design. It was thought that a standard was needed first to ensure reliable communication, and second to enable the interconnection of equipment produced by different manufacturers, thereby fostering the benefits of mass production and competition. From the need for reliability, the RS-232 standard was born. It specified signal voltages, signal timing, signal function, a protocol for information exchange, and mechanical connectors.

rs-232.txt · Last modified: 2006/10/15 09:35 (external edit)