EIA RS-422 serial line interface
From Computer History Wiki
The EIA RS-422 serial line interface standard (usually known simply as RS-422) is a serial line interface; it is a differential version of the single-ended predecessor RS-232, with an individual signal return line for each signal.
The use of differentials allows high speeds over longer distances; it also avoids issues with requiring a common ground.
See also
Further reading
- EIA RS-422 and RS-423, MicroNote #019 - good overview
