EIA RS-423 serial line interface
From Computer History Wiki
The EIA RS-423 serial line interface standard (usually known simply as RS-423) is a little-used serial line interface; it is a single-ended version of the companion differential RS-422, with an single common signal return line for all the signals.
See also
Further reading
- EIA RS-422 and RS-423, MicroNote #019 - good overview