A hardware interface commonly found on older PCs, usually with a 9-pin DE-9 socket/plug, on networking devices or servers also with RJ-45 socket/plug (otherwise commonly used for ethernet), or with a (much wider) 25-pin DB-25 socket/plug. Two common standards used with such an interface are RS-232 ...
I have a problem getting Serial Port working on INTEL NUC DE3815TYBE. I have Debian Wheezy installed with kernel 3.16.0-0.bpo.4-amd64. When I do: setserial -g /dev/ttyS* I get: /dev/ttyS0, UART: ...