English: serial ports. 232 simpler DE-9 only since the 1984 AT [post-xt, IBM 5170, with a 286] still sh** and hate coz vslow& +-12v anyway - there is a 3-wire jack subset too, &yost unix 8p8c(eth) 'phoneplug', &a DC 37 pin version too: now that's not for 232 but another, with +-6v 'only' (still huge swing) and nice diffpairs; shock: it has a complementary de9 connector too to fit yet moar lulz! not even the C shell was long enough for 2 wires... ;-); and this one's 232-ised version is depicted here; when they realized this ludicruous waste (misengineering? well, not: decades earlier.) is not going to be tolerated in the era of microchips and labor/assembly costs (typinoldtelcotimestotaldisregardformassmfgringsimplicity&chpness *pin counts, lessstandard sizes, multiple conns etc to bow to the vacuum-tube and mech tty legacy. d-sub tho is inherently expensive).