asus z690 proart motherboard

[tormod]

surprisingly this motherboard has a serial comport connector. since i do some modem development it will be of great interest to mak use of this. asus say that the external connector could be bought separately, i guess that this is then put in the back plane of the pc. i want to make a separat 9 pins connector in front, but i not sure of the pinout since the manual is confusing compared to descriptions of a 9 pins connector. any experience, i have not sees any pictures nor descriptions of the said asus comport extension-