# Addressing RS232 port



## balanga (Oct 19, 2018)

How do I tell whether FreeBSD can access an RS232 port?

What should appear under /dev ?

I don't see a /dev/ttyu*. The RS232 port is on a ThinkPad docking station and am not sure if I need to do anything to enable it...


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## SirDice (Oct 19, 2018)

See uart(4).


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## balanga (Oct 19, 2018)

Panic over...The CMOS battery in my ThinkPad T41p had discharged, and I'd overlooked the need to mark the Serial port as enabled (the default is disabled) when resetting CMOS settings.

Now I do have a /dev/ttyu0.


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