[Soekris] COM2 Problem with OpenBSD4.3 on NET4501

[Stuart Henderson]

On 2008-07-23, grice at iastate.edu <grice at iastate.edu> wrote:
> Great suggestions everyone!  We're definitely getting closer.  Indeed I am 
> certain the wiring is correct; that was one of the first things I checked.  
> Instead, this is looking more like an OpenBSD configuration or hardware 
> issue.  For example, if I jumper TX and RX together on the IDC10 header as 
> suggested above and run a simple loopback program (listed below), I receive 0 
> bytes back on the read. 

Please try a known working program until you are sure the hardware
is ok. With txd looped to rxd, when you "cu -l /dev/cua01" and type
something, it should be immediately displayed back.

> This program displays both 9600 for the old and new rates.

If I try that here, it leaves the port in a state where if I try and
use cu afterwards, it will receive but not transmit.

> I'm not entirely certain of how OpenBSD differentiates the tty and cua devices 

See tty(4) ("man 4 tty").