In message <02bb01c5704e$d00c3c70$6ea8a8c0@acervfr9okf50t>, "Brad du Plessis" w
rites:
>I'm running netbsd 2.0 stable and have just purchased a Siig CyberSerial 4S 
>com port expander as it was recommended on the Netbsd hardware compatibility 
>list. The card seems to be detected ok, but it doesn't seem to operate 
>correctly. I plugged in a modem and tested it with minicom, I got characters 
>echoing to the minicom terminal, but the modem was not responding to AT 
>commands.

Have you checked parity settings?  This feels like parity.

SIIG is simultaneously useless and helpful.  They insist that the card doesn't
work with anything but Windows, and they can't offer driver development
support, but in fact, it works out of the box on Mac OS X.

-s