how do I tell if my sio0 port is broken?

Pieter de Goeje pieter at
Tue Jan 16 10:24:41 UTC 2007

On Monday 15 January 2007 11:43, Zhang Weiwu wrote:
> Hello List. I guess my sio0 port is broken on my Thinkpad, OS is
> FreeBSD-6.1. Reason:
> 1) I have tested a null-modem serial cable is working by using it on a
> dumb-terminal and a headless server. With the same cable and same
> headless server, but replace dumb-terminal with my thinkpad, run
> $ tip com1
> connected
> Then, whatever key I press, nothing happens. Usually I should see login
> prompt after I pressed "Enter" key. Test was done with FreeBSD Generic
> kernel.
> 2) I have plugged a modem (with ordinary serial cable, not the
> null-modem one) on it and run minicom. If I type 'at' I should get 'OK'
> as prompt, but I didn't. The same modem and same cable work for another
> Linux box.
> 3) I go to BIOS and do a serial port test, test result is "OK", but I
> think bios have no knowledge if a port is broken when it's not connected
> to anything at all.
> So, I think next morning I should go and check if there are PCMCIA card
> that can provide an extra COM port, but before that I think I should
> write this letter to the list to see what you guys would do in this
> case: do you also think this looks like COM1 port is broken?
> Thank you very much for advices.
> Zhang Weiwu
Did you enable the tty in /etc/ttys?
For instance: 
ttyd0   "/usr/libexec/getty std.115200" xterm   on  secure

See man ttys for more info.

- Pieter de Goeje

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