[CentOS] finding the right serial port, enabling & configuring it [was: Re: fax software]

Tue Mar 29 15:35:49 UTC 2011
ken <gebser at mousecar.com>

On 03/28/2011 04:22 PM Robert Heller wrote:
> At Mon, 28 Mar 2011 15:53:50 -0400 CentOS mailing list <centos at centos.org> wrote:
> 
>> On 03/28/2011 05:59 AM Adam Tauno Williams wrote:
>>> On Sun, 2011-03-27 at 22:41 -0400, ken wrote:
>>>> It's been many years, but it seems that I have to receive a fax and
>>>> might have to send one too.  Is there a way to do this on CentOS 5.5?
>>>> (Hope so.)
>>> Hylafax;  has been quietly running at work, without incident, for years.
>>> <http://www.hylafax.org/content/Main_Page>
>> Thanks everyone for your suggestions.  I remember both of these packages
>> from years ago-- the last time I set up a fax.  At that time I bought an
>> internal modem-- not a Winmodem, one with jumpers on it to set the com
>> port and I believe the interrupt also.  Now, however, I'm working on a
>> laptop with a serial chip on the mainboard and it's a different story.
> 
> Is this an RS232 port connected to an external modem or is it some sort
> of internal modem?

Internal... on a laptop... so a winmodem.  :(


> 
>> I've been reading the Serial-HOWTO, but it's a huge doc and I hope I
>> don't need to read this entire monograph to get the serial port set up
>> for the modem so that the fax software can use it.
>>
>> I've run minicom to see if I can dial out with it-- to test if I have
>> the modem's serial port enabled and configured properly.  So far, no
>> joy.  Anyone have tips to set up the modem so that efax or (more likely)
>> hylafax can use it?
> 
> Almost all *internal* modems (esp. on laptops) are Winmodems and are
> thus pretty close to useless under Linux.  It might be easier / cheaper
> / less agravating to just go down to Best Buy and buy a Creative
> Blaster analog RS232 serial modem.  Something like $50US.  Note: most
> newer laptops don't have an external RS232 connection, so you will need
> to get a USB=>RS232 adapter, most of which work out-of-the-box under
> Linux. (Don't get a USB connected analog modem -- most of these are
> Winmodems or something equally odd.)

Yeah, I think you're right about the Winmodem.  "setserial -g
/dev/ttyS*" showed just two recognized serial ports.  Rebooting and
checking the BIOS told me that the second one was for the IR (InfraRed)
device.  This laptop does have a regular serial port on it (I insisted
on it when I was shopping).  I also have a PCMCIA slot and an old modem
card from a previous laptop, so that might be a better option than
wrestling with a winmodem.  I don't know yet....


> 
> Otherwise, what does:
> 
> /bin/setserial -g /dev/ttyS*
> 
> display?
> 
> (You might need to be root to do this:
> 
> sudo /bin/setserial -g /dev/ttyS*

Did this (see above) and the "serial port" (or whatever) which the modem
is supposed to be connected to doesn't even show up.  From what I've
gathered from the Serial-HOWTO, the modem (again, winmodem) is a PnP
("plug-n-play")... I'm guessing this thing (from "scanpci -v"):

pci bus 0x0000 cardnum 0x1f function 0x00: vendor 0x8086 device 0x24cc
 Intel Corporation 82801DBM (ICH4-M) LPC Interface Bridge
  STATUS    0x0280  COMMAND 0x010f
  CLASS     0x06 0x01 0x00  REVISION 0x01
  BIST      0x00  HEADER 0x80  LATENCY 0x00  CACHE 0x00
  BYTE_0    0x01  BYTE_1  0x08  BYTE_2  0x00  BYTE_3  0x00

I've hunted around for a driver for this, got some indication that there
might be one, but I haven't found it yet.


> 
> )
> 
> For example my IBM Thinkpad X31 gives this:
> 
> gollum.deepsoft.com% sudo /bin/setserial -g /dev/ttyS*
> /dev/ttyS0, UART: undefined, Port: 0x03f8, IRQ: 4
> /dev/ttyS1, UART: unknown, Port: 0x02f8, IRQ: 3
> /dev/ttyS2, UART: unknown, Port: 0x03e8, IRQ: 4
> /dev/ttyS3, UART: unknown, Port: 0x02e8, IRQ: 3
> 
> I think /dev/ttyS0 is the IR port, which I don't use.  The Winmodem does
> not show up as a /dev/ttyS* port, since it is not really a serial port
> at all.

I got exactly the same output.  Rebooting and going into the BIOS, I
found that my IR card was bound to COM2 (ttyS1) and so moved it to COM4,
thinking maybe that would uncover the modem's port... but no.

I've got a couple dozen other things I need to do... and the person who
was going to fax me something is scanning the doc and attaching it to an
email, so I don't need the fax anymore.  So I'm bagging this project for
now.  Down the road, however, I want to set up an answering machine app
on this same machine, so I'll likely come back to all this.  So in the
meantime, if anyone has any info on the driver which is going to light
up this winmodem, give me a little shout.

Thanks much to everyone who replied... all good tips... much appreciated.