On 4/24/08, Nefastor <[EMAIL PROTECTED]> wrote: > > > Brian Dessent wrote: > > > > Nefastor wrote: > > > >> (...) I don't know which of Cygwin's /dev/tty device corresponds to which > >> serial > >> port on my PC (that is, I only know the COM port number). I can "sort of > >> guess" /dev/tty0 is COM1, but that's a guess, and I'd prefer some > >> certainty. > > > > Cygwin works the same as Linux, /dev/ttyS0 is the first serial device, > > /dev/ttyS1 is the second, etc. Please consult the users guide: > > <http://cygwin.com/cygwin-ug-net/using-specialnames.html>. > > > > > > That I have, Brian. What itches me is that I'm facing some kind of special > case : My machine has two serial port, one on the MoBo and a USB-serial > adapter, yet Windows calls them COM1 and COM3. I've searched the whole > Device Manager but couldn't find any device that would be COM2. And I can > rename COM1 to COM2. > > Speaking of Windows' DM, it's rather quirky on the serial ports : I noticed > that if I unplug my USB cable (COM3) and try to change the name of COM1, in > the drop down box COM3 is listed as "in use" :confused: %-|. > > So, I have a machine with two serial ports but no COM2, AND I can change the > COM port number to whatever I want, plus Windows seems to have a bad case of > "phantom limb syndrome". Getting back to your answer : how can know for sure > what Cygwin calls "the first port", or "the second port" ? > > Trial and error is obviously not what I'm after, rather I need a way for my > program to know for sure what port it's dealing with. To help me write that > program I'd need to know : > > - is there a fixed relationship between COM port number "X" and dev/ttyS > number "Y", such as Y = X - 1 ? For instance, if I change my COM port number > from 3 to 7, will the dev/ttyS number go from 2 to 6, or will it remain > unchanged ? > > - if it remains unchanged, I'm assuming Cygwin does some sort of port > enumeration : is that process deterministic ? > > Additionally, can you point me to documentation on how to retrieve device / > driver info from my program ? That way, worst case scenario, I can have the > program look for the correct port on its own. > > Thank you for your time, I know I'm asking for a lot of stuff but I've got > the feeling the answers would be useful to many.:-)
What motherboard do you have? It's always possible that there is a riser pinout for a serial port somewhere in the front of the board for connection to a front panel mount. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
