[ntp:questions] Setting the COM port for the NMEA driver

Dave Hart davehart at gmail.com
Sat May 9 10:56:46 UTC 2009

> COM3 is used by a built-in modem.

Are you using the modem?  If not, try disabling it in device manager
and see if the USB moves to COM3: after the next boot.  On Unix, this
is handled by creating a symlink in /dev, so the underlying device
name doesn't matter.  Windows lacks symlinks (at least exposed to the
API, the Object Manager namespace internally uses things very similar
to symlinks to map, for example \DosDevices\COM1: to \Device\Serial0.
Though I don't recommend it, it's conceivable you could mess with
these object manager links to achieve what you want.  You'd probably
have to change the link after the driver started each time, as it is
the driver that creates the OM namespace links during driver startup.

As for changing the mapping by editing the registry, that's only going
to work if you find the backing store for the so-called COM Port
Database.  Search engines might help you find something that has
worked for others.

Good luck,
Dave Hart

More information about the questions mailing list