On Mon, Apr 1, 2013 at 5:20 PM, W Strater <wstrater@yahoo.com> wrote:
I am trying to access a Garmin Nuvi 270 from a Raspberry Pi.

As it says at http://www.gpsbabel.org/htmldoc-development/fmt_garmin.html, Nuvi is not a Garmin Protocol device.   The device shows up like a disk drive; you copy GPX files to and from it.

 
> /dev/disk/by-id/usb-Garmin_nuvi_Flash_0000cd9c6cb6-0:0
> /dev/disk/by-id/usb-Garmin_nuvi_SD_Card_0000cd9c6cb6-0:1

...confirming what our doc says.

Mount that device and you're on your way.  Use GPSBabel to create/parse the GPX if you like.

Enjoy.
RJL