NMEA 0183 (or NMEA for short) is a standard protocol, used by
GPS receivers to transmit data. It has been defined by the US
based National Marine Electronics Association for communication between marine electronic
devices. In the context of HoudahGeo it is used as an
alternative to the more widely used GPX format.
The popular Sony GPS-CS1KA device is the most
prominent example of devices which use NMEA rather than
GPX to store track information. HoudahGeo supports both
formats and thus works fine with devices from many
manufacturers including Garmin, Magellan and Sony.
The Sony GPS-CS1KA is however said to
have trouble mounting on PPC Macs. This is appears to be
a bug in Mac OS X which does not affect Intel Macs. On
PPC Macs you might have better luck accessing the track
logs using a third party tool, like LoadMyTracks, which does not appear
to rely on the system's ability to mount the device as a
drive.