The machine that will ultimately be running the software for this
application is an Asus Eeepc. This doesn't have any PCMCIA or even
ExpressCard slots. It has to be USB.

I am still waiting for a replacement adapter to test with. However, I am
currently mostly suspecting poor drivers. When I start to get bad data, you
can see from the NMEA packets that some of it *looks* alright. Well, furthe=
r
investigation reveals that fragments of it contain NMEA fragments from 30+
seconds ago (some of the NMEA sentences have the time in them). This really
smacks to me of some sort of buffer over or underrun in the driver code.

Obviously there is the possibility of a similar buffer error in my PIC code=
,
but I have added some extra code to zero the buffers before each use. Also,
an error in the code on the PIC would manifest itself irrespective of what
kind of serial port it was connected to.

I have a couple of the FTDI chips in my drawer, I guess the optimal solutio=
n
is to integrate the USB-Serial converter into my project. I hoped that this
would not be necessary because it's added complexity, but if that means
reliablility then I shall have to do it.

Thanks for your help so far everyone.
Slip
--=20
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