Hi. I replied to this thread a couple of days ago but as I had posted with a link my post got sent to moderation.I'll try it again here with and try to avoid moderation.
Have you found this thread (remove the *) h*t*t*p*:*/*/*forums.oztivo.n*e*t*/showthread.php?1524
I have the Topfield shown with the serial converter built by Inaxeon (my nephew). It works excellently however it would require a converter to be built and I am not sure if a later model Topfield has serial capability. I can get the details of the converter if required.