On Wed, 25 Jun 2008, Chris Moulding wrote: > Many thanks, Bob for your detailed clear explanation of the > situation regarding modems. It looks like my best option is to > find a suitable KISS modem circuit to convert the data on transmit > and receive. It would also make it compatible with all APRS > programs.
FWIW my first entry into packet was an XR2211 hooked to a radio's speaker jack and a uP interrupt pin. I coded the receive routines and interrupt handler in assembly, ran them inside a Forth interpreter. I also computed the CRC16. I wouldn't recommend doing it that way, but it did work. That was on a 0.79MHz 6803 as I recall. I didn't do transmit on that setup, only receive. That was in early '85 I think. All of that is taken care of if you start with a KISS TNC. The Tracker2, the OT1+, the TT4, and the TNC-X can all do it for very small $$. Some of them may be able to do 300 baud as well. -- Curt, WE7U. archer at eskimo dot com http://www.eskimo.com/~archer Lotto: A tax on people who are bad at math. - unknown Windows: Microsoft's tax on computer illiterates. - WE7U. The world DOES revolve around me: I picked the coordinate system!" _______________________________________________ Xastir mailing list [email protected] http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir
