On Nov 24, 2010, at 9:34 PM, Vitaliy wrote: > I shall assume that a > 9600 baud pure-FSK modem IC does not exist. :) Don't some of the low cost wireless transceivers claim to do 9600bps =20 FSK ? Doing it in 20k of bandwidth seems like it would be pretty tricky, =20 though. On phones we got 1/5th of supposed total bandwidths (600bps out of =20 3000Hz bandwidth?) BillW --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .