Thanks in regards the datacode. So I have chips from a fairly recent batch.
Also am using the 1284 rather than 1284P. Maybe it's the 'P' pico-power version that
has the RX0 sensitivity problem, as I figure draping the RX0 line around the xtal pins
like I did should aggravate any noise issues, but uploads are solid. I plan to get some
1284P chips soon to try.
Does anyone know of a very large sketch I could try uploading? For my 32KB sketch, I
just created a humungus initialized data array, clearly far over the RAM size for the
chip.
One other question - there was talk on some of the other threads about Arduino-central
producing a standard pinout for 1284P chips. Is that a possiblility?