I wrote earlier:
> The question is,  is it OK to use MAX3221E to replace the MAX221, without
> modifying the circuit?

Update: TI's datasheet states "C3 can be connected to VCC or GND."  Will 
test empirically on Thursday. :) 

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist