I had written a long program using ATtiny84(A). Due to non-availability of the IC and introduction of a better alternative ATtiny841 I tried to change the def84 to def841 and compiled. But the new program behaved differently, specially the PortA Bit 6 and 7 and the reset pin (Pin disabled in programmer). Am I missing something or some definition change ? May be some other register relating to new Debugging feature is interfering. Compiler didn't raise any error. Kindly suggest.