>I want to know if I can switch to 16F84 without updating my >programmer or assembler.. The answer is probably. There is more ram in the F84 so the assembler will not complile code for these extra locations. You cannot simulate the F84 on the older simulators for the same reason, and fuses are configured differently. (I forget which one). Tony Just when I thought I knew it all, I learned that I didn't.