putchar works but printf does not ... my putchar is used by printf so the problem must be in my code somewhere?? I started deleting sections of code until my printf started to work ... then I narrowed it down to a single statement ... statement in - it worked, statement out - printf didn't work ... the statement was in a routine that did not get executed .. deleting other statements made printf work ... the program was only 5161 bytes when I reached to go/no go condition Have you ever heard of anything like this??? Any ideas on how to find out what is going on??