Greetings: I'm using a 16C84. I am using pins 1-7 as output and pin 0 as input, for the INT interrupt. My question: If I write to PORTB as a whole, will I cause an INT interrupt? My guess: No, INT samples the pin, not the latch. The write will write to the latch only, and pins set as input (RB0, aka INT) will not be affected. The other question: Aren't the interrupt flags set even when GIE is cleared? Will an interrupt occur when GIE is then set? My guess: I can't reason this one out from the databook. I think that when GIE is set that any interrupts with their enable and flag bits will cause an interrupt to occur Right? Thanks for any help. Regards, Mick Reed - electrical engineering student - michael.reed@bbs.chemek.cc.or.us