This is a continuation of another thread, where I thought that my IcePic2 was acting differently than my EEPROM 17C756A. It transpires that if I try and run my code on any of the four EEPROM 17C756A's I have, I get the same couple of inputs not working properly. If I blow the same program into an OTP version of the same chip, then everything starts acting the way it should again, my question is, what is the difference between an EEPROM and a OTP version of the same chip (all inputs have external pull-ups). Your help would be very much appreciated. TIA