Does mplab have any reserved words that cannot be used in a .asm file. I have a call to 'TX' and 'TX1'. The program runs on the pic but when I go into 'debug/change program counter/' and enter TX it jumps to any random line in the .asm file, if I then single step or animate it runs from the ramdomly chosen posistion. Also when upgrading mplab is it possible to upgrade without changeing my custom toolbar setup. Many thanks, , , , The Samaratans........They bring a smile to an empty heart.