By the way, read the compiler's readme file, there was/is some bug about the compiler not returning long structures/variables in an interrupt safe way. > I use a keyboard matrix .... > .... of a number of other peripherals which are > less timing sensitive. > That seems ok, but what is it the erroneous behaviour? Oscar -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist