sergio masci allotrope.net> writes: > I haven't used C30 but you might find something like "isnan" in math.h. isnan should be a macro that is equivalent to checking all sizeof(x) bytes of x for equality with 0xff. Peter -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist