Dennis Crawley wrote: > Yes. but is still confusing. > You can't reset Constants values once they been initialized. (e.g > #define, constant directives) First, #define doesn't create a constant. That's what EQU does. #define defines a in-line string substitution macro, which is very different from a constant. Second, you can't easily redefine string substitution macros defined with #define. You'd have to do a #undef followed by a new #define. > With Cblock you create constants related to an incremental address No. CBLOCK only creates constants with incremental *values*. You can misuse this mechanism to create constants that happen to have addresses of RAM locations, then use the constants as the names of variables, but that would be very bad programming. > (yes you can reserve consecutive addresses with res directive). In fact that is the *only* way to do so in MPASM. ******************************************************************** Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products (978) 742-9014. Gold level PIC consultants since 2000. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist