now I hope I've got it: You can use the option -Cni (no integral promotion on characters) to avoid promotion of characters to integrals. Please note that there seams to be a fault in the manual regarding the two char multiplication with -Cni. To get the option above please follow the way: Edit & ''project'' Settings [Alt+F7] & Compiler for ST7 and then select Options & Optimizations & [x] no integral promotion on characters That would suppress _CMPS. But I think you agree - the result is the same? Ciao WoRo