Does anyone know if there is a way to make a #define in 'C' visible to A51 code (or visa-versa)? I know how to make a header file in Hi-Tech C51 that will let 'C' and 'A51 definitions coexist, but can't figure out how to this with Keil. In Hi-Tech's C51 compiler you can create a common ('C' and 'A51') header file like this: ; #define C_1 1 ; #define C_2 2 ; #define C_3 3 ;#if (0) ASSEM_1 EQU 1 ASSEM_2 EQU 2 ASSEM_3 EQU 3 ;#endif But when I try this in Keil it chokes on the ; before the #define. Any ideas?