I have a product where most is in C, but for speed reasons abt 2% is in assembler. A few constants are thus defined in 2 places <constants.h> #define VALUE 5 <constants.inc> VALUE EQU 5 This is a maintenance nightmare, is there a method to make a change of the value in one place suffice.
If you're using uVision, go to the 'Books' tab in the Project window. The PDF files are all on the free CD, and get installed into the Keil\C51\Hlp folder on installation: C51.pdf - C51 manual A51.pdf - A51 manual GS51.pdf - Getting Started guide (the nearest there is to a uVision Manual).