Most compiler vendors supply a wide variety of generic and chip-specific header files with their compilers. Didn't you get them? There's a good chance that you already have them, but the compiler might not be installed properly sa as to be able to locate the INC directory. Check your compiler documentation.

Unless you're using a vanilla 8051, you will probably want to locate the corresponding header file(s) for the derivativeyou are using, with its particular SFR definitions.

If you are unable to locate the chip header files for your chip, you can always take one of the generic header files that you DO have, and modify it according the the compiler's style of SFR and bit definitions, and the chip datasheet.

Dennis