One way is to actually look in the hex file, you can open this in an editor, and look at the hex record address fields. Normally the record with the highest address is toward the end of the file. The address of this record plus the number of bytes in the record will addup to the maximum address in your program.

Another way to see program size it to have the assembler generate a listing file. You can look in there to see the generated code and the highest address used.

In many of my projects I put an assembler language label at the end of the source file similar to as follows:

    ...
    RET            ;end of last subroutine
;
CODE_TOP:
;
    END

Now I can look at the symbol table or cross reference listing to see the size of the code which will be equal to the value of CODE_TOP.

Michael Karas