Hi,

I'm using Turbo c++ 4.0, and get this error:
"Linker error: Undefined symbol _Add_Ext in module ..\PROJECTS\ADD.C in
module ADD.OBJ"

This are the steps I've done before compilation (and please correct me):
1) compiling the Assembly code file ADD_EXT.ASM with MASM 6.11:
masm ADD_EXT.ASM
I didn't do the linking so i had ADD_EXT.OBJ
This is the Assembly code:

   ; Listing 2.7. The MASM portion of an external example.

.MODEL MEDIUM     ; This tells the procedure to use the
                  ; MEDIUM memory model.

EXTRN first:WORD,second:WORD,third:WORD

.CODE             ; This is the beginning of the code.

_Add_Ext PROC FAR  ; The procedure is type FAR.
mov AX,first      ; This moves the first number into the
         		  ; accumulator.
add AX,second     ; This adds the second number to the
		          ; accumulator.
mov third,AX      ; This stores the result back into
		          ; third.

_Add_Ext ENDP      ; This procedure ends here.

END               ; This is the end of the code segment.

2) This is the C ADD.C code

   // Listing 2.6 The C portion of an external example.

#include <stdio.h>

int first=1,second=2,third=0;  // These are the integers with
			       // which we want to work.
extern Add_Ext();

void main(void)
{
  printf("\nBefore adding third = %d",third);
  Add_Ext();                   // This calls the assembly
			       // program that will add
			       // externals.
  printf("\nAfter adding third = %d",third);
  getchar();
}// end main
   

3) Compiling the ADD.C file and getting the error I mentioned.
The ADD_EXT.OBJ and ADD_EXT.ASM are in the same directory.
There isn't any problem with the #include <stdio.h> since
I managed to compile and run a simple "Hello World" program.

Thanks in advance for your help.