G'Day Paul,

 PE> y = 3 * x;
Turbo C help on "invalid use of pointer" : 
Pointers can only be used with addition, subtraction, assignment,
comparison, indirection (*) or arrow (->).
Your source file used a pointer with some other operator.

 PE> Come to think of it, I think I remember something about pointers
 PE> not being allowed to be divided either.  But there is certainly
 PE> a reason to want to do that.
 PE> middle = (start + end) / 2;

I've tried this with: middle = (char*) ( ( (int)start + (int)end ) \2)
Although (int)middle gives the correct result, middle points somewhere else.

So i thought, ohkay perhaps we're losing the segment(?), try this then...
 
middle = (char*)MK_FP( FP_SEG(start),FP_OFF((int)start + (int)end ) /2 );

Dammit, it was this simple all the time, and it works :-) 

Of course one could use something less professional like..
middle = &start[sizeof(start)/2+1]; 

 PE> I think I remember reading that you had to go:
 PE> middle = start + (end - start) / 2;
Yep, this is better,since it does away with the need for sizeof(). 

How about this then :
Actually it does not compile with ANSI on, but i can't see for the life
of me why, any ideas ?

#include 
#include  /* everyone should have this by now */

#define P_ADD(ptr1,ptr2) \
  (MK_FP ( FP_SEG(ptr1) , FP_OFF((unsigned)ptr1 + (unsigned)ptr2)))

#define P_DIV(ptr1,num) \
  (MK_FP ( FP_SEG(ptr1) , FP_OFF((unsigned)ptr1 / num)))

main()
{
 char *start = "012*456";
 char *end = &start[7];
 char *middle;
 middle = (char*) P_DIV((char*)P_ADD(start,end),2);
 printf("\nThe middle of %s is %c",start,*middle);
 return 0;
}


Maybe i can come up with some other ways of making code unreadable :-)
                         
   L8r Frank (fadam{at}ozemail.com.au).   

___ Blue Wave/DOS v2.21

--- Maximus 3.01