Pointer and Access types

Pointer objects can be either near or far pointers.

32-bit compilers:
near pointer values occupy four bytes of storage.  They are interpreted as anunsigned offset from the data group. The empty pointer value contains the value zero.

far pointer values occupy eight bytes of storage.  The firstfour bytes are an offset and the second four are the segment. The empty pointer valuecontains the value zero. This pointer type is only supported for DOS extended targets.

16-bit compilers:
near pointer values occupy two bytes of storage.  They are interpreted as anunsigned offset from the data group. The empty pointer value contains the value FFFF.

far pointer values occupy four bytes of storage.  The firsttwo bytes are an offset and the second two are the segment. The empty pointer valuecontains the value 0:FFFF.

The empty pointer value is the constant NIL for Modula-2 andnull for Ada95.