The following notes,  keyed  to comments in each program, explain
    the differences:

    Note 1 - BASE_AFT.C no longer refers to the _segment baseseg. All
   _based variables become _far variables.

    Note 2 - With Borland C++, there is no need  to  allocate a based
    heap.  The Microsoft C6.0a _bmalloc calls become farmalloc calls.

    Note  3  -  If you use based variables as arguments to standard C
    functions, you need to recast based heap pointers to far pointers
    to eliminate compiler  warning  messages. This is not needed with
    far heap pointers.

    Note 4 - Do a farfree function call instead of a  _bfree function
    call, and remove the _bfreeseg function call.

    You could  handle some of these changes transparently through the
    C preprocessor with #defines,  but  because  all  program changes
    cannot be managed this way, you would have a less clearly written
    program to maintain as  a  result.  Instead,  we suggest that you
    make the changes one by one directly in source code, as  shown in
    BASE_AFT.C.