INT 2F PU - Borland C++ DPMILOAD.EXE - GET AVAILABLE MEMORY
        AX = FB42h
        BX = 0003h
Return: DX:AX = size of largest free block in paragraphs
                0000h:0000h on error (BC3.0 version only)
Note:   AX and DX are destroyed on error, but no other error indicator is
          returned, under the BC++ 2.0 version of DPMILOAD