Int EC  - Exact - Runtime Interface Multiplexor                            [r]

   AX = function number (0000h to 0140h)
   STACK:  DWORD address to return to
       any arguments required by function

Return: STACK: return address popped, but otherwise unchanged
Desc:  this is the interface from applications to the runtime system by Exact
     Automatisering B.V. of the Netherlands.  By using this interrupt,
     it can provide DLL-style capabilities under MS-DOS.

Note:  the interrupt handler removes the return address and flags placed on
     the stack by the INT EC, then jumps to the appropriate function