INT 15H 5302H: Interface Connect (Prot. Mode/16-bit)

 Expects: AX    5302H
          BX    0000H (power device ID = System BIOS)
 Returns: AH    APM error code (if CF=CY) else...
          AX:BX Protected mode entry address
          CX    protected mode data segment
    Info: This function informs the BIOS that you intend to cooperate with
          the BIOS in power management while the CPU is in 16-bit protected
          mode. (see INT 15H 5301H for related info).

    AX:BX On return, this is a real-mode segment:offset address that can be
          used as the entry point for accessing APM services while the CPU
          is in 16-bit protected mode (see notes).

       CX On return, this is a real-mode segment of a data area that APM
          will use later on.

   Notes: On return, you must prepare selectors in either the LDT or GDT so
          that CS and DS will be valid while APM is operating.  See
          DPMI API  for info on preparing selectors.

          After making this connection (and preparing the selectors), you
          can access power management fns while in 16-bit protected mode by
          preparing AX (et al.) and issuing a FAR CALL to the address
          returned in AX:BX.

See Also: APM API
          About APM