APM API Error/Return Codes

 The Intel/Microsoft Advanced Power Management functions indicate failure
 by setting the Carry Flag and returning one of following error codes in
 the AH register:

 01H APM functionality disabled

 02H Interface connection already established
 03H Interface not connected
 04H Real mode connection not established
 05H 16-bit protected-mode interface already established
 06H 16-bit protected-mode interface not supported
 07H 32-bit protected-mode interface already established
 08H 32-bit protected-mode interface not supported

 09H Unrecognized APM Device ID
 0aH Parameter in CX is out of range

 60H Can't enter requested state

 80H No power management events pending

 86H (reserved) no APM present

See Also: APM API
          About APM
          INT 15H (Misc AT Services)