Int 15 Fn 530B  - Advanced Power Management Specification - Get Power Man  [p]

   AX = 530Bh

Return: CF clear if successful
       BX = event code
       0001h system stand-by request
       0002h system suspend request
       0003h normal resume system notification
       0004h critical resume system notification
       0005h battery low notification
   CF set on error
       AH = error code (03h,80h) (see AX=5300h)

Notes: although power management events are often asynchronous, notification
     will not be made until polled via this call to permit software to
     only receive event notification when it is prepared to process
     power management events; since these events are not very time-
     critical, it should be sufficient to poll once or twice per second
   the critical resume notification is made after the system resumes
     from an emergency suspension; normally, the system BIOS only notifies
     its partner that it wishes to suspend and relies on the partner to
     actually request the suspension, but no notification is made on an
     emergency suspension
   should not be called from within a hardware interrupt handler to avoid
     reentrance problems

See Also: AX=5307h,AX=5307h/BX=0001h/CX=0001h,AX=5307h/BX=0001h/CX=0002h