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APPENDIX C:
Acquisition of Suspend/Resume Event and Power Status
Overview
Suspend/Resume event is notified by multiplex interrupt (INT2Fh). If any event such as power
ON/OFF occurs, consequently the interrupt (INT2Fh) will occur. An application can acquire the
event by catching the interrupt. Since the interrupt INT2Fh is multiplex interrupt, application must
reset values in all the registers to the previous values after catching the interrupt and then return the
control to the old-vector.
Broadcast for Power Event
INT2Fh
Input:
AH = 53h
AL = 0Bh
BH = (Reserved)
BL = 1 System wait request
= 2 System abortion request
= 3 Normal resume notification (if the method of the previous OFF
is by normal suspend.)
= 4 Critical resume notification (if the method of the previous OFF is by
critical suspend.)
= 5 Battery state notification
Output:
BH = 80h Application refuses request.
= 00h Others
The power event is notified by POWER.EXE. In order to use the notification function,
POWER.EXE must be pre-installed. An application must check first if the
POWER.EXE has been installed or not by using the functions detailed below.
Function to Check POWER.EXE
INT2Fh
Input:
AH = 54h
AL = 00h
Output:
AX = 5400h Not installed.
= others Version numbers
BH = 50h “P”
BL = 4Dh “M”
