Intermec 6200 Reference Guide

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The APM BIOS specification defines event codes for various APM events.

NORAPM.DLL collects these events from the APM BIOS and either handles

them directly or broadcasts them to the system components (Windows drivers,

applications, and DOS TSRs.)  System components can use the events to monitor

system configuration and power state changes.  Additionally, some APM events

have responses that can implement cooperative power management.
Definitions of the event codes are provided in the APMCODES.H C/C++ header

file, in Appendix B, Common PEN*KEY 6000 Series Information.  In the header

file, each event is given two definitions, one for Windows and one for APM BIOS

and DOS APMĆaware TSRs.  Two definitions are provided because the values

chosen by Microsoft to represent the APM events in the Windows 3.1

WINDOWS.H header file are different from the values defined in the

Intel/Microsoft APM BIOS Specification.  In the APMCODES.H file, Windows

codes are identified by a prefix of 

PWR_

" and BIOS/DOS codes start with 

APM_.

"

NORAPM.DLL broadcasts APM events to four classes of system components:

"

Windows Applications

Windows applications receive APM event broadcasts by means of the

message procedures of any topĆlevel windows that they own.  The message

format is:
Msg:

WM_POWER

 (defined in WINDOWS.H)

wParam:

PWR_*

 event code defined in APMCODES.H or WINDOWS.H

lParam:

Optional NORAND 32Ćbit APM event parameter

Returns:

Application should return 

PWR_FAIL

 (from WINDOWS.H) if it wants to

reject an event; otherwise, 

PWR_OK

 should be returned.

"

Windows Installable Drivers

Windows installable drivers receive APM event broadcasts by means of

their 

DriverProc

 

entry points.  The message format is:

Msg:

DRV_POWER

 (defined in WINDOWS.H)

lParam1:

PWR_*

 event code defined in APMCODES.H or WINDOWS.H.

1Param2:

Optional NORAND 32Ćbit APM event parameter

Returns:

The driver should return 

PWR_FAIL

 or 

PWR_OK

"

DOS RealĆMode Drivers and TSRs

DOS realĆmode system components receive APM event broadcasts through

software interrupt 2Fh.  A driver or TSR that hooks the broadcast should

nest to previous owners of the interrupt before handling it, even if it is set

to fail the call.  This approach allows other drivers an opportunity to see the

event, even if it is failed.  The message format is:
AX:

530Bh, the APM event broadcast ID

BX:

APM_* event code defined in APMCODES.H.

CX:DX:

Optional 32Ćbit NORAND APM event parameter

Returns:

BX should be set to 0 for success or 80h to fail the event.