'===========================================================================
' Subject: DETECT WINDOWS ENHANCED MODE       Date: 10-01-98 (21:46)       
'  Author: Leandro Pardini                    Code: QB, QBasic, PDS        
'  Origin: lpardini@cefex.com               Packet: MISC.ABC
'===========================================================================
'======================================== <lpardini@cefex.com> =
' May 1992
' This demo shows you how to detect Windows, and how to prevent
' the user to swap out. It'll only detect Windows Enhanced mode
' and not Windows Standard Mode;  however StartCriticalCode and
' EndCriticalCode WILL work in Standard Mode.
'---------------------------------------------------------------
' Oct 1998
' Today I found this thing in my harddisk  and checked it under
' Windows 98; it works perfectly. Maybe someone's can find this
' useful...
'===============================================================

'$STATIC
DEFINT A-Z

DECLARE FUNCTION WindowsActive% ()
DECLARE SUB EndCriticalCode ()
DECLARE SUB StartCriticalCode ()

Version% = WindowsActive%
IF Version% = 0 THEN
   PRINT "Windows isn't active."
ELSE
   CLS
   PRINT USING "Windows version #.## is active."; Version% / 100
   PRINT STRING$(60, 205)
   PRINT "Press any key to StartCriticalCode."
   WHILE INKEY$ = "": WEND
   CALL StartCriticalCode
   PRINT "Now you can't swap out to Windows."
   PRINT STRING$(60, 205)
   PRINT "Press any key to EndCriticalCode."
   WHILE INKEY$ = "": WEND
   CALL EndCriticalCode
   PRINT "Now you can swap out to Windows."
   PRINT STRING$(60, 205)
   PRINT "Press any key to end this demo."
   WHILE INKEY$ = "": WEND
END IF

'======================================== <lpardini@cefex.com> =
' Reenables Windows swapping after a call to StartCriticalCode.
'===============================================================
SUB EndCriticalCode
DIM Asm AS STRING * 6
MID$(Asm, 1, 6) = CHR$(184) + MKI$(5762) + CHR$(205) + CHR$(47) + CHR$(203)
DEF SEG = VARSEG(Asm): CALL ABSOLUTE(VARPTR(Asm)): DEF SEG
END SUB

'======================================== <lpardini@cefex.com> =
' Prevents Windows from swapping out.
'===============================================================
SUB StartCriticalCode
DIM Asm AS STRING * 6
MID$(Asm, 1, 6) = CHR$(184) + MKI$(5761) + CHR$(205) + CHR$(47) + CHR$(203)
DEF SEG = VARSEG(Asm): CALL ABSOLUTE(VARPTR(Asm)): DEF SEG
END SUB

'======================================== <lpardini@cefex.com> =
' Determines whether Windows is active and if so which version.
'===============================================================
FUNCTION WindowsActive%
DIM Asm AS STRING * 13
MID$(Asm, 1, 5) = CHR$(184) + MKI$(5632) + CHR$(205) + CHR$(47)
MID$(Asm, 6, 5) = CHR$(104) + MKI$(VARSEG(AX)) + CHR$(31) + CHR$(163)
MID$(Asm, 11, 3) = MKI$(VARPTR(AX)) + CHR$(203)
DEF SEG = VARSEG(Asm): CALL ABSOLUTE(VARPTR(Asm)): DEF SEG
IF (AX AND &HFF <> 0) AND (AX AND &HFF <> &H80) AND (AX <> &H1600) THEN
WindowsActive% = ((AX AND &HFF) * 100) + AX \ 256
END IF
END FUNCTION