)
Call DOSMGR entry point with:
	AX = 0000h get DOSMGR version
	    Return: CF clear
		    AX = version (AH = major, AL = minor)
	AX = 0001h set critical focus
	    Return: CF clear
	AX = 0002h crash current virtual machine
	    Return: never
	    Note:   displays message box stating that "application has been
		      stopped by the DOSMGR device"
	AX = 0003h enter critical section
	    Note:   this function assumes that the code for INT 2A/AX=8001h
		      and INT 2A/AX=8002h have been modified for Windows
	AX = 0004h get VM ID byte
	    Return: CF clear if successful
			ES:DI -> VM ID byte
		    CF set on error
	    Note:   this function fails if the INT 2A modifications have not
		      yet been applied
	AX = 0005h inform Windows of possible media change
	    BL = drive number (00h=A:)
	    Return: CF clear if successful
		    CF set on error
SeeAlso: #01282 at INT 20"Windows",#02655,#02657