INT 15 C - OS HOOK - SysReq KEY ACTIVITY (ATIBM PC AT,PSIBM PS/2, any model)
	AH = 85h
	AL = SysReq key action (00h pressed, 01h released)
	CF clear
Return: CF clear if successful
	    AH = 00h
	CF set on error
	    AH = status (see #00496)
Notes:	called by keyboard decode routine
	the default handler simply returns successfully; programs which wish
	  to monitor the SysReq key must hook this call
	the SysReq key is often labeled SysRq
SeeAlso: INT 09