INT 61 - Atari Portfolio - GET/SET INT 09 REVECTORING                           
	AH = 20h
	AL = function
	    00h get INT 09 revectoring state
	    01h set state
		DL = new state (00h disable, 01h enable)
Return: if function 00h
	    DL = new state (00h disabled, 01h enabled)
Desc:	specify whether INT 09 is automatically revectored to the BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly.,
	  preventing applications from using their own INT 09 handler on the
	  incompatible keyboard hardware
SeeAlso: AH=1Eh"Portfolio",AH=1Fh"Portfolio",AH=24h"Portfolio"