Int 61 Fn 20  - Atari Portfolio - Get/set Int 09 Revectoring               [b]

   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,
     preventing applications from using their own INT 09 handler on the
     incompatible keyboard hardware

See Also: AH=1Eh"Portfolio",AH=1Fh"Portfolio",AH=24h"Portfolio"