Int 2F Fn 1607  - Ms Windows - "v86mmgr" Virtual Device Api                [W]

   AX = 1607h
   BX = 0006h (VxD identifier of "V86MMGR")
   CX = 0000h

Return: AX = status
       0000h if local A20 state changed
       1607h if A20 unchanged
       other if global A20 state changed

See Also: AX=1607h"CALL OUT API"