INT 2F - MS Windows - WINDOWS ENH MODE & 286 DOSX EXIT BROADCAST
        AX = 1606h
        DX = flags
            bit 0 = 0 if Windows enhanced-mode exit
            bit 0 = 1 if Microsoft 286 DOS extender exit
            bits 1-15 reserved (undefined)
Notes:  if the init broadcast fails (AX=1605h returned CX <> 0), then this
          broadcast will be issued immediately.
        this call will be issued in real mode
SeeAlso: AX=1605h,AX=1609h

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