INT 2F U - DOS 3+ internal - INVOKE CRITICAL ERROR
        AX = 1206h
        DI = error code
        BP:SI -> device driver header
        SS = DOS DS (must be using a DOS internal stack)
        STACK: WORD value to be passed to INT 24 in AX
Return: AL = 0-3 for Abort, Retry, Ignore, Fail
        STACK unchanged