WR1
setsioreg(sc->sc_ctl, WR1, sc->sc_wr[WR1]);
setsioreg(sc->sc_ctl, WR1, sc->sc_wr[WR1]); /* now interrupt driven */
sioreg(REG(0, WR1), WR1_RXALLS); /* Interrupted All Char. */
sioreg(REG(1, WR1), WR1_RXALLS); /* Interrupted All Char. */