ATN
iha_set_ssig(sc, REQ | BSY | SEL | ATN, 0);
iha_set_ssig(sc, REQ | BSY | SEL | ATN, 0);
iha_set_ssig(sc, REQ | BSY | SEL | ATN, 0);
iha_set_ssig(sc, REQ | BSY | SEL, ATN);
iha_set_ssig(sc, REQ | BSY | SEL, ATN);
iha_set_ssig(sc, REQ | BSY | SEL, ATN);
iha_set_ssig(sc, REQ | BSY | SEL, ATN);
iha_set_ssig(sc, REQ | BSY | SEL, ATN);
iha_set_ssig(sc, REQ | BSY | SEL, ATN);
iha_set_ssig(sc, REQ | BSY | SEL | ATN, 0);
bus_space_write_1(sc->sc_iot, sc->sc_ioh, ATN, attn_type | (devno<<5));