ESS_MREG_INTR_ST  483 dev/isa/ess.c  		ess_write_mix_reg(sc, ESS_MREG_INTR_ST, v);
ESS_MREG_INTR_ST  489 dev/isa/ess.c  		ess_write_mix_reg(sc, ESS_MREG_INTR_ST, ESS_IS_ES1888);