IER_SET
out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
out_8(&via1[IER], CB1_INT | IER_SET);
out_8(&via1[IER], IER_SET | SR_INT | CB1_INT);
out_8(&via1[IER], IER_SET | SR_INT | CB1_INT);