+psw_read_ov(void)
+{
+ return psw_read_bit(PSW_BIT_OV);
+}
+
+void
+psw_write_ov(int ov)
+{
+ psw_write_bit(PSW_BIT_OV, ov);
+}
+
+void
+psw_set_ov(void)
+{
+ psw_write_bit(PSW_BIT_OV, 1);
+}
+
+void
+psw_clr_ov(void)
+{
+ psw_write_bit(PSW_BIT_OV, 0);
+}
+
+/*
+ * Compute parity of bits in accumulator:
+ * parity = 0: even number of ones in accumulator
+ * parity = 1: odd number of ones in accumulator
+ */
+void
+psw_compute_parity_bit(void)