+#define SECDAY ((unsigned)(24*60*60)) /* seconds per day */
+#define SECYR ((unsigned)(365*SECDAY)) /* per common year */
+/*
+ * TODRZERO is the what the TODR should contain when the ``year'' begins.
+ * The TODR should always contain a number between 0 and SECYR+SECDAY.
+ */
+#define TODRZERO ((unsigned)(1<<28))
+
+#define YRREF 1970
+#define LEAPYEAR(year) ((year)%4==0 && year != 2000) /* good till 2100 */
+
+/*
+ * Start a 60 HZ clock.
+ */
+#define clkstart() {\
+ mtpr(NICR, -16667); /* 16.667 milli-seconds */\
+ mtpr(ICCS, ICCS_RUN+ICCS_IE+ICCS_TRANS+ICCS_INT+ICCS_ERR);\
+}
+#define clkreld() mtpr(ICCS, ICCS_RUN+ICCS_IE+ICCS_INT+ICCS_ERR)