/* Pin interrupt on rising edge of clock */
#define IBM4704_INT_INIT() do { EICRA |= ((1<<ISC11)|(1<<ISC10)); } while (0)
-#define IBM4704_INT_ON() do { EIMSK |= (1<<INT1); } while (0)
+#define IBM4704_INT_ON() do { EIFR |= (1<<INTF1); EIMSK |= (1<<INT1); } while (0)
#define IBM4704_INT_OFF() do { EIMSK &= ~(1<<INT1); } while (0)
#define IBM4704_INT_VECT INT1_vect