--- z80pack-1.17/z80sim/sim7.c	2008-10-20 22:02:48.000000000 +0200
+++ z80pack-1.18/z80sim/sim7.c	2010-03-31 13:14:05.000000000 +0200
@@ -470,7 +470,19 @@
 
 static int op_rb0iyd(int data)		/* RES 0,(IY+d) */
 {
+#ifdef BUS_8080
+	cpu_bus = CPU_WO | CPU_MEMR;
+#endif
+#ifdef FRONTPANEL
+	fp_sampleLightGroup(0, 0);
+#endif
 	*(ram +	IY + data) &= ~1;
+#ifdef BUS_8080
+	cpu_bus = 0;
+#endif
+#ifdef FRONTPANEL
+	fp_sampleLightGroup(0, 0);
+#endif
 	return(23);
 }