diff --git a/src/mame/drivers/tubep.c b/src/mame/drivers/tubep.c
index 08a44d329b6..bfff3e237a3 100644
--- a/src/mame/drivers/tubep.c
+++ b/src/mame/drivers/tubep.c
@@ -270,6 +270,7 @@ ADDRESS_MAP_END
 static TIMER_CALLBACK( tubep_scanline_callback )
 {
 	int scanline = param;
+	static const char *const cputags[] = { "mcu", "nsc" };
 
 	curr_scanline = scanline;//for debugging
 
@@ -297,14 +298,14 @@ static TIMER_CALLBACK( tubep_scanline_callback )
 	{
 		logerror("/nmi CPU#3\n");
 		tubep_vblank_end(); /* switch buffered sprite RAM page */
-		cputag_set_input_line(machine, "nsc", INPUT_LINE_NMI, ASSERT_LINE);
+		cputag_set_input_line(machine, cputags[(cputag_get_cpu(machine, "nsc") != NULL) ? 1 : 0], INPUT_LINE_NMI, ASSERT_LINE);
 	}
 	/* CPU #3 MS2010-A NMI */
 	/* deactivates at the start of VBLANK signal which happens at the beginning of scanline number 240*/
 	if (scanline == 240)
 	{
 		logerror("CPU#3 nmi clear\n");
-		cputag_set_input_line(machine, "nsc", INPUT_LINE_NMI, CLEAR_LINE);
+		cputag_set_input_line(machine, cputags[(cputag_get_cpu(machine, "nsc") != NULL) ? 1 : 0], INPUT_LINE_NMI, CLEAR_LINE);
 	}
 
 
diff --git a/src/mame/video/tubep.c b/src/mame/video/tubep.c
index 1db89b0293e..02803410cfb 100644
--- a/src/mame/video/tubep.c
+++ b/src/mame/video/tubep.c
@@ -454,7 +454,9 @@ WRITE8_HANDLER( tubep_background_c000_w )
 
 static TIMER_CALLBACK( sprite_timer_callback )
 {
-	cputag_set_input_line(machine, "nsc", 0, ASSERT_LINE);
+	static const char *const cputags[] = { "mcu", "nsc" };
+
+	cputag_set_input_line(machine, cputags[(cputag_get_cpu(machine, "nsc") != NULL) ? 1 : 0], 0, ASSERT_LINE);
 }
 
 
@@ -529,6 +531,8 @@ static void draw_sprite(running_machine *machine)
 
 WRITE8_HANDLER( tubep_sprite_control_w )
 {
+	static const char *const cputags[] = { "mcu", "nsc" };
+
 	if (offset < 10)
 	{
 		/*graph_ctrl[offset] = data;*/
@@ -583,7 +587,7 @@ WRITE8_HANDLER( tubep_sprite_control_w )
             /SINT line will be reasserted in XSize * YSize cycles (RH0 signal cycles)
             */
 			/* 1.clear the /SINT interrupt line */
-			cputag_set_input_line(space->machine, "nsc", 0, CLEAR_LINE);
+			cputag_set_input_line(space->machine, cputags[(cputag_get_cpu(space->machine, "nsc") != NULL) ? 1 : 0], 0, CLEAR_LINE);
 
 			/* 2.assert /SINT again after this time */
 			timer_set( space->machine, attotime_mul(ATTOTIME_IN_HZ(19968000/8), (XSize+1)*(YSize+1)), NULL, 0, sprite_timer_callback);