diff --git a/src/mame/drivers/rocnrope.c b/src/mame/drivers/rocnrope.c
index eacb74e3379..257ffd6e7d7 100644
--- a/src/mame/drivers/rocnrope.c
+++ b/src/mame/drivers/rocnrope.c
@@ -33,6 +33,8 @@ WRITE8_MEMBER(rocnrope_state::rocnrope_interrupt_vector_w)
 WRITE8_MEMBER(rocnrope_state::irq_mask_w)
 {
 	m_irq_mask = data & 1;
+	if (!m_irq_mask)
+		m_maincpu->set_input_line(0, CLEAR_LINE);
 }
 
 /*************************************
@@ -57,7 +59,7 @@ static ADDRESS_MAP_START( rocnrope_map, AS_PROGRAM, 8, rocnrope_state )
 	AM_RANGE(0x8000, 0x8000) AM_WRITE(watchdog_reset_w)
 	AM_RANGE(0x8080, 0x8080) AM_WRITE(rocnrope_flipscreen_w)
 	AM_RANGE(0x8081, 0x8081) AM_DEVWRITE("timeplt_audio", timeplt_audio_device, sh_irqtrigger_w)  /* cause interrupt on audio CPU */
-	AM_RANGE(0x8082, 0x8082) AM_WRITENOP    /* interrupt acknowledge??? */
+	AM_RANGE(0x8082, 0x8082) AM_WRITENOP    /* ??? */
 	AM_RANGE(0x8083, 0x8083) AM_WRITENOP    /* Coin counter 1 */
 	AM_RANGE(0x8084, 0x8084) AM_WRITENOP    /* Coin counter 2 */
 	AM_RANGE(0x8087, 0x8087) AM_WRITE(irq_mask_w)
@@ -187,8 +189,8 @@ GFXDECODE_END
 
 INTERRUPT_GEN_MEMBER(rocnrope_state::vblank_irq)
 {
-	if(m_irq_mask)
-		device.execute().set_input_line(0, HOLD_LINE);
+	if (m_irq_mask)
+		device.execute().set_input_line(0, ASSERT_LINE);
 }