diff --git a/src/mame/drivers/artmagic.c b/src/mame/drivers/artmagic.c
index d35343a4e42..597201dc0ec 100644
--- a/src/mame/drivers/artmagic.c
+++ b/src/mame/drivers/artmagic.c
@@ -129,6 +129,12 @@ static WRITE16_HANDLER( control_w )
  *
  *************************************/
 
+static TIMER_CALLBACK( irq_off )
+{
+	hack_irq = 0;
+	update_irq_state(machine);
+}
+
 static READ16_HANDLER( ultennis_hack_r )
 {
 	/* IRQ5 points to: jsr (a5); rte */
@@ -136,8 +142,7 @@ static READ16_HANDLER( ultennis_hack_r )
 	{
 		hack_irq = 1;
 		update_irq_state(machine);
-		hack_irq = 0;
-		update_irq_state(machine);
+		timer_set(ATTOTIME_IN_USEC(1), NULL, 0, irq_off);
 	}
 	return input_port_read(machine, "300000");
 }
diff --git a/src/mame/drivers/cischeat.c b/src/mame/drivers/cischeat.c
index fd53f7358b2..d2ebe977591 100644
--- a/src/mame/drivers/cischeat.c
+++ b/src/mame/drivers/cischeat.c
@@ -1896,8 +1896,8 @@ static INTERRUPT_GEN( interrupt_scudhamm )
 {
 	switch ( cpu_getiloops() )
 	{
-		case 0:		cpunum_set_input_line(machine, 0, 3, PULSE_LINE);	// update palette, layers etc. Not the sprites.
-		case 14:	cpunum_set_input_line(machine, 0, 2, PULSE_LINE);	// "real" vblank. It just sets a flag that
+		case 0:		cpunum_set_input_line(machine, 0, 3, HOLD_LINE);	// update palette, layers etc. Not the sprites.
+		case 14:	cpunum_set_input_line(machine, 0, 2, HOLD_LINE);	// "real" vblank. It just sets a flag that
 														// the main loop polls before updating the sprites.
 	}
 }
@@ -1949,8 +1949,8 @@ static INTERRUPT_GEN( interrupt_armchmp2)
 {
 	switch ( cpu_getiloops() )
 	{
-		case 0:		cpunum_set_input_line(machine, 0, 4, PULSE_LINE);
-		case 14:	cpunum_set_input_line(machine, 0, 2, PULSE_LINE);
+		case 0:		cpunum_set_input_line(machine, 0, 4, HOLD_LINE);
+		case 14:	cpunum_set_input_line(machine, 0, 2, HOLD_LINE);
 	}
 }
 
diff --git a/src/mame/drivers/fuukifg2.c b/src/mame/drivers/fuukifg2.c
index ab55ed32f01..a5f3de13224 100644
--- a/src/mame/drivers/fuukifg2.c
+++ b/src/mame/drivers/fuukifg2.c
@@ -425,23 +425,31 @@ static const ym3812_interface fuuki16_ym3812_intf =
             also used for water effects and titlescreen linescroll on gogomile
 */
 
+static TIMER_CALLBACK( irq_off )
+{
+	cpunum_set_input_line(machine, 0, param, CLEAR_LINE);
+}
+
 static TIMER_CALLBACK( level_1_interrupt_callback )
 {
-	cpunum_set_input_line(machine, 0, 1, PULSE_LINE);
+	cpunum_set_input_line(machine, 0, 1, ASSERT_LINE);
+	timer_set(ATTOTIME_IN_USEC(1), NULL, 1, irq_off);
 	timer_set(video_screen_get_time_until_pos(machine->primary_screen, 248, 0), NULL, 0, level_1_interrupt_callback);
 }
 
 
 static TIMER_CALLBACK( vblank_interrupt_callback )
 {
-	cpunum_set_input_line(machine, 0, 3, PULSE_LINE);	// VBlank IRQ
+	cpunum_set_input_line(machine, 0, 3, ASSERT_LINE);	// VBlank IRQ
+	timer_set(ATTOTIME_IN_USEC(1), NULL, 3, irq_off);
 	timer_set(video_screen_get_time_until_vblank_start(machine->primary_screen), NULL, 0, vblank_interrupt_callback);
 }
 
 
 static TIMER_CALLBACK( raster_interrupt_callback )
 {
-	cpunum_set_input_line(machine, 0, 5, PULSE_LINE);	// Raster Line IRQ
+	cpunum_set_input_line(machine, 0, 5, ASSERT_LINE);	// Raster Line IRQ
+	timer_set(ATTOTIME_IN_USEC(1), NULL, 5, irq_off);
 	video_screen_update_partial(machine->primary_screen, video_screen_get_vpos(machine->primary_screen));
 	timer_adjust_oneshot(raster_interrupt_timer, video_screen_get_frame_period(machine->primary_screen), 0);
 }
diff --git a/src/mame/drivers/fuukifg3.c b/src/mame/drivers/fuukifg3.c
index 06c05d5cbe9..1bf5d0b6514 100644
--- a/src/mame/drivers/fuukifg3.c
+++ b/src/mame/drivers/fuukifg3.c
@@ -543,23 +543,31 @@ GFXDECODE_END
 
 ***************************************************************************/
 
+static TIMER_CALLBACK( irq_off )
+{
+	cpunum_set_input_line(machine, 0, param, CLEAR_LINE);
+}
+
 static TIMER_CALLBACK( level_1_interrupt_callback )
 {
-	cpunum_set_input_line(machine, 0, 1, PULSE_LINE);
+	cpunum_set_input_line(machine, 0, 1, ASSERT_LINE);
+	timer_set(ATTOTIME_IN_USEC(1), NULL, 1, irq_off);
 	timer_set(video_screen_get_time_until_pos(machine->primary_screen, 248, 0), NULL, 0, level_1_interrupt_callback);
 }
 
 
 static TIMER_CALLBACK( vblank_interrupt_callback )
 {
-	cpunum_set_input_line(machine, 0, 3, PULSE_LINE);	// VBlank IRQ
+	cpunum_set_input_line(machine, 0, 3, ASSERT_LINE);	// VBlank IRQ
+	timer_set(ATTOTIME_IN_USEC(1), NULL, 3, irq_off);
 	timer_set(video_screen_get_time_until_vblank_start(machine->primary_screen), NULL, 0, vblank_interrupt_callback);
 }
 
 
 static TIMER_CALLBACK( raster_interrupt_callback )
 {
-	cpunum_set_input_line(machine, 0, 5, PULSE_LINE);	// Raster Line IRQ
+	cpunum_set_input_line(machine, 0, 5, ASSERT_LINE);	// Raster Line IRQ
+	timer_set(ATTOTIME_IN_USEC(1), NULL, 5, irq_off);
 	video_screen_update_partial(machine->primary_screen, video_screen_get_vpos(machine->primary_screen));
 	timer_adjust_oneshot(raster_interrupt_timer, video_screen_get_frame_period(machine->primary_screen), 0);
 }
diff --git a/src/mame/drivers/gticlub.c b/src/mame/drivers/gticlub.c
index df90a0e5437..519af445580 100644
--- a/src/mame/drivers/gticlub.c
+++ b/src/mame/drivers/gticlub.c
@@ -1151,12 +1151,16 @@ ROM_START( hangplt )
         ROM_LOAD32_WORD( "685a14.12w",   0x000000, 0x400000, CRC(87437739) SHA1(0d45637af40938a54d5efd29c125b0fafd55f9a4) )
 ROM_END
 
+static TIMER_CALLBACK( irq_off )
+{
+	cpunum_set_input_line(machine, 1, param, CLEAR_LINE);
+}
+
 static void sound_irq_callback(running_machine *machine, int irq)
 {
-	if (irq == 0)
-		cpunum_set_input_line(machine, 1, INPUT_LINE_IRQ1, PULSE_LINE);
-	else
-		cpunum_set_input_line(machine, 1, INPUT_LINE_IRQ2, PULSE_LINE);
+	int line = (irq == 0) ? INPUT_LINE_IRQ1 : INPUT_LINE_IRQ2;
+	cpunum_set_input_line(machine, 1, line, ASSERT_LINE);
+	timer_set(ATTOTIME_IN_USEC(1), NULL, line, irq_off);
 }
 
 static DRIVER_INIT(gticlub)
diff --git a/src/mame/drivers/itech8.c b/src/mame/drivers/itech8.c
index 51d56478898..48b2460b3eb 100644
--- a/src/mame/drivers/itech8.c
+++ b/src/mame/drivers/itech8.c
@@ -567,11 +567,17 @@ void itech8_update_interrupts(running_machine *machine, int periodic, int tms340
  *
  *************************************/
 
+static TIMER_CALLBACK( irq_off )
+{
+	itech8_update_interrupts(machine, 0, -1, -1);
+}
+
+
 static INTERRUPT_GEN( generate_nmi )
 {
 	/* signal the NMI */
 	itech8_update_interrupts(machine, 1, -1, -1);
-	itech8_update_interrupts(machine, 0, -1, -1);
+	timer_set(ATTOTIME_IN_USEC(1), NULL, 0, irq_off);
 
 	if (FULL_LOGGING) logerror("------------ VBLANK (%d) --------------\n", video_screen_get_vpos(machine->primary_screen));
 }
diff --git a/src/mame/drivers/merit.c b/src/mame/drivers/merit.c
index c4898523fd9..a35eb808b58 100644
--- a/src/mame/drivers/merit.c
+++ b/src/mame/drivers/merit.c
@@ -812,7 +812,7 @@ static INPUT_PORTS_START( bigappg )
 	PORT_DIPSETTING(    0x80, DEF_STR( Off ) )
 	PORT_DIPSETTING(    0x00, DEF_STR( On ) )
 
-	PORT_START("IN3")
+	PORT_START("DSW")
 	PORT_DIPNAME( 0x01, 0x01, "4" )
 	PORT_DIPSETTING(    0x01, DEF_STR( Off ) )
 	PORT_DIPSETTING(    0x00, DEF_STR( On ) )
@@ -858,7 +858,7 @@ static const ppi8255_interface ppi8255_intf[2] =
 		NULL						/* Port C write */
 	},
 	{
-		DEVICE8_PORT("IN3"),		/* Port A read */
+		DEVICE8_PORT("DSW"),		/* Port A read */
 		NULL,						/* Port B read */
 		NULL,						/* Port C read */
 		NULL,						/* Port A write */
diff --git a/src/mame/drivers/model2.c b/src/mame/drivers/model2.c
index a2e16dcb356..1be11e34d0a 100644
--- a/src/mame/drivers/model2.c
+++ b/src/mame/drivers/model2.c
@@ -1728,8 +1728,10 @@ static void scsp_irq(running_machine *machine, int irq)
 	if (irq > 0)
 	{
 		scsp_last_line = irq;
-		cpunum_set_input_line(machine, 1, irq, PULSE_LINE);
+		cpunum_set_input_line(machine, 1, irq, ASSERT_LINE);
 	}
+	else
+		cpunum_set_input_line(machine, 1, -irq, CLEAR_LINE);
 }
 
 static const scsp_interface scsp_config =
diff --git a/src/mame/drivers/model3.c b/src/mame/drivers/model3.c
index 2d8b2163383..641a1f592c9 100644
--- a/src/mame/drivers/model3.c
+++ b/src/mame/drivers/model3.c
@@ -4269,8 +4269,10 @@ static void scsp_irq(running_machine *machine, int irq)
  	if (irq > 0)
 	{
 		scsp_last_line = irq;
-		cpunum_set_input_line(machine, 1, irq, PULSE_LINE);
+		cpunum_set_input_line(machine, 1, irq, ASSERT_LINE);
 	}
+	else
+		cpunum_set_input_line(machine, 1, -irq, CLEAR_LINE);
 }
 
 static const scsp_interface scsp_config =
diff --git a/src/mame/drivers/zr107.c b/src/mame/drivers/zr107.c
index f9a02edbfec..4d535cef218 100644
--- a/src/mame/drivers/zr107.c
+++ b/src/mame/drivers/zr107.c
@@ -830,12 +830,16 @@ MACHINE_DRIVER_END
 
 /*****************************************************************************/
 
+static TIMER_CALLBACK( irq_off )
+{
+	cpunum_set_input_line(machine, 1, param, CLEAR_LINE);
+}
+
 static void sound_irq_callback(running_machine *machine, int irq)
 {
-	if (irq == 0)
-		cpunum_set_input_line(machine, 1, INPUT_LINE_IRQ1, PULSE_LINE);
-	else
-		cpunum_set_input_line(machine, 1, INPUT_LINE_IRQ2, PULSE_LINE);
+	int line = (irq == 0) ? INPUT_LINE_IRQ1 : INPUT_LINE_IRQ2;
+	cpunum_set_input_line(machine, 1, line, ASSERT_LINE);
+	timer_set(ATTOTIME_IN_USEC(1), NULL, line, irq_off);
 }
 
 static void init_zr107(running_machine *machine)