diff --git a/src/emu/cpu/psx/psx.c b/src/emu/cpu/psx/psx.c
index 95d841b773d..d47802f7af5 100644
--- a/src/emu/cpu/psx/psx.c
+++ b/src/emu/cpu/psx/psx.c
@@ -3165,12 +3165,6 @@ psxcpu_device *psxcpu_device::getcpu( device_t &device, const char *cputag )
 	return downcast<psxcpu_device *>( device.subdevice( cputag ) );
 }
 
-void psxcpu_device::irq_set( device_t &device, const char *cputag, UINT32 bitmask )
-{
-	psxirq_device *irq = getcpu( device, cputag )->subdevice<psxirq_device>("irq");
-	irq->set( bitmask );
-}
-
 void psxcpu_device::install_sio_handler( device_t &device, const char *cputag, int n_port, psx_sio_handler p_f_sio_handler )
 {
 	psxsio_device *sio = getcpu( device, cputag )->subdevice<psxsio_device>("sio");
diff --git a/src/emu/cpu/psx/psx.h b/src/emu/cpu/psx/psx.h
index 7323fbf0081..b42ec76c4b1 100644
--- a/src/emu/cpu/psx/psx.h
+++ b/src/emu/cpu/psx/psx.h
@@ -145,7 +145,6 @@ public:
 	static psxcpu_device *getcpu( device_t &device, const char *cputag );
 	static void install_sio_handler( device_t &device, const char *cputag, int n_port, psx_sio_handler p_f_sio_handler );
 	static void sio_input( device_t &device, const char *cputag, int n_port, int n_mask, int n_data );
-	static void irq_set( device_t &device, const char *cputag, UINT32 bitmask );
 
 protected:
 	psxcpu_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, address_map_constructor internal_map);
diff --git a/src/mame/drivers/zn.c b/src/mame/drivers/zn.c
index 1d2658f9688..d8bbe9e4b0d 100644
--- a/src/mame/drivers/zn.c
+++ b/src/mame/drivers/zn.c
@@ -1471,18 +1471,12 @@ Notes:
       *2                  - Unpopulated DIP28 socket
 */
 
-/* IRQ */
-
-void psx_irq_set( running_machine &machine, UINT32 data )
-{
-	psxcpu_device::irq_set( *machine.device("maincpu^"), "maincpu", data );
-}
-
 static void atpsx_interrupt(device_t *device, int state)
 {
 	if (state)
 	{
-		psx_irq_set(device->machine(), 0x400);
+		psxirq_device *psxirq = (psxirq_device *) machine.device("maincpu:irq");
+		psxirq->intin10();
 	}
 }
 
@@ -2053,7 +2047,8 @@ static void jdredd_ide_interrupt(device_t *device, int state)
 {
 	if (state)
 	{
-		psx_irq_set(device->machine(), 0x400);
+		psxirq_device *psxirq = (psxirq_device *) machine.device("maincpu:irq");
+		psxirq->intin10();
 	}
 }
 
@@ -2155,7 +2150,8 @@ WRITE32_MEMBER(zn_state::acpsx_10_w)
 WRITE32_MEMBER(zn_state::nbajamex_80_w)
 {
 	verboselog( machine(), 0, "nbajamex_80_w( %08x, %08x, %08x )\n", offset, data, mem_mask );
-	psx_irq_set(machine(), 0x400);
+	psxirq_device *psxirq = (psxirq_device *) machine.device("maincpu:irq");
+	psxirq->intin10();
 }
 
 READ32_MEMBER(zn_state::nbajamex_08_r)
diff --git a/src/mame/includes/psx.h b/src/mame/includes/psx.h
index 35c5ab9acca..69914c81c45 100644
--- a/src/mame/includes/psx.h
+++ b/src/mame/includes/psx.h
@@ -27,7 +27,6 @@ public:
 extern void psx_driver_init( running_machine &machine );
 DECLARE_WRITE32_HANDLER( psx_com_delay_w );
 DECLARE_READ32_HANDLER( psx_com_delay_r );
-extern void psx_irq_set( running_machine &, UINT32 );
 extern void psx_sio_install_handler( running_machine &, int, psx_sio_handler );
 extern void psx_sio_input( running_machine &, int, int, int );