diff --git a/src/drivers/asteroid.c b/src/drivers/asteroid.c
index 6366d15e4..0c27f4313 100644
--- a/src/drivers/asteroid.c
+++ b/src/drivers/asteroid.c
@@ -539,6 +539,22 @@ INPUT_PORTS_START( astdelux )
 	PORT_DIPSETTING (	0xa0, "1 each 4" )
 	PORT_DIPSETTING (	0xc0, "1 each 2" )
 	PORT_DIPSETTING (	0xe0, "None" )
+
+	PORT_START /* fake IN4 - inverter circuit */
+	PORT_DIPNAME( 0x01, 0x00, DEF_STR( Cabinet ) )
+	PORT_DIPSETTING(    0x00, DEF_STR( Upright ) )
+	PORT_DIPSETTING(    0x01, DEF_STR( Cocktail ) )
+
+	PORT_START /* IN5 - asteroid_cocktail_port0 */
+	PORT_BIT( 0x08, IP_ACTIVE_HIGH, IPT_BUTTON3 | IPF_PLAYER2)
+	PORT_BIT( 0x10, IP_ACTIVE_HIGH, IPT_BUTTON1 | IPF_PLAYER2)
+	PORT_BIT( 0xe7, IP_ACTIVE_HIGH, IPT_UNUSED )
+
+	PORT_START /* IN6 - asteroid_cocktail_port1 */
+	PORT_BIT( 0x1f, IP_ACTIVE_HIGH, IPT_UNUSED )
+	PORT_BIT( 0x20, IP_ACTIVE_HIGH, IPT_BUTTON2 | IPF_PLAYER2)
+	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT | IPF_2WAY | IPF_PLAYER2)
+	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT  | IPF_2WAY | IPF_PLAYER2)
 INPUT_PORTS_END
 
 
@@ -884,6 +900,8 @@ static DRIVER_INIT( asterock )
 
 static DRIVER_INIT( astdelux )
 {
+	asteroid_install_inv = true;
+
 	OVERLAY_START( astdelux_overlay )
 		OVERLAY_RECT( 0.0, 0.0, 1.0, 1.0, MAKE_ARGB(0x04,0x88,0xff,0xff) )
 	OVERLAY_END
diff --git a/src/machine/asteroid_machine.c b/src/machine/asteroid_machine.c
index 9ade3c407..f8e71f87a 100644
--- a/src/machine/asteroid_machine.c
+++ b/src/machine/asteroid_machine.c
@@ -196,6 +196,14 @@ WRITE_HANDLER( astdelux_bank_switch_w )
 			RAM[0x300 + i] = temp;
 		}
 	}
+
+	if (asteroid_install_inv)
+	{
+		/* player selection is bit 0x80 */
+		optional_io_active = (readinputport(asteroid_cocktail_switch) && (data & 0x80))?1:0;
+		avg_set_flip_x( optional_io_active );
+		avg_set_flip_y( optional_io_active );
+	}
 }