diff --git a/src/mame/drivers/zac2650.c b/src/mame/drivers/zac2650.c
index f1df74b5474..51a5dc47686 100644
--- a/src/mame/drivers/zac2650.c
+++ b/src/mame/drivers/zac2650.c
@@ -10,6 +10,7 @@
 
 #include "emu.h"
 #include "cpu/s2650/s2650.h"
+#include "sound/s2636.h"
 
 #include "tinv2650.lh"
 
@@ -260,6 +261,10 @@ static MACHINE_DRIVER_START( tinvader )
 	MDRV_VIDEO_UPDATE(tinvader)
 
 	/* sound hardware */
+	MDRV_SPEAKER_STANDARD_MONO("mono")
+
+	MDRV_SOUND_ADD("s2636snd", S2636, 0)
+	MDRV_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.25)
 MACHINE_DRIVER_END
 
 static WRITE8_HANDLER( tinvader_sound_w )
@@ -314,6 +319,6 @@ ROM_START( dodgem )
 ROM_END
 
 
-GAME( 1978, sia2650,  0,       tinvader, sinvader, 0, ROT270, "Zelco / Zaccaria", "Super Invader Attack", GAME_NO_SOUND )
-GAMEL(1978, tinv2650, sia2650, tinvader, tinvader, 0, ROT270, "Zelco / Zaccaria", "The Invaders",         GAME_NO_SOUND, layout_tinv2650 )
-GAME( 1979, dodgem,   0,       tinvader, dodgem,   0, ROT0,   "Zaccaria",         "Dodgem",               GAME_NO_SOUND )
+GAME( 1978, sia2650,  0,       tinvader, sinvader, 0, ROT270, "Zelco / Zaccaria", "Super Invader Attack", 0 )
+GAMEL(1978, tinv2650, sia2650, tinvader, tinvader, 0, ROT270, "Zelco / Zaccaria", "The Invaders",         0, layout_tinv2650 )
+GAME( 1979, dodgem,   0,       tinvader, dodgem,   0, ROT0,   "Zaccaria",         "Dodgem",               0 )
diff --git a/src/mame/video/zac2650.c b/src/mame/video/zac2650.c
index c615b396892..408cdd88e56 100644
--- a/src/mame/video/zac2650.c
+++ b/src/mame/video/zac2650.c
@@ -5,6 +5,7 @@
 /*************************************************************/
 
 #include "emu.h"
+#include "sound/s2636.h"
 
 UINT8 *zac2650_s2636_0_ram;
 static bitmap_t *spritebitmap;
@@ -38,6 +39,10 @@ WRITE8_HANDLER( zac_s2636_w )
 	zac2650_s2636_0_ram[offset] = data;
 	gfx_element_mark_dirty(space->machine->gfx[1], offset/8);
 	gfx_element_mark_dirty(space->machine->gfx[2], offset/8);
+	if (offset == 0xc7)
+	{
+		s2636_soundport_w(space->machine->device("s2636snd"), 0, data);
+	}
 }
 
 READ8_HANDLER( tinvader_port_0_r )