diff --git a/src/mame/drivers/segag80r.cpp b/src/mame/drivers/segag80r.cpp
index 5114de3366a..c6111903b3c 100644
--- a/src/mame/drivers/segag80r.cpp
+++ b/src/mame/drivers/segag80r.cpp
@@ -124,9 +124,9 @@
  *
  *************************************/
 
-#define CPU_CLOCK           8000000     /* not used when video board is connected */
-#define VIDEO_CLOCK         15468000
-#define SINDBADM_SOUND_CLOCK 8000000
+#define CPU_CLOCK           8_MHz_XTAL     /* not used when video board is connected */
+#define VIDEO_CLOCK         15.46848_MHz_XTAL
+#define SINDBADM_SOUND_CLOCK 8_MHz_XTAL
 
 #define PIXEL_CLOCK         (VIDEO_CLOCK/3)
 
@@ -974,10 +974,10 @@ MACHINE_CONFIG_START(segag80r_state::sindbadm)
 	MCFG_GENERIC_LATCH_8_ADD("soundlatch")
 
 	/* sound hardware */
-	MCFG_SOUND_ADD("sn1", SN76496, SINDBADM_SOUND_CLOCK/4)
+	MCFG_SOUND_ADD("sn1", SN76496, SINDBADM_SOUND_CLOCK/2) /* matches PCB videos, correct? */
 	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "speaker", 1.0)
 
-	MCFG_SOUND_ADD("sn2", SN76496, SINDBADM_SOUND_CLOCK/2)
+	MCFG_SOUND_ADD("sn2", SN76496, SINDBADM_SOUND_CLOCK/4) /* matches PCB videos, correct? */
 	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "speaker", 1.0)
 MACHINE_CONFIG_END
 
diff --git a/src/mame/drivers/system1.cpp b/src/mame/drivers/system1.cpp
index 87671d3f5bb..d25b72b165f 100644
--- a/src/mame/drivers/system1.cpp
+++ b/src/mame/drivers/system1.cpp
@@ -15,6 +15,8 @@ DIP locations verified from manual for:
 
 TODO: - remove patch in nobb if possible and fully understand the
         ports involved in the protection
+      - different XTAL/divider configurations for some Star Jacker
+        cabinets? See you.tube/-a7srHVPb_U
 
 *******************************************************************************