diff --git a/src/mame/drivers/byvid.cpp b/src/mame/drivers/byvid.cpp
index ef556d3f1bf..4daa493d361 100644
--- a/src/mame/drivers/byvid.cpp
+++ b/src/mame/drivers/byvid.cpp
@@ -576,8 +576,7 @@ WRITE_LINE_MEMBER( by133_state::u7_cb2_w )
 	// red led
 	m_beep->set_clock(950);
 	m_beep->set_state(state);
-	if (!m_sound_int_handler.isnull())
-		m_sound_int_handler(state);
+	m_sound_int_handler(state);
 }
 
 WRITE_LINE_MEMBER( by133_state::u10_cb2_w )
@@ -619,11 +618,7 @@ void by133_state::u7_b_w(u8 data)
 	//machine().scheduler().synchronize();
 	m_u7b = data;
 	// Handle sound
-	if (!m_sound_select_handler.isnull())
-	{
-		//u8 sound = (m_u11b & 0x0f) | ((data & 0x02) << 3);
-		m_sound_select_handler(data & 15);
-	}
+	m_sound_select_handler(data & 0x1f);
 }
 
 u8 by133_state::u10_a_r()
diff --git a/src/mame/drivers/gts80.cpp b/src/mame/drivers/gts80.cpp
index df13261d116..d1048191ff1 100644
--- a/src/mame/drivers/gts80.cpp
+++ b/src/mame/drivers/gts80.cpp
@@ -8,7 +8,7 @@ Gottlieb System 80
 An evolution of the original system 1, again plagued by numerous problems. The R6502 and R6532 replaced the
 ancient 4-bit spider chips, but the problems of poor-quality PCBs, bad connectors and no common grounding were
 still there. Like most pinball machines, the leaky battery could destroy everything, as could an unnoticed
-stuck-on solenoid. If the machine was left on was a while, it could lock up, so a reset board (watchdog) was
+stuck-on solenoid. If the machine was left on for a while, it could lock up, so a reset board (watchdog) was
 added.
 
 Here are the key codes to enable play: (may need to hit X to start a ball)
diff --git a/src/mame/drivers/st_mp200.cpp b/src/mame/drivers/st_mp200.cpp
index 9f37e6f1e53..04a042547a1 100644
--- a/src/mame/drivers/st_mp200.cpp
+++ b/src/mame/drivers/st_mp200.cpp
@@ -1154,7 +1154,7 @@ GAME(1980,  stargzr,    0,          st_mp200,   mp200, st_mp200_state, init_st_m
 GAME(1982,  dragfist,   0,          st_mp200,   mp200, st_mp200_state, init_st_mp200, ROT0, "Stern",     "Dragonfist",                  MACHINE_IS_SKELETON_MECHANICAL)
 GAME(1982,  cue,        0,          st_mp200,   mp200, st_mp200_state, init_st_mp200, ROT0, "Stern",     "Cue (Prototype)",             MACHINE_IS_SKELETON_MECHANICAL)
 
-// multiball, unusable
+// multiball
 GAME(1980,  nineball,   0,          st_mp200,   mp200, st_mp200_state, init_st_mp200, ROT0, "Stern",     "Nine Ball",                   MACHINE_IS_SKELETON_MECHANICAL)
 GAME(1981,  lightnin,   0,          st_mp201,   mp200, st_mp200_state, init_st_mp201, ROT0, "Stern",     "Lightning",                   MACHINE_IS_SKELETON_MECHANICAL)
 GAME(1980,  flight2k,   0,          st_mp201,   mp200, st_mp200_state, init_st_mp201, ROT0, "Stern",     "Flight 2000",                 MACHINE_IS_SKELETON_MECHANICAL)