diff --git a/src/devices/cpu/mcs48/mcs48.h b/src/devices/cpu/mcs48/mcs48.h
index c37f9899d9b..3640286a524 100644
--- a/src/devices/cpu/mcs48/mcs48.h
+++ b/src/devices/cpu/mcs48/mcs48.h
@@ -59,7 +59,7 @@ enum
 ***************************************************************************/
 
 #define MCS48_LC_CLOCK(_L, _C) \
-	(1 / (2 * 3.14159265358979323846 * sqrt(_L * _C)))
+	(1 / (2 * M_PI * sqrt(_L * _C)))
 
 #define MCS48_ALE_CLOCK(_clock) \
 	attotime::from_hz(_clock/(3*5))
diff --git a/src/devices/sound/vgm_visualizer.cpp b/src/devices/sound/vgm_visualizer.cpp
index bab3c909ddf..6dc37c4e87b 100644
--- a/src/devices/sound/vgm_visualizer.cpp
+++ b/src/devices/sound/vgm_visualizer.cpp
@@ -88,7 +88,7 @@ void vgmviz_device::device_start()
 
 void vgmviz_device::fill_window()
 {
-	float window_pos_delta = (3.14159265358979f * 2) / FFT_LENGTH;
+	float window_pos_delta = (M_PI * 2) / FFT_LENGTH;
 	float power = 0;
 	for (int i = 0; i < (FFT_LENGTH / 2) + 1; i++)
 	{
diff --git a/src/frontend/mame/ui/info.cpp b/src/frontend/mame/ui/info.cpp
index 32b081d7a16..b5b9626a87e 100644
--- a/src/frontend/mame/ui/info.cpp
+++ b/src/frontend/mame/ui/info.cpp
@@ -84,7 +84,7 @@ void get_general_warnings(std::ostream &buf, running_machine &machine, machine_f
 	{
 		if (bad_roms)
 			buf << '\n';
-		buf << _("There are known problems with this system\n\n");
+		buf << _("There are known problems with this system:\n\n");
 	}
 
 	// add a warning if any ROMs are flagged BAD_DUMP/NO_DUMP
@@ -139,10 +139,20 @@ void get_system_warnings(std::ostream &buf, running_machine &machine, machine_fl
 		buf << _("Screen flipping in cocktail mode is not supported.\n");
 	if (flags & ::machine_flags::REQUIRES_ARTWORK)
 		buf << _("This system requires external artwork files.\n");
+
+	// add the 'BTANB' warnings
 	if (flags & ::machine_flags::IS_INCOMPLETE)
+	{
+		if (buf.tellp() > start_position)
+			buf << '\n';
 		buf << _("This system was never completed. It may exhibit strange behavior or missing elements that are not bugs in the emulation.\n");
+	}
 	if (flags & ::machine_flags::NO_SOUND_HW)
-		buf << _("This system has no sound hardware, MAME will produce no sounds, this is expected behaviour.\n");
+	{
+		if (buf.tellp() > start_position)
+			buf << '\n';
+		buf << _("This system has no sound hardware, MAME will produce no sounds, this is expected behavior.\n");
+	}
 
 	// these are more severe warnings
 	if (flags & ::machine_flags::MECHANICAL)
diff --git a/src/mame/namco/cgang.cpp b/src/mame/namco/cgang.cpp
index 35556baead1..73ccdef6b0e 100644
--- a/src/mame/namco/cgang.cpp
+++ b/src/mame/namco/cgang.cpp
@@ -192,9 +192,9 @@ private:
 	u8 m_cg_motor_on = 0;
 	u8 m_cg_motor_dir = 0;
 
-	int m_cg_motor_clk[5];
-	int m_cg_motor_pos[5];
-	int m_en_pos[5];
+	int m_cg_motor_clk[5] = { };
+	int m_cg_motor_pos[5] = { };
+	int m_en_pos[5] = { };
 
 	emu_timer *m_sol_filter[5];
 	TIMER_CALLBACK_MEMBER(output_sol) { m_en_sol[param >> 1] = param & 1; }
@@ -849,7 +849,7 @@ ROM_START( cgang )
 	ROM_LOAD("cg2_9c_e02a.9c", 0x00000, 0x20000, CRC(f9a3f8a0) SHA1(5ad8b408d36397227019afd15c3516f85488c6df) ) // handwritten label seen on one PCB
 
 	ROM_REGION( 0x20000, "adpcm1", 0 )
-	ROM_LOAD("cg2_9e_586e.9e", 0x00000, 0x20000, CRC(40e7f60b) SHA1(af641b0562db1ae033cee67df583d178fd8c93f3) ) // handwritten label seen on one PCB
+	ROM_LOAD("cg2_9e_586e.9e", 0x00000, 0x20000, CRC(40e7f60b) SHA1(af641b0562db1ae033cee67df583d178fd8c93f3) ) // "
 ROM_END
 
 } // anonymous namespace
diff --git a/src/mame/nintendo/cx4fn.ipp b/src/mame/nintendo/cx4fn.ipp
index 60b0adff0e4..f9a6e069a3a 100644
--- a/src/mame/nintendo/cx4fn.ipp
+++ b/src/mame/nintendo/cx4fn.ipp
@@ -13,10 +13,6 @@
 #include <cmath>
 #define CX4_Tan(a) (CX4_CosTable[a] ? ((((int32_t)CX4_SinTable[a]) << 16) / CX4_CosTable[a]) : 0x80000000)
 #define CX4_sar(b, n) ((b) >> (n))
-#ifdef PI
-#undef PI
-#endif
-#define PI 3.1415926535897932384626433832795
 
 //Wireframe Helpers
 static void CX4_C4TransfWireFrame(void)
@@ -26,17 +22,17 @@ static void CX4_C4TransfWireFrame(void)
 	cx4.c4z = (double)cx4.C4WFZVal - 0x95;
 
 	//Rotate X
-	cx4.tanval = -(double)cx4.C4WFX2Val * PI * 2 / 128;
+	cx4.tanval = -(double)cx4.C4WFX2Val * M_PI * 2 / 128;
 	cx4.c4y2   = cx4.c4y * cos(cx4.tanval) - cx4.c4z * sin(cx4.tanval);
 	cx4.c4z2   = cx4.c4y * sin(cx4.tanval) + cx4.c4z * cos(cx4.tanval);
 
 	//Rotate Y
-	cx4.tanval = -(double)cx4.C4WFY2Val * PI * 2 / 128;
+	cx4.tanval = -(double)cx4.C4WFY2Val * M_PI * 2 / 128;
 	cx4.c4x2   = cx4.c4x * cos(cx4.tanval)  + cx4.c4z2 * sin(cx4.tanval);
 	cx4.c4z    = cx4.c4x * -sin(cx4.tanval) + cx4.c4z2 * cos(cx4.tanval);
 
 	//Rotate Z
-	cx4.tanval = -(double)cx4.C4WFDist * PI * 2 / 128;
+	cx4.tanval = -(double)cx4.C4WFDist * M_PI * 2 / 128;
 	cx4.c4x    = cx4.c4x2 * cos(cx4.tanval) - cx4.c4y2 * sin(cx4.tanval);
 	cx4.c4y    = cx4.c4x2 * sin(cx4.tanval) + cx4.c4y2 * cos(cx4.tanval);
 
@@ -75,17 +71,17 @@ static void CX4_C4TransfWireFrame2(void)
 	cx4.c4z = (double)cx4.C4WFZVal;
 
 	//Rotate X
-	cx4.tanval = -(double)cx4.C4WFX2Val * PI * 2 / 128;
+	cx4.tanval = -(double)cx4.C4WFX2Val * M_PI * 2 / 128;
 	cx4.c4y2   = cx4.c4y * cos(cx4.tanval) - cx4.c4z * sin(cx4.tanval);
 	cx4.c4z2   = cx4.c4y * sin(cx4.tanval) + cx4.c4z * cos(cx4.tanval);
 
 	//Rotate Y
-	cx4.tanval = -(double)cx4.C4WFY2Val * PI * 2 / 128;
+	cx4.tanval = -(double)cx4.C4WFY2Val * M_PI * 2 / 128;
 	cx4.c4x2   = cx4.c4x * cos(cx4.tanval)  + cx4.c4z2 * sin(cx4.tanval);
 	cx4.c4z    = cx4.c4x * -sin(cx4.tanval) + cx4.c4z2 * cos(cx4.tanval);
 
 	//Rotate Z
-	cx4.tanval = -(double)cx4.C4WFDist * PI * 2 / 128;
+	cx4.tanval = -(double)cx4.C4WFDist * M_PI * 2 / 128;
 	cx4.c4x    = cx4.c4x2 * cos(cx4.tanval) - cx4.c4y2 * sin(cx4.tanval);
 	cx4.c4y    = cx4.c4x2 * sin(cx4.tanval) + cx4.c4y2 * cos(cx4.tanval);
 
diff --git a/src/mame/nintendo/cx4ops.ipp b/src/mame/nintendo/cx4ops.ipp
index eadc5ddb9b8..03f6200aadc 100644
--- a/src/mame/nintendo/cx4ops.ipp
+++ b/src/mame/nintendo/cx4ops.ipp
@@ -132,7 +132,7 @@ static void CX4_op1f(address_space &space)
 	else
 	{
 		cx4.tanval = ((double)cx4.C41FYVal) / ((double)cx4.C41FXVal);
-		cx4.C41FAngleRes = (int16_t)(atan(cx4.tanval) / (PI * 2) * 512);
+		cx4.C41FAngleRes = (int16_t)(atan(cx4.tanval) / (M_PI * 2) * 512);
 		cx4.C41FAngleRes = cx4.C41FAngleRes;
 		if(cx4.C41FXVal < 0)
 		{
diff --git a/src/mame/vtech/socrates.cpp b/src/mame/vtech/socrates.cpp
index ed0c3c4cda9..261cac587b8 100644
--- a/src/mame/vtech/socrates.cpp
+++ b/src/mame/vtech/socrates.cpp
@@ -742,8 +742,8 @@ rgb_t socrates_state::create_color(uint8_t color)
 	int const chromaindex = color&0x0F;
 	int const swappedcolor = ((color&0xf0)>>4)|((color&0x0f)<<4);
 	double finalY = (1/LUMAMAX) * lumatable[swappedcolor];
-	double const finalI = (M_I * (cos((phaseangle[chromaindex]/180)*3.141592653589793)))* ((1/CHROMAMAX)*chromaintensity[swappedcolor]);
-	double const finalQ = (M_Q * (sin((phaseangle[chromaindex]/180)*3.141592653589793)))* ((1/CHROMAMAX)*chromaintensity[swappedcolor]);
+	double const finalI = (M_I * (cos((phaseangle[chromaindex]/180)*M_PI)))* ((1/CHROMAMAX)*chromaintensity[swappedcolor]);
+	double const finalQ = (M_Q * (sin((phaseangle[chromaindex]/180)*M_PI)))* ((1/CHROMAMAX)*chromaintensity[swappedcolor]);  
 	if (finalY > 1) finalY = 1; // clamp luma
 	// calculate the R, G and B values here, neato matrix math
 	double finalR = (finalY*1)+(finalI*0.9563)+(finalQ*0.6210);