diff --git a/src/emu/sound/k053260.c b/src/emu/sound/k053260.c
index d0b3762b5c5..36b30a0cee4 100644
--- a/src/emu/sound/k053260.c
+++ b/src/emu/sound/k053260.c
@@ -397,7 +397,6 @@ READ8_MEMBER( k053260_device::k053260_r )
 
 				return status;
 			}
-		break;
 
 		case 0x2e: /* read ROM */
 			if ( m_mode & 1 )
diff --git a/src/emu/sound/zsg2.c b/src/emu/sound/zsg2.c
index b9dd8bd3272..c6eef40947d 100644
--- a/src/emu/sound/zsg2.c
+++ b/src/emu/sound/zsg2.c
@@ -448,6 +448,4 @@ READ16_MEMBER(zsg2_device::read)
 	{
 		return control_r(offset - 0x300);
 	}
-
-	return 0;
 }
diff --git a/src/emu/video/h63484.c b/src/emu/video/h63484.c
index 0744943b149..6eefec617ee 100644
--- a/src/emu/video/h63484.c
+++ b/src/emu/video/h63484.c
@@ -711,7 +711,6 @@ bool h63484_device::set_dot(INT16 x, INT16 y, INT16 px, INT16 py)
 		case 0x03:
 			fatalerror("HD63484 color modes (Pattern RAM indirect)\n");
 			// TODO
-			break;
 	}
 
 	return false;
@@ -1766,7 +1765,6 @@ void h63484_device::process_fifo()
 		default:
 			printf("%04x\n",m_cr);
 			fatalerror("stop!\n");
-			break;
 	}
 }
 
diff --git a/src/emu/video/voodoo.c b/src/emu/video/voodoo.c
index e65b49ab283..b4f38a606a1 100644
--- a/src/emu/video/voodoo.c
+++ b/src/emu/video/voodoo.c
@@ -1654,7 +1654,6 @@ static UINT32 cmdfifo_execute(voodoo_state *v, cmdfifo_info *f)
 				case 2:     /* RET */
 					if (LOG_CMDFIFO) logerror("  RET $%06X\n", target);
 					fatalerror("RET in CMDFIFO!\n");
-					break;
 
 				case 3:     /* JMP LOCAL FRAME BUFFER */
 					if (LOG_CMDFIFO) logerror("  JMP LOCAL FRAMEBUF $%06X\n", target);
@@ -1670,7 +1669,6 @@ static UINT32 cmdfifo_execute(voodoo_state *v, cmdfifo_info *f)
 				default:
 					osd_printf_debug("INVALID JUMP COMMAND!\n");
 					fatalerror("  INVALID JUMP COMMAND\n");
-					break;
 			}
 			break;
 
@@ -2889,7 +2887,6 @@ static INT32 register_w(voodoo_state *v, offs_t offset, UINT32 data)
 			/* send tmu config data to the frame buffer */
 			v->send_config = (TREXINIT_SEND_TMU_CONFIG(data) > 0);
 			goto default_case;
-			break;
 
 		/* these registers are referenced in the renderer; we must wait for pending work before changing */
 		case chromaRange:
@@ -4571,7 +4568,6 @@ WRITE32_MEMBER( voodoo_banshee_device::banshee_agp_w )
 
 		case cmdBump0:
 			fatalerror("cmdBump0\n");
-			break;
 
 		case cmdRdPtrL0:
 			v->fbi.cmdfifo[0].rdptr = data;
@@ -4608,7 +4604,6 @@ WRITE32_MEMBER( voodoo_banshee_device::banshee_agp_w )
 
 		case cmdBump1:
 			fatalerror("cmdBump1\n");
-			break;
 
 		case cmdRdPtrL1:
 			v->fbi.cmdfifo[1].rdptr = data;
@@ -4956,7 +4951,6 @@ void voodoo_device::common_start_voodoo(UINT8 type)
 
 		default:
 			fatalerror("Unsupported voodoo card in voodoo_start!\n");
-			break;
 	}
 
 	/* set the type, and initialize the chip mask */
diff --git a/src/mame/drivers/airbustr.c b/src/mame/drivers/airbustr.c
index 41f59aef56d..7d11e568369 100644
--- a/src/mame/drivers/airbustr.c
+++ b/src/mame/drivers/airbustr.c
@@ -245,7 +245,7 @@ READ8_MEMBER(airbustr_state::devram_r)
 				return (x & 0x00ff) >> 0;
 			else
 				return (x & 0xff00) >> 8;
-		}   break;
+		}
 
 		/* Reading eff4, F0 times must yield at most 80-1 consecutive
 		   equal values */
diff --git a/src/mame/drivers/bmcbowl.c b/src/mame/drivers/bmcbowl.c
index 165c37f2d3c..c1eab7c59fc 100644
--- a/src/mame/drivers/bmcbowl.c
+++ b/src/mame/drivers/bmcbowl.c
@@ -215,7 +215,6 @@ READ16_MEMBER(bmcbowl_state::bmc_protection_r)
 				case 0x1013: return 0;
 				default:         return 0x46<<8;
 			}
-			break;
 	}
 	logerror("Protection read @ %X\n",space.device().safe_pcbase());
 	return machine().rand();
diff --git a/src/mame/drivers/cbasebal.c b/src/mame/drivers/cbasebal.c
index 63c8ead0ccc..f9ed7179cb2 100644
--- a/src/mame/drivers/cbasebal.c
+++ b/src/mame/drivers/cbasebal.c
@@ -51,7 +51,6 @@ READ8_MEMBER(cbasebal_state::bankedram_r)
 			return m_palette->basemem().read8(offset);
 		else
 			return 0;
-		break;
 	default:
 		return cbasebal_scrollram_r(space, offset); /* SCROLL */
 	}
diff --git a/src/mame/drivers/chihiro.c b/src/mame/drivers/chihiro.c
index 6a8273c50b5..09513f3e383 100644
--- a/src/mame/drivers/chihiro.c
+++ b/src/mame/drivers/chihiro.c
@@ -1989,37 +1989,29 @@ UINT32 nv2a_renderer::texture_get_texel(int number,int x,int y)
 		switch (c) {
 		case 0:
 			return 0xff000000 + convert_r5g6b5_r8g8b8(color0);
-			break;
 		case 1:
 			return 0xff000000 + convert_r5g6b5_r8g8b8(color1);
-			break;
 		case 2:
 			cb = pal5bit(((color0m2 & 0x003e) + (color1 & 0x001f)) / 3);
 			cg = pal6bit(((color0m2 & 0x0fc0) + (color1 & 0x07e0)) / 3 >> 5);
 			cr = pal5bit(((color0m2 & 0x1f000) + color1) / 3 >> 11);
 			return 0xff000000 | (cr << 16) | (cg << 8) | (cb);
-			break;
 		case 3:
 			cb = pal5bit(((color1m2 & 0x003e) + (color0 & 0x001f)) / 3);
 			cg = pal6bit(((color1m2 & 0x0fc0) + (color0 & 0x07e0)) / 3 >> 5);
 			cr = pal5bit(((color1m2 & 0x1f000) + color0) / 3 >> 11);
 			return 0xff000000 | (cr << 16) | (cg << 8) | (cb);
-			break;
 		case 4:
 			return 0xff000000 + convert_r5g6b5_r8g8b8(color0);
-			break;
 		case 5:
 			return 0xff000000 + convert_r5g6b5_r8g8b8(color1);
-			break;
 		case 6:
 			cb = pal5bit(((color0 & 0x001f) + (color1 & 0x001f)) / 2);
 			cg = pal6bit(((color0 & 0x07e0) + (color1 & 0x07e0)) / 2 >> 5);
 			cr = pal5bit(((color0 & 0xf800) + (color1 & 0xf800)) / 2 >> 11);
 			return 0xff000000 | (cr << 16) | (cg << 8) | (cb);
-			break;
 		default:
 			return 0xff000000;
-			break;
 		}
 	case DXT3:
 		bx = x >> 2;
@@ -2038,24 +2030,19 @@ UINT32 nv2a_renderer::texture_get_texel(int number,int x,int y)
 		switch (c) {
 		case 0:
 			return ((ca + (ca << 4)) << 24) + convert_r5g6b5_r8g8b8(color0);
-			break;
 		case 1:
 			return ((ca + (ca << 4)) << 24) + convert_r5g6b5_r8g8b8(color1);
-			break;
 		case 2:
 			cb = pal5bit((2 * (color0 & 0x001f) + (color1 & 0x001f)) / 3);
 			cg = pal6bit((2 * (color0 & 0x07e0) + (color1 & 0x07e0)) / 3 >> 5);
 			cr = pal5bit((2 * (color0 & 0xf800) + (color1 & 0xf800)) / 3 >> 11);
 			return ((ca + (ca << 4)) << 24) | (cr << 16) | (cg << 8) | (cb);
-			break;
 		default:
 			cb = pal5bit(((color0 & 0x001f) + 2 * (color1 & 0x001f)) / 3);
 			cg = pal6bit(((color0 & 0x07e0) + 2 * (color1 & 0x07e0)) / 3 >> 5);
 			cr = pal5bit(((color0 & 0xf800) + 2 * (color1 & 0xf800)) / 3 >> 11);
 			return ((ca + (ca << 4)) << 24) | (cr << 16) | (cg << 8) | (cb);
-			break;
 		}
-		break;
 	case A4R4G4B4:
 		to = dilated0[texture[number].dilate][x] + dilated1[texture[number].dilate][y]; // offset of texel in texture memory
 		a4r4g4b4 = *(((UINT16 *)texture[number].buffer) + to); // get texel color
@@ -2144,22 +2131,18 @@ UINT32 nv2a_renderer::texture_get_texel(int number,int x,int y)
 		switch (c) {
 		case 0:
 			return (ca << 24) + convert_r5g6b5_r8g8b8(color0);
-			break;
 		case 1:
 			return (ca << 24) + convert_r5g6b5_r8g8b8(color1);
-			break;
 		case 2:
 			cb = pal5bit((2 * (color0 & 0x001f) + (color1 & 0x001f)) / 3);
 			cg = pal6bit((2 * (color0 & 0x07e0) + (color1 & 0x07e0)) / 3 >> 5);
 			cr = pal5bit((2 * (color0 & 0xf800) + (color1 & 0xf800)) / 3 >> 11);
 			return (ca << 24) | (cr << 16) | (cg << 8) | (cb);
-			break;
 		default:
 			cb = pal5bit(((color0 & 0x001f) + 2 * (color1 & 0x001f)) / 3);
 			cg = pal6bit(((color0 & 0x07e0) + 2 * (color1 & 0x07e0)) / 3 >> 5);
 			cr = pal5bit(((color0 & 0xf800) + 2 * (color1 & 0xf800)) / 3 >> 11);
 			return (ca << 24) | (cr << 16) | (cg << 8) | (cb);
-			break;
 		}
 	default:
 		return 0xff00ff00;
@@ -2192,7 +2175,6 @@ void nv2a_renderer::write_pixel(int x, int y, UINT32 color)
 		switch (alpha_func) {
 		case nv2a_renderer::NEVER:
 			return;
-			break;
 		case nv2a_renderer::ALWAYS:
 		default:
 			break;
@@ -3563,49 +3545,36 @@ float nv2a_renderer::combiner_map_input_select(int code,int index)
 		case 0:
 		default:
 			return combiner.register_zero[index];
-		break;
 		case 1:
 			return combiner.register_color0[index];
-		break;
 		case 2:
 			return combiner.register_color1[index];
-		break;
 		case 3:
 			return combiner.register_fogcolor[index];
-		break;
 		case 4:
 			return combiner.register_primarycolor[index];
-		break;
 		case 5:
 			return combiner.register_secondarycolor[index];
-		break;
 		case 8:
 			return combiner.register_texture0color[index];
-		break;
 		case 9:
 			return combiner.register_texture1color[index];
-		break;
 		case 10:
 			return combiner.register_texture2color[index];
-		break;
 		case 11:
 			return combiner.register_texture3color[index];
-		break;
 		case 12:
 			return combiner.register_spare0[index];
-		break;
 		case 13:
 			return combiner.register_spare1[index];
-		break;
 		case 14:
 			return combiner.variable_sumclamp[index];
-		break;
 		case 15:
 			return combiner.variable_EF[index];
-		break;
 	}
 
-	return 0;
+	// never executed
+	//return 0;
 }
 
 float *nv2a_renderer::combiner_map_input_select3(int code)
@@ -3614,49 +3583,36 @@ float *nv2a_renderer::combiner_map_input_select3(int code)
 		case 0:
 		default:
 			return combiner.register_zero;
-		break;
 		case 1:
 			return combiner.register_color0;
-		break;
 		case 2:
 			return combiner.register_color1;
-		break;
 		case 3:
 			return combiner.register_fogcolor;
-		break;
 		case 4:
 			return combiner.register_primarycolor;
-		break;
 		case 5:
 			return combiner.register_secondarycolor;
-		break;
 		case 8:
 			return combiner.register_texture0color;
-		break;
 		case 9:
 			return combiner.register_texture1color;
-		break;
 		case 10:
 			return combiner.register_texture2color;
-		break;
 		case 11:
 			return combiner.register_texture3color;
-		break;
 		case 12:
 			return combiner.register_spare0;
-		break;
 		case 13:
 			return combiner.register_spare1;
-		break;
 		case 14:
 			return combiner.variable_sumclamp;
-		break;
 		case 15:
 			return combiner.variable_EF;
-		break;
 	}
 
-	return 0;
+	// never executed
+	//return 0;
 }
 
 float *nv2a_renderer::combiner_map_output_select3(int code)
@@ -3664,50 +3620,34 @@ float *nv2a_renderer::combiner_map_output_select3(int code)
 	switch (code) {
 		case 0:
 			return 0;
-		break;
 		case 1:
 			return 0;
-		break;
 		case 2:
 			return 0;
-		break;
 		case 3:
 			return 0;
-		break;
 		case 4:
 			return combiner.register_primarycolor;
-		break;
 		case 5:
 			return combiner.register_secondarycolor;
-		break;
 		case 8:
 			return combiner.register_texture0color;
-		break;
 		case 9:
 			return combiner.register_texture1color;
-		break;
 		case 10:
 			return combiner.register_texture2color;
-		break;
 		case 11:
 			return combiner.register_texture3color;
-		break;
 		case 12:
 			return combiner.register_spare0;
-		break;
 		case 13:
 			return combiner.register_spare1;
-		break;
 		case 14:
 			return 0;
-		break;
 		case 15:
 		default:
 			return 0;
-		break;
 	}
-
-	return 0;
 }
 
 float nv2a_renderer::combiner_map_input_function(int code,float value)
@@ -3717,33 +3657,26 @@ float nv2a_renderer::combiner_map_input_function(int code,float value)
 	switch (code) {
 		case 0:
 			return MAX(0.0,value);
-		break;
 		case 1:
 			t=MAX(value, 0.0);
 			return 1.0 - MIN(t, 1.0);
-		break;
 		case 2:
 			return 2.0 * MAX(0.0, value) - 1.0;
-		break;
 		case 3:
 			return -2.0 * MAX(0.0, value) + 1.0;
-		break;
 		case 4:
 			return MAX(0.0, value) - 0.5;
-		break;
 		case 5:
 			return -MAX(0.0, value) + 0.5;
-		break;
 		case 6:
 			return value;
-		break;
 		case 7:
 		default:
 			return -value;
-		break;
 	}
 
-	return 0;
+	// never executed
+	//return 0;
 }
 
 void nv2a_renderer::combiner_map_input_function3(int code,float *data)
@@ -3786,7 +3719,6 @@ void nv2a_renderer::combiner_map_input_function3(int code,float *data)
 		break;
 		case 6:
 			return;
-		break;
 		case 7:
 		default:
 			data[0]=-data[0];
diff --git a/src/mame/drivers/cops.c b/src/mame/drivers/cops.c
index 6f4e06152f6..f23f5cbc695 100644
--- a/src/mame/drivers/cops.c
+++ b/src/mame/drivers/cops.c
@@ -366,7 +366,6 @@ READ8_MEMBER(cops_state::io1_r)
 			logerror("Unknown io1_r, offset = %03x\n", offset);
 			return 0;
 	}
-	return 0;
 }
 
 WRITE8_MEMBER(cops_state::io1_w)
diff --git a/src/mame/drivers/cps3.c b/src/mame/drivers/cps3.c
index 40828e4ac50..d43a9eab3a2 100644
--- a/src/mame/drivers/cps3.c
+++ b/src/mame/drivers/cps3.c
@@ -1768,7 +1768,6 @@ READ32_MEMBER(cps3_state::cps3_eeprom_r)
 	//  if(DEBUG_PRINTF) printf("unk read eeprom addr %04x, mask %08x\n", addr, mem_mask);
 		return 0x00000000;
 	}
-	return 0x00000000;
 }
 
 WRITE32_MEMBER(cps3_state::cps3_eeprom_w)
diff --git a/src/mame/drivers/firebeat.c b/src/mame/drivers/firebeat.c
index d61f7a0a15c..1f8f3c04459 100644
--- a/src/mame/drivers/firebeat.c
+++ b/src/mame/drivers/firebeat.c
@@ -1905,7 +1905,6 @@ int firebeat_state::ibutton_w(UINT8 data)
 				default:
 				{
 					fatalerror("ibutton: unknown normal mode cmd %02X\n", data);
-					break;
 				}
 			}
 			break;
diff --git a/src/mame/drivers/gottlieb.c b/src/mame/drivers/gottlieb.c
index 7c929f3f71f..c448b28e53e 100644
--- a/src/mame/drivers/gottlieb.c
+++ b/src/mame/drivers/gottlieb.c
@@ -391,7 +391,8 @@ READ8_MEMBER(gottlieb_state::laserdisc_status_r)
 		m_laserdisc_audio_address %= AUDIORAM_SIZE;
 		return result;
 	}
-	return 0;
+	// never executed
+	//return 0;
 }
 
 
diff --git a/src/mame/drivers/hitpoker.c b/src/mame/drivers/hitpoker.c
index 588a1e3aa9f..bbc29e6279a 100644
--- a/src/mame/drivers/hitpoker.c
+++ b/src/mame/drivers/hitpoker.c
@@ -215,7 +215,8 @@ READ8_MEMBER(hitpoker_state::eeprom_r)
 	return ret;
 	/*** ***/
 
-	return m_eeprom_data[m_eeprom_index & 0xfff];
+	// FIXME: never executed
+	//return m_eeprom_data[m_eeprom_index & 0xfff];
 }
 
 READ8_MEMBER(hitpoker_state::hitpoker_pic_r)
diff --git a/src/mame/drivers/igs017.c b/src/mame/drivers/igs017.c
index 01b61863a51..c2d3c3db950 100644
--- a/src/mame/drivers/igs017.c
+++ b/src/mame/drivers/igs017.c
@@ -2372,8 +2372,6 @@ READ16_MEMBER(igs017_state::lhzb2a_prot_r)
 
 			logerror("%s: read bitswap - val %04x -> %02x\n", machine().describe_context(), m_prot_val, res);
 			return res;
-
-			break;
 		}
 
 		default:
diff --git a/src/mame/drivers/jpmsys5.c b/src/mame/drivers/jpmsys5.c
index 3ee751bab27..60b28265a9a 100644
--- a/src/mame/drivers/jpmsys5.c
+++ b/src/mame/drivers/jpmsys5.c
@@ -687,7 +687,6 @@ READ16_MEMBER(jpmsys5_state::coins_awp_r)
 		{
 			return ioport("COINS")->read() << 8;
 		}
-		break;
 		default:
 		{
 			logerror("coins read offset: %x",offset);
diff --git a/src/mame/drivers/lethal.c b/src/mame/drivers/lethal.c
index 33fa87091a5..e3cf9f0db34 100644
--- a/src/mame/drivers/lethal.c
+++ b/src/mame/drivers/lethal.c
@@ -319,7 +319,6 @@ READ8_MEMBER(lethal_state::guns_r)
 				return 0;
 			else
 				return (232 - GUNY(1));
-			break;
 		case 2:
 			return GUNX(2) >> 1;
 		case 3:
@@ -327,7 +326,6 @@ READ8_MEMBER(lethal_state::guns_r)
 				return 0;
 			else
 				return (232 - GUNY(2));
-			break;
 	}
 
 	return 0;
diff --git a/src/mame/drivers/magictg.c b/src/mame/drivers/magictg.c
index 159c2cba6af..035e8555f80 100644
--- a/src/mame/drivers/magictg.c
+++ b/src/mame/drivers/magictg.c
@@ -691,7 +691,6 @@ READ32_MEMBER( magictg_state::adsp_idma_data_r )
 	else
 	{
 		fatalerror("????\n");
-		return 0;
 	}
 }
 
diff --git a/src/mame/drivers/mitchell.c b/src/mame/drivers/mitchell.c
index 7957105337a..52ec26797a2 100644
--- a/src/mame/drivers/mitchell.c
+++ b/src/mame/drivers/mitchell.c
@@ -224,13 +224,11 @@ READ8_MEMBER(mitchell_state::input_r)
 				return mahjong_input_r(space, offset - 1);
 			else
 				return ioport("IN0")->read();
-			break;
 		case 2:     /* Block Block - dial control */
 			if (offset)
 				return block_input_r(space, offset - 1);
 			else
 				return ioport("IN0")->read();
-			break;
 		case 3:     /* Super Pang - simulate START 1 press to initialize EEPROM */
 			return ioport(portnames[offset])->read();
 	}
diff --git a/src/mame/drivers/model1.c b/src/mame/drivers/model1.c
index 6083e6219a3..750cdacdfdc 100644
--- a/src/mame/drivers/model1.c
+++ b/src/mame/drivers/model1.c
@@ -781,8 +781,9 @@ WRITE16_MEMBER(model1_state::network_ctl_w)
 WRITE16_MEMBER(model1_state::md1_w)
 {
 	COMBINE_DATA(m_display_list1+offset);
-	if(0 && offset)
-		return;
+	// never executed
+	//if(0 && offset)
+	//	return;
 	if(1 && m_dump)
 		logerror("TGP: md1_w %x, %04x @ %04x (%x)\n", offset, data, mem_mask, space.device().safe_pc());
 }
@@ -790,8 +791,9 @@ WRITE16_MEMBER(model1_state::md1_w)
 WRITE16_MEMBER(model1_state::md0_w)
 {
 	COMBINE_DATA(m_display_list0+offset);
-	if(0 && offset)
-		return;
+	// never executed
+	//if(0 && offset)
+	//	return;
 	if(1 && m_dump)
 		logerror("TGP: md0_w %x, %04x @ %04x (%x)\n", offset, data, mem_mask, space.device().safe_pc());
 }
diff --git a/src/mame/drivers/model2.c b/src/mame/drivers/model2.c
index 7b98fd29481..daebac9422b 100644
--- a/src/mame/drivers/model2.c
+++ b/src/mame/drivers/model2.c
@@ -143,7 +143,6 @@ bool model2_state::copro_fifoin_pop(device_t *device, UINT32 *result,UINT32 offs
 			return false;
 
 		fatalerror("Copro FIFOIN underflow (at %08X)\n", device->safe_pc());
-		return false;
 	}
 
 	r = m_copro_fifoin_data[m_copro_fifoin_rpos++];
@@ -203,7 +202,6 @@ void model2_state::copro_fifoin_push(device_t *device, UINT32 data, UINT32 offse
 	if (m_copro_fifoin_num == COPRO_FIFOIN_SIZE)
 	{
 		fatalerror("Copro FIFOIN overflow (at %08X)\n", device->safe_pc());
-		return;
 	}
 
 	//printf("COPRO FIFOIN at %08X, %08X, %f\n", device->safe_pc(), data, *(float*)&data);
@@ -272,7 +270,6 @@ void model2_state::copro_fifoout_push(device_t *device, UINT32 data,UINT32 offse
 	if (m_copro_fifoout_num == COPRO_FIFOOUT_SIZE)
 	{
 		fatalerror("Copro FIFOOUT overflow (at %08X)\n", device->safe_pc());
-		return;
 	}
 
 //  logerror("COPRO FIFOOUT PUSH %08X, %f, %d\n", data, *(float*)&data,state->m_copro_fifoout_num);
@@ -308,7 +305,6 @@ WRITE32_MEMBER(model2_state::copro_tgp_fifoout_push)
 	if (m_copro_fifoout_num == COPRO_FIFOOUT_SIZE)
 	{
 		fatalerror("Copro FIFOOUT overflow (at %08X)\n", m_tgp->pc());
-		return;
 	}
 
 //  logerror("COPRO FIFOOUT PUSH %08X, %f, %d\n", data, *(float*)&data,m_copro_fifoout_num);
diff --git a/src/mame/drivers/mpu5hw.c b/src/mame/drivers/mpu5hw.c
index 901b2368571..d872c920f73 100644
--- a/src/mame/drivers/mpu5hw.c
+++ b/src/mame/drivers/mpu5hw.c
@@ -152,7 +152,6 @@ READ32_MEMBER(mpu5_state::mpu5_mem_r)
 				case 0xf0:
 				{
 					return asic_r32(space, offset&3,mem_mask);
-					break;
 				}
 				
 				default:
diff --git a/src/mame/drivers/namcos21.c b/src/mame/drivers/namcos21.c
index eb4d6de3887..fd57178b861 100644
--- a/src/mame/drivers/namcos21.c
+++ b/src/mame/drivers/namcos21.c
@@ -793,9 +793,7 @@ RenderSlaveOutput( running_machine &machine, UINT16 data )
 	namcos21_state *state = machine.driver_data<namcos21_state>();
 	if( state->m_mpDspState->slaveOutputSize >= 4096 )
 	{
-		logerror( "FATAL ERROR: SLAVE OVERFLOW (0x%x)\n",state->m_mpDspState->slaveOutputBuffer[0]  );
-		exit(1);
-		return;
+		fatalerror( "FATAL ERROR: SLAVE OVERFLOW (0x%x)\n",state->m_mpDspState->slaveOutputBuffer[0]  );
 	}
 
 	/* append word to slave output buffer */
diff --git a/src/mame/drivers/nbmj9195.c b/src/mame/drivers/nbmj9195.c
index 1165b16d77d..b3f4c0c98ca 100644
--- a/src/mame/drivers/nbmj9195.c
+++ b/src/mame/drivers/nbmj9195.c
@@ -130,26 +130,20 @@ READ8_MEMBER(nbmj9195_state::mscoutm_cpu_portb_r)
 	{
 	case 0x01:
 		return ioport("KEY0")->read();
-		break;
 	case 0x02:
 		return ioport("KEY1")->read();
-		break;
 	case 0x04:
 		return ioport("KEY2")->read();
-		break;
 	case 0x08:
 		return ioport("KEY3")->read();
-		break;
 	case 0x10:
 		return ioport("KEY4")->read();
-		break;
 	default:
 		return (ioport("KEY0")->read() & ioport("KEY1")->read() & ioport("KEY2")->read()
 			& ioport("KEY3")->read() & ioport("KEY4")->read());
-		break;
 	}
-
-	return 0xff;
+	// never executed
+	//return 0xff;
 }
 
 READ8_MEMBER(nbmj9195_state::mscoutm_cpu_portc_r)
@@ -159,25 +153,20 @@ READ8_MEMBER(nbmj9195_state::mscoutm_cpu_portc_r)
 	{
 	case 0x01:
 		return ioport("KEY5")->read();
-		break;
 	case 0x02:
 		return ioport("KEY6")->read();
-		break;
 	case 0x04:
 		return ioport("KEY7")->read();
-		break;
 	case 0x08:
 		return ioport("KEY8")->read();
-		break;
 	case 0x10:
 		return ioport("KEY9")->read();
-		break;
 	default:
 		return (ioport("KEY5")->read() & ioport("KEY6")->read() & ioport("KEY7")->read()
 			& ioport("KEY8")->read() & ioport("KEY9")->read());
-		break;
 	}
-	return 0xff;
+	// never executed
+	//return 0xff;
 }
 
 
@@ -213,24 +202,19 @@ READ8_MEMBER(nbmj9195_state::others_cpu_portb_r)
 	{
 	case 0x01:
 		return ioport("KEY0")->read();
-		break;
 	case 0x02:
 		return ioport("KEY1")->read();
-		break;
 	case 0x04:
 		return ioport("KEY2")->read();
-		break;
 	case 0x08:
 		return ioport("KEY3")->read();
-		break;
 	case 0x10:
 		return ((ioport("KEY4")->read() & 0x7f) | (nbmj9195_dipsw_r() << 7));
-		break;
 	default:
 		return (ioport("KEY0")->read() & ioport("KEY1")->read() & ioport("KEY2")->read() & ioport("KEY3")->read() & (ioport("KEY4")->read() & 0x7f));
-		break;
 	}
-	return 0xff;
+	// ever executed
+	//return 0xff;
 }
 
 READ8_MEMBER(nbmj9195_state::others_cpu_portc_r)
@@ -240,24 +224,19 @@ READ8_MEMBER(nbmj9195_state::others_cpu_portc_r)
 	{
 	case 0x01:
 		return ioport("KEY5")->read();
-		break;
 	case 0x02:
 		return ioport("KEY6")->read();
-		break;
 	case 0x04:
 		return ioport("KEY7")->read();
-		break;
 	case 0x08:
 		return ioport("KEY8")->read();
-		break;
 	case 0x10:
 		return ioport("KEY9")->read() & 0x7f;
-		break;
 	default:
 		return (ioport("KEY5")->read() & ioport("KEY6")->read() & ioport("KEY7")->read() & ioport("KEY8")->read() & (ioport("KEY9")->read() & 0x7f));
-		break;
 	}
-	return 0xff;;
+	// never executed
+	//return 0xff;
 }
 
 
diff --git a/src/mame/drivers/segas24.c b/src/mame/drivers/segas24.c
index 7046cabe155..3d9191d76f6 100644
--- a/src/mame/drivers/segas24.c
+++ b/src/mame/drivers/segas24.c
@@ -852,7 +852,6 @@ void segas24_state::irq_timer_start(int old_tmode)
 	}
 	case 2:
 		fatalerror("egas24_state::irq_timer_start - case 2\n");
-		break;
 	case 3: {
 		int count = 0x1000 - irq_tval;
 		irq_timer->adjust(attotime::from_hz(TIMER_CLOCK)*count);
diff --git a/src/mame/drivers/seibuspi.c b/src/mame/drivers/seibuspi.c
index c788b4f126e..dca91db0de4 100644
--- a/src/mame/drivers/seibuspi.c
+++ b/src/mame/drivers/seibuspi.c
@@ -957,7 +957,8 @@ READ32_MEMBER(seibuspi_state::ejsakura_keyboard_r)
 		default:
 			return ioport("SYSTEM")->read();
 	}
-	return 0xffffffff;
+	// never executed
+	//return 0xffffffff;
 }
 
 WRITE32_MEMBER(seibuspi_state::ejsakura_input_select_w)
diff --git a/src/mame/drivers/vega.c b/src/mame/drivers/vega.c
index 349b48b3ee3..7c26477c29b 100644
--- a/src/mame/drivers/vega.c
+++ b/src/mame/drivers/vega.c
@@ -303,16 +303,13 @@ READ8_MEMBER(vega_state::extern_r)
 		{
 			return m_i8255->read( space, m_p2_data>>6); /* A6,A7 -> A0,A1 */
 		}
-		break;
 
 		case 1: /* 04-07 */
 		{
 			/* AY 3-8910 */
 			m_ay8910->data_w(space, 0, offset);
 			return 0xff;//mame_rand(space.machine);
-
 		}
-		break;
 
 		case 2: /* 08-0b */
 		{
@@ -327,9 +324,7 @@ READ8_MEMBER(vega_state::extern_r)
 				//register r ?
 				return m_ins8154->ins8154_r(space,offset&0x7f);
 			}
-
 		}
-		break;
 #if 0
 		case 3: /* 0c-0f */
 		{
diff --git a/src/mame/drivers/viper.c b/src/mame/drivers/viper.c
index cda792c6923..42a747923a0 100644
--- a/src/mame/drivers/viper.c
+++ b/src/mame/drivers/viper.c
@@ -1521,7 +1521,8 @@ static UINT32 voodoo3_pci_r(device_t *busdevice, device_t *device, int function,
 		default:
 			fatalerror("voodoo3_pci_r: %08X at %08X\n", reg, device->machine().device("maincpu")->safe_pc());
 	}
-	return 0;
+	// never executed
+	//return 0;
 }
 
 static void voodoo3_pci_w(device_t *busdevice, device_t *device, int function, int reg, UINT32 data, UINT32 mem_mask)
@@ -1744,7 +1745,7 @@ void viper_state::DS2430_w(int bit)
 				{
 					case 0x33:      ds2430_state = DS2430_STATE_READ_ROM; break;
 					case 0xcc:      ds2430_state = DS2430_STATE_MEM_FUNCTION; break;
-					default:        fatalerror("DS2430_w: unimplemented rom command %02X\n", ds2430_cmd); break;
+					default:        fatalerror("DS2430_w: unimplemented rom command %02X\n", ds2430_cmd);
 				}
 			}
 			break;
@@ -1758,7 +1759,7 @@ void viper_state::DS2430_w(int bit)
 				switch (ds2430_cmd)
 				{
 					case 0xf0:      ds2430_state = DS2430_STATE_READ_MEM_ADDRESS; break;
-					default:        fatalerror("DS2430_w: unimplemented mem function %02X\n", ds2430_cmd); break;
+					default:        fatalerror("DS2430_w: unimplemented mem function %02X\n", ds2430_cmd);
 				}
 			}
 			break;
diff --git a/src/mame/machine/balsente.c b/src/mame/machine/balsente.c
index 95cceb8712a..846931eb776 100644
--- a/src/mame/machine/balsente.c
+++ b/src/mame/machine/balsente.c
@@ -754,7 +754,6 @@ READ8_MEMBER(balsente_state::balsente_counter_8253_r)
 				m_counter[which].readbyte = 0;
 				return (m_counter[which].count >> 8) & 0xff;
 			}
-			break;
 	}
 	return 0;
 }
diff --git a/src/mame/machine/harddriv.c b/src/mame/machine/harddriv.c
index dee08c13ca0..15a12dad64e 100644
--- a/src/mame/machine/harddriv.c
+++ b/src/mame/machine/harddriv.c
@@ -1144,7 +1144,8 @@ READ16_MEMBER( harddriv_state::hdds3_sdsp_control_r )
 			return m_ds3sdsp_regs[offset];
 	}
 
-	return 0xff;
+	// never executed
+	//return 0xff;
 }
 
 
@@ -1209,7 +1210,8 @@ READ16_MEMBER( harddriv_state::hdds3_xdsp_control_r )
 			return m_ds3xdsp_regs[offset];
 	}
 
-	return 0xff;
+	// never executed
+	//return 0xff;
 }
 
 
diff --git a/src/mame/machine/igs025.c b/src/mame/machine/igs025.c
index 86eaa07c080..73b63ac853f 100644
--- a/src/mame/machine/igs025.c
+++ b/src/mame/machine/igs025.c
@@ -290,9 +290,6 @@ READ16_MEMBER(igs025_device::killbld_igs025_prot_r)
 						default: // >= 5
 							return 0x3f00 | BITSWAP8(m_kb_prot_hold, 5, 2, 9, 7, 10, 13, 12, 15);
 						}
-
-						return 0x3f00;
-						//return 0;
 		}
 
 		case 0x40:
diff --git a/src/mame/machine/kaneko_hit.c b/src/mame/machine/kaneko_hit.c
index fe115f42eb3..b1b90dc2f3f 100644
--- a/src/mame/machine/kaneko_hit.c
+++ b/src/mame/machine/kaneko_hit.c
@@ -120,7 +120,6 @@ READ16_MEMBER(kaneko_hit_device::kaneko_hit_r)
 
 		default:
 			fatalerror("kaneko_hit_r called, but m_hittype not set\n");
-			return 0;
 	}
 }
 
@@ -134,7 +133,6 @@ WRITE16_MEMBER(kaneko_hit_device::kaneko_hit_w)
 
 		default:
 			fatalerror("kaneko_hit_r called, but m_hittype not set\n");
-			break;
 	}
 }
 
diff --git a/src/mame/machine/model1.c b/src/mame/machine/model1.c
index 6fb232bf5da..10f565f533f 100644
--- a/src/mame/machine/model1.c
+++ b/src/mame/machine/model1.c
@@ -2078,7 +2078,6 @@ static void copro_fifoin_push(address_space &space, UINT32 data)
 	if (state->m_copro_fifoin_num == FIFO_SIZE)
 	{
 		fatalerror("Copro FIFOIN overflow (at %08X)\n", space.device().safe_pc());
-		return;
 	}
 
 	state->m_copro_fifoin_data[state->m_copro_fifoin_wpos++] = data;
@@ -2123,7 +2122,6 @@ WRITE32_MEMBER(model1_state::copro_fifoout_push)
 	if (m_copro_fifoout_num == FIFO_SIZE)
 	{
 		fatalerror("Copro FIFOOUT overflow (at %08X)\n", m_tgp->pc());
-		return;
 	}
 
 	m_copro_fifoout_data[m_copro_fifoout_wpos++] = data;
diff --git a/src/mame/machine/model3.c b/src/mame/machine/model3.c
index 882f33721e1..6d28e7e0e6b 100644
--- a/src/mame/machine/model3.c
+++ b/src/mame/machine/model3.c
@@ -315,7 +315,6 @@ static UINT8 rtc_get_reg(running_machine &machine, int reg)
 
 		default:
 			fatalerror("RTC-72421: Unknown reg %02X\n", reg);
-			return 0;
 	}
 }
 
diff --git a/src/mame/machine/namcos2.c b/src/mame/machine/namcos2.c
index fdb7328e045..ef7995e1851 100644
--- a/src/mame/machine/namcos2.c
+++ b/src/mame/machine/namcos2.c
@@ -346,7 +346,6 @@ READ16_MEMBER( namcos2_state::namcos2_68k_key_r )
 	//  case 3: popmessage("blah %08x",space.device().safe_pc());
 		default: return space.machine().rand();
 		}
-		break;
 
 	case NAMCOS2_SUPER_WSTADIUM_92:
 		switch(offset)
diff --git a/src/mame/machine/nb1413m3.c b/src/mame/machine/nb1413m3.c
index d5a399cad7b..a919ccad469 100644
--- a/src/mame/machine/nb1413m3.c
+++ b/src/mame/machine/nb1413m3.c
@@ -350,7 +350,6 @@ READ8_MEMBER( nb1413m3_device::inputport1_r )
 				case 0x04:  return 0xff;
 				default:    return 0xff;
 			}
-			break;
 		case NB1413M3_MSJIKEN:
 		case NB1413M3_TELMAHJN:
 			if (root.ioport("DSWA")->read() & 0x80)
@@ -367,7 +366,6 @@ READ8_MEMBER( nb1413m3_device::inputport1_r )
 				}
 			}
 			else return root.ioport("JAMMA2")->read();
-			break;
 		case NB1413M3_PAIRSNB:
 		case NB1413M3_PAIRSTEN:
 		case NB1413M3_OHPAIPEE:
@@ -384,7 +382,6 @@ READ8_MEMBER( nb1413m3_device::inputport1_r )
 				default:    return (root.ioport("KEY0")->read() & root.ioport("KEY1")->read() & root.ioport("KEY2")->read()
 									& root.ioport("KEY3")->read() & root.ioport("KEY4")->read());
 			}
-			break;
 	}
 }
 
@@ -402,7 +399,6 @@ READ8_MEMBER( nb1413m3_device::inputport2_r )
 				case 0x04:  return root.ioport("IN2")->read();
 				default:    return 0xff;
 			}
-			break;
 		case NB1413M3_MSJIKEN:
 		case NB1413M3_TELMAHJN:
 			if (root.ioport("DSWA")->read() & 0x80)
@@ -419,7 +415,6 @@ READ8_MEMBER( nb1413m3_device::inputport2_r )
 				}
 			}
 			else return root.ioport("JAMMA1")->read();
-			break;
 		case NB1413M3_PAIRSNB:
 		case NB1413M3_PAIRSTEN:
 		case NB1413M3_OHPAIPEE:
@@ -436,7 +431,6 @@ READ8_MEMBER( nb1413m3_device::inputport2_r )
 				default:    return (root.ioport("KEY5")->read() & root.ioport("KEY6")->read() & root.ioport("KEY7")->read()
 									& root.ioport("KEY8")->read() & root.ioport("KEY9")->read());
 			}
-			break;
 	}
 }
 
diff --git a/src/mame/machine/stvprot.c b/src/mame/machine/stvprot.c
index 4f3d2798c86..83ecbdb4535 100644
--- a/src/mame/machine/stvprot.c
+++ b/src/mame/machine/stvprot.c
@@ -493,7 +493,8 @@ UINT32 sss_prot_read_callback( address_space &space, int protaddr, UINT32 key )
 			return res;
 	}
 
-	return 0;
+	// never executed
+	//return 0;
 }
 
 UINT32 astrass_prot_read_callback( address_space &space, int protaddr, UINT32 key )
@@ -537,7 +538,8 @@ UINT32 elandore_prot_read_callback( address_space &space, int protaddr, UINT32 k
 			return res;
 	}
 
-	return 0;
+	// never executed
+	//return 0;
 }
 
 UINT32 ffreveng_prot_read_callback( address_space &space, int protaddr, UINT32 key )
diff --git a/src/mame/machine/williams.c b/src/mame/machine/williams.c
index 54df58dd788..d9e2fd1650d 100644
--- a/src/mame/machine/williams.c
+++ b/src/mame/machine/williams.c
@@ -645,7 +645,7 @@ READ8_MEMBER(williams2_state::tshoot_input_port_0_3_r)
 	return (data & 0xc0) | gun;
 
 	// FIXME: this code is never reached
-	return 0;
+	//return 0;
 }
 
 
diff --git a/src/mame/video/k001604.c b/src/mame/video/k001604.c
index 38b88783e21..adc5f0e2130 100644
--- a/src/mame/video/k001604.c
+++ b/src/mame/video/k001604.c
@@ -252,7 +252,7 @@ void k001604_device::draw_back_layer( bitmap_rgb32 &bitmap, const rectangle &cli
 		case 0: window_xmask = (128 * tile_size) - 1; break;
 		case 2: window_xmask = (64 * tile_size) - 1; break;
 		case 3: window_xmask = (32 * tile_size) - 1; break;
-		default: fatalerror("k001604_draw_back_layer(): layer_size %d\n", layer_size); break;
+		default: fatalerror("k001604_draw_back_layer(): layer_size %d\n", layer_size);
 	}
 
 	window_ymask = pixmap.height() - 1;
diff --git a/src/mame/video/k051960.c b/src/mame/video/k051960.c
index e429927f153..24fd16f21eb 100644
--- a/src/mame/video/k051960.c
+++ b/src/mame/video/k051960.c
@@ -279,8 +279,6 @@ READ8_MEMBER( k051960_device::k051937_r )
 		//logerror("%04x: read unknown 051937 address %x\n", device->cpu->safe_pc(), offset);
 		return 0;
 	}
-
-	return 0;
 }
 
 WRITE8_MEMBER( k051960_device::k051937_w )
diff --git a/src/mame/video/leland.c b/src/mame/video/leland.c
index 1c409e622bf..3938b07e4c7 100644
--- a/src/mame/video/leland.c
+++ b/src/mame/video/leland.c
@@ -109,7 +109,6 @@ WRITE8_MEMBER(leland_state::leland_scroll_w)
 
 		default:
 			fatalerror("Unexpected leland_gfx_port_w\n");
-			break;
 	}
 }
 
diff --git a/src/mame/video/metro.c b/src/mame/video/metro.c
index 77633f7463b..01fa17106e0 100644
--- a/src/mame/video/metro.c
+++ b/src/mame/video/metro.c
@@ -218,9 +218,6 @@ inline UINT8 metro_state::get_tile_pix( UINT16 code, UINT8 x, UINT8 y, int big,
 		else
 			return 0;
 	}
-
-	// shouldn't get here..
-	return 0;
 }
 
 
diff --git a/src/mame/video/model2.c b/src/mame/video/model2.c
index 19abb77ba98..43d9fefcc12 100644
--- a/src/mame/video/model2.c
+++ b/src/mame/video/model2.c
@@ -1248,7 +1248,6 @@ static void model2_3d_push( raster_state *raster, UINT32 input )
 			{
 				fatalerror( "SEGA 3D: Unknown rasterizer command %08x\n", raster->cur_command );
 			}
-			break;
 		}
 	}
 	else
diff --git a/src/mame/video/model3.c b/src/mame/video/model3.c
index 922907481bf..aaa5904a002 100644
--- a/src/mame/video/model3.c
+++ b/src/mame/video/model3.c
@@ -689,7 +689,6 @@ void model3_state::real3d_upload_texture(UINT32 header, UINT32 *data)
 			break;
 		default:
 			fatalerror("Unknown texture type: %02X\n", header >> 24);
-			break;
 	}
 }
 
diff --git a/src/mame/video/namcos22.c b/src/mame/video/namcos22.c
index 4ee5eb27bfe..463a09b96a9 100644
--- a/src/mame/video/namcos22.c
+++ b/src/mame/video/namcos22.c
@@ -703,7 +703,6 @@ void namcos22_renderer::render_scene_nodes(screen_device &screen, bitmap_rgb32 &
 
 					default:
 						fatalerror("invalid node->type\n");
-						break;
 				}
 				free_scenenode(node);
 				node = next;
diff --git a/src/mame/video/nycaptor.c b/src/mame/video/nycaptor.c
index 5323135eb1f..ad7653f9c2f 100644
--- a/src/mame/video/nycaptor.c
+++ b/src/mame/video/nycaptor.c
@@ -21,8 +21,6 @@ int nycaptor_state::nycaptor_spot(  )
 		return m_sharedram[0x299] ? m_sharedram[0x298] : 0;
 	else
 		return 0;
-
-	return 0;
 }
 
 TILE_GET_INFO_MEMBER(nycaptor_state::get_tile_info)
diff --git a/src/mame/video/scn2674.c b/src/mame/video/scn2674.c
index 15f2f1569a7..830fe255b21 100644
--- a/src/mame/video/scn2674.c
+++ b/src/mame/video/scn2674.c
@@ -588,8 +588,6 @@ WRITE8_MEMBER( scn2674_device::mpu4_vid_scn2674_w )
 			m_scn2674_spl1 = (data & 0x40);
 			m_scn2674_spl2 = (data & 0x80);
 			break;
-
-		break;
 	}
 }
 
diff --git a/src/mame/video/thief.c b/src/mame/video/thief.c
index 7c2428a23d8..19debf657ee 100644
--- a/src/mame/video/thief.c
+++ b/src/mame/video/thief.c
@@ -228,7 +228,6 @@ READ8_MEMBER(thief_state::thief_coprocessor_r){
 			int result = 0xc000 | (addr>>3);
 			return (offset==0x03)?(result>>8):(result&0xff);
 		}
-		break;
 
 	case GFX_PORT:
 		{
@@ -255,7 +254,6 @@ READ8_MEMBER(thief_state::thief_coprocessor_r){
 				return 0x80>>dx; // no flip
 			}
 		}
-		break;
 	}
 
 	return thief_coprocessor.param[offset];
diff --git a/src/mame/video/ygv608.c b/src/mame/video/ygv608.c
index dddefc0c47d..fd7f334bdca 100644
--- a/src/mame/video/ygv608.c
+++ b/src/mame/video/ygv608.c
@@ -1050,7 +1050,6 @@ READ16_MEMBER( ygv608_device::read )
 			}
 			return (data << 8);
 		}
-		break;
 
 		case 0x01: /* P#1 - sprite data port */
 			data = m_sprite_attribute_table.b[m_regs.s.saa];
@@ -1096,7 +1095,6 @@ READ16_MEMBER( ygv608_device::read )
 			}
 			return (data << 8);
 		}
-		break;
 
 		case 0x05:
 			break;