diff --git a/src/emu/devcb.h b/src/emu/devcb.h
index 2df5b6e1b39..1dcb8e49a20 100644
--- a/src/emu/devcb.h
+++ b/src/emu/devcb.h
@@ -117,7 +117,7 @@ UINT8 devcb_stub(device_t *device, offs_t offset)
 
 // static template for a read16 stub function that calls through a given READ16_MEMBER
 template<class _Class, UINT16 (_Class::*_Function)(address_space &, offs_t, UINT16)>
-UINT16 devcb_stub16(device_t *device, offs_t offset, UINT16 mask=0xffff)
+UINT16 devcb_stub16(device_t *device, offs_t offset, UINT16 mask)
 {
 	_Class *target = downcast<_Class *>(device);
 	return (target->*_Function)(*device->machine().memory().first_space(), offset, mask);
@@ -141,7 +141,7 @@ void devcb_stub(device_t *device, offs_t offset, UINT8 data)
 
 // static template for a write16 stub function that calls through a given WRITE16_MEMBER
 template<class _Class, void (_Class::*_Function)(address_space &, offs_t, UINT16, UINT16)>
-void devcb_stub16(device_t *device, offs_t offset, UINT16 data, UINT16 mask=0xffff)
+void devcb_stub16(device_t *device, offs_t offset, UINT16 data, UINT16 mask)
 {
 	_Class *target = downcast<_Class *>(device);
 	(target->*_Function)(*device->machine().memory().first_space(), offset, data, mask);
diff --git a/src/lib/formats/adam_cas.c b/src/lib/formats/adam_cas.c
index 521d2c9c1e1..1e8e328b517 100644
--- a/src/lib/formats/adam_cas.c
+++ b/src/lib/formats/adam_cas.c
@@ -58,7 +58,7 @@ static casserr_t coladam_ddp_identify ( cassette_image *cass, struct CassetteOpt
 // Store byte of data
 casserr_t coladam_put_byte(cassette_image *cass, int channel, double *time_index, int byte, int *prev_sign)
 {
-	casserr_t err;
+	casserr_t err = CASSETTE_ERROR_SUCCESS;
 	for (int i = 0; i < 8; i++)
 	{
 		if(byte & 0x80)
@@ -127,7 +127,7 @@ static casserr_t coladam_ddp_load( cassette_image *cass )
 	double time = 0.;
 	int i, block, prev_sign=-1;
 	UINT8 buffer[0x400];
-	casserr_t err;
+	casserr_t err = CASSETTE_ERROR_SUCCESS;
 
 	// It would appear that data packs that originally had the type GW data layout and headers work fine when converted to type
 	// HE. Thus we set all tapes to type HE.
@@ -194,10 +194,7 @@ static casserr_t coladam_ddp_load( cassette_image *cass )
 		}
 	}
 
-	if (err)
-		return err;
-
-	return CASSETTE_ERROR_SUCCESS;
+	return err;
 }
 
 
diff --git a/src/lib/formats/flopimg.c b/src/lib/formats/flopimg.c
index bb551aeb5dd..c416d2c4ca0 100644
--- a/src/lib/formats/flopimg.c
+++ b/src/lib/formats/flopimg.c
@@ -1162,7 +1162,7 @@ UINT32 floppy_image_format_t::bitn_r(const UINT32 *buffer, int offset, int count
 {
 	UINT32 r = 0;
 	for(int i=0; i<count; i++)
-		r = (r << 1) | bit_r(buffer, offset+i);
+		r = (r << 1) | (UINT32) bit_r(buffer, offset+i);
 	return r;
 }
 
diff --git a/src/lib/formats/pasti_dsk.c b/src/lib/formats/pasti_dsk.c
index 2e08b5ac1d4..9e61f29546c 100644
--- a/src/lib/formats/pasti_dsk.c
+++ b/src/lib/formats/pasti_dsk.c
@@ -535,7 +535,7 @@ void pasti_format::map_sectors_in_track(wd_obs &obs, wd_sect_info *sect_infos)
 			int hpos = (i+3) % tsize;
 			int j;
 			bool synced = false;
-			int bcount, tend;
+			int bcount=0, tend=0;
 			int best_bcount=0, best_j=0;
 			for(j=0; j != obs.sector_count; j++) {
 				match_mfm_data(obs, hpos, obs.sectors[j].id, 6, hbyte, bcount, tend, synced);
diff --git a/src/mame/drivers/cubeqst.c b/src/mame/drivers/cubeqst.c
index 6d8fbd14383..e00e654cfbc 100644
--- a/src/mame/drivers/cubeqst.c
+++ b/src/mame/drivers/cubeqst.c
@@ -535,8 +535,8 @@ static MACHINE_CONFIG_START( cubeqst, cubeqst_state )
 	MCFG_LASERDISC_SIMUTREK_ADD("laserdisc")
 	MCFG_LASERDISC_OVERLAY_STATIC(CUBEQST_HBLANK, CUBEQST_VCOUNT, cubeqst)
 	MCFG_LASERDISC_OVERLAY_CLIP(0, 320-1, 0, 256-8)
-	MCFG_LASERDISC_OVERLAY_POSITION(0.002, -0.018)
-	MCFG_LASERDISC_OVERLAY_SCALE(1.0, 1.030)
+	MCFG_LASERDISC_OVERLAY_POSITION(0.002f, -0.018f)
+	MCFG_LASERDISC_OVERLAY_SCALE(1.0f, 1.030f)
 
 	MCFG_LASERDISC_SCREEN_ADD_NTSC("screen", "laserdisc")
 
diff --git a/src/mame/drivers/globalfr.c b/src/mame/drivers/globalfr.c
index d0c7cf295e1..258e643ba2e 100644
--- a/src/mame/drivers/globalfr.c
+++ b/src/mame/drivers/globalfr.c
@@ -38,7 +38,7 @@ static WRITE16_HANDLER(vfd_w)
 {
 	globalfr_state *state = space->machine().driver_data<globalfr_state>();
 
-	int clock = (data & 0x40);
+	bool clock = (data & 0x40) != 0;
 	int datline = (data & 0x80);
 
 	//Unlike MPU4, this uses positive transitions on both lines, so this may be a similar, but not identical component
diff --git a/src/mame/drivers/igs017.c b/src/mame/drivers/igs017.c
index ce1f5ae7760..3043d767885 100644
--- a/src/mame/drivers/igs017.c
+++ b/src/mame/drivers/igs017.c
@@ -1854,8 +1854,8 @@ READ16_MEMBER(igs017_state::lhzb2a_magic_r)
 	{
 		case 0x03:
 		{
-			UINT8 a = BITSWAP8(m_prot[0], 9,9,1,9,2,5,4,7);	// 9 means 0 value
-			UINT8 b = BITSWAP8(m_prot[1], 5,2,9,7,9,9,9,9);
+			UINT8 a = BITSWAP8((UINT16)m_prot[0], 9,9,1,9,2,5,4,7);	// 9 means 0 value
+			UINT8 b = BITSWAP8((UINT16)m_prot[1], 5,2,9,7,9,9,9,9);
 			return a | b;
 		}
 
diff --git a/src/mame/video/galaxia.c b/src/mame/video/galaxia.c
index 09a58dd95da..7afe14c01af 100644
--- a/src/mame/video/galaxia.c
+++ b/src/mame/video/galaxia.c
@@ -210,7 +210,7 @@ SCREEN_UPDATE_IND16( astrowar )
 		{
 			// NOTE: similar to zac2650.c, the sprite chip runs at a different frequency than the background generator
 			// the exact timing ratio is unknown, so we'll have to do with guesswork
-			float s_ratio = 256.0 / 196.0;
+			float s_ratio = 256.0f / 196.0f;
 
 			float sx = x * s_ratio;
 			if ((int)(sx + 0.5) > cliprect.max_x)
diff --git a/src/mame/video/gticlub.c b/src/mame/video/gticlub.c
index c68ad1915a7..e1a11e21737 100644
--- a/src/mame/video/gticlub.c
+++ b/src/mame/video/gticlub.c
@@ -1,3 +1,4 @@
+#include <float.h>
 #include "emu.h"
 #include "cpu/sharc/sharc.h"
 #include "machine/konppc.h"
@@ -564,7 +565,7 @@ static void draw_scanline_2d(void *dest, INT32 scanline, const poly_extent *exte
 		if (color & 0xff000000)
 		{
 			fb[x] = color;
-			zb[x] = 0x7fffffff;		// FIXME
+			zb[x] = FLT_MAX;		// FIXME
 		}
 	}
 }
@@ -609,7 +610,7 @@ static void draw_scanline_2d_tex(void *dest, INT32 scanline, const poly_extent *
 		if (color & 0xff000000)
 		{
 			fb[x] = color;
-			zb[x] = 0x7fffffff;		// FIXME
+			zb[x] = FLT_MAX;		// FIXME
 		}
 
 		u += du;
diff --git a/src/mame/video/rdptpipe.c b/src/mame/video/rdptpipe.c
index 64067e6b599..df412614ff5 100644
--- a/src/mame/video/rdptpipe.c
+++ b/src/mame/video/rdptpipe.c
@@ -1372,7 +1372,7 @@ UINT32 N64TexturePipeT::Fetch(INT32 s, INT32 t, INT32 tilenum, const rdp_poly_st
 	tbase += tile[tilenum].tmem;
 	UINT32 tpal	= tile[tilenum].palette;
 
-	UINT32 index = (tformat << 4) | (tsize << 2) | (object.OtherModes.en_tlut << 1) | object.OtherModes.tlut_type;
+	UINT32 index = (tformat << 4) | (tsize << 2) | ((UINT32) object.OtherModes.en_tlut << 1) | (UINT32) object.OtherModes.tlut_type;
 
 	return ((this)->*(TexelFetch[index]))(s, t, tbase, tpal, userdata);
 }