diff --git a/src/mame/machine/super80.cpp b/src/mame/machine/super80.cpp
index 7f508155974..ef1bc072a3b 100644
--- a/src/mame/machine/super80.cpp
+++ b/src/mame/machine/super80.cpp
@@ -91,7 +91,7 @@ TIMER_DEVICE_CALLBACK_MEMBER( super80_state::kansas_r )
 TIMER_DEVICE_CALLBACK_MEMBER( super80_state::timer_h )
 {
 	uint8_t go_fast = 0;
-	if ( (!BIT(m_portf0, 2)) | (!BIT(m_io_config->read(), 1)) )    // bit 2 of port F0 is low, OR user turned on config switch
+	if ( (!BIT(m_portf0, 2)) || (!BIT(m_io_config->read(), 1)) )    // bit 2 of port F0 is low, OR user turned on config switch
 		go_fast++; // must be 1 at boot so banking works correctly
 
 	/* code to slow down computer to 1 MHz by halting cpu on every second frame */
diff --git a/src/mame/video/m90.cpp b/src/mame/video/m90.cpp
index c0d3fa21dcb..a8786d7b19b 100644
--- a/src/mame/video/m90.cpp
+++ b/src/mame/video/m90.cpp
@@ -150,7 +150,7 @@ void m90_state::bomblord_draw_sprites(screen_device &screen, bitmap_ind16 &bitma
 	int x,y,sprite,colour,fx,fy;
 
 
-	while ((offs < m_spriteram.bytes()/2) & (m_spriteram[offs+0] != 0x8000))
+	while ((offs < m_spriteram.bytes()/2) && (m_spriteram[offs+0] != 0x8000))
 	{
 		last_sprite = offs;
 		offs += 4;
@@ -187,7 +187,7 @@ void m90_state::dynablsb_draw_sprites(screen_device &screen, bitmap_ind16 &bitma
 	int offs = 0, last_sprite = 0;
 	int x,y,sprite,colour,fx,fy;
 
-	while ((offs < m_spriteram.bytes()/2) & (m_spriteram[offs+0] != 0xffff))
+	while ((offs < m_spriteram.bytes()/2) && (m_spriteram[offs+0] != 0xffff))
 	{
 		last_sprite = offs;
 		offs += 4;
diff --git a/src/mame/video/powervr2.cpp b/src/mame/video/powervr2.cpp
index 8e27751f6b1..936ddd0b518 100644
--- a/src/mame/video/powervr2.cpp
+++ b/src/mame/video/powervr2.cpp
@@ -1392,7 +1392,7 @@ uint32_t powervr2_device::spg_status_r()
 	uint32_t vsync = ((screen().vpos() >= spg_vbstart) || (screen().vpos() < spg_vbend)) ? 0 : 1;
 	uint32_t hsync = ((screen().hpos() >= spg_hbstart) || (screen().hpos() < spg_hbend)) ? 0 : 1;
 	// FIXME: following is just a wild guess
-	uint32_t blank = ((screen().vpos() >= spg_vbstart) || (screen().vpos() < spg_vbend) |
+	uint32_t blank = ((screen().vpos() >= spg_vbstart) || (screen().vpos() < spg_vbend) ||
 					(screen().hpos() >= spg_hbstart) || (screen().hpos() < spg_hbend)) ? 0 : 1;
 	if(vo_control & 4) { blank^=1; }
 	if(vo_control & 2) { vsync^=1; }