diff --git a/source/Debugger/Debug.cpp b/source/Debugger/Debug.cpp
index 864c7c00..eb8419f5 100644
--- a/source/Debugger/Debug.cpp
+++ b/source/Debugger/Debug.cpp
@@ -8080,7 +8080,7 @@ void OutputTraceLine ()
 
 	if (g_bTraceFileWithVideoScanner)
 	{
-		uint16_t addr = NTSC_VideoGetScannerAddress(0);
+		uint16_t addr = NTSC_VideoGetScannerAddress();
 		BYTE data = mem[addr];
 
 		fprintf( g_hTraceFile,
diff --git a/source/Memory.cpp b/source/Memory.cpp
index 1ddba2f1..b1378c61 100644
--- a/source/Memory.cpp
+++ b/source/Memory.cpp
@@ -1507,34 +1507,24 @@ BYTE MemReadFloatingBus(const ULONG uExecutedCycles)
 {
 #if 0
 	// NTSC: It is tempting to replace with
-	//     return NTSC_VideoGetScannerAddress( uExecutedCycles );
+	//     return NTSC_VideoGetScannerAddress( );
 	// But that breaks "Rainbow" Bug #254 if NTSC_VideoGetScannerAddress() is not correct.
 	// This is out of sync with VideoGetScannerAddress() due to two reasons:
 	// a) returning a cached copy of g_aHorzClockMemAddress
 	//    Fixed by calling: updateVideoScannerAddressTXT or updateVideoScannerAddressHGR()
 	// b) A bug? in APPLE_IIE_HORZ_CLOCK_OFFSET[0][8] containing the incorrect value of 0x006F
-	uint16_t addr1 = NTSC_VideoGetScannerAddress( uExecutedCycles );
+	uint16_t addr1 = NTSC_VideoGetScannerAddress();
 	uint16_t addr2 = VideoGetScannerAddress(NULL, uExecutedCycles);
-	uint8_t  byte1 = mem[ addr1 ];
-	uint8_t  byte2 = mem[ addr2 ];
-
-	if( byte1 != byte2 )
-		mem[ 0x2000 ] ^= 0xFF;
+	_ASSERT(addr1 == addr2);
 #endif
-	// return mem[ VideoGetScannerAddress(NULL, uExecutedCycles) ];
-	uint16_t addr = NTSC_VideoGetScannerAddress( uExecutedCycles );
-	return mem[ addr ] ; // cycles is ignored
+	return mem[ VideoGetScannerAddress(NULL, uExecutedCycles) ];
 }
 
 //===========================================================================
 
 BYTE MemReadFloatingBus(const BYTE highbit, const ULONG uExecutedCycles)
 {
-	// NTSC: It is tempting to replace with
-	//     return NTSC_VideoGetScannerAddress( uExecutedCycles );
-	// But that breaks "Rainbow" Bug #254
-	// BYTE r= NTSC_VideoGetByte( uExecutedCycles );
-	BYTE r = *(LPBYTE)(mem + VideoGetScannerAddress(NULL, uExecutedCycles));
+	BYTE r = MemReadFloatingBus(uExecutedCycles);
 	return (r & ~0x80) | ((highbit) ? 0x80 : 0);
 }
 
diff --git a/source/NTSC.cpp b/source/NTSC.cpp
index ed4e33f5..3bd43517 100644
--- a/source/NTSC.cpp
+++ b/source/NTSC.cpp
@@ -287,7 +287,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 	static unsigned APPLE_IIE_HORZ_CLOCK_OFFSET[5][VIDEO_SCANNER_MAX_HORZ] =
 	{
-		{0x0068,0x0068,0x0069,0x006A,0x006B,0x006C,0x006D,0x006E,0x006F, // bug? 0x106F
+		{0x0068,0x0068,0x0069,0x006A,0x006B,0x006C,0x006D,0x006E,0x006F, // bug? 0x106F - see comment in Memory.cpp, MemReadFloatingBus(const ULONG)
 		 0x0070,0x0071,0x0072,0x0073,0x0074,0x0075,0x0076,0x0077,
 		 0x0078,0x0079,0x007A,0x007B,0x007C,0x007D,0x007E,0x007F,
 		 0x0000,0x0001,0x0002,0x0003,0x0004,0x0005,0x0006,0x0007,
@@ -1475,12 +1475,12 @@ uint32_t*NTSC_VideoGetChromaTable( bool bHueTypeMonochrome, bool bMonitorTypeCol
 }
 
 //===========================================================================
-uint16_t NTSC_VideoGetScannerAddress ( unsigned long cycles6502 )
-{
-	(void)cycles6502;
 
-	int nHires   = (g_uVideoMode & VF_HIRES) && !(g_uVideoMode & VF_TEXT); // (SW_HIRES && !SW_TEXT) ? 1 : 0;
-	if( nHires )
+// NB. NTSC video-scanner doesn't get updated during full-speed, so video-dependent Apple II code can hang
+uint16_t NTSC_VideoGetScannerAddress ( void )
+{
+	bool bHires = (g_uVideoMode & VF_HIRES) && !(g_uVideoMode & VF_TEXT); // SW_HIRES && !SW_TEXT
+	if( bHires )
 		updateVideoScannerAddressHGR();
 	else
 		updateVideoScannerAddressTXT();
@@ -1752,7 +1752,7 @@ void NTSC_VideoInitChroma()
 
 //===========================================================================
 
-// NB. NTSC video-scanner doesn't get updated during full-speed, so video-dependent code can hang
+// NB. NTSC video-scanner doesn't get updated during full-speed, so video-dependent Apple II code can hang
 //bool NTSC_VideoIsVbl ()
 //{
 //	return (g_nVideoClockVert >= VIDEO_SCANNER_Y_DISPLAY) && (g_nVideoClockVert < VIDEO_SCANNER_MAX_VERT);
diff --git a/source/NTSC.h b/source/NTSC.h
index d652b67b..58f851d6 100644
--- a/source/NTSC.h
+++ b/source/NTSC.h
@@ -11,7 +11,7 @@
 	extern void     NTSC_SetVideoStyle();
 	extern void     NTSC_SetVideoTextMode( int cols );
 	extern uint32_t*NTSC_VideoGetChromaTable( bool bHueTypeMonochrome, bool bMonitorTypeColorTV );
-	extern uint16_t NTSC_VideoGetScannerAddress( unsigned long cycles6502 );
+	extern uint16_t NTSC_VideoGetScannerAddress( void );
 	extern void     NTSC_VideoInit( uint8_t *pFramebuffer );
 	extern void     NTSC_VideoReinitialize( DWORD cyclesThisFrame );
 	extern void     NTSC_VideoInitAppleType();
diff --git a/source/Video.cpp b/source/Video.cpp
index 2d66095f..055c6846 100644
--- a/source/Video.cpp
+++ b/source/Video.cpp
@@ -886,7 +886,7 @@ BYTE VideoCheckVbl ( ULONG uExecutedCycles )
 	bool bVblBar = VideoGetVblBar(uExecutedCycles);
 	// NTSC: It is tempting to replace with
 	//     bool bVblBar = !NTSC_VideoIsVbl();
-	// But during full-speed, the NTSC video-scanner is not updated, so video-dependent code can hang
+	// But during full-speed, the NTSC video-scanner is not updated, so video-dependent Apple II code can hang
 
 	BYTE r = KeybGetKeycode();
 	return (r & ~0x80) | (bVblBar ? 0x80 : 0);