diff --git a/Machines/Atari2600.cpp b/Machines/Atari2600.cpp
index da3bf02d5..24fba8389 100644
--- a/Machines/Atari2600.cpp
+++ b/Machines/Atari2600.cpp
@@ -20,7 +20,7 @@ Machine::Machine()
 	_horizontalTimer = 0;
 	_lastOutputStateDuration = 0;
 	_lastOutputState = OutputState::Sync;
-	_crt = new Outputs::CRT(228, 262, 1, 1);
+	_crt = new Outputs::CRT(228, 262, 1, 2);
 	_piaTimerStatus = 0xff;
 	memset(_collisions, 0xff, sizeof(_collisions));
 	_rom = nullptr;
@@ -146,8 +146,9 @@ void Machine::get_output_pixel(uint8_t *pixel, int offset)
 		if (playerPixels[0] || missilePixels[0]) outputColour = _playerColour[0];
 	}
 
-	// map that colour to an RGBA
-	*pixel = outputColour;
+	// map that colour to separate Y and phase components
+	pixel[0] = (outputColour << 4)&0xe0;
+    pixel[1] = outputColour&0xf0;
 }
 
 // in imputing the knowledge that all we're dealing with is the rollover from 159 to 0,
@@ -230,7 +231,7 @@ void Machine::output_pixels(unsigned int count)
 		if(_horizontalTimer < (_vBlankExtend ? 152 : 160))
 		{
 			if(_outputBuffer)
-				get_output_pixel(&_outputBuffer[_lastOutputStateDuration], 159 - _horizontalTimer);
+				get_output_pixel(&_outputBuffer[_lastOutputStateDuration << 1], 159 - _horizontalTimer);
 
 			// increment all graphics counters
 			increment_object_counter(0);
diff --git a/OSBindings/Mac/Clock Signal/CSCathodeRayView.m b/OSBindings/Mac/Clock Signal/CSCathodeRayView.m
index 6bf8fa5bf..f2494471c 100644
--- a/OSBindings/Mac/Clock Signal/CSCathodeRayView.m	
+++ b/OSBindings/Mac/Clock Signal/CSCathodeRayView.m	
@@ -212,12 +212,12 @@ const char *fragmentShader =
 	"uniform sampler2D texID;\n"
 	"uniform float alpha;\n"
 	"\n"
-	"float sample(float c, float angle)\n"
+	"float sample(vec2 coordinate, float angle)\n"
 	"{\n"
-		"float y = 0.1 + mod(c * 128.0, 8.0) * 0.1125;\n"
-		"float rawCh = (c * 16.0);\n"
-		"float aOffset = 6.283185308 * floor(rawCh) / 17.0;\n"
-		"return y + step(1.0, rawCh) * 0.1 * sin(angle + aOffset);\n"
+        "vec2 c = texture(texID, coordinate).rg;"
+		"float y = 0.1 + c.x * 0.91071428571429;\n"
+		"float aOffset = 6.283185308 * c.y;\n"
+		"return y + step(0.0625, c.y) * 0.1 * sin(angle + aOffset);\n"
 	"}\n"
 	"\n"
 	"void main(void)\n"
@@ -229,13 +229,15 @@ const char *fragmentShader =
 		"angles[0] = angle + vec4(3.7699111848, 5.0265482464, 0.0, 1.2566370616);\n"
 		"angles[1] = angle + vec4(2.5132741232, 5.6548667772, 0.6283185308, 0.0);\n"
 		"\n"
-		"samples[0] = vec4(sample(texture(texID, srcCoordinatesVarying[0]).r, angles[0].x),"
-		"	sample(texture(texID, srcCoordinatesVarying[1]).r, angles[0].y),"
-		"	sample(texture(texID, srcCoordinatesVarying[2]).r, angles[0].z),"
-		"	sample(texture(texID, srcCoordinatesVarying[3]).r, angles[0].w));\n"
-		"samples[1] = vec4(sample(texture(texID, srcCoordinatesVarying[4]).r, angles[1].x),"
-		"	sample(texture(texID, srcCoordinatesVarying[5]).r, angles[1].y),"
-		"	sample(texture(texID, srcCoordinatesVarying[6]).r, angles[1].z),"
+		"samples[0] = vec4("
+        "   sample(srcCoordinatesVarying[0], angles[0].x),"
+		"	sample(srcCoordinatesVarying[1], angles[0].y),"
+		"	sample(srcCoordinatesVarying[2], angles[0].z),"
+		"	sample(srcCoordinatesVarying[3], angles[0].w));\n"
+		"samples[1] = vec4("
+        "   sample(srcCoordinatesVarying[4], angles[1].x),"
+		"	sample(srcCoordinatesVarying[5], angles[1].y),"
+		"	sample(srcCoordinatesVarying[6], angles[1].z),"
 		"	1.0);\n"
 		"float y = dot(vec4(0.2, 0.2, 0.2, 0.2), samples[0]) + dot(vec4(0.2, 0.0, 0.0, 0.0), samples[1]);\n"
 		"\n"