diff --git a/Machines/Electron/Electron.cpp b/Machines/Electron/Electron.cpp
index c6fe3f06f..44bacb00d 100644
--- a/Machines/Electron/Electron.cpp
+++ b/Machines/Electron/Electron.cpp
@@ -379,12 +379,19 @@ inline void Machine::update_display()
 		{
 			const int current_line = _displayOutputPosition >> 7;
 			const int line_position = _displayOutputPosition & 127;
+			const int cycles_left = _frameCycles - _displayOutputPosition;
 
 			// all lines then start with 9 cycles of sync
-			if(!line_position)
+			if(line_position < 9)
 			{
-				_crt.output_sync(9 * crt_cycles_multiplier);
-				_displayOutputPosition += 9;
+				int remaining_period = std::min(9 - line_position, cycles_left);
+				_displayOutputPosition += remaining_period;
+
+				if(line_position + remaining_period == 9)
+				{
+//					printf("!%d!", 9);
+					_crt.output_sync(9 * crt_cycles_multiplier);
+				}
 			}
 			else
 			{
@@ -395,33 +402,37 @@ inline void Machine::update_display()
 
 				if(isBlankLine)
 				{
-					if(line_position == 9)
-					{
-						_crt.output_blank(119 * crt_cycles_multiplier);
-						_displayOutputPosition += 119;
-					}
+					int remaining_period = std::min(128 - line_position, cycles_left);
+					_crt.output_blank((unsigned int)remaining_period * crt_cycles_multiplier);
+//					printf(".[%d]", remaining_period);
+					_displayOutputPosition += remaining_period;
 				}
 				else
 				{
 					// there are then 15 cycles of blank, 80 cycles of pixels, and 24 further cycles of blank
-					if(line_position == 9)
+					if(line_position < 24)
 					{
-						_crt.output_blank(15 * crt_cycles_multiplier);
-						_displayOutputPosition += 15;
+						int remaining_period = std::min(24 - line_position, cycles_left);
+						_crt.output_blank((unsigned int)remaining_period * crt_cycles_multiplier);
+//						printf("/(%d)(%d)[%d]", 24 - line_position, cycles_left, remaining_period);
+						_displayOutputPosition += remaining_period;
 
-						switch(_screenMode)
+						if(line_position + remaining_period == 24)
 						{
-							case 0: case 3:				_currentOutputDivider = 1; break;
-							case 1:	case 4: case 6:		_currentOutputDivider = 2; break;
-							case 2: case 5:				_currentOutputDivider = 4; break;
+							switch(_screenMode)
+							{
+								case 0: case 3:				_currentOutputDivider = 1; break;
+								case 1:	case 4: case 6:		_currentOutputDivider = 2; break;
+								case 2: case 5:				_currentOutputDivider = 4; break;
+							}
+
+							_crt.allocate_write_area(80 * crt_cycles_multiplier / _currentOutputDivider);
+							_currentLine = _writePointer = (uint8_t *)_crt.get_write_target_for_buffer(0);
+
+							if(current_line == first_graphics_line)
+								_startLineAddress = _startScreenAddress;
+							_currentScreenAddress = _startLineAddress;
 						}
-
-						_crt.allocate_write_area(80 * crt_cycles_multiplier / _currentOutputDivider);
-						_currentLine = _writePointer = (uint8_t *)_crt.get_write_target_for_buffer(0);
-
-						if(current_line == first_graphics_line)
-							_startLineAddress = _startScreenAddress;
-						_currentScreenAddress = _startLineAddress;
 					}
 
 					if(line_position >= 24 && line_position < 104)
@@ -446,6 +457,7 @@ inline void Machine::update_display()
 
 						int pixels_to_output = std::min(_frameCycles - _displayOutputPosition, 104 - line_position);
 						_displayOutputPosition += pixels_to_output;
+//						printf("<- %d ->", pixels_to_output);
 						if(_screenMode >= 4)
 						{
 							// just shifting wouldn't be enough if both
@@ -514,23 +526,29 @@ inline void Machine::update_display()
 
 #undef GetNextPixels
 
-					if(line_position == 104)
+					if(line_position >= 104)
 					{
-						_currentOutputLine++;
-						if(!(_currentOutputLine&7))
-						{
-							_startLineAddress += ((_screenMode < 4) ? 80 : 40)*8 - 7;
-						}
-						else
-							_startLineAddress++;
+						int pixels_to_output = std::min(_frameCycles - _displayOutputPosition, 128 - line_position);
+						_crt.output_blank((unsigned int)pixels_to_output * crt_cycles_multiplier);
+						_displayOutputPosition += pixels_to_output;
 
-						if(_writePointer)
-							_crt.output_data((unsigned int)((_writePointer - _currentLine) * _currentOutputDivider), _currentOutputDivider);
-						else
-							_crt.output_data(80 * crt_cycles_multiplier, _currentOutputDivider);
-						_crt.output_blank(24 * crt_cycles_multiplier);
-						_displayOutputPosition += 24;
-						_currentLine = nullptr;
+						if(line_position + pixels_to_output == 128)
+						{
+							_currentOutputLine++;
+//							printf("\n%d: ", _currentOutputLine);
+							if(!(_currentOutputLine&7))
+							{
+								_startLineAddress += ((_screenMode < 4) ? 80 : 40)*8 - 7;
+							}
+							else
+								_startLineAddress++;
+
+							if(_writePointer)
+								_crt.output_data((unsigned int)((_writePointer - _currentLine) * _currentOutputDivider), _currentOutputDivider);
+							else
+								_crt.output_data(80 * crt_cycles_multiplier, _currentOutputDivider);
+							_currentLine = nullptr;
+						}
 					}
 				}
 			}
@@ -708,6 +726,12 @@ inline void Tape::set_data_register(uint8_t value)
 	_output_bits_remaining = 9;
 }
 
+inline uint8_t Tape::get_data_register()
+{
+	int shift = std::max(_bits_since_start - 7, 0);
+	return (uint8_t)(_data_register >> shift);
+}
+
 inline void Tape::run_for_cycles(unsigned int number_of_cycles)
 {
 	if(_is_enabled)
diff --git a/Machines/Electron/Electron.hpp b/Machines/Electron/Electron.hpp
index 7e2db617d..d730be65a 100644
--- a/Machines/Electron/Electron.hpp
+++ b/Machines/Electron/Electron.hpp
@@ -63,7 +63,7 @@ class Tape {
 
 		void set_tape(std::shared_ptr<Storage::Tape> tape);
 
-		inline uint8_t get_data_register() { return (uint8_t)(_data_register >> 2); }
+		inline uint8_t get_data_register();
 		inline void set_data_register(uint8_t value);
 		inline void set_counter(uint8_t value);
 
diff --git a/OSBindings/Mac/Clock Signal/Documents/ElectronDocument.swift b/OSBindings/Mac/Clock Signal/Documents/ElectronDocument.swift
index 2e2f31dc4..ba3243a39 100644
--- a/OSBindings/Mac/Clock Signal/Documents/ElectronDocument.swift	
+++ b/OSBindings/Mac/Clock Signal/Documents/ElectronDocument.swift	
@@ -28,7 +28,7 @@ class ElectronDocument: MachineDocument {
 		super.windowControllerDidLoadNib(aController)
 		electron.view = openGLView
 		electron.audioQueue = self.audioQueue
-		openGLView.frameBounds = CGRectMake(0.0225, 0.0625, 0.75, 0.75)
+//		openGLView.frameBounds = CGRectMake(0.0225, 0.0625, 0.75, 0.75)
 	}
 
 	override var windowNibName: String? {
diff --git a/OSBindings/Mac/Clock Signal/Views/CSCathodeRayView.m b/OSBindings/Mac/Clock Signal/Views/CSCathodeRayView.m
index 3ba042ca0..7f08a7107 100644
--- a/OSBindings/Mac/Clock Signal/Views/CSCathodeRayView.m	
+++ b/OSBindings/Mac/Clock Signal/Views/CSCathodeRayView.m	
@@ -302,10 +302,8 @@ static CVReturn DisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeSt
 		@"phase = srcCoordinates.x * 6.283185308;\n"
 		"\n"
 		"srcCoordinatesVarying[0] = vec2(srcCoordinates.x / textureSize.x, (srcCoordinates.y + 0.5) / textureSize.y);\n"
-		"srcCoordinatesVarying[3] = srcCoordinatesVarying[0] + vec2(0.375 / textureSize.x, 0.0);\n"
-		"srcCoordinatesVarying[2] = srcCoordinatesVarying[0] + vec2(0.125 / textureSize.x, 0.0);\n"
-		"srcCoordinatesVarying[1] = srcCoordinatesVarying[0] - vec2(0.125 / textureSize.x, 0.0);\n"
-		"srcCoordinatesVarying[0] = srcCoordinatesVarying[0] - vec2(0.325 / textureSize.x, 0.0);\n";
+		"srcCoordinatesVarying[1] = srcCoordinatesVarying[0] - vec2(0.5 / textureSize.x, 0.0);\n"
+		"srcCoordinatesVarying[2] = srcCoordinatesVarying[0] - vec2(0.25 / textureSize.x, 0.0);\n";
 
 	NSString *const rgbVertexShaderGlobals =
 		@"out vec2 srcCoordinatesVarying[5];\n";
@@ -385,21 +383,22 @@ static CVReturn DisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeSt
 		"const mat3 yiqToRGB = mat3(1.0, 1.0, 1.0, 1.1389784, -0.3240608, -1.3176884, 0.6490692, -0.6762444, 1.7799756);\n";
 
 	NSString *const ntscFragmentShaderBody =
-		@"vec4 angles = vec4(phase) + vec4(-2.35619449019234, -0.78539816339745, 0.78539816339745, 2.35619449019234);\n"
-		"vec4 samples = vec4("
+		@"vec3 angles = vec3(phase) + vec3(0.0, -3.141592654, -1.570796327);\n"
+		"vec3 samples = vec3("
 		"   sample(srcCoordinatesVarying[0], angles.x),"
 		"	sample(srcCoordinatesVarying[1], angles.y),"
-		"	sample(srcCoordinatesVarying[2], angles.z),"
-		"	sample(srcCoordinatesVarying[3], angles.w)"
+		"	sample(srcCoordinatesVarying[2], angles.z)"
 		");\n"
 		"\n"
-		"float y = dot(vec4(0.25), samples);\n"
-		"samples -= vec4(y);\n"
+		"float y = dot(vec2(0.5), samples.xy);\n"
+		"samples -= vec3(y);\n"
 		"\n"
-		"float i = dot(cos(angles), samples);\n"
-		"float q = dot(sin(angles), samples);\n"
+		"float i = dot(vec3(0.75), cos(angles) * samples);\n"
+		"float q = dot(vec3(0.75), sin(angles) * samples);\n"
 		"\n"
-		"fragColour = 5.0 * texture(shadowMaskTexID, shadowMaskCoordinates) * vec4(yiqToRGB * vec3(y, i, q), 1.0);//sin(lateralVarying));\n";
+		"fragColour = vec4(yiqToRGB * vec3(y, i, q), 1.0);\n"; //sin(lateralVarying));
+		// 5.0 * texture(shadowMaskTexID, shadowMaskCoordinates) *
+//		"float y2 = dot(vec2(0.5), samples.zw);\n"
 
 	NSString *const rgbFragmentShaderGlobals =
 		@"in vec2 srcCoordinatesVarying[5];\n"; // texture(shadowMaskTexID, shadowMaskCoordinates) *
diff --git a/Outputs/CRT.cpp b/Outputs/CRT.cpp
index efd4451ea..e87d8b8c2 100644
--- a/Outputs/CRT.cpp
+++ b/Outputs/CRT.cpp
@@ -275,7 +275,7 @@ void CRT::advance_cycles(unsigned int number_of_cycles, unsigned int source_divi
 			position_y(5) = InternalToUInt16(kCRTFixedPointOffset + _rasterPosition.y + _beamWidth[lengthMask].y);
 
 			// if this is a data run then advance the buffer pointer
-			if(type == Type::Data) tex_x += next_run_length / (_time_multiplier * source_divider);
+			if(type == Type::Data && source_divider) tex_x += next_run_length / (_time_multiplier * source_divider);
 
 			// if this is a data or level run then store the end point
 			tex_x(2) = tex_x(3) = tex_x(5) = tex_x;