diff --git a/Machines/Atari2600/TIA.cpp b/Machines/Atari2600/TIA.cpp
index 15d2c36dc..0e5630e9b 100644
--- a/Machines/Atari2600/TIA.cpp
+++ b/Machines/Atari2600/TIA.cpp
@@ -137,7 +137,7 @@ void TIA::set_output_mode(Atari2600::TIA::OutputMode output_mode) {
 				"uint y = c & 14u;"
 				"uint iPhase = (c >> 4);"
 
-				"float phaseOffset = 6.283185308 * (float(iPhase) + 3.0) / 13.0  + 5.074880441076923;"
+				"float phaseOffset = 6.283185308 * float(iPhase) / 13.0 + 5.074880441076923;"
 				"return mix(float(y) / 14.0, step(1, iPhase) * cos(phase + phaseOffset), amplitude);"
 			"}");
 		display_type = Outputs::CRT::DisplayType::NTSC60;
diff --git a/Machines/Oric/Video.cpp b/Machines/Oric/Video.cpp
index bfb857782..a4107101a 100644
--- a/Machines/Oric/Video.cpp
+++ b/Machines/Oric/Video.cpp
@@ -42,6 +42,7 @@ VideoOutput::VideoOutput(uint8_t *memory) :
 			"return (float(texValue) - 4.0) / 20.0;"
 		"}"
 	);
+	crt_->set_composite_function_type(Outputs::CRT::CRT::CompositeSourceType::DiscreteFourSamplesPerCycle, 0.0f);
 
 	set_output_device(Outputs::CRT::Television);
 	crt_->set_visible_area(crt_->get_rect_for_area(50, 224, 16 * 6, 40 * 6, 4.0f / 3.0f));
diff --git a/Outputs/CRT/CRT.cpp b/Outputs/CRT/CRT.cpp
index cb0aed7cd..5b4cf0cdc 100644
--- a/Outputs/CRT/CRT.cpp
+++ b/Outputs/CRT/CRT.cpp
@@ -62,6 +62,14 @@ void CRT::set_new_display_type(unsigned int cycles_per_line, DisplayType display
 	}
 }
 
+void CRT::set_composite_function_type(CompositeSourceType type, float offset_of_first_sample) {
+	if(type == DiscreteFourSamplesPerCycle) {
+		colour_burst_phase_adjustment_ = (uint8_t)(offset_of_first_sample * 256.0f) & 63;
+	} else {
+		colour_burst_phase_adjustment_ = 0xff;
+	}
+}
+
 CRT::CRT(unsigned int common_output_divisor, unsigned int buffer_depth) :
 	sync_capacitor_charge_level_(0),
 	is_receiving_sync_(false),
@@ -272,7 +280,8 @@ void CRT::output_scan(const Scan *const scan) {
 			colour_burst_phase_ = (position_phase + scan->phase) & 255;
 			colour_burst_amplitude_ = scan->amplitude;
 
-			colour_burst_phase_ = (colour_burst_phase_ & ~63) + 32;
+			if(colour_burst_phase_adjustment_ != 0xff)
+				colour_burst_phase_ = (colour_burst_phase_ & ~63) + colour_burst_phase_adjustment_;
 		}
 	}
 
diff --git a/Outputs/CRT/CRT.hpp b/Outputs/CRT/CRT.hpp
index f9025f740..3f3847cf8 100644
--- a/Outputs/CRT/CRT.hpp
+++ b/Outputs/CRT/CRT.hpp
@@ -59,7 +59,7 @@ class CRT {
 		};
 		void output_scan(const Scan *scan);
 
-		uint8_t colour_burst_phase_, colour_burst_amplitude_;
+		uint8_t colour_burst_phase_, colour_burst_amplitude_, colour_burst_phase_adjustment_;
 		bool is_writing_composite_run_;
 
 		unsigned int phase_denominator_, phase_numerator_, colour_cycle_numerator_;
@@ -252,6 +252,26 @@ class CRT {
 			});
 		}
 
+		enum CompositeSourceType {
+			/// The composite function provides continuous output.
+			Continuous,
+			/// The composite function provides discrete output with four unique values per colour cycle.
+			DiscreteFourSamplesPerCycle
+		};
+
+		/*! Provides information about the type of output the composite sampling function provides — discrete or continuous.
+
+			This is necessary because the CRT implementation samples discretely and therefore can use fewer intermediate
+			samples if it can exactly duplicate the sampling rate and placement of the composite sampling function.
+
+			A continuous function is assumed by default.
+
+			@param type The type of output provided by the function supplied to `set_composite_sampling_function`.
+			@param offset_of_first_sample The relative position within a full cycle of the colour subcarrier at which the
+			first sample falls. E.g. 0.125 means "at 1/8th of the way through the complete cycle".
+		*/
+		void set_composite_function_type(CompositeSourceType type, float offset_of_first_sample = 0.0f);
+
 		/*!	Sets a function that will map from whatever data the machine provided to an RGB signal.
 
 			If the output mode is composite then a default mapping from RGB to the display's composite
diff --git a/StaticAnalyser/Commodore/Disk.cpp b/StaticAnalyser/Commodore/Disk.cpp
index 890289a07..fa54e613c 100644
--- a/StaticAnalyser/Commodore/Disk.cpp
+++ b/StaticAnalyser/Commodore/Disk.cpp
@@ -24,6 +24,7 @@ class CommodoreGCRParser: public Storage::Disk::Controller {
 		CommodoreGCRParser() : Storage::Disk::Controller(4000000, 1, 300), shift_register_(0), track_(1) {
 			drive.reset(new Storage::Disk::Drive);
 			set_drive(drive);
+			set_motor_on(true);
 		}
 
 		struct Sector {