diff --git a/OSBindings/Mac/Clock Signal/Views/CSCathodeRayView.m b/OSBindings/Mac/Clock Signal/Views/CSCathodeRayView.m
index f8ef0992c..3ba042ca0 100644
--- a/OSBindings/Mac/Clock Signal/Views/CSCathodeRayView.m	
+++ b/OSBindings/Mac/Clock Signal/Views/CSCathodeRayView.m	
@@ -228,7 +228,7 @@ static CVReturn DisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeSt
 	BOOL hadFrame = _crtFrame ? YES : NO;
 	_crtFrame = crtFrame;
 
-	glBufferData(GL_ARRAY_BUFFER, _crtFrame->number_of_runs * kCRTSizeOfVertex * 6, _crtFrame->runs, GL_DYNAMIC_DRAW);
+	glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)(_crtFrame->number_of_vertices * _crtFrame->size_per_vertex), _crtFrame->vertices, GL_DYNAMIC_DRAW);
 
 	glBindTexture(GL_TEXTURE_2D, _textureName);
 	if(_textureSize.width != _crtFrame->size.width || _textureSize.height != _crtFrame->size.height)
@@ -512,7 +512,7 @@ static CVReturn DisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeSt
 	if (_crtFrame)
 	{
 		if(_textureSizeUniform >= 0) glUniform2f(_textureSizeUniform, _crtFrame->size.width, _crtFrame->size.height);
-		glDrawArrays(GL_TRIANGLES, 0, (GLsizei)(_crtFrame->number_of_runs*6));
+		glDrawArrays(GL_TRIANGLES, 0, (GLsizei)_crtFrame->number_of_vertices);
 	}
 
 	CGLFlushDrawable([[self openGLContext] CGLContextObj]);
diff --git a/Outputs/CRT.cpp b/Outputs/CRT.cpp
index e36e01bec..a581b3df9 100644
--- a/Outputs/CRT.cpp
+++ b/Outputs/CRT.cpp
@@ -15,6 +15,18 @@ using namespace Outputs;
 static const uint32_t kCRTFixedPointRange	= 0xf7ffffff;
 static const uint32_t kCRTFixedPointOffset	= 0x04000000;
 
+typedef uint16_t	kCRTPositionType;
+typedef uint16_t	kCRTTexCoordType;
+typedef uint8_t		kCRTLateralType;
+typedef uint8_t		kCRTPhaseType;
+
+//static const size_t kCRTVertexOffsetOfPosition = 0;
+//static const size_t kCRTVertexOffsetOfTexCoord = 4;
+//static const size_t kCRTVertexOffsetOfLateral = 8;
+//static const size_t kCRTVertexOffsetOfPhase = 9;
+//
+//static const int kCRTSizeOfVertex = 10;
+
 #define kRetraceXMask	0x01
 #define kRetraceYMask	0x02
 
@@ -394,6 +406,8 @@ CRTFrameBuilder::CRTFrameBuilder(uint16_t width, uint16_t height, unsigned int n
 	frame.size.height = height;
 	frame.number_of_buffers = number_of_buffers;
 	frame.buffers = new CRTBuffer[number_of_buffers];
+	frame.size_per_vertex = kCRTSizeOfVertex;
+	frame.geometry_mode = CRTGeometryModeTriangles;
 
 	for(int buffer = 0; buffer < number_of_buffers; buffer++)
 	{
@@ -413,7 +427,7 @@ CRTFrameBuilder::~CRTFrameBuilder()
 
 void CRTFrameBuilder::reset()
 {
-	frame.number_of_runs = 0;
+	frame.number_of_vertices = 0;
 	_next_write_x_position = _next_write_y_position = 0;
 	frame.dirty_size.width = 0;
 	frame.dirty_size.height = 1;
@@ -421,22 +435,21 @@ void CRTFrameBuilder::reset()
 
 void CRTFrameBuilder::complete()
 {
-	frame.runs = &_all_runs[0];
+	frame.vertices = &_all_runs[0];
 }
 
 uint8_t *CRTFrameBuilder::get_next_run()
 {
 	const size_t vertices_per_run = 6;
-	const size_t size_of_run = kCRTSizeOfVertex * vertices_per_run;
 
 	// get a run from the allocated list, allocating more if we're about to overrun
-	if(frame.number_of_runs * size_of_run >= _all_runs.size())
+	if((frame.number_of_vertices + vertices_per_run) * frame.size_per_vertex >= _all_runs.size())
 	{
-		_all_runs.resize(_all_runs.size() + size_of_run * 200);
+		_all_runs.resize(_all_runs.size() + frame.size_per_vertex * vertices_per_run * 100);
 	}
 
-	uint8_t *next_run = &_all_runs[frame.number_of_runs * size_of_run];
-	frame.number_of_runs++;
+	uint8_t *next_run = &_all_runs[frame.number_of_vertices * frame.size_per_vertex];
+	frame.number_of_vertices += vertices_per_run;
 
 	return next_run;
 }
diff --git a/Outputs/CRTFrame.h b/Outputs/CRTFrame.h
index d63799a37..14ebf3ea2 100644
--- a/Outputs/CRTFrame.h
+++ b/Outputs/CRTFrame.h
@@ -22,21 +22,37 @@ typedef struct {
 	uint16_t width, height;
 } CRTSize;
 
-typedef struct {
-	CRTSize size, dirty_size;
+typedef enum {
+	CRTGeometryModeTriangles
+} CRTGeometryMode;
 
+typedef struct {
+	/** The total size, in pixels, of the pixel buffer storage. Guaranteed to be a power of two. */
+	CRTSize size;
+
+	/** The portion of the pixel buffer that has been changed since the last time this set of buffers was provided. */
+	CRTSize dirty_size;
+
+	/** The number of individual buffers that adds up to the complete pixel buffer. */
 	unsigned int number_of_buffers;
+
+	/** A C array of those buffers. */
 	CRTBuffer *buffers;
 
-	unsigned int number_of_runs;
-	uint8_t *runs;
+	/** The number of vertices that constitute the output. */
+	unsigned int number_of_vertices;
+
+	/** The type of output. */
+	CRTGeometryMode geometry_mode;
+
+	/** The size of each vertex in bytes. */
+	size_t size_per_vertex;
+
+	/** The vertex data. */
+	uint8_t *vertices;
 } CRTFrame;
 
-typedef uint16_t	kCRTPositionType;
-typedef uint16_t	kCRTTexCoordType;
-typedef uint8_t		kCRTLateralType;
-typedef uint8_t		kCRTPhaseType;
-
+// TODO: these should be private to whomever builds the shaders
 static const size_t kCRTVertexOffsetOfPosition = 0;
 static const size_t kCRTVertexOffsetOfTexCoord = 4;
 static const size_t kCRTVertexOffsetOfLateral = 8;