diff --git a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj
index 5b14a58d8..302b21d38 100644
--- a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj	
+++ b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj	
@@ -157,6 +157,7 @@
 		4B1EDB451E39A0AC009D6819 /* chip.png in Resources */ = {isa = PBXBuildFile; fileRef = 4B1EDB431E39A0AC009D6819 /* chip.png */; };
 		4B228CD524D773B40077EF25 /* CSScanTarget.mm in Sources */ = {isa = PBXBuildFile; fileRef = 4B228CD424D773B30077EF25 /* CSScanTarget.mm */; };
 		4B228CD924DA12C60077EF25 /* CSScanTargetView.m in Sources */ = {isa = PBXBuildFile; fileRef = 4B228CD824DA12C60077EF25 /* CSScanTargetView.m */; };
+		4B228CDB24DA41890077EF25 /* ScanTarget.metal in Sources */ = {isa = PBXBuildFile; fileRef = 4B228CDA24DA41880077EF25 /* ScanTarget.metal */; };
 		4B2530F4244E6774007980BF /* fm.json in Resources */ = {isa = PBXBuildFile; fileRef = 4B2530F3244E6773007980BF /* fm.json */; };
 		4B2A332D1DB86821002876E3 /* OricOptions.xib in Resources */ = {isa = PBXBuildFile; fileRef = 4B2A332B1DB86821002876E3 /* OricOptions.xib */; };
 		4B2A539F1D117D36003C6002 /* CSAudioQueue.m in Sources */ = {isa = PBXBuildFile; fileRef = 4B2A53911D117D36003C6002 /* CSAudioQueue.m */; };
@@ -1009,6 +1010,7 @@
 		4B228CD624D773CA0077EF25 /* CSScanTarget.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = CSScanTarget.h; sourceTree = "<group>"; };
 		4B228CD724DA12C50077EF25 /* CSScanTargetView.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = CSScanTargetView.h; sourceTree = "<group>"; };
 		4B228CD824DA12C60077EF25 /* CSScanTargetView.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = CSScanTargetView.m; sourceTree = "<group>"; };
+		4B228CDA24DA41880077EF25 /* ScanTarget.metal */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.metal; name = ScanTarget.metal; path = "Clock Signal/ScanTarget/ScanTarget.metal"; sourceTree = "<group>"; };
 		4B24095A1C45DF85004DA684 /* Stepper.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = Stepper.hpp; sourceTree = "<group>"; };
 		4B2530F3244E6773007980BF /* fm.json */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.json; path = fm.json; sourceTree = "<group>"; };
 		4B2A332C1DB86821002876E3 /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.xib; name = Base; path = "Clock Signal/Base.lproj/OricOptions.xib"; sourceTree = SOURCE_ROOT; };
@@ -3323,6 +3325,7 @@
 		4BB73E951B587A5100552FC2 = {
 			isa = PBXGroup;
 			children = (
+				4B228CDA24DA41880077EF25 /* ScanTarget.metal */,
 				4BC3C67A24C9230F0027BF76 /* BufferingScanTarget.cpp */,
 				4BC3C67B24C9230F0027BF76 /* BufferingScanTarget.hpp */,
 				4BC76E6A1C98F43700E6EF73 /* Accelerate.framework */,
@@ -4687,6 +4690,7 @@
 				4BA61EB01D91515900B3C876 /* NSData+StdVector.mm in Sources */,
 				4BDA00E022E644AF00AC3CD0 /* CSROMReceiverView.m in Sources */,
 				4BD191F42191180E0042E144 /* ScanTarget.cpp in Sources */,
+				4B228CDB24DA41890077EF25 /* ScanTarget.metal in Sources */,
 				4B228CD524D773B40077EF25 /* CSScanTarget.mm in Sources */,
 				4BCD634922D6756400F567F1 /* MacintoshDoubleDensityDrive.cpp in Sources */,
 				4B0F94FE208C1A1600FE41D9 /* NIB.cpp in Sources */,
diff --git a/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm b/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm
index a423db496..d378305ff 100644
--- a/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm	
+++ b/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm	
@@ -12,12 +12,43 @@
 
 @implementation CSScanTarget {
 	id<MTLCommandQueue> _commandQueue;
+
+	// TEST ONLY: to check that I'm drawing _something_, I'm heading towards ye standard
+	// Gouraud shading triangle. https://metalbyexample.com/up-and-running-2/ is providing
+	// much of the inspiration, albeit that I'm proceeding via MKLView.
+	id<MTLFunction> _vertexShader;
+	id<MTLFunction> _fragmentShader;
+	id<MTLBuffer> _positionBuffer;
+	id<MTLBuffer> _colourBuffer;
+	id<MTLRenderPipelineState> _gouraudPipeline;
 }
 
 - (nonnull instancetype)initWithView:(nonnull MTKView *)view {
 	self = [super init];
 	if(self) {
 		_commandQueue = [view.device newCommandQueue];
+
+		// Generate some static buffers. AS A TEST.
+		constexpr float positions[] = {
+			0.0f,	0.5f,	0.0f,	1.0f,
+			-0.5f,	-0.5f,	0.0f,	1.0f,
+			0.5f,	-0.5f,	0.0f,	1.0f,
+		};
+		constexpr float colours[] = {
+			1.0f, 0.0f, 0.0f, 1.0f,
+			0.0f, 1.0f, 0.0f, 1.0f,
+			0.0f, 0.0f, 1.0f, 1.0f,
+		};
+		_positionBuffer = [view.device newBufferWithBytes:positions length:sizeof(positions) options:MTLResourceOptionCPUCacheModeDefault];
+		_colourBuffer = [view.device newBufferWithBytes:colours length:sizeof(colours) options:MTLResourceOptionCPUCacheModeDefault];
+
+		// Generate TEST pipeline.
+		id<MTLLibrary> library = [view.device newDefaultLibrary];
+		MTLRenderPipelineDescriptor *pipelineDescriptor = [[MTLRenderPipelineDescriptor alloc] init];
+		pipelineDescriptor.vertexFunction = [library newFunctionWithName:@"vertex_main"];
+		pipelineDescriptor.fragmentFunction = [library newFunctionWithName:@"fragment_main"];
+		pipelineDescriptor.colorAttachments[0].pixelFormat = view.colorPixelFormat;
+		_gouraudPipeline = [view.device newRenderPipelineStateWithDescriptor:pipelineDescriptor error:nil];
 	}
 	return self;
 }
@@ -30,7 +61,8 @@
  @param size New drawable size in pixels
  */
 - (void)mtkView:(nonnull MTKView *)view drawableSizeWillChange:(CGSize)size {
-	NSLog(@"New size: %@", NSStringFromSize(size));
+	// I think (?) I don't care about this; the MKLView has already handled resizing the backing,
+	// which will naturally change the viewport.
 }
 
 /*!
@@ -39,12 +71,18 @@
  @discussion Called on the delegate when it is asked to render into the view
  */
 - (void)drawInMTKView:(nonnull MTKView *)view {
+	// Generate a command encoder for the view.
 	id <MTLCommandBuffer> commandBuffer = [_commandQueue commandBuffer];
 	MTLRenderPassDescriptor *const descriptor = view.currentRenderPassDescriptor;
 	id <MTLRenderCommandEncoder> encoder = [commandBuffer renderCommandEncoderWithDescriptor:descriptor];
 
-	// TODO: the drawing (!)
+	// Drawing. Just the test triangle, as described above.
+	[encoder setRenderPipelineState:_gouraudPipeline];
+	[encoder setVertexBuffer:_positionBuffer offset:0 atIndex:0];
+	[encoder setVertexBuffer:_colourBuffer offset:0 atIndex:1];
+	[encoder drawPrimitives:MTLPrimitiveTypeTriangle vertexStart:0 vertexCount:3 instanceCount:1];
 
+	// Complete encoding.
 	[encoder endEncoding];
 
 	// "Register the drawable's presentation".
diff --git a/OSBindings/Mac/Clock Signal/ScanTarget/ScanTarget.metal b/OSBindings/Mac/Clock Signal/ScanTarget/ScanTarget.metal
new file mode 100644
index 000000000..6e5e1bef3
--- /dev/null
+++ b/OSBindings/Mac/Clock Signal/ScanTarget/ScanTarget.metal	
@@ -0,0 +1,28 @@
+//
+//  ScanTarget.metal
+//  Clock Signal
+//
+//  Created by Thomas Harte on 04/08/2020.
+//  Copyright © 2020 Thomas Harte. All rights reserved.
+//
+
+#include <metal_stdlib>
+using namespace metal;
+
+struct ColoredVertex {
+	float4 position [[position]];
+	float4 color;
+};
+
+vertex ColoredVertex vertex_main(	constant float4 *position [[buffer(0)]],
+									constant float4 *color [[buffer(1)]],
+									uint vid [[vertex_id]]) {
+	ColoredVertex vert;
+	vert.position = position[vid];
+	vert.color = color[vid];
+	return vert;
+}
+
+fragment float4 fragment_main(ColoredVertex vert [[stage_in]]) {
+	return vert.color;
+}