diff --git a/base/vulkanexamplebase.cpp b/base/vulkanexamplebase.cpp
index 028920df..00ef0112 100644
--- a/base/vulkanexamplebase.cpp
+++ b/base/vulkanexamplebase.cpp
@@ -242,8 +242,8 @@ void VulkanExampleBase::nextFrame()
 	frameCounter++;
 	auto tEnd = std::chrono::high_resolution_clock::now();
 	auto tDiff = std::chrono::duration<double, std::milli>(tEnd - tStart).count();
-#if defined(VK_USE_PLATFORM_MACOS_MVK)
-    frameTimer = (float)tDiff / 100.0f;     // SRS - Divide by 100 for macOS - perhaps shorter tDiff due to background rendering?
+#if (defined(VK_USE_PLATFORM_IOS_MVK) || defined(VK_USE_PLATFORM_MACOS_MVK))
+    frameTimer = (float)tDiff * refreshPeriod;      // SRS - Multiply by the display refresh period due to fixed vsync rendering on iOS and macOS
 #else
 	frameTimer = (float)tDiff / 1000.0f;
 #endif
diff --git a/base/vulkanexamplebase.h b/base/vulkanexamplebase.h
index 14644f6b..4d5befcd 100644
--- a/base/vulkanexamplebase.h
+++ b/base/vulkanexamplebase.h
@@ -254,6 +254,7 @@ public:
 	int64_t lastTapTime = 0;
 #elif (defined(VK_USE_PLATFORM_IOS_MVK) || defined(VK_USE_PLATFORM_MACOS_MVK))
 	void* view;
+    double refreshPeriod = 1.0/60.0;        // SRS - default refreshPeriod for 60 fps display
 #elif defined(VK_USE_PLATFORM_DIRECTFB_EXT)
 	bool quit = false;
 	IDirectFB *dfb = nullptr;
diff --git a/xcode/MVKExample.cpp b/xcode/MVKExample.cpp
index df8ac5e5..b1dc66dd 100644
--- a/xcode/MVKExample.cpp
+++ b/xcode/MVKExample.cpp
@@ -11,15 +11,19 @@
 #include "examples.h"
 
 /*
-void MVKExample::renderFrame() {                    // SRS - don't need to expose VulkanExampleBase::renderFrame() to DemoViewController
+void MVKExample::renderFrame() {                                // SRS - don't need to expose VulkanExampleBase::renderFrame() to DemoViewController
     _vulkanExample->renderFrame();
 }
 */
 
-void MVKExample::displayLinkOutputCb() {            // SRS - expose VulkanExampleBase::displayLinkOutputCb() to DemoViewController
+void MVKExample::displayLinkOutputCb() {                        // SRS - expose VulkanExampleBase::displayLinkOutputCb() to DemoViewController
     _vulkanExample->displayLinkOutputCb();
 }
 
+void MVKExample::getRefreshPeriod(double refreshPeriod) {       // SRS - get the actual refresh period of the display
+    _vulkanExample->refreshPeriod = refreshPeriod;
+}
+
 void MVKExample::windowWillResize(float x, float y) {
     _vulkanExample->windowWillResize(x, y);
 }
@@ -85,14 +89,22 @@ void MVKExample::mouseUp(double x, double y) {
     _vulkanExample->mouseButtons.left = false;
 }
 
-void MVKExample::otherMouseDown() {
+void MVKExample::rightMouseDown() {
     _vulkanExample->mouseButtons.right = true;
 }
 
-void MVKExample::otherMouseUp() {
+void MVKExample::rightMouseUp() {
     _vulkanExample->mouseButtons.right = false;
 }
 
+void MVKExample::otherMouseDown() {
+    _vulkanExample->mouseButtons.middle = true;
+}
+
+void MVKExample::otherMouseUp() {
+    _vulkanExample->mouseButtons.middle = false;
+}
+
 void MVKExample::mouseDragged(double x, double y) {
     _vulkanExample->mouseDragged(x, y);
 }
@@ -109,7 +121,7 @@ MVKExample::MVKExample(void* view) {
     _vulkanExample = new VulkanExample();
     _vulkanExample->initVulkan();
     _vulkanExample->setupWindow(view);
-//    _vulkanExample->initSwapchain();              // SRS - initSwapchain() is now part of VulkanExampleBase::prepare()
+    //_vulkanExample->initSwapchain();                          // SRS - initSwapchain() is now part of VulkanExampleBase::prepare()
     _vulkanExample->prepare();
 }
 
diff --git a/xcode/MVKExample.h b/xcode/MVKExample.h
index 34cb35e6..254f3485 100644
--- a/xcode/MVKExample.h
+++ b/xcode/MVKExample.h
@@ -15,6 +15,7 @@ class MVKExample {
 public:
     //void renderFrame();                           // SRS - don't need to expose VulkanExampleBase::renderFrame() to DemoViewController
     void displayLinkOutputCb();                     // SRS - expose VulkanExampleBase::displayLinkOutputCb() to DemoViewController
+    void getRefreshPeriod(double refreshPeriod);    // SRS - get the actual refresh period of the display
     
     void windowWillResize(float x, float y);        // SRS - expose window resize events to DemoViewController
     void windowDidResize();
@@ -25,6 +26,8 @@ public:
     
     void mouseDown(double x, double y);             // SRS - expose mouse events to DemoViewController
     void mouseUp(double x, double y);
+    void rightMouseDown();
+    void rightMouseUp();
     void otherMouseDown();
     void otherMouseUp();
     void mouseDragged(double x, double y);
diff --git a/xcode/macos/DemoViewController.mm b/xcode/macos/DemoViewController.mm
index a58a81d1..d135854b 100644
--- a/xcode/macos/DemoViewController.mm
+++ b/xcode/macos/DemoViewController.mm
@@ -48,7 +48,14 @@ MVKExample* _mvkExample;
     CVDisplayLinkStart(_displayLink);
 }
 
-// SRS - Handle window resize events
+// SRS - get the actual refresh period of the display
+-(void) viewWillAppear {
+    [super viewWillAppear];
+    
+    _mvkExample->getRefreshPeriod(CVDisplayLinkGetActualOutputVideoRefreshPeriod(_displayLink));
+}
+
+// SRS - Handle window resize events (FIXME: resizeable window not yet supported at init)
 -(NSSize) windowWillResize:(NSWindow*) sender toSize:(NSSize)frameSize {
     CVDisplayLinkStop(_displayLink);
     _mvkExample->windowWillResize(frameSize.width, frameSize.height);
@@ -118,6 +125,14 @@ MVKExample* _mvkExample;
     _mvkExample->mouseUp(point.x, point.y);
 }
 
+-(void) rightMouseDown:(NSEvent*) theEvent {
+    _mvkExample->rightMouseDown();
+}
+
+-(void) rightMouseUp:(NSEvent*) theEvent {
+    _mvkExample->rightMouseUp();
+}
+
 -(void) otherMouseDown:(NSEvent*) theEvent {
     _mvkExample->otherMouseDown();
 }
@@ -131,6 +146,16 @@ MVKExample* _mvkExample;
     _mvkExample->mouseDragged(point.x, point.y);
 }
 
+-(void) rightMouseDragged:(NSEvent*) theEvent {
+    auto point = [self getMouseLocalPoint:theEvent];
+    _mvkExample->mouseDragged(point.x, point.y);
+}
+
+-(void) otherMouseDragged:(NSEvent*) theEvent {
+    auto point = [self getMouseLocalPoint:theEvent];
+    _mvkExample->mouseDragged(point.x, point.y);
+}
+
 -(void) mouseMoved:(NSEvent*) theEvent {
     auto point = [self getMouseLocalPoint:theEvent];
     _mvkExample->mouseDragged(point.x, point.y);