Enables the Oric for 50/60Hz mode switching, inventing PAL60 for the purpose.

Machines/Oric/Video.cpp

@@ -26,12 +26,27 @@ namespace {
 VideoOutput::VideoOutput(uint8_t *memory) :
 		ram_(memory),
 		crt_(64*6, 1, Outputs::Display::Type::PAL50, Outputs::Display::InputDataType::Red1Green1Blue1),
+		frequency_mismatch_warner_(*this),
 		v_sync_start_position_(PAL50VSyncStartPosition), v_sync_end_position_(PAL50VSyncEndPosition),
 		counter_period_(PAL50Period) {
-	crt_.set_visible_area(crt_.get_rect_for_area(54, 224, 16 * 6, 40 * 6, 4.0f / 3.0f));
 	crt_.set_phase_linked_luminance_offset(-1.0f / 8.0f);
 	data_type_ = Outputs::Display::InputDataType::Red1Green1Blue1;
 	crt_.set_input_data_type(data_type_);
+	crt_.set_delegate(&frequency_mismatch_warner_);
+	update_crt_frequency();
+}
+
+void VideoOutput::register_crt_frequency_mismatch() {
+	crt_is_60Hz_ ^= true;
+	update_crt_frequency();
+}
+
+void VideoOutput::update_crt_frequency() {
+	// Set the proper frequency...
+	crt_.set_new_display_type(64*6, crt_is_60Hz_ ? Outputs::Display::Type::PAL60 : Outputs::Display::Type::PAL50);
+
+	// ... but also pick an appropriate crop rectangle.
+	crt_.set_visible_area(crt_.get_rect_for_area(crt_is_60Hz_ ? 26 : 54, 224, 16 * 6, 40 * 6, 4.0f / 3.0f));
 }
 
 void VideoOutput::set_display_type(Outputs::Display::DisplayType display_type) {
@@ -92,8 +107,8 @@ void VideoOutput::set_colour_rom(const std::vector<uint8_t> &rom) {
 }
 
 void VideoOutput::run_for(const Cycles cycles) {
-	// Vertical: 0-39: pixels; otherwise blank; 48-53 sync, 54-56 colour burst
+	// Horizontal: 0-39: pixels; otherwise blank; 48-53 sync, 54-56 colour burst.
-	// Horizontal: 0-223: pixels; otherwise blank; 256-259 sync
+	// Vertical: 0-223: pixels; otherwise blank; 256-259 (50Hz) or 234-238 (60Hz) sync.
 
 #define clamp(action)	\
 	if(cycles_run_for <= number_of_cycles) { action; } else cycles_run_for = number_of_cycles;

Machines/Oric/Video.hpp

@@ -29,21 +29,27 @@ class VideoOutput {
 		void set_display_type(Outputs::Display::DisplayType display_type);
 		Outputs::Display::ScanStatus get_scaled_scan_status() const;
 
+		void register_crt_frequency_mismatch();
+
 	private:
 		uint8_t *ram_;
 		Outputs::CRT::CRT crt_;
+		Outputs::CRT::CRTFrequencyMismatchWarner<VideoOutput> frequency_mismatch_warner_;
+		bool crt_is_60Hz_ = false;
 
-		// Counters and limits
+		void update_crt_frequency();
+
+		// Counters and limits.
 		int counter_ = 0, frame_counter_ = 0;
 		int v_sync_start_position_, v_sync_end_position_, counter_period_;
 
-		// Output target and device
+		// Output target and device.
 		uint8_t *rgb_pixel_target_;
 		uint32_t *composite_pixel_target_;
 		uint32_t colour_forms_[8];
 		Outputs::Display::InputDataType data_type_;
 
-		// Registers
+		// Registers.
 		uint8_t ink_, paper_;
 
 		int character_set_base_address_ = 0xb400;

Outputs/CRT/CRT.cpp

@@ -111,8 +111,10 @@ void CRT::set_brightness(float brightness) {
 void CRT::set_new_display_type(int cycles_per_line, Outputs::Display::Type displayType) {
 	switch(displayType) {
 		case Outputs::Display::Type::PAL50:
+		case Outputs::Display::Type::PAL60:
 			scan_target_modals_.intended_gamma = 2.8f;
-			set_new_timing(cycles_per_line, 312, Outputs::Display::ColourSpace::YUV, 709379, 2500, 5, true);	// i.e. 283.7516 colour cycles per line; 2.5 lines = vertical sync.
+			set_new_timing(cycles_per_line, (displayType == Outputs::Display::Type::PAL50) ? 312 : 262, Outputs::Display::ColourSpace::YUV, 709379, 2500, 5, true);
+					// i.e. 283.7516 colour cycles per line; 2.5 lines = vertical sync.
 		break;
 
 		case Outputs::Display::Type::NTSC60:

Outputs/CRT/CRT.hpp

@@ -9,6 +9,7 @@
 #ifndef CRT_hpp
 #define CRT_hpp
 
+#include <array>
 #include <cstdint>
 #include <limits>
 #include <memory>

Outputs/ScanTarget.hpp

@@ -18,6 +18,7 @@ namespace Display {
 
 enum class Type {
 	PAL50,
+	PAL60,
 	NTSC60
 };