Add dummy retrace interrupt.

Machines/Acorn/Archimedes/Archimedes.cpp

@@ -60,18 +60,24 @@ class ConcreteMachine:
 			// Hence, required ticks are:
 			//
 			// 	* CPU: 24;
-			//	* video: 12;	[TODO]
+			//	* video: 12;
 			//	* timers: 2;
 			//	* audio: 1.
 
-			tick_cpu();		tick_cpu();		tick_cpu();		tick_cpu();
-			tick_cpu();		tick_cpu();		tick_cpu();		tick_cpu();
-			tick_cpu();		tick_cpu();		tick_cpu();		tick_cpu();
+			tick_cpu();		tick_cpu();		tick_video();
+			tick_cpu();		tick_cpu();		tick_video();
+			tick_cpu();		tick_cpu();		tick_video();
+			tick_cpu();		tick_cpu();		tick_video();
+			tick_cpu();		tick_cpu();		tick_video();
+			tick_cpu();		tick_cpu();		tick_video();
 			tick_timers();
 
-			tick_cpu();		tick_cpu();		tick_cpu();		tick_cpu();
-			tick_cpu();		tick_cpu();		tick_cpu();		tick_cpu();
-			tick_cpu();		tick_cpu();		tick_cpu();		tick_cpu();
+			tick_cpu();		tick_cpu();		tick_video();
+			tick_cpu();		tick_cpu();		tick_video();
+			tick_cpu();		tick_cpu();		tick_video();
+			tick_cpu();		tick_cpu();		tick_video();
+			tick_cpu();		tick_cpu();		tick_video();
+			tick_cpu();		tick_cpu();		tick_video();
 			tick_timers();
 			tick_audio();
 		}
@@ -203,6 +209,7 @@ class ConcreteMachine:
 
 		void tick_timers()	{	executor_.bus.tick_timers();	}
 		void tick_audio()	{	executor_.bus.tick_audio();		}
+		void tick_video()	{	executor_.bus.tick_video();		}
 
 		// MARK: - MediaTarget
 		bool insert_media(const Analyser::Static::Media &) override {

Machines/Acorn/Archimedes/InputOutputController.hpp

@@ -13,6 +13,8 @@
 #include "CMOSRAM.hpp"
 #include "Keyboard.hpp"
 #include "Sound.hpp"
+#include "Video.hpp"
+
 
 namespace Archimedes {
 
@@ -312,26 +314,36 @@ struct InputOutputController {
 	InputOutputController(InterruptObserverT &observer) :
 		observer_(observer),
 		keyboard_(serial_),
-		sound_(*this)
+		sound_(*this),
+		video_(*this, sound_)
 	{
 		irq_a_.status = IRQA::SetAlways | IRQA::PowerOnReset;
 		irq_b_.status = 0x00;
 		fiq_.status = 0x80;				// 'set always'.
 
 		i2c_.add_peripheral(&cmos_, 0xa0);
-		update_sound_interrupt();
+		update_interrupts();
 	}
 
 	Sound<InputOutputController> &sound() {
 		return sound_;
 	}
 
-	void update_sound_interrupt() {
+	Video<InputOutputController, Sound<InputOutputController>> &video() {
+		return video_;
+	}
+
+	void update_interrupts() {
 		if(sound_.interrupt()) {
 			irq_b_.set(IRQB::SoundBufferPointerUsed);
 		} else {
 			irq_b_.clear(IRQB::SoundBufferPointerUsed);
 		}
+
+		if(video_.interrupt()) {
+			irq_a_.set(IRQA::VerticalFlyback);
+		}
+
 		observer_.update_interrupts();
 	}
 
@@ -374,8 +386,9 @@ private:
 	I2C::Bus i2c_;
 	CMOSRAM cmos_;
 
-	// Audio.
+	// Audio and video.
 	Sound<InputOutputController> sound_;
+	Video<InputOutputController, Sound<InputOutputController>> video_;
 };
 
 }

Machines/Acorn/Archimedes/MemoryController.hpp

@@ -32,7 +32,7 @@ static_assert(BitMask<15, 14>::value == 49152);
 template <typename InterruptObserverT>
 struct MemoryController {
 	MemoryController(InterruptObserverT &observer) :
-		ioc_(observer), vidc_(observer, ioc_.sound()) {}
+		ioc_(observer) {}
 
 	int interrupt_mask() const {
 		return ioc_.interrupt_mask();
@@ -127,7 +127,7 @@ struct MemoryController {
 
 			case Zone::VideoController:
 				// TODO: handle byte writes correctly.
-				vidc_.write(source);
+				ioc_.video().write(source);
 			break;
 
 			case Zone::PhysicallyMappedRAM:
@@ -214,6 +214,9 @@ struct MemoryController {
 		// stop allowing it to use the bus?
 		ioc_.sound().tick();
 	}
+	void tick_video() {
+		ioc_.video().tick();
+	}
 
 	private:
 		Log::Logger<Log::Source::ARMIOC> logger;
@@ -253,7 +256,6 @@ struct MemoryController {
 		std::array<uint8_t, 4*1024*1024> ram_{};
 		std::array<uint8_t, 2*1024*1024> rom_;
 		InputOutputController<InterruptObserverT> ioc_;
-		Video<InterruptObserverT, Sound<InputOutputController<InterruptObserverT>>> vidc_;
 
 		template <typename IntT>
 		IntT &physical_ram(uint32_t address) {

Machines/Acorn/Archimedes/Sound.hpp

@@ -88,7 +88,7 @@ private:
 
 	void set_buffer_valid(bool valid) {
 		next_buffer_valid_ = valid;
-		observer_.update_sound_interrupt();
+		observer_.update_interrupts();
 	}
 
 	void set_halted(bool halted) {

Machines/Acorn/Archimedes/Video.hpp

@@ -21,6 +21,9 @@ struct Video {
 
 	void write(uint32_t value) {
 		const auto target = (value >> 24) & 0xfc;
+		const auto timing_value = [](uint32_t value) -> uint32_t {
+			return (value >> 14) & 0x3ff;
+		};
 
 		switch(target) {
 			case 0x00:	case 0x04:	case 0x08:	case 0x0c:
@@ -40,24 +43,31 @@ struct Video {
 
 			case 0x80:
 				logger.error().append("TODO: Video horizontal period: %d", (value >> 14) & 0x3ff);
+				horizontal_.period = timing_value(value);
 			break;
 			case 0x84:
 				logger.error().append("TODO: Video horizontal sync width: %d", (value >> 14) & 0x3ff);
+				horizontal_.sync_width = timing_value(value);
 			break;
 			case 0x88:
 				logger.error().append("TODO: Video horizontal border start: %d", (value >> 14) & 0x3ff);
+				horizontal_.border_start = timing_value(value);
 			break;
 			case 0x8c:
 				logger.error().append("TODO: Video horizontal display start: %d", (value >> 14) & 0x3ff);
+				horizontal_.display_start = timing_value(value);
 			break;
 			case 0x90:
 				logger.error().append("TODO: Video horizontal display end: %d", (value >> 14) & 0x3ff);
+				horizontal_.display_end = timing_value(value);
 			break;
 			case 0x94:
 				logger.error().append("TODO: Video horizontal border end: %d", (value >> 14) & 0x3ff);
+				horizontal_.border_end = timing_value(value);
 			break;
 			case 0x98:
 				logger.error().append("TODO: Video horizontal cursor end: %d", (value >> 14) & 0x3ff);
+				horizontal_.cursor_end = timing_value(value);
 			break;
 			case 0x9c:
 				logger.error().append("TODO: Video horizontal interlace: %d", (value >> 14) & 0x3ff);
@@ -65,27 +75,35 @@ struct Video {
 
 			case 0xa0:
 				logger.error().append("TODO: Video vertical period: %d", (value >> 14) & 0x3ff);
+				vertical_.period = timing_value(value);
 			break;
 			case 0xa4:
 				logger.error().append("TODO: Video vertical sync width: %d", (value >> 14) & 0x3ff);
+				vertical_.sync_width = timing_value(value);
 			break;
 			case 0xa8:
 				logger.error().append("TODO: Video vertical border start: %d", (value >> 14) & 0x3ff);
+				vertical_.border_start = timing_value(value);
 			break;
 			case 0xac:
 				logger.error().append("TODO: Video vertical display start: %d", (value >> 14) & 0x3ff);
+				vertical_.display_start = timing_value(value);
 			break;
 			case 0xb0:
 				logger.error().append("TODO: Video vertical display end: %d", (value >> 14) & 0x3ff);
+				vertical_.display_end = timing_value(value);
 			break;
 			case 0xb4:
 				logger.error().append("TODO: Video vertical border end: %d", (value >> 14) & 0x3ff);
+				vertical_.border_end = timing_value(value);
 			break;
 			case 0xb8:
 				logger.error().append("TODO: Video vertical cursor start: %d", (value >> 14) & 0x3ff);
+				vertical_.cursor_start = timing_value(value);
 			break;
 			case 0xbc:
 				logger.error().append("TODO: Video vertical cursor end: %d", (value >> 14) & 0x3ff);
+				vertical_.cursor_end = timing_value(value);
 			break;
 
 			case 0xe0:
@@ -112,10 +130,42 @@ struct Video {
 		}
 	}
 
+	void tick() {
+		++position_;
+		if(position_ >= horizontal_.period * vertical_.period) {
+			entered_sync_ = true;
+			position_ = 0;
+			observer_.update_interrupts();
+		}
+	}
+
+	bool interrupt() {
+		// Guess: edge triggered?
+		const bool interrupt = entered_sync_;
+		entered_sync_ = false;
+		return interrupt;
+	}
+
 private:
 	Log::Logger<Log::Source::ARMIOC> logger;
 	InterruptObserverT &observer_;
 	SoundT &sound_;
+
+	// TODO: real video output.
+	int position_ = 0;
+
+	struct Dimension {
+		uint32_t period = 0;
+		uint32_t sync_width = 0;
+		uint32_t border_start = 0;
+		uint32_t border_end = 0;
+		uint32_t display_start = 0;
+		uint32_t display_end = 0;
+		uint32_t cursor_start = 0;
+		uint32_t cursor_end = 0;
+	};
+	Dimension horizontal_, vertical_;
+	bool entered_sync_ = false;
 };
 
 }