Attempt to add interrupts.

Machines/Commodore/Plus4/Interrupts.hpp

@@ -0,0 +1,68 @@
+//
+//  Interrupts.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 12/12/2024.
+//  Copyright © 2024 Thomas Harte. All rights reserved.
+//
+
+#pragma once
+
+#include "../../../Processors/6502/6502.hpp"
+
+namespace Commodore::Plus4 {
+
+struct Interrupts {
+public:
+	struct Delegate {
+		virtual void set_irq_line(bool) = 0;
+	};
+
+	Interrupts(Delegate &delegate) : delegate_(delegate) {}
+
+	enum Flag {
+		Timer3 = 0x40,
+		Timer2 = 0x10,
+		Timer1 = 0x08,
+		Raster = 0x02,
+	};
+
+	uint8_t status() const {
+		return status_ | ((status_ & mask_) ? 0x80 : 0x00);
+	}
+
+	uint8_t mask() const {
+		return mask_;
+	}
+
+	void set_status(const uint8_t status) {
+		status_ = status & 0x7f;
+		update_output();
+	}
+
+	void apply(const uint8_t interrupt) {
+		status_ |= interrupt;
+		update_output();
+	}
+
+	void set_mask(const uint8_t mask) {
+		mask_ = mask;
+		update_output();
+	}
+
+private:
+	void update_output() {
+		const bool set = status_ & mask_;
+		if(set != last_set_) {
+			delegate_.set_irq_line(set);
+			last_set_ = set;
+		}
+	}
+
+	Delegate &delegate_;
+	uint8_t status_;
+	uint8_t mask_;
+	bool last_set_ = false;
+};
+
+}

Machines/Commodore/Plus4/Plus4.cpp

@@ -8,6 +8,7 @@
 
 #include "Plus4.hpp"
 
+#include "Interrupts.hpp"
 #include "Pager.hpp"
 #include "Video.hpp"
 
@@ -21,6 +22,8 @@ namespace {
 
 class Timers {
 public:
+	Timers(Interrupts &interrupts) : interrupts_(interrupts) {}
+
 	template <int offset>
 	void write(const uint8_t value) {
 		const auto load_low = [&](uint16_t &target) {
@@ -78,16 +81,24 @@ private:
 
 		// Check for interrupt.
 		if(!timers_[timer]) {
+			switch(timer) {
+				case 0:	interrupts_.apply(Interrupts::Flag::Timer1);	break;
+				case 1:	interrupts_.apply(Interrupts::Flag::Timer2);	break;
+				case 2:	interrupts_.apply(Interrupts::Flag::Timer3);	break;
+			}
 		}
 	}
 
 	uint16_t timers_[3]{};
 	uint16_t timer0_reload_ = 0xffff;
 	bool paused_[3]{};
+
+	Interrupts &interrupts_;
 };
 
 class ConcreteMachine:
 	public CPU::MOS6502::BusHandler,
+	public Interrupts::Delegate,
 	public MachineTypes::TimedMachine,
 	public MachineTypes::ScanProducer,
 	public MachineTypes::MediaTarget,
@@ -95,7 +106,9 @@ class ConcreteMachine:
 public:
 	ConcreteMachine(const Analyser::Static::Commodore::Target &target, const ROMMachine::ROMFetcher &rom_fetcher) :
 		m6502_(*this),
-		video_(map_)
+		interrupts_(*this),
+		timers_(interrupts_),
+		video_(map_, interrupts_)
 	{
 		// PAL: 8867240 divided by 5 or 4?
 		// NTSC: 7159090?
@@ -155,12 +168,24 @@ public:
 		} else {
 			if(isReadOperation(operation)) {
 				switch(address) {
-					case 0xff00:	*value = timers_.read<0>();	break;
-					case 0xff01:	*value = timers_.read<1>();	break;
-					case 0xff02:	*value = timers_.read<2>();	break;
-					case 0xff03:	*value = timers_.read<3>();	break;
-					case 0xff04:	*value = timers_.read<4>();	break;
-					case 0xff05:	*value = timers_.read<5>();	break;
+					case 0xff00:	*value = timers_.read<0>();		break;
+					case 0xff01:	*value = timers_.read<1	>();	break;
+					case 0xff02:	*value = timers_.read<2>();		break;
+					case 0xff03:	*value = timers_.read<3>();		break;
+					case 0xff04:	*value = timers_.read<4>();		break;
+					case 0xff05:	*value = timers_.read<5>();		break;
+
+					case 0xff08:
+						// TODO: keyboard.
+						*value = 0xff;
+					break;
+
+					case 0xff09:	*value = interrupts_.status();	break;
+					case 0xff0a:	*value = interrupts_.mask();	break;
+
+					case 0xff0b:	*value = video_.read<0xff0b>();	break;
+					case 0xff1c:	*value = video_.read<0xff1c>();	break;
+					case 0xff1d:	*value = video_.read<0xff1d>();	break;
 
 					default:
 						printf("TODO: TED read at %04x\n", address);
@@ -174,6 +199,19 @@ public:
 					case 0xff04:	timers_.write<4>(*value);	break;
 					case 0xff05:	timers_.write<5>(*value);	break;
 
+					case 0xff08:
+						// TODO: keyboard.
+					break;
+
+					case 0xff09:
+						interrupts_.set_status(*value);
+					break;
+					case 0xff0a:
+						interrupts_.set_mask(*value);
+						video_.write<0xff0a>(*value);
+					break;
+					case 0xff0b:	video_.write<0xff0b>(*value);	break;
+
 					case 0xff06:	video_.write<0xff06>(*value);	break;
 					case 0xff07:	video_.write<0xff07>(*value);	break;
 					case 0xff0c:	video_.write<0xff0c>(*value);	break;
@@ -198,6 +236,10 @@ public:
 private:
 	CPU::MOS6502::Processor<CPU::MOS6502::Personality::P6502, ConcreteMachine, true> m6502_;
 
+	void set_irq_line(bool active) override {
+		m6502_.set_irq_line(active);
+	}
+
 	void page_rom() {
 		map_.page<PagerSide::Read, 0x8000, 16384>(basic_.data());
 		map_.page<PagerSide::Read, 0xc000, 16384>(kernel_.data());
@@ -227,6 +269,7 @@ private:
 	std::vector<uint8_t> kernel_;
 	std::vector<uint8_t> basic_;
 
+	Interrupts interrupts_;
 	Cycles timers_subcycles_;
 	Timers timers_;
 	Video video_;

Machines/Commodore/Plus4/Video.hpp

@@ -8,6 +8,7 @@
 
 #pragma once
 
+#include "Interrupts.hpp"
 #include "Pager.hpp"
 
 #include "../../../Numeric/UpperBound.hpp"
@@ -19,14 +20,26 @@ namespace Commodore::Plus4 {
 
 struct Video {
 public:
-	Video(const Commodore::Plus4::Pager &pager) :
+	Video(const Commodore::Plus4::Pager &pager, Interrupts &interrupts) :
 		crt_(465, 1, Outputs::Display::Type::PAL50, Outputs::Display::InputDataType::Luminance8Phase8),
-		pager_(pager)
+		pager_(pager),
+		interrupts_(interrupts)
 	{
 		// TODO: perfect crop.
 		crt_.set_visible_area(Outputs::Display::Rect(0.075f, 0.065f, 0.85f, 0.85f));
 	}
 
+	template <uint16_t address>
+	uint8_t read() const {
+		switch(address) {
+			case 0xff0b:	return uint8_t(raster_interrupt_);
+			case 0xff1c:	return uint8_t(vertical_counter_ >> 8);
+			case 0xff0d:	return uint8_t(vertical_counter_);
+		}
+
+		return 0xff;
+	}
+
 	template <uint16_t address>
 	void write(const uint8_t value) {
 		const auto load_high10 = [&](uint16_t &target) {
@@ -65,6 +78,13 @@ public:
 				screen_memory_address_ = uint16_t((value & 0xf8) << 8);
 			break;
 
+			case 0xff0a:
+				raster_interrupt_ = (raster_interrupt_ & 0x00ff) | ((value & 1) << 8);
+			break;
+			case 0xff0b:
+				raster_interrupt_ = (raster_interrupt_ & 0xff00) | value;
+			break;
+
 			case 0xff0c:	load_high10(cursor_address_);			break;
 			case 0xff0d:	load_low8(cursor_address_);				break;
 			case 0xff1a:	load_high10(character_row_address_);	break;
@@ -144,6 +164,9 @@ public:
 				case 257:	if(!is_ntsc_) vertical_sync_ = false;	break;	// PAL vsync end.
 				case 269:	if(!is_ntsc_) vertical_blank_ = false;	break;	// PAL vertical blank end.
 			}
+			if(raster_interrupt_ == vertical_counter_) {
+				interrupts_.apply(Interrupts::Flag::Raster);
+			}
 
 			const auto next = Numeric::upper_bound<
 				0, 3, 288, 290, 296, 304, 307, 315, 328, 336, 344, 358, 376, 384, 390, 400, 416, 424, 432, 440, 451, 465
@@ -216,7 +239,7 @@ public:
 				break;
 
 				case 376:	// Increment vertical line.
-					++vertical_counter_;
+					vertical_counter_ = (vertical_counter_ + 1) & 0x1ff;
 				break;
 
 				case 384:	// Burst start, end of screen — clear vertical line, vertical sub and character reload registers.
@@ -274,6 +297,8 @@ private:
 	uint16_t character_generator_address_ = 0;
 	uint16_t screen_memory_address_ = 0;
 
+	int raster_interrupt_ = 0x1ff;
+
 	// Field position.
 	int horizontal_counter_ = 0;
 	int vertical_counter_ = 0;
@@ -304,6 +329,7 @@ private:
 	std::array<uint16_t, 5> background_{};
 
 	const Commodore::Plus4::Pager &pager_;
+	Interrupts &interrupts_;
 };
 
 }

OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj

@@ -1299,6 +1299,7 @@
 		4B03291F2D0923E300C51EB5 /* Video.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = Video.hpp; sourceTree = "<group>"; };
 		4B0329202D0A78DC00C51EB5 /* UpperBound.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = UpperBound.hpp; sourceTree = "<group>"; };
 		4B0329212D0A8C4700C51EB5 /* Pager.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = Pager.hpp; sourceTree = "<group>"; };
+		4B0329222D0BD32500C51EB5 /* Interrupts.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = Interrupts.hpp; sourceTree = "<group>"; };
 		4B0333AD2094081A0050B93D /* AppleDSK.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = AppleDSK.cpp; sourceTree = "<group>"; };
 		4B0333AE2094081A0050B93D /* AppleDSK.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = AppleDSK.hpp; sourceTree = "<group>"; };
 		4B046DC31CFE651500E9E45E /* ScanProducer.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = ScanProducer.hpp; sourceTree = "<group>"; };
@@ -3395,6 +3396,7 @@
 			isa = PBXGroup;
 			children = (
 				4B596EB02D037E8800FBF4B1 /* Plus4.cpp */,
+				4B0329222D0BD32500C51EB5 /* Interrupts.hpp */,
 				4B0329212D0A8C4700C51EB5 /* Pager.hpp */,
 				4B596EAF2D037E8800FBF4B1 /* Plus4.hpp */,
 				4B03291F2D0923E300C51EB5 /* Video.hpp */,