Attempts to bring audio to the Apple II.

By factoring the audio toggle out from the MSX.

Components/AudioToggle/AudioToggle.cpp

@@ -0,0 +1,38 @@
+//
+//  AudioToggle.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 17/04/2018.
+//  Copyright © 2018 Thomas Harte. All rights reserved.
+//
+
+#include "AudioToggle.hpp"
+
+using namespace Audio;
+
+Audio::Toggle::Toggle(Concurrency::DeferringAsyncTaskQueue &audio_queue) :
+	audio_queue_(audio_queue) {}
+
+void Toggle::get_samples(std::size_t number_of_samples, std::int16_t *target) {
+	for(std::size_t sample = 0; sample < number_of_samples; ++sample) {
+		target[sample] = level_;
+	}
+}
+
+void Toggle::set_sample_volume_range(std::int16_t range) {
+	volume_ = range;
+}
+
+void Toggle::skip_samples(const std::size_t number_of_samples) {}
+
+void Toggle::set_output(bool enabled) {
+	if(is_enabled_ == enabled) return;
+	is_enabled_ = enabled;
+	audio_queue_.defer([=] {
+		level_ = enabled ? volume_ : 0;
+	});
+}
+
+bool Toggle::get_output() {
+	return is_enabled_;
+}

Components/AudioToggle/AudioToggle.hpp

@@ -0,0 +1,39 @@
+//
+//  AudioToggle.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 17/04/2018.
+//  Copyright © 2018 Thomas Harte. All rights reserved.
+//
+
+#ifndef AudioToggle_hpp
+#define AudioToggle_hpp
+
+#include "../../Outputs/Speaker/Implementation/SampleSource.hpp"
+#include "../../Concurrency/AsyncTaskQueue.hpp"
+
+namespace Audio {
+
+/*!
+	Provides a sample source that can programmatically be set to one of two values.
+*/
+class Toggle: public Outputs::Speaker::SampleSource {
+	public:
+		Toggle(Concurrency::DeferringAsyncTaskQueue &audio_queue);
+
+		void get_samples(std::size_t number_of_samples, std::int16_t *target);
+		void set_sample_volume_range(std::int16_t range);
+		void skip_samples(const std::size_t number_of_samples);
+
+		void set_output(bool enabled);
+		bool get_output();
+
+	private:
+		bool is_enabled_ = false;
+		int16_t level_ = 0, volume_ = 0;
+		Concurrency::DeferringAsyncTaskQueue &audio_queue_;
+};
+
+}
+
+#endif /* AudioToggle_hpp */

Machines/AppleII/AppleII.cpp

@@ -13,6 +13,9 @@
 #include "../Utility/MemoryFuzzer.hpp"
 
 #include "../../Processors/6502/6502.hpp"
+#include "../../Components/AudioToggle/AudioToggle.hpp"
+
+#include "../../Outputs/Speaker/Implementation/LowpassSpeaker.hpp"
 
 #include "Video.hpp"
 
@@ -48,6 +51,9 @@ class ConcreteMachine:
 		void update_video() {
 			video_->run_for(cycles_since_video_update_.flush());
 		}
+		void update_audio() {
+			speaker_.run_for(cycles_since_audio_update_.divide(Cycles(16)));
+		}
 
 		uint8_t ram_[48*1024];
 		std::vector<uint8_t> rom_;
@@ -55,11 +61,19 @@ class ConcreteMachine:
 		uint16_t rom_start_address_;
 		uint8_t keyboard_input_ = 0x00;
 
+		Concurrency::DeferringAsyncTaskQueue audio_queue_;
+		Audio::Toggle audio_toggle_;
+		Outputs::Speaker::LowpassSpeaker<Audio::Toggle> speaker_;
+		Cycles cycles_since_audio_update_;
+
 	public:
 		ConcreteMachine():
 		 	m6502_(*this),
-		 	video_bus_handler_(ram_) {
+		 	video_bus_handler_(ram_),
+		 	audio_toggle_(audio_queue_),
+		 	speaker_(audio_toggle_) {
 			set_clock_rate(1022727);
+			speaker_.set_input_rate(7159089.0f / 16.0f);
 			Memory::Fuzz(ram_, sizeof(ram_));
 		}
 
@@ -77,11 +91,12 @@ class ConcreteMachine:
 		}
 
 		Outputs::Speaker::Speaker *get_speaker() override {
-			return nullptr;
+			return &speaker_;
 		}
 
 		Cycles perform_bus_operation(CPU::MOS6502::BusOperation operation, uint16_t address, uint8_t *value) {
 			++ cycles_since_video_update_;
+			cycles_since_audio_update_ += Cycles(7);
 
 			switch(address) {
 				default:
@@ -109,7 +124,6 @@ class ConcreteMachine:
 								update_video();
 							}
 							ram_[address] = *value;
-//							printf("%04x <- %02x\n", address, *value);
 						}
 					}
 				break;
@@ -126,16 +140,22 @@ class ConcreteMachine:
 				case 0xc010:
 					keyboard_input_ &= 0x7f;
 				break;
+
+				case 0xc030:
+					update_audio();
+					audio_toggle_.set_output(!audio_toggle_.get_output());
+				break;
 			}
 
 			// The Apple II has a slightly weird timing pattern: every 65th CPU cycle is stretched
 			// by an extra 1/7th. That's because one cycle lasts 3.5 NTSC colour clocks, so after
 			// 65 cycles a full line of 227.5 colour clocks have passed. But the high-rate binary
 			// signal approximation that produces colour needs to be in phase, so a stretch of exactly
-			// 0.5 further colour cycles is added.
+			// 0.5 further colour cycles is added. The video class handles that implicitly, but it
+			// needs to be accumulated here for the audio.
 			cycles_into_current_line_ = (cycles_into_current_line_ + 1) % 65;
 			if(!cycles_into_current_line_) {
-				// Do something. Do something else.
+				++ cycles_since_audio_update_;
 			}
 
 			return Cycles(1);
@@ -143,6 +163,8 @@ class ConcreteMachine:
 
 		void flush() {
 			update_video();
+			update_audio();
+			audio_queue_.perform();
 		}
 
 		bool set_rom_fetcher(const std::function<std::vector<std::unique_ptr<std::vector<uint8_t>>>(const std::string &machine, const std::vector<std::string> &names)> &roms_with_names) override {

Machines/MSX/MSX.cpp

@@ -23,6 +23,7 @@
 #include "../../Components/1770/1770.hpp"
 #include "../../Components/9918/9918.hpp"
 #include "../../Components/8255/i8255.hpp"
+#include "../../Components/AudioToggle/AudioToggle.hpp"
 #include "../../Components/AY38910/AY38910.hpp"
 #include "../../Components/KonamiSCC/KonamiSCC.hpp"
 
@@ -50,44 +51,6 @@ std::vector<std::unique_ptr<Configurable::Option>> get_options() {
 	);
 }
 
-/*!
-	Provides a sample source that can programmatically be set to one of two values.
-*/
-class AudioToggle: public Outputs::Speaker::SampleSource {
-	public:
-		AudioToggle(Concurrency::DeferringAsyncTaskQueue &audio_queue) :
-			audio_queue_(audio_queue) {}
-
-		void get_samples(std::size_t number_of_samples, std::int16_t *target) {
-			for(std::size_t sample = 0; sample < number_of_samples; ++sample) {
-				target[sample] = level_;
-			}
-		}
-
-		void set_sample_volume_range(std::int16_t range) {
-			volume_ = range;
-		}
-
-		void skip_samples(const std::size_t number_of_samples) {}
-
-		void set_output(bool enabled) {
-			if(is_enabled_ == enabled) return;
-			is_enabled_ = enabled;
-			audio_queue_.defer([=] {
-				level_ = enabled ? volume_ : 0;
-			});
-		}
-
-		bool get_output() {
-			return is_enabled_;
-		}
-
-	private:
-		bool is_enabled_ = false;
-		int16_t level_ = 0, volume_ = 0;
-		Concurrency::DeferringAsyncTaskQueue &audio_queue_;
-};
-
 class AYPortHandler: public GI::AY38910::PortHandler {
 	public:
 		AYPortHandler(Storage::Tape::BinaryTapePlayer &tape_player) : tape_player_(tape_player) {}
@@ -600,7 +563,7 @@ class ConcreteMachine:
 
 		class i8255PortHandler: public Intel::i8255::PortHandler {
 			public:
-				i8255PortHandler(ConcreteMachine &machine, AudioToggle &audio_toggle, Storage::Tape::BinaryTapePlayer &tape_player) :
+				i8255PortHandler(ConcreteMachine &machine, Audio::Toggle &audio_toggle, Storage::Tape::BinaryTapePlayer &tape_player) :
 					machine_(machine), audio_toggle_(audio_toggle), tape_player_(tape_player) {}
 
 				void set_value(int port, uint8_t value) {
@@ -637,7 +600,7 @@ class ConcreteMachine:
 
 			private:
 				ConcreteMachine &machine_;
-				AudioToggle &audio_toggle_;
+				Audio::Toggle &audio_toggle_;
 				Storage::Tape::BinaryTapePlayer &tape_player_;
 		};
 
@@ -647,10 +610,10 @@ class ConcreteMachine:
 
 		Concurrency::DeferringAsyncTaskQueue audio_queue_;
 		GI::AY38910::AY38910 ay_;
-		AudioToggle audio_toggle_;
+		Audio::Toggle audio_toggle_;
 		Konami::SCC scc_;
-		Outputs::Speaker::CompoundSource<GI::AY38910::AY38910, AudioToggle, Konami::SCC> mixer_;
+		Outputs::Speaker::CompoundSource<GI::AY38910::AY38910, Audio::Toggle, Konami::SCC> mixer_;
-		Outputs::Speaker::LowpassSpeaker<Outputs::Speaker::CompoundSource<GI::AY38910::AY38910, AudioToggle, Konami::SCC>> speaker_;
+		Outputs::Speaker::LowpassSpeaker<Outputs::Speaker::CompoundSource<GI::AY38910::AY38910, Audio::Toggle, Konami::SCC>> speaker_;
 
 		Storage::Tape::BinaryTapePlayer tape_player_;
 		bool tape_player_is_sleeping_ = false;

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

@@ -208,6 +208,8 @@
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 		4B58601E1F806AB200AEE2E3 /* MFMSectorDump.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B58601C1F806AB200AEE2E3 /* MFMSectorDump.cpp */; };
 		4B59199C1DAC6C46005BB85C /* OricTAP.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B59199A1DAC6C46005BB85C /* OricTAP.cpp */; };
+		4B595FAD2086DFBA0083CAA8 /* AudioToggle.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B595FAC2086DFBA0083CAA8 /* AudioToggle.cpp */; };
+		4B595FAE2086DFBA0083CAA8 /* AudioToggle.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B595FAC2086DFBA0083CAA8 /* AudioToggle.cpp */; };
 		4B5FADBA1DE3151600AEC565 /* FileHolder.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B5FADB81DE3151600AEC565 /* FileHolder.cpp */; };
 		4B5FADC01DE3BF2B00AEC565 /* Microdisc.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B5FADBE1DE3BF2B00AEC565 /* Microdisc.cpp */; };
 		4B643F3A1D77AD1900D431D6 /* CSStaticAnalyser.mm in Sources */ = {isa = PBXBuildFile; fileRef = 4B643F391D77AD1900D431D6 /* CSStaticAnalyser.mm */; };
@@ -856,6 +858,8 @@
 		4B58601D1F806AB200AEE2E3 /* MFMSectorDump.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = MFMSectorDump.hpp; sourceTree = "<group>"; };
 		4B59199A1DAC6C46005BB85C /* OricTAP.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = OricTAP.cpp; sourceTree = "<group>"; };
 		4B59199B1DAC6C46005BB85C /* OricTAP.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = OricTAP.hpp; sourceTree = "<group>"; };
+		4B595FAB2086DFBA0083CAA8 /* AudioToggle.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = AudioToggle.hpp; sourceTree = "<group>"; };
+		4B595FAC2086DFBA0083CAA8 /* AudioToggle.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = AudioToggle.cpp; sourceTree = "<group>"; };
 		4B5FADB81DE3151600AEC565 /* FileHolder.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = FileHolder.cpp; sourceTree = "<group>"; };
 		4B5FADB91DE3151600AEC565 /* FileHolder.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = FileHolder.hpp; sourceTree = "<group>"; };
 		4B5FADBE1DE3BF2B00AEC565 /* Microdisc.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = Microdisc.cpp; path = Oric/Microdisc.cpp; sourceTree = "<group>"; };
@@ -1929,6 +1933,15 @@
 			path = Views;
 			sourceTree = "<group>";
 		};
+		4B595FAA2086DFBA0083CAA8 /* AudioToggle */ = {
+			isa = PBXGroup;
+			children = (
+				4B595FAB2086DFBA0083CAA8 /* AudioToggle.hpp */,
+				4B595FAC2086DFBA0083CAA8 /* AudioToggle.cpp */,
+			);
+			path = AudioToggle;
+			sourceTree = "<group>";
+		};
 		4B643F3B1D77AD6D00D431D6 /* StaticAnalyser */ = {
 			isa = PBXGroup;
 			children = (
@@ -2837,6 +2850,7 @@
 		4BC9DF4A1D04691600F44158 /* Components */ = {
 			isa = PBXGroup;
 			children = (
+				4B595FAA2086DFBA0083CAA8 /* AudioToggle */,
 				4BD468F81D8DF4290084958B /* 1770 */,
 				4BC9DF4B1D04691600F44158 /* 6522 */,
 				4B1E85791D174DEC001EF87D /* 6532 */,
@@ -3607,6 +3621,7 @@
 				4B055AE31FAE9B6F0060FFFF /* TextureBuilder.cpp in Sources */,
 				4BB0A65D2045009000FB3688 /* ColecoVision.cpp in Sources */,
 				4BB0A65C2044FD3000FB3688 /* SN76489.cpp in Sources */,
+				4B595FAE2086DFBA0083CAA8 /* AudioToggle.cpp in Sources */,
 				4B055AB91FAE86170060FFFF /* Acorn.cpp in Sources */,
 				4B055A931FAE85B50060FFFF /* BinaryDump.cpp in Sources */,
 				4B89452D201967B4007DE474 /* Tape.cpp in Sources */,
@@ -3652,6 +3667,7 @@
 				4B07835A1FC11D10001D12BB /* Configurable.cpp in Sources */,
 				4B8334951F5E25B60097E338 /* C1540.cpp in Sources */,
 				4B89453C201967B4007DE474 /* StaticAnalyser.cpp in Sources */,
+				4B595FAD2086DFBA0083CAA8 /* AudioToggle.cpp in Sources */,
 				4B1497921EE4B5A800CE2596 /* ZX8081.cpp in Sources */,
 				4B643F3F1D77B88000D431D6 /* DocumentController.swift in Sources */,
 				4B4518861F75E91A00926311 /* MFMDiskController.cpp in Sources */,