Add a target for I2C activity.

Components/I2C/I2C.cpp

@@ -0,0 +1,35 @@
+//
+//  I2C.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 16/03/2024.
+//  Copyright © 2024 Thomas Harte. All rights reserved.
+//
+
+#include "I2C.hpp"
+
+using namespace I2C;
+
+void Bus::set_data(bool pulled) {
+	set_clock_data(clock_, pulled);
+}
+bool Bus::data() {
+	return data_;
+}
+
+void Bus::set_clock(bool pulled) {
+	set_clock_data(pulled, data_);
+}
+bool Bus::clock() {
+	return clock_;
+}
+
+void Bus::set_clock_data(bool clock_pulled, bool data_pulled) {
+	// TODO: all intelligence.
+	clock_ = clock_pulled;
+	data_ = data_pulled;
+}
+
+void Bus::add_peripheral(Peripheral *peripheral, int address) {
+	peripherals_[address] = peripheral;
+}

Components/I2C/I2C.hpp

@@ -0,0 +1,39 @@
+//
+//  I2C.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 16/03/2024.
+//  Copyright © 2024 Thomas Harte. All rights reserved.
+//
+
+#pragma once
+
+#include <unordered_map>
+
+namespace I2C {
+
+/// Provides the virtual interface for an I2C peripheral; attaching this to a bus
+/// provides automatic protocol handling.
+class Peripheral {
+
+};
+
+class Bus {
+public:
+	void set_data(bool pulled);
+	bool data();
+
+	void set_clock(bool pulled);
+	bool clock();
+
+	void set_clock_data(bool clock_pulled, bool data_pulled);
+
+	void add_peripheral(Peripheral *, int address);
+
+private:
+	bool data_ = false;
+	bool clock_ = false;
+	std::unordered_map<int, Peripheral *> peripherals_;
+};
+
+}

Machines/Acorn/Archimedes/Archimedes.cpp

@@ -16,6 +16,7 @@
 
 #include "../../../InstructionSets/ARM/Executor.hpp"
 #include "../../../Outputs/Log.hpp"
+#include "../../../Components/I2C/I2C.hpp"
 
 #include <algorithm>
 #include <array>
@@ -385,7 +386,9 @@ struct Interrupts {
 
 			case 0x3200000 & AddressMask:
 				logger.error().append("TODO: IOC control read");
-				value = 0;
+				value = control_;
+				value &= ~(i2c_.clock() ? 2 : 0);
+				value &= ~(i2c_.data() ? 1 : 0);
 			return true;
 
 			case 0x3200004 & AddressMask:
@@ -465,6 +468,10 @@ struct Interrupts {
 			break;
 
 			case 0x320'0000 & AddressMask:
+				control_ = value;
+				i2c_.set_clock_data(!(value & 2), !(value & 1));
+
+				// TODO: rest relates to floppy control, maybe?
 				logger.error().append("TODO: IOC control write %02x", value);
 			return true;
 
@@ -572,6 +579,7 @@ struct Interrupts {
 	}
 
 private:
+	// IRQA, IRQB and FIQ states.
 	struct Interrupt {
 		uint8_t status, mask;
 		uint8_t request() const {
@@ -587,6 +595,7 @@ private:
 	};
 	Interrupt irq_a_, irq_b_, fiq_;
 
+	// The IOCs four counters.
 	struct Counter {
 		uint16_t value;
 		uint16_t reload;
@@ -594,8 +603,15 @@ private:
 	};
 	Counter counters_[4];
 
+	// The KART and keyboard beyond it.
 	HalfDuplexSerial serial_;
 	Keyboard keyboard_;
+
+	// The control register.
+	uint8_t control_ = 0xff;
+
+	// The I2C bus.
+	I2C::Bus i2c_;
 };
 
 /// Primarily models the MEMC.

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

@@ -215,6 +215,8 @@
 		4B228CDB24DA41890077EF25 /* ScanTarget.metal in Sources */ = {isa = PBXBuildFile; fileRef = 4B228CDA24DA41880077EF25 /* ScanTarget.metal */; };
 		4B2530F4244E6774007980BF /* fm.json in Resources */ = {isa = PBXBuildFile; fileRef = 4B2530F3244E6773007980BF /* fm.json */; };
 		4B25B5F925BD083C00362C84 /* DiskIIDrive.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B80CD6D2568A82600176FCC /* DiskIIDrive.cpp */; };
+		4B2A1CD52BA62066004496CE /* I2C.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B2A1CD32BA62066004496CE /* I2C.cpp */; };
+		4B2A1CD62BA62066004496CE /* I2C.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B2A1CD32BA62066004496CE /* I2C.cpp */; };
 		4B2A332D1DB86821002876E3 /* OricOptions.xib in Resources */ = {isa = PBXBuildFile; fileRef = 4B2A332B1DB86821002876E3 /* OricOptions.xib */; };
 		4B2A539F1D117D36003C6002 /* CSAudioQueue.m in Sources */ = {isa = PBXBuildFile; fileRef = 4B2A53911D117D36003C6002 /* CSAudioQueue.m */; };
 		4B2B3A4B1F9B8FA70062DABF /* Typer.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B2B3A471F9B8FA70062DABF /* Typer.cpp */; };
@@ -1351,6 +1353,8 @@
 		4B24095A1C45DF85004DA684 /* Stepper.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = Stepper.hpp; sourceTree = "<group>"; };
 		4B2530F3244E6773007980BF /* fm.json */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.json; path = fm.json; sourceTree = "<group>"; };
 		4B262BFF29691F55002EC0F7 /* PersonalityTraits.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = PersonalityTraits.hpp; sourceTree = "<group>"; };
+		4B2A1CD32BA62066004496CE /* I2C.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; name = I2C.cpp; path = I2C/I2C.cpp; sourceTree = "<group>"; };
+		4B2A1CD42BA62066004496CE /* I2C.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; name = I2C.hpp; path = I2C/I2C.hpp; sourceTree = "<group>"; };
 		4B2A332C1DB86821002876E3 /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.xib; name = Base; path = "Clock Signal/Base.lproj/OricOptions.xib"; sourceTree = SOURCE_ROOT; };
 		4B2A3B5A29993DFA007CE366 /* Storage.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = Storage.hpp; sourceTree = "<group>"; };
 		4B2A3B5B29995FF6007CE366 /* LineBuffer.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = LineBuffer.hpp; sourceTree = "<group>"; };
@@ -4826,6 +4830,8 @@
 				4BF0BC6E2973318E00CCA2B5 /* RP5C01 */,
 				4B0ACBFF237756EC008902D0 /* Serial */,
 				4BB0A6582044FD3000FB3688 /* SN76489 */,
+				4B2A1CD32BA62066004496CE /* I2C.cpp */,
+				4B2A1CD42BA62066004496CE /* I2C.hpp */,
 			);
 			name = Components;
 			path = ../../Components;
@@ -5874,6 +5880,7 @@
 				4B055A9E1FAE85DA0060FFFF /* G64.cpp in Sources */,
 				4B055AB81FAE860F0060FFFF /* ZX80O81P.cpp in Sources */,
 				4B055AB01FAE86070060FFFF /* PulseQueuedTape.cpp in Sources */,
+				4B2A1CD62BA62066004496CE /* I2C.cpp in Sources */,
 				4B0F1C1D2604EA1000B85C66 /* Keyboard.cpp in Sources */,
 				4B055AAC1FAE85FD0060FFFF /* PCMSegment.cpp in Sources */,
 				4BB307BC235001C300457D33 /* 6850.cpp in Sources */,
@@ -6069,6 +6076,7 @@
 				4B4518A11F75FD1C00926311 /* D64.cpp in Sources */,
 				4BCE0052227CE8CA000CA200 /* DiskIICard.cpp in Sources */,
 				4BF0BC68297108D600CCA2B5 /* MemorySlotHandler.cpp in Sources */,
+				4B2A1CD52BA62066004496CE /* I2C.cpp in Sources */,
 				4BCF1FA41DADC3DD0039D2E7 /* Oric.cpp in Sources */,
 				4BD67DCB209BE4D700AB2146 /* StaticAnalyser.cpp in Sources */,
 				4BB4BFB922A4372F0069048D /* StaticAnalyser.cpp in Sources */,

OSBindings/Qt/clksignal.pro

@@ -71,11 +71,12 @@ SOURCES += \
 	$$SRC/Components/AudioToggle/*.cpp \
 	$$SRC/Components/AY38910/*.cpp \
 	$$SRC/Components/DiskII/*.cpp \
+	$$SRC/Components/I2C/*.cpp \
 	$$SRC/Components/KonamiSCC/*.cpp \
 	$$SRC/Components/OPx/*.cpp \
-	$$SRC/Components/SN76489/*.cpp \
-	$$SRC/Components/Serial/*.cpp \
 	$$SRC/Components/RP5C01/*.cpp \
+	$$SRC/Components/Serial/*.cpp \
+	$$SRC/Components/SN76489/*.cpp \
 \
 	$$SRC/Inputs/*.cpp \
 \
@@ -202,12 +203,13 @@ HEADERS += \
 	$$SRC/Components/AudioToggle/*.hpp \
 	$$SRC/Components/AY38910/*.hpp \
 	$$SRC/Components/DiskII/*.hpp \
+	$$SRC/Components/I2C/*.hpp \
 	$$SRC/Components/KonamiSCC/*.hpp \
 	$$SRC/Components/OPx/*.hpp \
 	$$SRC/Components/OPx/Implementation/*.hpp \
+	$$SRC/Components/RP5C01/*.hpp \
 	$$SRC/Components/Serial/*.hpp \
 	$$SRC/Components/SN76489/*.hpp \
-	$$SRC/Components/RP5C01/*.hpp \
 \
 	$$SRC/Concurrency/*.hpp \
 \

OSBindings/SDL/SConstruct

@@ -56,6 +56,7 @@ SOURCES += glob.glob('../../Components/9918/Implementation/*.cpp')
 SOURCES += glob.glob('../../Components/AudioToggle/*.cpp')
 SOURCES += glob.glob('../../Components/AY38910/*.cpp')
 SOURCES += glob.glob('../../Components/DiskII/*.cpp')
+SOURCES += glob.glob('../../Components/I2C/*.cpp')
 SOURCES += glob.glob('../../Components/KonamiSCC/*.cpp')
 SOURCES += glob.glob('../../Components/OPx/*.cpp')
 SOURCES += glob.glob('../../Components/RP5C01/*.cpp')

cmake/CLK_SOURCES.cmake

@@ -55,6 +55,7 @@ set(CLK_SOURCES
 	Components/DiskII/DiskIIDrive.cpp
 	Components/DiskII/IWM.cpp
 	Components/DiskII/MacintoshDoubleDensityDrive.cpp
+	Components/I2C/I2C.cpp
 	Components/KonamiSCC/KonamiSCC.cpp
 	Components/OPx/OPLL.cpp
 	Components/RP5C01/RP5C01.cpp