Timex 2048 emulation

README.md

@@ -1,7 +1,7 @@
 ![Build and Test](https://github.com/oldbit-com/Spectron/actions/workflows/build.yml/badge.svg)
 
-# Spectron ― ZX Spectrum 16/48/128 Emulator ☺
-Here is Spectron, my personal ZX Spectrum emulator written in C# and Avalonia UI. It emulates the classic ZX Spectrum 16K, 48K, and 128K computers.
+# Spectron ― ZX Spectrum 16/48/128/TC2048 Emulator ☺
+Here is Spectron, my personal ZX Spectrum emulator written in C# and Avalonia UI. It emulates the classic ZX Spectrum 16K, 48K, 128K and Timex Computer 2048.
 
 It is accurate and stable, capable of running most games and demos without issues, including support for loading protected tapes.
 
@@ -14,7 +14,7 @@ The ZX Spectrum was my first computer, and I still have a deep affection for it.
 ![Main Window](docs/default.png?raw=true "Main Window")
 
 ## Features
-- [x] Emulation of classic machines: ZX Spectrum 16K, 48K, and 128K
+- [x] Emulation of classic machines: ZX Spectrum 16K, 48K, 128K and Timex Computer 2048
 - [x] Time Machine: Rewind and continue from any point in the past
 - [x] State persistence: Emulator state is automatically saved and restored on restart
 - [x] Wide format support: SNA, SZX, Z80, TAP, TZX, MDR, TRD, and SCL (including ZIP archives)
@@ -37,6 +37,7 @@ The ZX Spectrum was my first computer, and I still have a deep affection for it.
 - [x] Built-in debugger
 - [x] Favorites manager
 - [x] Screen effects: Blur and CRT/Scanlines
+- [x] TC2048 extended graphics support (hi-res and hi-color)
 - [x] And more to come...
 
 Spectron relies on several custom libraries developed specifically for this project:

src/Spectron.Emulation/Devices/Audio/AY/AyDevice.cs

@@ -171,9 +171,9 @@ private void SetRegisterValue(int register, byte value)
         }
     }
 
-    // Register port 0xFFFD is decoded as: A15=1,A14=1 & A1=0
+    // Register port 0xFFFD is decoded as: A15=1,A14=1 & A1=0 for ZX Spectrum
     private static bool IsRegisterPort(Word address) => (address & 0xC002) == 0xC000;
 
-    // Data port 0xBFFD is decoded as: A15=1 & A1=0
+    // Data port 0xBFFD is decoded as: A15=1 & A1=0 for ZX Spectrum
     private static bool IsDataPort(Word address) => (address & 0x8002) == 0x8000;
 }

src/Spectron.Emulation/Devices/Audio/AudioManager.cs

@@ -80,15 +80,15 @@ public bool IsAyEnabled
 
     public bool IsAySupportedStandardSpectrum { get; set; } = true;
 
-    internal AudioManager(Clock clock, CassettePlayer? cassettePlayer, HardwareSettings hardware)
+    internal AudioManager(Clock clock, CassettePlayer? cassettePlayer, HardwareSettings hardware, Func<Word, bool> isUlaPort)
     {
         IsAySupported = hardware.HasAyChip;
 
         var statesPerSample = (double)hardware.TicksPerFrame / SamplesPerFrame;
 
         _beeperAudio = new BeeperAudio(clock, statesPerSample, hardware.ClockMhz);
 
-        Beeper = new BeeperDevice(cassettePlayer)
+        Beeper = new BeeperDevice(cassettePlayer, isUlaPort)
         {
             OnUpdateBeeper = _beeperAudio.Update
         };

src/Spectron.Emulation/Devices/Audio/Beeper/BeeperDevice.cs

@@ -5,16 +5,21 @@ namespace OldBit.Spectron.Emulation.Devices.Audio.Beeper;
 internal class BeeperDevice : IDevice
 {
     private readonly CassettePlayer? _cassettePlayer;
+    private readonly Func<Word, bool> _isUlaPort;
 
     internal bool IsEnabled { get; set; }
 
     internal Action<byte> OnUpdateBeeper { get; init; } = _ => { };
 
-    internal BeeperDevice(CassettePlayer? cassettePlayer) => _cassettePlayer = cassettePlayer;
+    internal BeeperDevice(CassettePlayer? cassettePlayer, Func<Word, bool> isUlaPort)
+    {
+        _cassettePlayer = cassettePlayer;
+        _isUlaPort = isUlaPort;
+    }
 
     public void WritePort(Word address, byte value)
     {
-        if (!IsEnabled || !Ula.IsUlaPort(address))
+        if (!IsEnabled || !_isUlaPort(address))
         {
             return;
         }

src/Spectron.Emulation/Devices/FloatingBus.cs

@@ -14,22 +14,24 @@ internal sealed class FloatingBus : IDevice
     private readonly HardwareSettings _hardware;
     private readonly IMemory _memory;
     private readonly Clock _clock;
+    private readonly Func<Word, bool> _isUlaPort;
     private readonly Dictionary<int, Word> _floatingBusAddressIndex = new();
 
     public bool IsEnabled { get; set; } = true;
 
-    internal FloatingBus(HardwareSettings hardware, IMemory memory, Clock clock)
+    internal FloatingBus(HardwareSettings hardware, IMemory memory, Clock clock, Func<Word, bool> isUlaPort)
     {
         _hardware = hardware;
         _memory = memory;
         _clock = clock;
+        _isUlaPort = isUlaPort;
 
         BuildFloatingBusTable();
     }
 
     public byte? ReadPort(Word address)
     {
-        if (!IsEnabled || Ula.IsUlaPort(address))
+        if (!IsEnabled || _isUlaPort(address))
         {
             return null;
         }

src/Spectron.Emulation/Devices/Ula.cs

@@ -6,6 +6,7 @@
 namespace OldBit.Spectron.Emulation.Devices;
 
 internal sealed class Ula(
+    ComputerType computerType,
     KeyboardState keyboardState,
     ScreenBuffer screenBuffer,
     Z80 cpu,
@@ -35,7 +36,8 @@ public void WritePort(Word address, byte value)
         screenBuffer.UpdateBorder(color, cpu.Clock.FrameTicks);
     }
 
-    internal static bool IsUlaPort(Word address) => (address & 0x01) == 0x00;
+    internal bool IsUlaPort(Word address) =>
+        computerType == ComputerType.Timex2048 ? (address & 0xFF) == 0xFE : (address & 0x01) == 0x00;
 
     private void UpdateEarBit(ref byte value)
     {

src/Spectron.Emulation/Devices/UlaTimex.cs

@@ -0,0 +1,81 @@
+using OldBit.Spectron.Emulation.Screen;
+
+namespace OldBit.Spectron.Emulation.Devices;
+
+public sealed class UlaTimex : IDevice
+{
+    private byte _lastControlValue;
+
+    internal const int ControlPort = 0xFF;
+    internal ScreenMode ScreenMode { get; private set; }
+    internal Color Paper { get; private set; }
+    internal Color Ink { get; private set; }
+
+    internal event EventHandler<EventArgs>? ScreenModeChanged;
+
+    public byte? ReadPort(Word address)
+    {
+        if ((address & 0xFF) != ControlPort)
+        {
+            return null;
+        }
+
+        return _lastControlValue;
+    }
+
+    public void WritePort(Word address, byte value)
+    {
+        if ((address & 0xFF) != ControlPort)
+        {
+            return;
+        }
+
+        ScreenMode = (value & 0b111) switch
+        {
+            0b000 => ScreenMode.Spectrum,
+            0b001 => ScreenMode.TimexSecondScreen,
+            0b010 => ScreenMode.TimexHiColor,
+            0b011 => ScreenMode.TimexHiColorAlt,
+            0b100 => ScreenMode.TimexHiResAttr,
+            0b101 => ScreenMode.TimexHiResAttrAlt,
+            0b110 => ScreenMode.TimexHiRes,
+            0b111 => ScreenMode.TimexHiResDouble,
+            _ => ScreenMode
+        };
+
+        Ink = (value & 0b111_000) switch
+        {
+            0b000_000 => SpectrumPalette.Black,
+            0b001_000 => SpectrumPalette.BrightBlue,
+            0b010_000 => SpectrumPalette.BrightRed,
+            0b011_000 => SpectrumPalette.BrightMagenta,
+            0b100_000 => SpectrumPalette.BrightGreen,
+            0b101_000 => SpectrumPalette.BrightCyan,
+            0b110_000 => SpectrumPalette.BrightYellow,
+            0b111_000 => SpectrumPalette.BrightWhite,
+            _ => throw new ArgumentOutOfRangeException(nameof(value))
+        };
+
+        Paper = (value & 0b111_000) switch
+        {
+            0b000_000 => SpectrumPalette.BrightWhite,
+            0b001_000 => SpectrumPalette.BrightYellow,
+            0b010_000 => SpectrumPalette.BrightCyan,
+            0b011_000 => SpectrumPalette.BrightGreen,
+            0b100_000 => SpectrumPalette.BrightMagenta,
+            0b101_000 => SpectrumPalette.BrightRed,
+            0b110_000 => SpectrumPalette.BrightBlue,
+            0b111_000 => SpectrumPalette.Black,
+            _ => throw new ArgumentOutOfRangeException(nameof(value))
+        };
+
+        if (_lastControlValue != value)
+        {
+            ScreenModeChanged?.Invoke(this, EventArgs.Empty);
+        }
+
+        _lastControlValue = value;
+    }
+
+    internal void Reset() => WritePort(ControlPort, 0);
+}

src/Spectron.Emulation/Emulator.cs

@@ -31,15 +31,16 @@ public sealed class Emulator
     private readonly ILogger _logger;
     private readonly SpectrumBus _spectrumBus;
     private readonly EmulatorTimer _emulationTimer;
-    private readonly IEmulatorMemory _memory;
+    private readonly FloatingBus _floatingBus;
+    private readonly Ula _ula;
+    private readonly ScreenMemoryHandler _screenMemoryHandler;
 
     private bool _isDebuggerResume;
     private bool _invalidateScreen;
     private bool _isAcceleratedTapeSpeed;
     private bool _isNmiRequested;
     private bool _isDebuggerBreak;
     private long _ticksSinceReset;
-    private FloatingBus _floatingBus = null!;
 
     public delegate void FrameEvent(FrameBuffer frameBuffer, AudioBuffer audioBuffer);
     public event FrameEvent? FrameCompleted;
@@ -71,16 +72,17 @@ public bool IsFloatingBusEnabled
     public RomType RomType { get; }
 
     public Z80 Cpu { get; }
-    public IEmulatorMemory Memory => _memory;
+    public IEmulatorMemory Memory { get; }
     public IBus Bus => _spectrumBus;
     public DivMmcDevice DivMmc { get; }
     public Beta128Device Beta128 { get; }
     public Interface1Device Interface1 { get; }
     public ZxPrinter Printer { get; }
+    public UlaTimex? UlaTimex { get; }
+    public ScreenBuffer ScreenBuffer { get; }
 
     public int TicksPerFrame => _hardware.TicksPerFrame;
 
-    internal ScreenBuffer ScreenBuffer { get; }
     internal UlaPlus UlaPlus { get; }
 
     internal Emulator(
@@ -107,11 +109,21 @@ internal Emulator(
         GamepadManager = gamepadManager;
         ComputerType = emulatorArgs.ComputerType;
         RomType = emulatorArgs.RomType;
-        _memory = emulatorArgs.Memory;
+        Memory = emulatorArgs.Memory;
 
         UlaPlus = new UlaPlus();
         _spectrumBus = new SpectrumBus();
+
         ScreenBuffer = new ScreenBuffer(hardware, emulatorArgs.Memory, UlaPlus);
+
+        if (ComputerType == ComputerType.Timex2048)
+        {
+            UlaTimex = new UlaTimex();
+        }
+
+        _screenMemoryHandler = new ScreenMemoryHandler(Memory, ScreenBuffer);
+        _screenMemoryHandler.SetScreenMode(UlaTimex);
+
         Cpu = new Z80(emulatorArgs.Memory)
         {
             Clock =
@@ -126,15 +138,19 @@ internal Emulator(
         KeyboardState.Reset();
         TapeManager.Attach(Cpu, Memory, hardware);
 
-        AudioManager = new AudioManager(Cpu.Clock, tapeManager.CassettePlayer, hardware);
+        _ula = new Ula(hardware.ComputerType, KeyboardState, ScreenBuffer, Cpu, TapeManager);
+
+        _floatingBus = new FloatingBus(_hardware, Memory, Cpu.Clock, _ula.IsUlaPort);
+
+        AudioManager = new AudioManager(Cpu.Clock, tapeManager.CassettePlayer, hardware, _ula.IsUlaPort);
 
-        DivMmc = new DivMmcDevice(Cpu, _memory, logger);
-        Beta128 = new Beta128Device(Cpu, _hardware.ClockMhz, _memory, ComputerType, diskDriveManager);
-        Interface1 = microdriveManager.CreateDevice(Cpu, _memory);
+        DivMmc = new DivMmcDevice(Cpu, Memory, logger);
+        Beta128 = new Beta128Device(Cpu, _hardware.ClockMhz, Memory, ComputerType, diskDriveManager);
+        Interface1 = microdriveManager.CreateDevice(Cpu, Memory);
         Printer = new ZxPrinter();
 
-        SetupUlaAndDevices();
-        SetupEventHandlers();
+        AddDevices();
+        AddEventHandlers();
 
         _emulationTimer = new EmulatorTimer();
         _emulationTimer.Elapsed += OnTimerElapsed;
@@ -190,14 +206,15 @@ public void Reset()
         _ticksSinceReset = 0;
 
         AudioManager.ResetAudio();
-        _memory.Reset();
+        Memory.Reset();
         Cpu.Reset();
         ScreenBuffer.Reset();
         UlaPlus.Reset();
         KeyboardState.Reset();
         Interface1.Reset();
         DivMmc.Reset();
         Beta128.Reset();
+        UlaTimex?.Reset();
     }
 
     public void Break()
@@ -231,28 +248,25 @@ private void OnTimerElapsed(object? sender, EventArgs e)
         }
     }
 
-    private void SetupEventHandlers()
+    private void AddEventHandlers()
     {
-        _memory.MemoryUpdated += (address, _) =>
-        {
-            if (address < 0x5B00)
-            {
-                ScreenBuffer.UpdateScreen(address);
-            }
-        };
         Cpu.Clock.TicksAdded += (_, previousFrameTicks, _) => ScreenBuffer.UpdateScreen(previousFrameTicks);
         Cpu.BeforeInstruction += BeforeInstruction;
         UlaPlus.ActiveChanged += _ => _invalidateScreen = true;
         Beta128.DiskActivity += _ => DiskDriveManager.OnDiskActivity();
+
+        if (UlaTimex != null)
+        {
+            UlaTimex.ScreenModeChanged += (sender, _) =>
+                _screenMemoryHandler.SetScreenMode(sender as UlaTimex, Cpu.Clock.FrameTicks);
+        }
     }
 
-    private void SetupUlaAndDevices()
+    private void AddDevices()
     {
-        var ula = new Ula(KeyboardState, ScreenBuffer, Cpu, TapeManager);
-
-        _spectrumBus.AddDevice(ula);
+        _spectrumBus.AddDevice(_ula);
         _spectrumBus.AddDevice(UlaPlus);
-        _spectrumBus.AddDevice(_memory);
+        _spectrumBus.AddDevice(Memory);
         _spectrumBus.AddDevice(AudioManager.Beeper);
         _spectrumBus.AddDevice(AudioManager.Ay);
         _spectrumBus.AddDevice(Printer);
@@ -261,7 +275,11 @@ private void SetupUlaAndDevices()
         _spectrumBus.AddDevice(Beta128);
         _spectrumBus.AddDevice(new RtcDevice(DivMmc));
 
-        _floatingBus = new FloatingBus(_hardware, Memory, Cpu.Clock);
+        if (UlaTimex != null)
+        {
+            _spectrumBus.AddDevice(UlaTimex);
+        }
+
         _spectrumBus.AddDevice(_floatingBus);
 
         Cpu.AddBus(_spectrumBus);
@@ -371,7 +389,8 @@ private void BeforeInstruction(Word pc)
 
             // case 0x1AF1:
             // case RomRoutines.SAVE_ETC:
-            //    break;
+            //     SnapshotManager.Save("2048.szx", this);
+            //     break;
         }
     }
 }