using System.Drawing.Imaging; using System.Runtime.InteropServices; using System.Diagnostics; using System.Threading; using System.IO; using Core.Cpu; using Core.Io; using Core.Memory; namespace Desktop { public partial class Form1 : Form { private Z80 _cpu = null!; private MemoryBus _memoryBus = null!; private IO_Bus _simpleIoBus = null!; private ULA _ula = null!; private TapManager _tapManager = null!; private DebuggerForm? _debugger = null; private BeeperDevice _beeper = null!; private string _baseTitle = ""; private bool _isRunning = false; private bool _isPaused = false; public ushort? Breakpoint = null; public long TotalFrameCount = 0; public double FramesPerSecond = 0; public double TotalFrameTime = 0; public double FrameTime = 0; public bool highSpeed = false; public bool tapeLoaded = false; private volatile bool _pendingReset = false; public Form1() { InitializeComponent(); InitializeEmulator(); } private void InitializeEmulator() { try { _baseTitle = this.Text; _memoryBus = new MemoryBus(); _tapManager = new TapManager(); _simpleIoBus = new IO_Bus(_tapManager); _ula = new ULA(_memoryBus, _simpleIoBus); _beeper = new BeeperDevice(); _memoryBus.CrapRAMData(); byte[] romData = RomLoader.Load("48.rom"); _memoryBus.LoadRom(romData); _cpu = new Z80(_memoryBus, _simpleIoBus, _tapManager); _cpu.WaitStateCallback = _ula.GetContentionDelay; } catch (Exception ex) { MessageBox.Show($"Failed to initialize emulator:\n{ex.Message}", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } StartEmulationLoop(); } private void StartEmulationLoop() { if (_isRunning) return; _isRunning = true; _isPaused = false; bool wasHighSpeed = false; Task.Run(() => { try { const int TStatesPerFrame = 69888; long nextScanlineTarget = _cpu.TotalTStates + TStatesPerFrame; var stopwatch = Stopwatch.StartNew(); var fpsStopwatch = Stopwatch.StartNew(); long scanlineCount = 0; long audioSampleCount = 0; while (_isRunning) { if (_pendingReset) { _cpu.Reset(); _memoryBus.CrapRAMData(); // Important! If RAM has garbage, the ROM boots instantly. If it has old data, it fails the RAM check! // Reset all local loop timing variables TotalFrameCount = 0; scanlineCount = 0; audioSampleCount = 0; nextScanlineTarget = TStatesPerFrame; stopwatch.Restart(); _pendingReset = false; } if (_isPaused) { stopwatch.Restart(); scanlineCount = 0; Thread.Sleep(10); continue; } // --- Breakpoint Check --- if (Breakpoint.HasValue && _cpu.PC == Breakpoint.Value) { _isPaused = true; continue; } long tStatesBefore = _cpu.TotalTStates; // --- Execute Instruction --- _cpu.Step(); int elapsedTStates = (int)(_cpu.TotalTStates - tStatesBefore); _tapManager.Update(elapsedTStates); if(highSpeed) { wasHighSpeed = true; } else if (wasHighSpeed) { stopwatch.Restart(); fpsStopwatch.Restart(); scanlineCount = 0; audioSampleCount = (long)(_cpu.TotalTStates / 79.365); // Snap audio to the current T-State time wasHighSpeed = false; } //Process audio at the correct time if (!highSpeed) { while (_cpu.TotalTStates >= (long)(audioSampleCount * 79.365)) { bool finalAudioOutput = _simpleIoBus.BeeperState ^ _tapManager.EarBit; _beeper.AddSample(finalAudioOutput); audioSampleCount++; } } // --- Check for End of Frame --- if (_cpu.TotalTStates >= nextScanlineTarget) { // Tell the ULA to draw one line of pixels if (!highSpeed || (TotalFrameCount % 10 == 0)) { _ula.RenderScanline((int)scanlineCount % 312); } nextScanlineTarget += 224; // Advance target by ONE line (224 T-States) scanlineCount++; // Hit the bottom of the screen (Line 312)? if (scanlineCount % 312 == 0) { _cpu.RequestInterrupt(); // 50Hz interrupt TotalFrameCount++; if (highSpeed) { if (TotalFrameCount % 10 == 0) { this.BeginInvoke((MethodInvoker)delegate { UpdateScreenBitmap(); this.Text = $"{_baseTitle} - FPS: {FramesPerSecond:F1}"; }); } } else { this.Invoke((MethodInvoker)delegate { UpdateScreenBitmap(); this.Text = $"{_baseTitle} - FPS: {FramesPerSecond:F1} - Tape Loaded: {tapeLoaded.ToString()}"; }); } // Throttle to real-time (50 FPS = 20ms) if (!highSpeed) { long targetTimeMs = (scanlineCount / 312) * 20; long elapsedMs = stopwatch.ElapsedMilliseconds; if (elapsedMs < targetTimeMs) { Thread.Sleep((int)(targetTimeMs - elapsedMs)); } } TotalFrameTime += fpsStopwatch.Elapsed.TotalMilliseconds; if (TotalFrameCount % 50 == 0) { FramesPerSecond = 1000.0 / (TotalFrameTime / 50.0); FrameTime = TotalFrameTime / 50.0; TotalFrameTime = 0; } fpsStopwatch.Restart(); } } } } catch (Exception ex) { _isPaused = true; this.Invoke((MethodInvoker)delegate { MessageBox.Show(ex.Message, "CPU Crash", MessageBoxButtons.OK, MessageBoxIcon.Error); }); } }); } private void UpdateScreenBitmap() { // Build the bitmap Bitmap bmp = new Bitmap(ULA.ScreenWidth, ULA.ScreenHeight, PixelFormat.Format32bppArgb); BitmapData bmpData = bmp.LockBits( new Rectangle(0, 0, ULA.ScreenWidth, ULA.ScreenHeight), ImageLockMode.WriteOnly, bmp.PixelFormat); // Pull the raw pixel data Marshal.Copy(_ula.FrameBuffer, 0, bmpData.Scan0, _ula.FrameBuffer.Length); bmp.UnlockBits(bmpData); if (picScreen.Image != null) picScreen.Image.Dispose(); picScreen.Image = bmp; } private void loadTAPToolStripMenuItem_Click(object sender, EventArgs e) { _isPaused = true; using (OpenFileDialog ofd = new OpenFileDialog()) { ofd.Filter = "Spectrum TAP Files|*.tap"; if (ofd.ShowDialog() == DialogResult.OK) { byte[] tapBytes = File.ReadAllBytes(ofd.FileName); _cpu._tapManager.LoadTapData(tapBytes); tapeLoaded = true; } } _isPaused = false; } private void fastLoadingToolStripMenuItem_Click(object sender, EventArgs e) { // Toggle the checkmark UI fastLoadingToolStripMenuItem.Checked = !fastLoadingToolStripMenuItem.Checked; // Tell the CPU to enable or disable the ROM hijack _cpu.EnableFastLoad = fastLoadingToolStripMenuItem.Checked; } private void openSNAToolStripMenuItem_Click(object sender, EventArgs e) { _isPaused = true; using (OpenFileDialog ofd = new OpenFileDialog()) { ofd.Filter = "Snapshot Files (sna,z80)|*.sna"; if (ofd.ShowDialog() == DialogResult.OK) { byte[] snaBytes = File.ReadAllBytes(ofd.FileName); _cpu.LoadSNA(snaBytes); } } _isPaused = false; } private void btnHighSpeedToggle_Click(object sender, EventArgs e) { this.HighSpeedToolStripMenuItem.Checked = !this.HighSpeedToolStripMenuItem.Checked; highSpeed = this.HighSpeedToolStripMenuItem.Checked ? true : false; } private void btnRun_Click(object sender, EventArgs e) => _isPaused = false; private void btnPause_Click(object sender, EventArgs e) => _isPaused = true; private void btnStep_Click(object sender, EventArgs e) { if (_isPaused) _cpu.Step(); } private void btnReset_Click(object sender, EventArgs e) { _pendingReset = true; _isPaused = true; _cpu.Reset(); _memoryBus.CleanRAMData(); _isPaused = false; } private void btnExit_Click(object sender, EventArgs e) { Environment.Exit(0); } private void openDebuggerToolStripMenuItem_Click(object sender, EventArgs e) { if (_debugger == null || _debugger.IsDisposed) { _debugger = new DebuggerForm(_cpu, _memoryBus, this); _debugger.Show(); } else { _debugger.BringToFront(); } } private void UpdateMatrix(int row, int col, bool isPressed) { if (isPressed) { // Clear the bit to 0 (Active-Low = Pressed) _simpleIoBus.KeyboardRows[row] &= (byte)~(1 << col); } else { // Set the bit back to 1 (Unpressed) _simpleIoBus.KeyboardRows[row] |= (byte)(1 << col); } } protected override void OnKeyDown(KeyEventArgs e) { HandleKey(e.KeyCode, true); base.OnKeyDown(e); } protected override void OnKeyUp(KeyEventArgs e) { HandleKey(e.KeyCode, false); base.OnKeyUp(e); } private void HandleKey(Keys key, bool isPressed) { switch (key) { //Row 0: case Keys.ShiftKey: UpdateMatrix(0, 0, isPressed); break; case Keys.Z: UpdateMatrix(0, 1, isPressed); break; case Keys.X: UpdateMatrix(0, 2, isPressed); break; case Keys.C: UpdateMatrix(0, 3, isPressed); break; case Keys.V: UpdateMatrix(0, 4, isPressed); break; // Row 1 case Keys.A: UpdateMatrix(1, 0, isPressed); break; case Keys.S: UpdateMatrix(1, 1, isPressed); break; case Keys.D: UpdateMatrix(1, 2, isPressed); break; case Keys.F: UpdateMatrix(1, 3, isPressed); break; case Keys.G: UpdateMatrix(1, 4, isPressed); break; //Row 2: case Keys.Q: UpdateMatrix(2, 0, isPressed); break; case Keys.W: UpdateMatrix(2, 1, isPressed); break; case Keys.E: UpdateMatrix(2, 2, isPressed); break; case Keys.R: UpdateMatrix(2, 3, isPressed); break; case Keys.T: UpdateMatrix(2, 4, isPressed); break; // Row 3: case Keys.D1: UpdateMatrix(3, 0, isPressed); break; case Keys.D2: UpdateMatrix(3, 1, isPressed); break; case Keys.D3: UpdateMatrix(3, 2, isPressed); break; case Keys.D4: UpdateMatrix(3, 3, isPressed); break; case Keys.D5: UpdateMatrix(3, 4, isPressed); break; // Row 4: case Keys.D0: UpdateMatrix(4, 0, isPressed); break; case Keys.D9: UpdateMatrix(4, 1, isPressed); break; case Keys.D8: UpdateMatrix(4, 2, isPressed); break; case Keys.D7: UpdateMatrix(4, 3, isPressed); break; case Keys.D6: UpdateMatrix(4, 4, isPressed); break; // Row 5: case Keys.P: UpdateMatrix(5, 0, isPressed); break; case Keys.O: UpdateMatrix(5, 1, isPressed); break; case Keys.I: UpdateMatrix(5, 2, isPressed); break; case Keys.U: UpdateMatrix(5, 3, isPressed); break; case Keys.Y: UpdateMatrix(5, 4, isPressed); break; // Row 6 case Keys.Enter: UpdateMatrix(6, 0, isPressed); break; case Keys.L: UpdateMatrix(6, 1, isPressed); break; case Keys.K: UpdateMatrix(6, 2, isPressed); break; case Keys.J: UpdateMatrix(6, 3, isPressed); break; case Keys.H: UpdateMatrix(6, 4, isPressed); break; // Row 7 case Keys.Space: UpdateMatrix(7, 0, isPressed); break; case Keys.ControlKey: UpdateMatrix(7, 1, isPressed); break; // Symbol Shift case Keys.M: UpdateMatrix(7, 2, isPressed); break; case Keys.N: UpdateMatrix(7, 3, isPressed); break; case Keys.B: UpdateMatrix(7, 4, isPressed); break; } } } }