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Added double buffering ish.

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This commit is contained in:
Marc Parsons
2026-05-21 17:25:57 +01:00
parent 9316a16ab9
commit cca1abf0be
3 changed files with 202 additions and 166 deletions
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3
Core/Cpu/Z80.cs
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@@ -1827,7 +1827,8 @@ namespace Core.Cpu
return 16; return 16;
} }
default: default:
throw new NotImplementedException($"Extended ED Opcode 0x{extendedOpcode:X2} at PC 0x{(PC - 1):X4} is not implemented."); return 8;
//throw new NotImplementedException($"Extended ED Opcode 0x{extendedOpcode:X2} at PC 0x{(PC - 1):X4} is not implemented.");
} }
} }

185
Core/Memory/SmsMemoryBus.cs
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@@ -42,41 +42,80 @@ namespace Core.Memory
public byte Read(ushort address) public byte Read(ushort address)
{ {
if (address < 0x4000) // ROM Slot 0 (0x0000 - 0x3FFF) if (address < 0x4000)
{ {
// SMS Hardware Quirk: The first 1KB (0x0000 - 0x03FF) is NEVER paged. if (address < 0x0400)
if (address < 0x0400) return ReadFromCartridge(0, address);
return ReadFromCartridge(_romBank0, address);
}
if (address < 0x8000) // ROM Slot 1 (0x4000 - 0x7FFF)
{
return ReadFromCartridge(_romBank1, address & 0x3FFF);
}
if (address < 0xC000) // ROM Slot 2 (0x8000 - 0xBFFF)
{
// --- THE MISSING LINK: Read from Save RAM if enabled! ---
if ((_mapperControl & 0x08) != 0)
{ {
int ramBank = (_mapperControl & 0x04) != 0 ? 1 : 0; return _cartridgeRom[address];
int ramOffset = (ramBank * 0x4000) + (address & 0x1FFF);
return _cartridgeRam[ramOffset];
} }
// Slot 0
// Otherwise, read from the ROM as usual return _cartridgeRom[(_romBank0 * 0x4000) + address];
return ReadFromCartridge(_romBank2, address & 0x3FFF); }
if (address < 0x8000)
{
// Slot 1
return _cartridgeRom[(_romBank1 * 0x4000) + (address - 0x4000)];
}
if (address < 0xC000)
{
// Slot 2 (Or SRAM)
if (SramUsed && (_mapperControl & 0x08) != 0)
return _cartridgeRam[address - 0x8000];
else
return _cartridgeRom[(_romBank2 * 0x4000) + (address - 0x8000)];
} }
// System RAM (0xC000 - 0xFFFF) // THE FIX 1: Bitwise AND perfectly forces 0xE000-0xFFFF to mirror down to 0xC000!
return _workRam[address & 0x1FFF]; return _workRam[address & 0x1FFF];
} }
public void Write(ushort address, byte value)
{
if (address < 0x8000) return; // Cannot write to physical ROM
if (address < 0xC000)
{
if (SramUsed && (_mapperControl & 0x08) != 0)
_cartridgeRam[address - 0x8000] = value;
return;
}
// THE FIX 1: Save to RAM using the mirror mask
_workRam[address & 0x1FFF] = value;
// THE FIX 2: Mapper Control Registers live at the very end of the mirrored RAM!
if (address >= 0xFFFC)
{
// Calculate the absolute maximum number of banks inside the currently loaded ROM
int totalBanks = _cartridgeRom.Length / 0x4000;
// Safety catch for empty slots
if (totalBanks == 0) totalBanks = 1;
if (address == 0xFFFC)
{
_mapperControl = value;
}
else if (address == 0xFFFD)
{
_romBank0 = value % totalBanks; // Force the bank to stay inside the array bounds!
}
else if (address == 0xFFFE)
{
_romBank1 = value % totalBanks;
}
else if (address == 0xFFFF)
{
_romBank2 = value % totalBanks;
}
}
}
//public byte Read(ushort address) //public byte Read(ushort address)
//{ //{
// if (address < 0x4000) // ROM Slot 0 (0x0000 - 0x3FFF) // if (address < 0x4000) // ROM Slot 0 (0x0000 - 0x3FFF)
// { // {
// // SMS Hardware Quirk: The first 1KB (0x0000 - 0x03FF) is NEVER paged. // // SMS Hardware Quirk: The first 1KB (0x0000 - 0x03FF) is NEVER paged.
// // It is hardwired to Bank 0 so the interrupt handlers don't crash.
// if (address < 0x0400) return ReadFromCartridge(0, address); // if (address < 0x0400) return ReadFromCartridge(0, address);
// return ReadFromCartridge(_romBank0, address); // return ReadFromCartridge(_romBank0, address);
@@ -87,103 +126,73 @@ namespace Core.Memory
// } // }
// if (address < 0xC000) // ROM Slot 2 (0x8000 - 0xBFFF) // if (address < 0xC000) // ROM Slot 2 (0x8000 - 0xBFFF)
// { // {
// // Check if Cartridge RAM is enabled (Bit 3 of Mapper Control) // // --- THE MISSING LINK: Read from Save RAM if enabled! ---
// if ((_mapperControl & 0x08) != 0) // if ((_mapperControl & 0x08) != 0)
// { // {
// // Bit 2 decides if we read the first 16KB half or the second 16KB half of the RAM chip
// int ramBank = (_mapperControl & 0x04) != 0 ? 1 : 0; // int ramBank = (_mapperControl & 0x04) != 0 ? 1 : 0;
// int ramOffset = (ramBank * 0x4000) + (address & 0x3FFF); // int ramOffset = (ramBank * 0x4000) + (address & 0x1FFF);
// return _cartridgeRam[ramOffset]; // return _cartridgeRam[ramOffset];
// } // }
// // Otherwise, read from the ROM as usual
// return ReadFromCartridge(_romBank2, address & 0x3FFF); // return ReadFromCartridge(_romBank2, address & 0x3FFF);
// } // }
// // If we are here, we are in System RAM (0xC000 - 0xFFFF) // // System RAM (0xC000 - 0xFFFF)
// // The & 0x1FFF handles the 8KB mirroring automatically!
// return _workRam[address & 0x1FFF]; // return _workRam[address & 0x1FFF];
//} //}
//public void Write(ushort address, byte value) //public void Write(ushort address, byte value)
//{ //{
// // --- 1. CARTRIDGE RAM (Save Data) ---
// if (address < 0xC000) // if (address < 0xC000)
// { // {
// // Bypass the lock if they are trying to save their game!
// if (address >= 0x8000 && (_mapperControl & 0x08) != 0) // if (address >= 0x8000 && (_mapperControl & 0x08) != 0)
// { // {
// SramUsed = true;
// int ramBank = (_mapperControl & 0x04) != 0 ? 1 : 0; // int ramBank = (_mapperControl & 0x04) != 0 ? 1 : 0;
// int ramOffset = (ramBank * 0x4000) + (address & 0x3FFF); // int ramOffset = (ramBank * 0x4000) + (address & 0x1FFF);
// _cartridgeRam[ramOffset] = value; // _cartridgeRam[ramOffset] = value;
// return;
// } // }
// // You cannot write to a ROM cartridge! // // You cannot write to a ROM cartridge!
// return; // return;
// } // }
// // --- 2. SYSTEM RAM --- // // Write to System RAM
// _workRam[address & 0x1FFF] = value; // _workRam[address & 0x1FFF] = value;
// // --- 3. SEGA MAPPER (With Hardware Mirroring!) --- // // --- THE SEGA MAPPER ---
// // By checking the masked address (address & 0x1FFF), we perfectly // if (address == 0xFFFC) // <-- ADD THIS
// // catch writes to 0xFFFC-0xFFFF *and* their 0xDFFC-0xDFFF mirrors! // {
// int mapperAddress = address & 0x1FFF; // _mapperControl = value;
// }
// else if (address == 0xFFFD)
// {
// _romBank0 = value;
// }
// if (mapperAddress == 0x1FFC) _mapperControl = value; // // Write to System RAM
// else if (mapperAddress == 0x1FFD) _romBank0 = value; // _workRam[address & 0x1FFF] = value;
// else if (mapperAddress == 0x1FFE) _romBank1 = value;
// else if (mapperAddress == 0x1FFF) _romBank2 = value; // // --- THE SEGA MAPPER ---
// // If the CPU wrote to the very top of memory, it is commanding a bank swap!
// if (address == 0xFFFD)
// {
// _romBank0 = value;
// }
// else if (address == 0xFFFE)
// {
// _romBank1 = value;
// }
// else if (address == 0xFFFF)
// {
// _romBank2 = value;
// }
//} //}
public void Write(ushort address, byte value)
{
if (address < 0xC000)
{
// Bypass the lock if they are trying to save their game!
if (address >= 0x8000 && (_mapperControl & 0x08) != 0)
{
SramUsed = true;
int ramBank = (_mapperControl & 0x04) != 0 ? 1 : 0;
int ramOffset = (ramBank * 0x4000) + (address & 0x1FFF);
_cartridgeRam[ramOffset] = value;
return;
}
// You cannot write to a ROM cartridge!
return;
}
// Write to System RAM
_workRam[address & 0x1FFF] = value;
// --- THE SEGA MAPPER ---
if (address == 0xFFFC) // <-- ADD THIS
{
_mapperControl = value;
}
else if (address == 0xFFFD)
{
_romBank0 = value;
}
// Write to System RAM
_workRam[address & 0x1FFF] = value;
// --- THE SEGA MAPPER ---
// If the CPU wrote to the very top of memory, it is commanding a bank swap!
if (address == 0xFFFD)
{
_romBank0 = value;
}
else if (address == 0xFFFE)
{
_romBank1 = value;
}
else if (address == 0xFFFF)
{
_romBank2 = value;
}
}
private byte ReadFromCartridge(int bankIndex, int offset) private byte ReadFromCartridge(int bankIndex, int offset)
{ {
if (!_isCartridgeLoaded) return 0xFF; // Floating bus if no game if (!_isCartridgeLoaded) return 0xFF; // Floating bus if no game

180
Desktop/Form1.cs
View File

@@ -63,11 +63,17 @@ namespace Desktop
PopulateIncludedRomsMenu(); PopulateIncludedRomsMenu();
} }
private void DrawScreen() private void DrawScreen(int[] safeFrame)
{ {
// Rapidly copy our VDP FrameBuffer into the Windows Bitmap // Rapidly the Frame into the Windows Bitmap
var data = _screenBitmap.LockBits(new Rectangle(0, 0, 256, 192), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb); var data = _screenBitmap.LockBits(new Rectangle(0, 0, 256, 192), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);
Marshal.Copy(_machine.VideoProcessor.FrameBuffer, 0, data.Scan0, _machine.VideoProcessor.FrameBuffer.Length);
//Frame buffer draw
Marshal.Copy(safeFrame, 0, data.Scan0, safeFrame.Length);
//Direct VDP draw
//Marshal.Copy(_machine.VideoProcessor.FrameBuffer, 0, data.Scan0, _machine.VideoProcessor.FrameBuffer.Length);
_screenBitmap.UnlockBits(data); _screenBitmap.UnlockBits(data);
this.Invalidate(); this.Invalidate();
TotalFrameCount++; TotalFrameCount++;
@@ -137,88 +143,108 @@ namespace Desktop
double nextFrameTargetTime = _stopwatch.Elapsed.TotalMilliseconds + TargetFrameTime; double nextFrameTargetTime = _stopwatch.Elapsed.TotalMilliseconds + TargetFrameTime;
double lastFpsUpdate = _stopwatch.Elapsed.TotalMilliseconds; double lastFpsUpdate = _stopwatch.Elapsed.TotalMilliseconds;
int framesThisSecond = 0; int framesThisSecond = 0;
try
while (IsRunning)
{ {
//targetFps = isTurboMode ? 1000 : 59.94; while (IsRunning)
//TargetFrameTime = 1000.0 / targetFps;
BeginInvoke((System.Windows.Forms.MethodInvoker)delegate
{ {
targetFps = isTurboMode ? 1000 : 59.94; //targetFps = isTurboMode ? 1000 : 59.94;
TargetFrameTime = 1000.0 / targetFps; //TargetFrameTime = 1000.0 / targetFps;
});
double frameStartTime = _stopwatch.Elapsed.TotalMilliseconds;
// --- POLL PHYSICAL CONTROLLER ---
if (XInput.XInputGetState(0, out XInput.XINPUT_STATE state) == 0)
{
ushort btns = state.Gamepad.wButtons;
byte padState = 0xFF;
if ((btns & 0x0001) != 0) padState &= 0xFE; // Up
if ((btns & 0x0002) != 0) padState &= 0xFD; // Down
if ((btns & 0x0004) != 0) padState &= 0xFB; // Left
if ((btns & 0x0008) != 0) padState &= 0xF7; // Right
if ((btns & 0x1000) != 0) padState &= 0xEF; // Button 1
if ((btns & 0x2000) != 0) padState &= 0xDF; // Button 2
// THE FIX: Constantly update the gamepad state, even when it's 0xFF!
_machine.IoBus.Joypad1Gamepad = padState;
}
// --------------------------------
_machine.RunFrame();
// 2. FIRE AND FORGET! Tell Windows to draw, but DO NOT WAIT for it to finish!
BeginInvoke((System.Windows.Forms.MethodInvoker)delegate { DrawScreen(); });
// 3. Safety catch
if (_machine.Breakpoint.HasValue && _machine.Cpu.PC == _machine.Breakpoint.Value)
{
IsRunning = false;
#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
BeginInvoke((System.Windows.Forms.MethodInvoker)delegate { _debugger?.uiUpdateTimer_Tick(null, EventArgs.Empty); });
#pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
break;
}
// 4. Calculate TRUE Frame Time (Compute Time) BEFORE we go to sleep!
FrameTime = _stopwatch.Elapsed.TotalMilliseconds - frameStartTime;
// --- HIGH PRECISION THROTTLE ---
while (_stopwatch.Elapsed.TotalMilliseconds < nextFrameTargetTime)
{
if (nextFrameTargetTime - _stopwatch.Elapsed.TotalMilliseconds > 2.0)
{
Thread.Sleep(1);
}
else
{
Thread.SpinWait(10);
}
}
double currentTime = _stopwatch.Elapsed.TotalMilliseconds;
TotalFrameCount++;
framesThisSecond++;
if (currentTime - lastFpsUpdate >= 1000.0)
{
FramesPerSecond = framesThisSecond / ((currentTime - lastFpsUpdate) / 1000.0);
framesThisSecond = 0;
lastFpsUpdate = currentTime;
BeginInvoke((System.Windows.Forms.MethodInvoker)delegate BeginInvoke((System.Windows.Forms.MethodInvoker)delegate
{ {
this.Text = $"{_romType} Parsons Master System 2026 - {_currentRomName} [FPS: {FramesPerSecond:F0}]"; targetFps = isTurboMode ? 1000 : 59.94;
TargetFrameTime = 1000.0 / targetFps;
}); });
double frameStartTime = _stopwatch.Elapsed.TotalMilliseconds;
// --- POLL PHYSICAL CONTROLLER ---
if (XInput.XInputGetState(0, out XInput.XINPUT_STATE state) == 0)
{
ushort btns = state.Gamepad.wButtons;
byte padState = 0xFF;
if ((btns & 0x0001) != 0) padState &= 0xFE; // Up
if ((btns & 0x0002) != 0) padState &= 0xFD; // Down
if ((btns & 0x0004) != 0) padState &= 0xFB; // Left
if ((btns & 0x0008) != 0) padState &= 0xF7; // Right
if ((btns & 0x1000) != 0) padState &= 0xEF; // Button 1
if ((btns & 0x2000) != 0) padState &= 0xDF; // Button 2
// THE FIX: Constantly update the gamepad state, even when it's 0xFF!
_machine.IoBus.Joypad1Gamepad = padState;
}
// --------------------------------
_machine.RunFrame();
int[] frozenFrame = (int[])_machine.VideoProcessor.FrameBuffer.Clone();
// 2. FIRE AND FORGET! Tell Windows to draw, but DO NOT WAIT for it to finish!
BeginInvoke((System.Windows.Forms.MethodInvoker)delegate { DrawScreen(frozenFrame); });
// 3. Safety catch
if (_machine.Breakpoint.HasValue && _machine.Cpu.PC == _machine.Breakpoint.Value)
{
IsRunning = false;
#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
BeginInvoke((System.Windows.Forms.MethodInvoker)delegate { _debugger?.uiUpdateTimer_Tick(null, EventArgs.Empty); });
#pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
break;
}
// 4. Calculate TRUE Frame Time (Compute Time) BEFORE we go to sleep!
FrameTime = _stopwatch.Elapsed.TotalMilliseconds - frameStartTime;
// --- HIGH PRECISION THROTTLE ---
while (_stopwatch.Elapsed.TotalMilliseconds < nextFrameTargetTime)
{
if (nextFrameTargetTime - _stopwatch.Elapsed.TotalMilliseconds > 2.0)
{
Thread.Sleep(1);
}
else
{
Thread.SpinWait(10);
}
}
double currentTime = _stopwatch.Elapsed.TotalMilliseconds;
TotalFrameCount++;
framesThisSecond++;
if (currentTime - lastFpsUpdate >= 1000.0)
{
FramesPerSecond = framesThisSecond / ((currentTime - lastFpsUpdate) / 1000.0);
framesThisSecond = 0;
lastFpsUpdate = currentTime;
BeginInvoke((System.Windows.Forms.MethodInvoker)delegate
{
this.Text = $"{_romType} Parsons Master System 2026 - {_currentRomName} [FPS: {FramesPerSecond:F0}]";
});
}
nextFrameTargetTime += TargetFrameTime;
if (currentTime > nextFrameTargetTime + TargetFrameTime)
{
nextFrameTargetTime = currentTime + TargetFrameTime;
}
} }
}
catch (Exception ex)
{
IsRunning = false;
nextFrameTargetTime += TargetFrameTime; this.Invoke((System.Windows.Forms.MethodInvoker)delegate
if (currentTime > nextFrameTargetTime + TargetFrameTime)
{ {
nextFrameTargetTime = currentTime + TargetFrameTime; MessageBox.Show(
} $"The Z80 CPU Panicked!\n\n" +
$"PC Address: 0x{_machine.Cpu.PC:X4}\n" +
$"Error: {ex.Message}\n\n" +
$"Stack Trace:\n{ex.StackTrace}",
"Fatal Emulator Crash",
MessageBoxButtons.OK,
MessageBoxIcon.Error);
});
} }
}); });
} }