#5 Work towards making the C64 emulator run at correct speed

hagronnestad · Sep 5, 2019 · 413efde · 413efde
1 parent 03f5795
commit 413efde
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Showing 2 changed files with 45 additions and 45 deletions.
diff --git a/ComputerSystems/Commodore64/C64.cs b/ComputerSystems/Commodore64/C64.cs
@@ -1,4 +1,6 @@
 using MicroProcessor.Cpu6502;
+using System.Diagnostics;
+using System.Threading;
 
 namespace Commodore64 {
     public class C64 {
@@ -15,5 +17,44 @@ public C64() {
             Cpu.Reset();
         }
 
+        public void Run() {
+            // CLOCK_PAL = 985248 Hz
+            // CLOCK_NTSC = 1022727 Hz
+
+            // CLOCK_VICII_PAL = 7881984 Hz
+            // CLOCK_VICII_NTSC = 8181816 Hz
+
+            var cpuClockSpeedPal = 1.0f / 985248;
+            var swCpuClock = Stopwatch.StartNew();
+            var swCiaInterrupt = Stopwatch.StartNew();
+
+
+            new Thread(() => {
+                while (true) {
+
+                    // CPU clock
+                    if (swCpuClock.Elapsed.TotalMilliseconds > cpuClockSpeedPal) {
+
+                        // Cycle the CPU
+                        Cpu.Cycle();
+
+                        // I have to work out how to properly time this
+                        Memory[0xD012] = Memory[0xD012] == 0 ? (byte)1 : (byte)0;
+
+                        swCpuClock.Restart();
+                    }
+
+                    // CIA interrupt
+                    if (swCiaInterrupt.Elapsed.TotalMilliseconds > (1000 / 60)) {
+                        Cpu.Interrupt();
+
+                        swCiaInterrupt.Restart();
+                    }
+
+                }
+
+            }).Start();
+        }
+
     }
 }
diff --git a/ComputerSystems/Commodore64/Program.cs b/ComputerSystems/Commodore64/Program.cs
@@ -1,7 +1,6 @@
 using Commodore64;
 using Commodore64.Enums;
 using System;
-using System.Threading;
 using System.Windows.Forms;
 
 namespace ComputerSystem.Commodore64 {
@@ -66,7 +65,7 @@ static void Main() {
 
                     }
 
-                // CTRL modifier
+                    // CTRL modifier
                 } else if (e.Modifiers == Keys.Control) {
                     switch (e.KeyCode) {
                         case Keys.D0:
@@ -101,7 +100,7 @@ static void Main() {
                             break;
                     }
 
-                // Shift+CTRL modifier
+                    // Shift+CTRL modifier
                 } else if (e.Modifiers == (Keys.Shift | Keys.Control)) {
                     switch (e.KeyCode) {
                         case Keys.D1:
@@ -130,7 +129,7 @@ static void Main() {
                             break;
                     }
 
-                // Shift modifier
+                    // Shift modifier
                 } else if (e.Modifiers == Keys.Shift) {
                     switch (e.KeyCode) {
                         case Keys.Home:
@@ -148,48 +147,8 @@ static void Main() {
                 c64.Cpu.Memory[0xC6] = 1;
             };
 
-            //Stopwatch sw = new Stopwatch();
-
-            new Thread(() => {
-                while (true) {
-                    //sw.Start();
-
-                    c64.Cpu.Step();
-
-                    //while (sw.Elapsed.TotalMilliseconds < 0.0004) {
-
-                    //}
-
-                    //sw.Stop();
-                    //sw.Reset();
-
-                    //if (c64.Cpu.TotalInstructions % 100000 == 0) {
-                    //    Debug.WriteLine($"{c64.Cpu.TotalInstructions}");
-                    //    Debug.WriteLine($"{c64.Cpu.PC:X2}");
-                    //}
-
-                    // Raster trigger thingy
-                    if ((c64.Cpu.TotalInstructions % 10000) < 30) {
-                        c64.Cpu.Memory[0xD012] = 0;
-                    } else {
-                        c64.Cpu.Memory[0xD012] = 1;
-                    }
-
-                    // Interrupt from CIA-chip
-                    if (c64.Cpu.TotalInstructions % 30000 == 0) {
-                        c64.Cpu.Interrupt();
-                    }
-                }
-
-            }).Start();
-
-            //new Thread(() => {
-            //    while (true) {
-            //        c64.Cpu.Memory[0xD012] = 0;
-            //        Thread.Sleep(20);
-            //    }
-            //}).Start();
 
+            c64.Run();
             Application.Run(form);
         }
     }