Added Snapshot save feature

Desktop/Desktop.csproj

@@ -14,9 +14,9 @@
     <None Remove="ROMS\Snapshot\GHILL48K.sna" />
     <None Remove="ROMS\Snapshot\manic.sna" />
     <None Remove="ROMS\TAP\Chuckie Egg.tap" />
-    <None Remove="ROMS\TAP\DizzyB-TreasureIsland.tap" />
+    <None Remove="ROMS\TAP\Grange Hill.TAP" />
-    <None Remove="ROMS\TAP\GHILL48K.TAP" />
+    <None Remove="ROMS\TAP\Manic Miner.TAP" />
-    <None Remove="ROMS\TAP\MANIC.TAP" />
+    <None Remove="ROMS\TAP\Treasure Island - Dizzy.tap" />
     <None Remove="ROMS\TAP\zexall.tap" />
   </ItemGroup>
 
@@ -36,13 +36,13 @@
     <EmbeddedResource Include="ROMS\TAP\Chuckie Egg.tap">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </EmbeddedResource>
-    <EmbeddedResource Include="ROMS\TAP\DizzyB-TreasureIsland.tap">
+    <EmbeddedResource Include="ROMS\TAP\Grange Hill.TAP">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </EmbeddedResource>
-    <EmbeddedResource Include="ROMS\TAP\GHILL48K.TAP">
+    <EmbeddedResource Include="ROMS\TAP\Manic Miner.TAP">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </EmbeddedResource>
-    <EmbeddedResource Include="ROMS\TAP\MANIC.TAP">
+    <EmbeddedResource Include="ROMS\TAP\Treasure Island - Dizzy.tap">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </EmbeddedResource>
     <EmbeddedResource Include="ROMS\TAP\zexall.tap">

Desktop/Form1.Designer.cs

@@ -31,6 +31,9 @@
             menuStrip1 = new MenuStrip();
             fileToolStripMenuItem = new ToolStripMenuItem();
             openToolStripMenuItem = new ToolStripMenuItem();
+            includedToolStripMenuItem = new ToolStripMenuItem();
+            tAPToolStripMenuItem1 = new ToolStripMenuItem();
+            sNAToolStripMenuItem1 = new ToolStripMenuItem();
             tAPToolStripMenuItem = new ToolStripMenuItem();
             sNAToolStripMenuItem = new ToolStripMenuItem();
             exitToolStripMenuItem = new ToolStripMenuItem();
@@ -43,16 +46,14 @@
             resetToolStripMenuItem1 = new ToolStripMenuItem();
             optionsToolStripMenuItem = new ToolStripMenuItem();
             HighSpeedToolStripMenuItem = new ToolStripMenuItem();
-            includedToolStripMenuItem = new ToolStripMenuItem();
+            saveSnapshotToolStripMenuItem = new ToolStripMenuItem();
-            tAPToolStripMenuItem1 = new ToolStripMenuItem();
-            sNAToolStripMenuItem1 = new ToolStripMenuItem();
             menuStrip1.SuspendLayout();
             SuspendLayout();
             // 
             // menuStrip1
             // 
             menuStrip1.ImageScalingSize = new Size(24, 24);
-            menuStrip1.Items.AddRange(new ToolStripItem[] { fileToolStripMenuItem, viewToolStripMenuItem, machineToolStripMenuItem, optionsToolStripMenuItem });
+            menuStrip1.Items.AddRange(new ToolStripItem[] { fileToolStripMenuItem, machineToolStripMenuItem, viewToolStripMenuItem, optionsToolStripMenuItem });
             menuStrip1.Location = new Point(0, 0);
             menuStrip1.Name = "menuStrip1";
             menuStrip1.Padding = new Padding(5, 2, 0, 2);
@@ -62,7 +63,7 @@
             // 
             // fileToolStripMenuItem
             // 
-            fileToolStripMenuItem.DropDownItems.AddRange(new ToolStripItem[] { openToolStripMenuItem, exitToolStripMenuItem });
+            fileToolStripMenuItem.DropDownItems.AddRange(new ToolStripItem[] { openToolStripMenuItem, saveSnapshotToolStripMenuItem, exitToolStripMenuItem });
             fileToolStripMenuItem.Name = "fileToolStripMenuItem";
             fileToolStripMenuItem.Size = new Size(46, 24);
             fileToolStripMenuItem.Text = "File";
@@ -71,9 +72,28 @@
             // 
             openToolStripMenuItem.DropDownItems.AddRange(new ToolStripItem[] { includedToolStripMenuItem, tAPToolStripMenuItem, sNAToolStripMenuItem });
             openToolStripMenuItem.Name = "openToolStripMenuItem";
-            openToolStripMenuItem.Size = new Size(128, 26);
+            openToolStripMenuItem.Size = new Size(224, 26);
             openToolStripMenuItem.Text = "Open";
             // 
+            // includedToolStripMenuItem
+            // 
+            includedToolStripMenuItem.DropDownItems.AddRange(new ToolStripItem[] { tAPToolStripMenuItem1, sNAToolStripMenuItem1 });
+            includedToolStripMenuItem.Name = "includedToolStripMenuItem";
+            includedToolStripMenuItem.Size = new Size(149, 26);
+            includedToolStripMenuItem.Text = "Included";
+            // 
+            // tAPToolStripMenuItem1
+            // 
+            tAPToolStripMenuItem1.Name = "tAPToolStripMenuItem1";
+            tAPToolStripMenuItem1.Size = new Size(121, 26);
+            tAPToolStripMenuItem1.Text = "TAP";
+            // 
+            // sNAToolStripMenuItem1
+            // 
+            sNAToolStripMenuItem1.Name = "sNAToolStripMenuItem1";
+            sNAToolStripMenuItem1.Size = new Size(121, 26);
+            sNAToolStripMenuItem1.Text = "SNA";
+            // 
             // tAPToolStripMenuItem
             // 
             tAPToolStripMenuItem.Name = "tAPToolStripMenuItem";
@@ -91,7 +111,7 @@
             // exitToolStripMenuItem
             // 
             exitToolStripMenuItem.Name = "exitToolStripMenuItem";
-            exitToolStripMenuItem.Size = new Size(128, 26);
+            exitToolStripMenuItem.Size = new Size(224, 26);
             exitToolStripMenuItem.Text = "Exit";
             exitToolStripMenuItem.Click += btnExit_Click;
             // 
@@ -154,28 +174,16 @@
             // HighSpeedToolStripMenuItem
             // 
             HighSpeedToolStripMenuItem.Name = "HighSpeedToolStripMenuItem";
-            HighSpeedToolStripMenuItem.Size = new Size(224, 26);
+            HighSpeedToolStripMenuItem.Size = new Size(170, 26);
             HighSpeedToolStripMenuItem.Text = "High Speed";
             HighSpeedToolStripMenuItem.Click += btnHighSpeedToggle_Click;
             // 
-            // includedToolStripMenuItem
+            // saveSnapshotToolStripMenuItem
             // 
-            includedToolStripMenuItem.DropDownItems.AddRange(new ToolStripItem[] { tAPToolStripMenuItem1, sNAToolStripMenuItem1 });
+            saveSnapshotToolStripMenuItem.Name = "saveSnapshotToolStripMenuItem";
-            includedToolStripMenuItem.Name = "includedToolStripMenuItem";
+            saveSnapshotToolStripMenuItem.Size = new Size(224, 26);
-            includedToolStripMenuItem.Size = new Size(149, 26);
+            saveSnapshotToolStripMenuItem.Text = "Save Snapshot";
-            includedToolStripMenuItem.Text = "Included";
+            saveSnapshotToolStripMenuItem.Click += SaveSNAMenuItem_Click;
-            // 
-            // tAPToolStripMenuItem1
-            // 
-            tAPToolStripMenuItem1.Name = "tAPToolStripMenuItem1";
-            tAPToolStripMenuItem1.Size = new Size(224, 26);
-            tAPToolStripMenuItem1.Text = "TAP";
-            // 
-            // sNAToolStripMenuItem1
-            // 
-            sNAToolStripMenuItem1.Name = "sNAToolStripMenuItem1";
-            sNAToolStripMenuItem1.Size = new Size(224, 26);
-            sNAToolStripMenuItem1.Text = "SNA";
             // 
             // Form1
             // 
@@ -212,5 +220,6 @@
         private ToolStripMenuItem includedToolStripMenuItem;
         private ToolStripMenuItem tAPToolStripMenuItem1;
         private ToolStripMenuItem sNAToolStripMenuItem1;
+        private ToolStripMenuItem saveSnapshotToolStripMenuItem;
     }
 }

Desktop/Form1.cs

@@ -237,6 +237,69 @@ namespace Desktop
             });
         }
 
+        private void SaveSNAMenuItem_Click(object? sender, EventArgs e)
+        {
+            _isPaused = true;
+            using (SaveFileDialog sfd = new SaveFileDialog())
+            {
+                sfd.Filter = "Spectrum SNA Files|*.sna";
+                if (sfd.ShowDialog() == DialogResult.OK)
+                {
+                    SaveSNA(sfd.FileName);
+                }
+            }
+            _isPaused = false;
+        }
+
+        public void SaveSNA(string filepath)
+        {
+            // 0. Back up the live state BEFORE modifying it
+            ushort originalSP = _cpu.SP;
+            byte originalMemLow = _memoryBus.Read((ushort)(_cpu.SP - 2));
+            byte originalMemHigh = _memoryBus.Read((ushort)(_cpu.SP - 1));
+
+            // 1. We must push the PC onto the stack before saving!
+            _cpu.SP -= 2;
+            _memoryBus.Write(_cpu.SP, (byte)(_cpu.PC & 0xFF));             // Low byte
+            _memoryBus.Write((ushort)(_cpu.SP + 1), (byte)(_cpu.PC >> 8)); // High byte
+
+            using (FileStream fs = new FileStream(filepath, FileMode.Create))
+            using (BinaryWriter bw = new BinaryWriter(fs))
+            {
+                // 2. Write the 27-byte Header
+                bw.Write(_cpu.I);
+                bw.Write(_cpu.HL_Prime.Low); bw.Write(_cpu.HL_Prime.High);
+                bw.Write(_cpu.DE_Prime.Low); bw.Write(_cpu.DE_Prime.High);
+                bw.Write(_cpu.BC_Prime.Low); bw.Write(_cpu.BC_Prime.High);
+                bw.Write(_cpu.AF_Prime.Low); bw.Write(_cpu.AF_Prime.High);
+
+                bw.Write(_cpu.HL.Low); bw.Write(_cpu.HL.High);
+                bw.Write(_cpu.DE.Low); bw.Write(_cpu.DE.High);
+                bw.Write(_cpu.BC.Low); bw.Write(_cpu.BC.High);
+                bw.Write(_cpu.IY.Low); bw.Write(_cpu.IY.High);
+                bw.Write(_cpu.IX.Low); bw.Write(_cpu.IX.High);
+
+                // IFF2 determines the interrupt state in SNA
+                bw.Write((byte)(_cpu.IFF2 ? 0x04 : 0x00));
+                bw.Write(_cpu.R);
+                bw.Write(_cpu.AF.Low); bw.Write(_cpu.AF.High);
+                bw.Write((byte)(_cpu.SP & 0xFF)); bw.Write((byte)(_cpu.SP >> 8));
+                bw.Write((byte)_cpu.InterruptMode);
+                bw.Write(_simpleIoBus.BorderColorIndex);
+
+                // 3. Dump the 48K RAM
+                for (int i = 0x4000; i <= 0xFFFF; i++)
+                {
+                    bw.Write(_memoryBus.Read((ushort)i));
+                }
+            }
+
+            // 4. RESTORE the emulator's state so the game can resume safely
+            _cpu.SP = originalSP;
+            _memoryBus.Write((ushort)(originalSP - 2), originalMemLow);
+            _memoryBus.Write((ushort)(originalSP - 1), originalMemHigh);
+        }
+
         private void PopulateIncludedTapsMenu()
         {
             // 1. Get the current assembly (your .exe)