#12 Save and load BASIC programs

hagronnestad · Sep 19, 2019 · 5dfea38 · 5dfea38
1 parent 472dd7b
commit 5dfea38
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Showing 5 changed files with 107 additions and 19 deletions.
diff --git a/ComputerSystems/Commodore64/C64MemoryLocations.cs b/ComputerSystems/Commodore64/C64MemoryLocations.cs
@@ -33,5 +33,8 @@ public static class C64MemoryLocations {
         /// Write: Raster line to generate interrupt at (bits #0-#7)
         /// </summary>
         public const ushort CURRENT_RASTER_LINE = 0xD012;
+
+        public const ushort POINTER_TO_BEGINNING_OF_BASIC_AREA_LO = 0x002B;
+        public const ushort POINTER_TO_BEGINNING_OF_BASIC_AREA_HI = 0x002C;
     }
 }
diff --git a/ComputerSystems/Commodore64/C64MemoryOffsets.cs b/ComputerSystems/Commodore64/C64MemoryOffsets.cs
@@ -17,5 +17,8 @@ public static class C64MemoryOffsets {
         /// 0x0277 - 0x0280
         /// </summary>
         public const ushort KEYBOARD_BUFFER = 0x0277;
+
+        public const ushort DEFAULT_BASIC_AREA_START = 0x0801;
+        public const ushort DEFAULT_BASIC_AREA_END = 0x9FFF;
     }
 }
diff --git a/ComputerSystems/Commodore64/FormC64Screen.Designer.cs b/ComputerSystems/Commodore64/FormC64Screen.Designer.cs
diff --git a/ComputerSystems/Commodore64/FormC64Screen.cs b/ComputerSystems/Commodore64/FormC64Screen.cs
@@ -7,6 +7,9 @@
 using System.Windows.Forms;
 using Extensions.Byte;
 using Extensions.Enums;
+using System.IO;
+using System.Linq;
+using System.Collections.Generic;
 
 namespace ComputerSystem.Commodore64 {
     public partial class FormC64Screen : Form {
@@ -185,5 +188,42 @@ private void BtnCopyScreenBuffer_Click(object sender, EventArgs e) {
         private void BtnCopyScaledScreenBuffer_Click(object sender, EventArgs e) {
             Clipboard.SetImage(_bC64ScreenOutputBuffer);
         }
+
+        private void BtnOpen_Click(object sender, EventArgs e) {
+            if (ofd.ShowDialog() == DialogResult.OK) {
+
+                var file = File.ReadAllBytes(ofd.FileName);
+
+                var address = BitConverter.ToUInt16(file, 0);
+                var data = file.Skip(2).ToArray();
+
+                for (int i = 0; i < data.Length; i++) {
+                    C64.Memory[address + i] = data[i];
+                }
+
+            }
+        }
+
+        private void BtnSave_Click(object sender, EventArgs e) {
+            if (sfd.ShowDialog() == DialogResult.OK) {
+
+                var basicAreaLength = C64MemoryOffsets.DEFAULT_BASIC_AREA_END - C64MemoryOffsets.DEFAULT_BASIC_AREA_START;
+                var data = new List<byte>();
+
+                data.AddRange(BitConverter.GetBytes((ushort)0x0801));
+
+                for (int i = 0; i < basicAreaLength; i++) {
+                    data.Add(C64.Memory[C64MemoryOffsets.DEFAULT_BASIC_AREA_START + i]);
+
+                    // TODO: Fix this horrible check
+                    // The BASIC program ends with 3 NULL-bytes, so break when we find them
+                    if (data.Count >= 3 && data.Skip(data.Count - 3).Take(3).All(x => x == 0x00)) {
+                        break;
+                    }
+                }
+
+                File.WriteAllBytes(sfd.FileName, data.ToArray());
+            }
+        }
     }
 }
diff --git a/ComputerSystems/Commodore64/FormC64Screen.resx b/ComputerSystems/Commodore64/FormC64Screen.resx
@@ -123,4 +123,10 @@
   <metadata name="toolMain.TrayLocation" type="System.Drawing.Point, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
     <value>232, 17</value>
   </metadata>
+  <metadata name="ofd.TrayLocation" type="System.Drawing.Point, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+    <value>333, 17</value>
+  </metadata>
+  <metadata name="sfd.TrayLocation" type="System.Drawing.Point, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+    <value>403, 17</value>
+  </metadata>
 </root>