Implemented OAM, SAT so sprites and background scrolling now work

Desktop/Form1.cs

@@ -31,6 +31,10 @@ namespace Desktop
             _machine = new SmsMachine();
 
             PopulateIncludedRomsMenu();
+
+            this.KeyPreview = true;
+            this.KeyDown += Form1_KeyDown;
+            this.KeyUp += Form1_KeyUp;
         }
 
         private void DrawScreen()
@@ -168,5 +172,45 @@ namespace Desktop
         {
             Environment.Exit(0);
         }
+
+        private void Form1_KeyDown(object sender, KeyEventArgs e)
+        {
+            UpdateJoypad(e.KeyCode, true);
+        }
+
+        private void Form1_KeyUp(object sender, KeyEventArgs e)
+        {
+            UpdateJoypad(e.KeyCode, false);
+        }
+
+        private void UpdateJoypad(Keys key, bool isPressed)
+        {
+            if (_machine == null) return;
+
+            byte bitMask = 0;
+
+            // Map your keys to the Sega hardware bits
+            switch (key)
+            {
+                case Keys.W: bitMask = 0x01; break; // Bit 0: Up
+                case Keys.S: bitMask = 0x02; break; // Bit 1: Down
+                case Keys.A: bitMask = 0x04; break; // Bit 2: Left
+                case Keys.D: bitMask = 0x08; break; // Bit 3: Right
+                case Keys.O: bitMask = 0x10; break; // Bit 4: Button 1 (Start/Action)
+                case Keys.P: bitMask = 0x20; break; // Bit 5: Button 2
+                default: return; // Ignore any other keys
+            }
+
+            if (isPressed)
+            {
+                // Active-Low: Clear the specific bit to 0 using a bitwise AND with a NOT mask
+                _machine.IoBus.Joypad1State &= (byte)~bitMask;
+            }
+            else
+            {
+                // Active-Low: Reset the specific bit to 1 using a bitwise OR mask
+                _machine.IoBus.Joypad1State |= bitMask;
+            }
+        }
     }
 }