Ammendments to Z80 to make it system agnostic.

Desktop/Form1.cs

@@ -50,7 +50,7 @@ namespace Desktop
                 _memoryBus.CrapRAMData();
                 byte[] romData = RomLoader.Load("48.rom");
                 _memoryBus.LoadRom(romData);
-                _cpu = new Z80(_memoryBus, _simpleIoBus, _tapManager);
+                _cpu = new Z80(_memoryBus, _simpleIoBus);
                 _cpu.WaitStateCallback = _ula.GetContentionDelay;
 
             }
@@ -112,6 +112,13 @@ namespace Desktop
 
                         long tStatesBefore = _cpu.TotalTStates;
 
+                        // --- HARDWARE INTERCEPTS ---
+                        if (_cpu.PC == 0x0556 && _tapManager.HasBlocks)
+                        {
+                                HandleInstantTapeLoad();
+                                _cpu.TotalTStates += 100; // Charge some arbitrary time for the fast load
+                        }
+
                         // --- Execute Instruction ---
                         _cpu.Step();
 
@@ -218,6 +225,52 @@ namespace Desktop
             });
         }
 
+        private void HandleInstantTapeLoad()
+        {
+            byte[] block = _tapManager.GetNextBlock(); // Your original Queue.Dequeue() method
+            if (block == null) return;
+
+            byte expectedFlag = _cpu.AF.High;
+            if (block[0] != expectedFlag)
+            {
+                // Block mismatch (e.g. found data when looking for a header)
+                // Clear the carry flag to simulate a tape loading error
+                _cpu.AF.Low &= unchecked((byte)~0x01);
+                ForceRet();
+                return;
+            }
+
+            int bytesToCopy = _cpu.DE.Word;
+
+            // Safety check just in case the TAP file is malformed
+            int actualBytes = Math.Min(bytesToCopy, block.Length - 1);
+
+            // Directly inject the payload into the RAM
+            for (int i = 0; i < actualBytes; i++)
+            {
+                _memoryBus.Write((ushort)(_cpu.IX.Word + i), block[i + 1]);
+            }
+
+            // --- Update Registers to match a PERFECT ROM Load ---
+            _cpu.IX.Word = (ushort)(_cpu.IX.Word + actualBytes);
+            _cpu.DE.Word = (ushort)(bytesToCopy - actualBytes); // Should hit 0
+            _cpu.HL.Word = 0x0000; // The ROM zeroes this out after calculating checksums
+
+            // Checksum Zero (A = 0x00), Success Flag / Zero Flag Set (F = 0x41)
+            _cpu.AF.Word = 0x0041;
+
+            ForceRet();
+        }
+
+        private void ForceRet()
+        {
+            // Pop the return address off the stack just like a real RET instruction
+            byte pcLow = _memoryBus.Read(_cpu.SP);
+            _cpu.SP++;
+            byte pcHigh = _memoryBus.Read(_cpu.SP);
+            _cpu.SP++;
+            _cpu.PC = (ushort)((pcHigh << 8) | pcLow);
+        }
         
 
         private void UpdateScreenBitmap()
@@ -246,21 +299,14 @@ namespace Desktop
                 if (ofd.ShowDialog() == DialogResult.OK)
                 {
                     byte[] tapBytes = File.ReadAllBytes(ofd.FileName);
-                    _cpu._tapManager.LoadTapData(tapBytes);
+                    _tapManager.LoadTapData(tapBytes);
                     tapeLoaded = true;
                 }
             }
             _isPaused = false;
         }
 
-        private void fastLoadingToolStripMenuItem_Click(object sender, EventArgs e)
-        {
-            // Toggle the checkmark UI
-            fastLoadingToolStripMenuItem.Checked = !fastLoadingToolStripMenuItem.Checked;
-
-            // Tell the CPU to enable or disable the ROM hijack
-            _cpu.EnableFastLoad = fastLoadingToolStripMenuItem.Checked;
-        }
+        
         private void openSNAToolStripMenuItem_Click(object sender, EventArgs e)
         {
             _isPaused = true;