Plus 3A implemented but not running

Core/Io/IO_Bus.cs

@@ -1,5 +1,6 @@
-using Core.Interfaces;
-using System.Diagnostics;
+using System.Diagnostics;
+using Core.Interfaces;
+using Core.Memory;
 using static System.Runtime.InteropServices.JavaScript.JSType;
 
 namespace Core.Io
@@ -11,10 +12,12 @@ namespace Core.Io
         public bool BeeperState { get; private set; } = false;
         public byte[] KeyboardRows = new byte[8] { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
         TapManager _tapManager = new TapManager();
+        MemoryBus _memory;
 
-        public IO_Bus(TapManager tapManager)
+        public IO_Bus(TapManager tapManager, MemoryBus memoryBus)
         {
             _tapManager = tapManager;
+            _memory = memoryBus;
         }
 
         public byte ReadPort(ushort portAddress)
@@ -64,6 +67,18 @@ namespace Core.Io
 
                 // Bit 3 handles the cassette MIC output
             }
+
+            // 128K Standard Paging Port (0x7FFD)
+            if ((portAddress & 0x8002) == 0)
+            {
+                _memory.HandlePaging(0x7FFD, portValue);
+            }
+
+            // +2A/+3 Extended Paging Port (0x1FFD)
+            if ((portAddress & 0xF002) == 0x1000)
+            {
+                _memory.HandlePaging(0x1FFD, portValue);
+            }
         }
     }
 }