Some minor changes and playing about

Core/Cpu/Z80.cs

@@ -1,5 +1,6 @@
 using System;
 using Core.Interfaces;
+using Core.Io;
 
 namespace Core.Cpu
 {
@@ -38,12 +39,12 @@ namespace Core.Cpu
 
         // The Memory Bus
         private readonly IMemory _memory;
-        private readonly IIoBus _ioBus;
+        private readonly IO_Bus _simpleIoBus;
 
-        public Z80(IMemory memory, IIoBus ioBus)
+        public Z80(IMemory memory, IO_Bus ioBus)
         {
             _memory = memory;
-            _ioBus = ioBus;
+            _simpleIoBus = ioBus;
             Reset();            
         }
 
@@ -122,15 +123,7 @@ namespace Core.Cpu
         // Placeholder for your hardware I/O
         private byte ReadPort(ushort portAddress)
         {
-            // If the port is 0xFE, the ROM is asking for keyboard/tape/ULA data!
-            // For now, we will return 0xFF (meaning "No keys are currently pressed")
-            if ((portAddress & 0xFF) == 0xFE)
-            {
-                return 0xFF;
-            }
-
-            // Default floating bus return
-            return 0xFF;
+            return _simpleIoBus.ReadPort(portAddress);
         }
 
         public int Step()
@@ -1086,7 +1079,7 @@ namespace Core.Cpu
                     // The Z80 puts 'A' on the top 8 bits, and 'n' on the bottom 8 bits of the port address
                     ushort portAddress = (ushort)((AF.High << 8) | portOffset);
 
-                    _ioBus.Write(portAddress, AF.High);
+                    _simpleIoBus.WritePort(portAddress, AF.High);
 
                     return 11;
                 case 0xd5: //push bc