1 files changed, 100 insertions, 0 deletions
diff --git a/Q1.core/Components/Bus.cs b/Q1.core/Components/Bus.cs
new file mode 100644
index 0000000..02b20a7
--- /dev/null
+++ b/Q1.core/Components/Bus.cs
@@ -0,0 +1,100 @@
+namespace Q1.core.Components;
+
+using Q1.core.Arch;
+
+public class Bus : IAddressable
+{
+    private Chip? _chip;
+    private readonly List<IAddressable> _devices;
+
+    public u16 AddressableStart { get; }
+    public u16 AddressableEnd { get; }
+
+    public Bus(u16 addressableStart, u16 addressableEnd)
+    {
+        this.AddressableStart = addressableStart;
+        this.AddressableEnd = addressableEnd;
+        this._devices = new();
+    }
+
+    public void SendInterrupt(u16 code)
+    {
+        if (this._chip == null)
+            throw new InvalidOperationException("Chip is not attached to bus");
+        
+        this._chip.Interrupt(code);
+    }
+    
+    public void AttachChip(Chip chip)
+    {
+        if (this._chip != null)
+            throw new InvalidOperationException("Bus already has a chip attached.");
+
+        this._chip = chip;
+        chip.Bus = this;
+    }
+
+    public void MountDevice(IAddressable device)
+    {
+        if (device.AddressableStart >= device.AddressableEnd)
+            throw new ArgumentException("Addressable range is invalid.", nameof(device));
+
+        int index = 0;
+        while (index < this._devices.Count && this._devices[index].AddressableStart < device.AddressableStart)
+            index++;
+
+        if (index > 0)
+        {
+            IAddressable prev = this._devices[index - 1];
+            if (device.AddressableStart < prev.AddressableEnd)
+                throw new InvalidOperationException("Address range overlaps with previous device.");
+        }
+
+        if (index < this._devices.Count)
+        {
+            IAddressable next = this._devices[index];
+            if (device.AddressableEnd > next.AddressableStart)
+                throw new InvalidOperationException("Address range overlaps with next device.");
+        }
+
+        this._devices.Insert(index, device);
+    }
+
+    private IAddressable? GetDevice(u16 address)
+    {
+        foreach (IAddressable device in this._devices)
+        {
+            if (address < device.AddressableStart)
+                break;
+
+            if (address < device.AddressableEnd)
+                return device;
+        }
+
+        return null;
+    }
+
+    public u8 Read(u16 address)
+    {
+        IAddressable? device = this.GetDevice(address);
+        if (device == null)
+            return 0;
+
+        return device.Read((u16) (address - device.AddressableStart));
+    }
+
+    public void Write(u16 address, u8 value)
+    {
+        IAddressable? device = this.GetDevice(address);
+        if (device == null)
+            return;
+
+        device.Write((u16) (address - device.AddressableStart), value);
+    }
+
+    public void Clock()
+    {
+        foreach (IAddressable addressable in this._devices)
+            addressable.Clock();
+    }
+}
+\ No newline at end of file