--- nono/vm/fdc.h	2026/04/29 17:04:28	1.1
+++ nono/vm/fdc.h	2026/04/29 17:04:35	1.1.1.2
@@ -1,6 +1,7 @@
 //
 // nono
-// Copyright (C) 2017 isaki@NetBSD.org
+// Copyright (C) 2020 nono project
+// Licensed under nono-license.txt
 //
 
 #pragma once
@@ -102,21 +103,22 @@ struct FDC {
 class FDCDevice
 	: public IODevice
 {
-	typedef IODevice inherited;
+	using inherited = IODevice;
  private:
 	static const int baseaddr = 0xe94000;
 
  public:
 	FDCDevice();
-	virtual ~FDCDevice();
+	~FDCDevice() override;
 
-	virtual void ResetHard();
+	void ResetHard() override;
 
-	virtual uint64 Read8(uint32 addr);
-	virtual uint64 Read16(uint32 addr);
-	virtual uint64 Write8(uint32 addr, uint32 data);
-	virtual uint64 Write16(uint32 addr, uint32 data);
-	virtual uint64 Peek8(uint32 addr);
+ protected:
+	// BusIO インタフェース
+	static const uint32 NPORT = 4;
+	uint64 Read(uint32 addr);
+	uint64 Write(uint32 addr, uint32 data);
+	uint64 Peek(uint32 addr);
 
  private:
 	uint32 ReadStatus();