--- nono/vm/sio.h	2026/04/29 17:04:28	1.1.1.1
+++ nono/vm/sio.h	2026/04/29 17:04:56	1.1.1.7
@@ -1,6 +1,7 @@
 //
 // nono
-// Copyright (C) 2018 isaki@NetBSD.org
+// Copyright (C) 2020 nono project
+// Licensed under nono-license.txt
 //
 
 #pragma once
@@ -8,25 +9,25 @@
 #include "device.h"
 #include "upd7201.h"
 
-class SIODevice
-	: public uPD7201Device
+class SIODevice : public uPD7201Device
 {
-	typedef uPD7201Device inherited;
+	using inherited = uPD7201Device;
  public:
 	SIODevice();
-	virtual ~SIODevice();
+	virtual ~SIODevice() override;
 
-	virtual void ResetHard();
-
-	virtual uint64 Read8(uint32);
-	virtual uint64 Read16(uint32);
-	virtual uint64 Write8(uint32, uint32);
-	virtual uint64 Write16(uint32, uint32);
-
-	void RxCh1(int);
+	// BusIO インタフェース
+	// (内蔵 ROM からのアクセス用に特別に public にしてある)
+	uint64 Read(uint32 offset);
+	uint64 Write(uint32 offset, uint32 data);
+
+ protected:
+	// BusIO インタフェース
+	static const uint32 NPORT = 4;
+	uint64 Peek(uint32 offset);
 
  private:
-	virtual void Interrupt();
+	void Interrupt() override;
 };
 
-extern SIODevice *gSIO;
+extern std::unique_ptr<SIODevice> gSIO;