--- nono/vm/bt454.h	2026/04/29 17:04:28	1.1
+++ nono/vm/bt454.h	2026/04/29 17:04:31	1.1.1.2
@@ -57,17 +57,16 @@ class BT454Device
 
 	virtual void ResetHard();
 
-	virtual uint64 Read8(uint32 addr);
-	virtual uint64 Read16(uint32 addr);
-	virtual uint64 Read32(uint32 addr);
-	virtual uint64 Write8(uint32 addr, uint32 data);
-	virtual uint64 Write16(uint32 addr, uint32 data);
-	virtual uint64 Write32(uint32 addr, uint32 data);
-	virtual uint64 Peek8(uint32 addr);
-
 	// ホストパレットのアドレスを取得
 	const uint8 *GetHostPalette() const { return reg.hostcolor; }
 
+ 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:
 	// レジスタ値からホストパレットを作成
 	void MakeHostColor(int addr);
@@ -80,4 +79,4 @@ class BT454Device
 	static const char rgbstr[3];
 };
 
-extern BT454Device *gBT454;
+extern std::unique_ptr<BT454Device> gBT454;