--- nono/vm/crtc.h	2026/04/29 17:05:17	1.1.1.9
+++ nono/vm/crtc.h	2026/04/29 17:05:28	1.1.1.11
@@ -81,7 +81,10 @@ struct CRTC
 	//     +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
 	// R23 |                          マスクパターン                       |
 	//     +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
-	// R24 |                       -                       |RC | 0 |FC |VI |
+	//
+	//      15  14  13  12  11  10   9   8   7   6   5   4   3   2   1   0
+	//     +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
+	// OP  |                       -                       |RC | 0 |FC |VI |
 	//     +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
 
 	uint16 r[24];
@@ -133,19 +136,20 @@ class CRTCDevice : public IODevice
 	using inherited = IODevice;
  public:
 	CRTCDevice();
-	virtual ~CRTCDevice() override;
+	~CRTCDevice() override;
 
 	bool Init() override;
 	void ResetHard(bool poweron) override;
 
- protected:
-	// BusIO インタフェース
-	static const uint NPORT = 0x800;
-	uint64 Read(uint32 offset);
-	uint64 Write(uint32 offset, uint32 data);
-	uint64 Peek(uint32 offset);
+	busdata Read(busaddr addr) override;
+	busdata Write(busaddr addr, uint32 data) override;
+	busdata Peek1(uint32 offset) override;
 
  private:
+	static inline uint32 Decoder(uint32 addr);
+
+	// ワード読み出し
+	busdata Peek2(uint32 addr) const;
 	// レジスタへの書き込み
 	void SetReg(uint32 offset, uint32 data);
 	// 動作ポートへの書き込み