--- nono/vm/upd7201.h	2026/04/29 17:04:28	1.1.1.1
+++ nono/vm/upd7201.h	2026/04/29 17:04:36	1.1.1.3
@@ -1,6 +1,7 @@
 //
 // nono
-// Copyright (C) 2018 isaki@NetBSD.org
+// Copyright (C) 2020 nono project
+// Licensed under nono-license.txt
 //
 
 #pragma once
@@ -213,12 +214,12 @@ struct SIO
 class uPD7201Device
 	: public IODevice
 {
-	typedef IODevice inherited;
+	using inherited = IODevice;
  public:
 	uPD7201Device();
-	virtual ~uPD7201Device();
+	~uPD7201Device() override;
 
-	virtual bool MonitorUpdate();
+	bool MonitorUpdate() override;
 
 	// 受信
 	bool Rx(int ch, uint32 data);
@@ -229,9 +230,11 @@ class uPD7201Device
 
 	void ResetChannel(struct SIO::channel *chan);
 	virtual uint8 ReadCtrl(struct SIO::channel *chan);
-	uint8 ReadData(int ch);
+	uint8 ReadData(struct SIO::channel *chan);
 	virtual void WriteCtrl(struct SIO::channel *chan, uint32 data);
 	void WriteData(struct SIO::channel *chan, uint32 data);
+	uint8 PeekCtrl(const struct SIO::channel *chan) const;
+	uint8 PeekData(const struct SIO::channel *chan) const;
 
 	// 割り込みを上げる (上位デバイスで用意する)
 	virtual void Interrupt() = 0;
@@ -241,6 +244,9 @@ class uPD7201Device
 	static const int bits_per_char[4];
 
  private:
+	uint8 ReadSR0(const struct SIO::channel *chan) const;
+	uint8 ReadSR1(const struct SIO::channel *chan) const;
+
 	void MonitorUpdateCh(int ch, int xbase, int ybase);
 	void MonitorReg(int, int, uint32 reg, const char * const *names);
 };