--- nono/vm/upd7201.h	2026/04/29 17:04:32	1.1.1.2
+++ 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);