--- nono/vm/sysport.h	2026/04/29 17:04:28	1.1.1.1
+++ nono/vm/sysport.h	2026/04/29 17:04:32	1.1.1.2
@@ -41,5 +41,8 @@ class SysportDevice
 	virtual uint64 Peek8(uint32 addr);
 
  private:
+	// アドレスデコーダ
+	uint64 Decoder(uint32 addr) const;
+
 	struct SYSPORT sysport {};
 };