--- nono/vm/busio.h	2026/04/29 17:04:35	1.1.1.2
+++ nono/vm/busio.h	2026/04/29 17:05:25	1.1.1.8
@@ -7,48 +7,54 @@
 // バスとデバイスとのインタフェース。
 // バスに対し、デバイスがどのように接続されているかを記述する。
 
+#pragma once
+
 #if !defined(SELFTEST)
 #include "device.h"
 #endif
 
 // バイトデバイスをバイト、ワード、ロングワードポートにミラー配置する共通部
 template <class T, int rshift>
-class BusIO_B_Base: public T
+class BusIO_B_Base : public T
 {
- private:
+ protected:
 	inline uint32 Decoder(uint32 addr) {
 		return (addr >> rshift) & (T::NPORT - 1);
 	}
 
  public:
-	uint64 Read8(uint32 addr) override {
+	busdata Read8(uint32 addr) override {
 		return T::Read(Decoder(addr));
 	}
 
-	uint64 Write8(uint32 addr, uint32 data) override {
+	busdata Write8(uint32 addr, uint32 data) override {
 		return T::Write(Decoder(addr), data);
 	}
 
-	uint64 Peek8(uint32 addr) override {
+	busdata Peek8(uint32 addr) override {
 		return T::Peek(Decoder(addr));
 	}
+
+	bool Poke8(uint32 addr, uint32 data) override {
+		return T::Poke(Decoder(addr), data);
+	}
 };
 
 // バイトデバイスをバイトのまま配置する。
 // NPORT によるミラーを行う以外はこれを使わないのと何も変わらない。
 template <class T>
-class BusIO_B: public BusIO_B_Base<T, 0> { };
+class BusIO_B : public BusIO_B_Base<T, 0> { };
 // バイトデバイスをワードにミラー配置する。
 template <class T>
-class BusIO_BB: public BusIO_B_Base<T, 1> { };
+class BusIO_BB : public BusIO_B_Base<T, 1> { };
 // バイトデバイスをロングワードにミラー配置する。
 template <class T>
-class BusIO_BBBB: public BusIO_B_Base<T, 2> { };
+class BusIO_BBBB : public BusIO_B_Base<T, 2> { };
 
 // ワードデバイスをワードのまま配置する。
 // NPORT によるミラーを行う以外はこれを使わないのと何も変わらない。
 template <class T>
-class BusIO_W: public T
+class BusIO_W : public T
 {
  private:
 	inline uint32 Decoder(uint32 addr) {
@@ -56,32 +62,32 @@ class BusIO_W: public T
 	}
 
  public:
-	uint64 Read8(uint32 addr) override {
+	// ワードポートからのバイト読み込みはワードで読んだ後必要な方を取る。
+	busdata Read8(uint32 addr) override {
 		if ((addr & 1) == 0) {
-			return T::Read(Decoder(addr)) >> 8;
+			busdata data = T::Read(Decoder(addr));
+			data >>= 8;
+			return data;
 		} else {
-			return T::Read(Decoder(addr)) & 0xff;
+			busdata data = T::Read(Decoder(addr));
+			data &= 0xff;
+			return data;
 		}
 	}
-	uint64 Read16(uint32 addr) override {
+	busdata Read16(uint32 addr) override {
 		return T::Read(Decoder(addr));
 	}
 
-	uint64 Write8(uint32 addr, uint32 data) override {
-		uint32 offset = Decoder(addr);
-		uint32 old = T::Read(offset);
-		if ((addr & 1) == 0) {
-			return T::Write(offset, ((data << 8) & 0xff00) | (old & 0x00ff));
-		} else {
-			return T::Write(offset, (old & 0xff00) | (data & 0x00ff));
-		}
+	// ワードポートにバイト書き込みするとデータバスは OP3 OP3 OP3 OP3。
+	busdata Write8(uint32 addr, uint32 data) override {
+		data |= data << 8;
+		return T::Write(Decoder(addr), data);
 	}
-	uint64 Write16(uint32 addr, uint32 data) override {
+	busdata Write16(uint32 addr, uint32 data) override {
 		return T::Write(Decoder(addr), data);
 	}
 
-
-	uint64 Peek8(uint32 addr) override {
+	busdata Peek8(uint32 addr) override {
 		if ((addr & 1) == 0) {
 			return T::Peek(Decoder(addr)) >> 8;
 		} else {
@@ -91,12 +97,12 @@ class BusIO_W: public T
 };
 
 /* XXX: stub
-class BusIO_L: public T
+class BusIO_L : public T
 */
 
 // バイトデバイスを偶数アドレスに配置し、奇数アドレスはバスエラー。
 template <class T>
-class BusIO_BE: public T
+class BusIO_BE : public T
 {
  private:
 	inline uint32 Decoder(uint32 addr) {
@@ -104,40 +110,43 @@ class BusIO_BE: public T
 	}
 
  public:
-	uint64 Read8(uint32 addr) override {
+	busdata Read8(uint32 addr) override {
 		if ((addr & 1) == 0) {
 			return T::Read(Decoder(addr));
 		} else {
-			return (int64)-1;
+			return busdata::BusErr;
 		}
 	}
-	uint64 Read16(uint32 addr) override {
-		return (T::Read(Decoder(addr)) << 8) | 0xff;
+	busdata Read16(uint32 addr) override {
+		busdata data = T::Read(Decoder(addr));
+		data <<= 8;
+		data |= 0xff;
+		return data;
 	}
 
-	uint64 Write8(uint32 addr, uint32 data) override {
+	busdata Write8(uint32 addr, uint32 data) override {
 		if ((addr & 1) == 0) {
 			return T::Write(Decoder(addr), data);
 		} else {
-			return (int64)-1;
+			return busdata::BusErr;
 		}
 	}
-	uint64 Write16(uint32 addr, uint32 data) override {
+	busdata Write16(uint32 addr, uint32 data) override {
 		return T::Write(Decoder(addr), data >> 8);
 	}
 
-	uint64 Peek8(uint32 addr) override {
+	busdata Peek8(uint32 addr) override {
 		if ((addr & 1) == 0) {
 			return T::Peek(Decoder(addr));
 		} else {
-			return (int64)-1;
+			return busdata::BusErr;
 		}
 	}
 };
 
 // バイトデバイスを奇数アドレスに配置し、偶数アドレスはバスエラー。
 template <class T>
-class BusIO_EB: public T
+class BusIO_EB : public T
 {
  private:
 	inline uint32 Decoder(uint32 addr) {
@@ -145,31 +154,33 @@ class BusIO_EB: public T
 	}
 
  public:
-	uint64 Read8(uint32 addr) override {
+	busdata Read8(uint32 addr) override {
 		if ((addr & 1) == 0) {
-			return (int64)-1;
+			return busdata::BusErr;
 		} else {
 			return T::Read(Decoder(addr));
 		}
 	}
-	uint64 Read16(uint32 addr) override {
-		return T::Read(Decoder(addr)) | 0xff00;
+	busdata Read16(uint32 addr) override {
+		busdata data = T::Read(Decoder(addr));
+		data |= 0xff00;
+		return data;
 	}
 
-	uint64 Write8(uint32 addr, uint32 data) override {
+	busdata Write8(uint32 addr, uint32 data) override {
 		if ((addr & 1) == 0) {
-			return (int64)-1;
+			return busdata::BusErr;
 		} else {
 			return T::Write(Decoder(addr), data);
 		}
 	}
-	uint64 Write16(uint32 addr, uint32 data) override {
+	busdata Write16(uint32 addr, uint32 data) override {
 		return T::Write(Decoder(addr), data & 0xff);
 	}
 
-	uint64 Peek8(uint32 addr) override {
+	busdata Peek8(uint32 addr) override {
 		if ((addr & 1) == 0) {
-			return (int64)-1;
+			return busdata::BusErr;
 		} else {
 			return T::Peek(Decoder(addr));
 		}
@@ -178,7 +189,7 @@ class BusIO_EB: public T
 
 // バイトデバイスを奇数アドレスに配置し、偶数アドレスは非接続。
 template <class T>
-class BusIO_FB: public T
+class BusIO_FB : public T
 {
  private:
 	inline uint32 Decoder(uint32 addr) {
@@ -186,29 +197,31 @@ class BusIO_FB: public T
 	}
 
  public:
-	uint64 Read8(uint32 addr) override {
+	busdata Read8(uint32 addr) override {
 		if ((addr & 1) == 0) {
 			return 0xff;
 		} else {
 			return T::Read(Decoder(addr));
 		}
 	}
-	uint64 Read16(uint32 addr) override {
-		return T::Read(Decoder(addr)) | 0xff00;
+	busdata Read16(uint32 addr) override {
+		busdata data = T::Read(Decoder(addr));
+		data |= 0xff00;
+		return data;
 	}
 
-	uint64 Write8(uint32 addr, uint32 data) override {
+	busdata Write8(uint32 addr, uint32 data) override {
 		if ((addr & 1) == 0) {
 			return 0;
 		} else {
 			return T::Write(Decoder(addr), data);
 		}
 	}
-	uint64 Write16(uint32 addr, uint32 data) override {
+	busdata Write16(uint32 addr, uint32 data) override {
 		return T::Write(Decoder(addr), data & 0xff);
 	}
 
-	uint64 Peek8(uint32 addr) override {
+	busdata Peek8(uint32 addr) override {
 		if ((addr & 1) == 0) {
 			return 0xff;
 		} else {
@@ -219,118 +232,101 @@ class BusIO_FB: public T
 
 // バイトデバイスをロングワードの先頭に配置し、他は非接続。
 template <class T>
-class BusIO_BFFF: public T
+class BusIO_BFFF : public T
 {
- private:
+ protected:
 	inline uint32 Decoder(uint32 addr) {
 		return (addr >> 2) & (T::NPORT - 1);
 	}
 
  public:
-	uint64 Read8(uint32 addr) override {
+	busdata Read8(uint32 addr) override {
 		if ((addr & 3) == 0) {
 			return T::Read(Decoder(addr));
 		} else {
 			return 0xff;
 		}
 	}
-	uint64 Read16(uint32 addr) override {
+	busdata Read16(uint32 addr) override {
 		if ((addr & 2) == 0) {
-			return (T::Read(Decoder(addr)) << 8) | 0xff;
+			busdata data = T::Read(Decoder(addr));
+			data <<= 8;
+			data |= 0xff;
+			return data;
 		} else {
 			return 0xffff;
 		}
 	}
-	uint64 Read32(uint32 addr) override {
-		return (T::Read(Decoder(addr)) << 24) | 0x00ffffff;
+	busdata Read32(uint32 addr) override {
+		busdata data = T::Read(Decoder(addr));
+		data <<= 24;
+		data |= 0x00ffffff;
+		return data;
 	}
 
-	uint64 Write8(uint32 addr, uint32 data) override {
+	busdata Write8(uint32 addr, uint32 data) override {
 		if ((addr & 3) == 0) {
 			return T::Write(Decoder(addr), data);
 		} else {
 			return 0;
 		}
 	}
-	uint64 Write16(uint32 addr, uint32 data) override {
+	busdata Write16(uint32 addr, uint32 data) override {
 		if ((addr & 2) == 0) {
 			return T::Write(Decoder(addr), data >> 8);
 		} else {
 			return 0;
 		}
 	}
-	uint64 Write32(uint32 addr, uint32 data) override {
+	busdata Write32(uint32 addr, uint32 data) override {
 		return T::Write(Decoder(addr), data >> 24);
 	}
 
-	uint64 Peek8(uint32 addr) override {
+	busdata Peek8(uint32 addr) override {
 		if ((addr & 3) == 0) {
 			return T::Peek(Decoder(addr));
 		} else {
 			return 0xff;
 		}
 	}
-};
 
-// ワードデバイスをロングワードにミラー配置する。
-template <class T>
-class BusIO_WW: public T
-{
- private:
-	inline uint32 Decoder(uint32 addr) {
-		return (addr >> 2) & (T::NPORT - 1);
-	}
- public:
-	uint64 Read8(uint32 addr) override {
-		if ((addr & 1) == 0) {
-			return T::Read(Decoder(addr)) >> 8;
-		} else {
-			return T::Read(Decoder(addr)) & 0xff;
-		}
-	}
-	uint64 Read16(uint32 addr) override {
-		return T::Read(Decoder(addr));
-	}
-
-	uint64 Write8(uint32 addr, uint32 data) override {
-		PANIC("not implemented\n");
-		return (int64)-1;	// XXX 未確認
-	}
-	uint64 Write16(uint32 addr, uint32 data) override {
-		return T::Write(Decoder(addr), data);
-	}
-
-	uint64 Peek8(uint32 addr) override {
-		if ((addr & 1) == 0) {
-			return T::Peek(Decoder(addr)) >> 8;
+	bool Poke8(uint32 addr, uint32 data) override {
+		if ((addr & 3) == 0) {
+			return T::Poke(Decoder(addr), data);
 		} else {
-			return T::Peek(Decoder(addr)) & 0xff;
+			// 非接続なので、書き換えようとしてもエラーも起きず何も起きない。
+			return true;
 		}
 	}
 };
 
 // ワードデバイスをロングワード先頭に配置し、他は非接続。
 template <class T>
-class BusIO_WF: public T
+class BusIO_WF : public T
 {
  private:
 	inline uint32 Decoder(uint32 addr) {
 		return (addr >> 2) & (T::NPORT - 1);
 	}
  public:
-	uint64 Read8(uint32 addr) override {
+	busdata Read8(uint32 addr) override {
+		busdata data;
 		switch (addr & 3) {
 		 case 0:
-			return T::Read(Decoder(addr)) >> 8;
+			data = T::Read(Decoder(addr));
+			data >>= 8;
+			return data;
 		 case 1:
-			return T::Read(Decoder(addr)) & 0xff;
+			data = T::Read(Decoder(addr));
+			data &= 0xff;
+			return data;
 		 case 2:
 		 case 3:
 			return 0xff;
 		}
 		__unreachable();
 	}
-	uint64 Read16(uint32 addr) override {
+	busdata Read16(uint32 addr) override {
 		if ((addr & 2) == 0) {
 			return T::Read(Decoder(addr));
 		} else {
@@ -338,18 +334,23 @@ class BusIO_WF: public T
 		}
 	}
 
-	uint64 Write8(uint32 addr, uint32 data) override {
-		PANIC("not implemented\n");
-		return 0;	// XXX 未確認
+	// バイト書き込みならデータバスは OP3 OP3 OP3 OP3。
+	busdata Write8(uint32 addr, uint32 data) override {
+		if ((addr & 2) == 0) {
+			data |= data << 8;
+			return T::Write(Decoder(addr), data);
+		} else {
+			return 0;
+		}
 	}
-	uint64 Write16(uint32 addr, uint32 data) override {
+	busdata Write16(uint32 addr, uint32 data) override {
 		if ((addr & 2) == 0) {
 			return T::Write(Decoder(addr), data);
 		} else {
 			return 0;
 		}
 	}
-	uint64 Peek8(uint32 addr) override {
+	busdata Peek8(uint32 addr) override {
 		switch (addr & 3) {
 		 case 0:
 			return T::Peek(Decoder(addr)) >> 8;
@@ -372,15 +373,15 @@ template <class T>
 class BusIO_X68kSPC : public T
 {
  private:
-	inline uint64 Decoder(uint32 addr) {
+	inline uint32 Decoder(uint32 addr) {
 		// SASI 跡地と SCSI を合わせて 0x40 バイトでミラーしている
 		return (addr >> 1) & (0x20 - 1);
 	}
 
  public:
-	uint64 Read8(uint32 addr) override {
+	busdata Read8(uint32 addr) override {
 		if ((addr & 1) == 0) {
-			return (uint64)-1;
+			return busdata::BusErr;
 		} else {
 			addr = Decoder(addr);
 			if (addr < 0x10) {
@@ -392,19 +393,21 @@ class BusIO_X68kSPC : public T
 			}
 		}
 	}
-	uint64 Read16(uint32 addr) override {
+	busdata Read16(uint32 addr) override {
 		addr = Decoder(addr);
 		if (addr < 0x10) {
 			// 前半16ポートは SASI 跡地
 			return 0xffff;
 		} else {
-			return T::Read(addr - 0x10) | 0xff00;
+			busdata data = T::Read(addr - 0x10);
+			data |= 0xff00;
+			return data;
 		}
 	}
 
-	uint64 Write8(uint32 addr, uint32 data) override {
+	busdata Write8(uint32 addr, uint32 data) override {
 		if ((addr & 1) == 0) {
-			return (uint64)-1;
+			return busdata::BusErr;
 		} else {
 			addr = Decoder(addr);
 			if (addr < 0x10) {
@@ -417,7 +420,7 @@ class BusIO_X68kSPC : public T
 			}
 		}
 	}
-	uint64 Write16(uint32 addr, uint32 data) override {
+	busdata Write16(uint32 addr, uint32 data) override {
 		addr = Decoder(addr);
 		if (addr < 0x10) {
 			// 前半16ポートは SASI 跡地。
@@ -429,9 +432,9 @@ class BusIO_X68kSPC : public T
 		}
 	}
 
-	uint64 Peek8(uint32 addr) override {
+	busdata Peek8(uint32 addr) override {
 		if ((addr & 1) == 0) {
-			return (uint64)-1;
+			return busdata::BusErr;
 		} else {
 			addr = Decoder(addr);
 			if (addr < 0x10) {