--- nono/vm/pluto.cpp	2026/04/29 17:05:21	1.1.1.10
+++ nono/vm/pluto.cpp	2026/04/29 17:05:25	1.1.1.11
@@ -60,7 +60,7 @@ PlutoDevice::rom[] = {
 	0x2e00,					//	.dc.b	".",0
 };
 
-uint64
+busdata
 PlutoDevice::Read8(uint32 addr)
 {
 	uint32 offset = addr - baseaddr;
@@ -75,10 +75,10 @@ PlutoDevice::Read8(uint32 addr)
 		}
 	}
 
-	return (uint64)-1;
+	return busdata::BusErr;
 }
 
-uint64
+busdata
 PlutoDevice::Read16(uint32 addr)
 {
 	uint32 offset = addr - baseaddr;
@@ -87,10 +87,10 @@ PlutoDevice::Read16(uint32 addr)
 		return rom[offset / 2];
 	}
 
-	return (uint64)-1;
+	return busdata::BusErr;
 }
 
-uint64
+busdata
 PlutoDevice::Read32(uint32 addr)
 {
 	uint32 offset = addr - baseaddr;
@@ -108,10 +108,10 @@ PlutoDevice::Read32(uint32 addr)
 	 default:
 		break;
 	}
-	return (uint64)-1;
+	return busdata::BusErr;
 }
 
-uint64
+busdata
 PlutoDevice::Write8(uint32 addr, uint32 data)
 {
 	switch (addr) {
@@ -125,14 +125,14 @@ PlutoDevice::Write8(uint32 addr, uint32
 	return 0;
 }
 
-uint64
+busdata
 PlutoDevice::Write16(uint32 addr, uint32 data)
 {
 	putlog(0, "未実装ワード書き込み $%06x", addr);
 	return 0;
 }
 
-uint64
+busdata
 PlutoDevice::Peek8(uint32 addr)
 {
 	uint32 offset = addr - baseaddr;
@@ -147,7 +147,7 @@ PlutoDevice::Peek8(uint32 addr)
 		}
 	}
 
-	return (uint64)-1;
+	return busdata::BusErr;
 }
 
 //
@@ -164,12 +164,12 @@ PlutoDevice::ROM_Load()
 
 	auto mainbus = GetMainbusDevice();
 	auto mainram = GetMainRAMDevice();
-	auto mpu680x0 = GetMPU680x0Device();
+	auto mpu680x0 = GetMPU680x0Device(mpu);
 	auto sram = GetSRAMDevice();
 
 	// ホストファイルをロード
 	LoadInfo info(gMainApp.exec_file);
-	if (mainram->LoadFromFile(&info) == false) {
+	if (mainram->LoadExec(&info) == false) {
 		return -1;
 	}
 
@@ -204,15 +204,15 @@ PlutoDevice::ROM_Load()
 	mpu680x0->reg.D[6] = 0xa1000004;
 	mpu680x0->reg.D[7] = 0;
 
-	mpu680x0->reg.A[7] = sram->GetRAMSize();
-	mpu680x0->reg.A[7] -= 4;
-	mainbus->Write32(mpu680x0->reg.A[7], info.end - info.start);	// esym
+	uint32 a7 = sram->GetRAMSize();
+	a7 -= 4;
+	mainbus->HVWrite32(a7, info.end - info.start);	// esym
+	a7 -= 4;
+	mainbus->HVWrite32(a7, sram->GetRAMSize());		// physsize
+	a7 -= 4;
+	mainbus->HVWrite32(a7, 0x00000000);				// firstpa
 
-	mpu680x0->reg.A[7] -= 4;
-	mainbus->Write32(mpu680x0->reg.A[7], sram->GetRAMSize());	// physsize
-
-	mpu680x0->reg.A[7] -= 4;
-	mainbus->Write32(mpu680x0->reg.A[7], 0x00000000);			// firstpa
+	mpu680x0->reg.A[7] = a7;
 
 	return info.entry;
 }