--- nono/vm/subram.cpp	2026/04/29 17:05:18	1.1.1.1
+++ nono/vm/subram.cpp	2026/04/29 17:05:25	1.1.1.2
@@ -43,14 +43,14 @@ SubRAMBaseDevice::ResetHard(bool poweron
 }
 
 // アドレスデコーダ
-inline uint64
+inline uint32
 SubRAMBaseDevice::Decoder(uint32 addr) const
 {
 	// たぶん 128KB というかサイズ分で折り返しイメージが見えるはず。要確認。
 	return addr % ramsize;
 }
 
-uint64
+busdata
 SubRAMBaseDevice::Read8(uint32 addr)
 {
 	uint32 offset = Decoder(addr);
@@ -59,7 +59,7 @@ SubRAMBaseDevice::Read8(uint32 addr)
 	return data;
 }
 
-uint64
+busdata
 SubRAMBaseDevice::Read16(uint32 addr)
 {
 	uint32 offset = Decoder(addr);
@@ -70,7 +70,7 @@ SubRAMBaseDevice::Read16(uint32 addr)
 	return data;
 }
 
-uint64
+busdata
 SubRAMBaseDevice::Read32(uint32 addr)
 {
 	uint32 offset = Decoder(addr);
@@ -83,7 +83,7 @@ SubRAMBaseDevice::Read32(uint32 addr)
 	return data;
 }
 
-uint64
+busdata
 SubRAMBaseDevice::Write8(uint32 addr, uint32 data)
 {
 	putlog(3, "$%08x.B <- $%02x", addr, data);
@@ -93,7 +93,7 @@ SubRAMBaseDevice::Write8(uint32 addr, ui
 	return 0;
 }
 
-uint64
+busdata
 SubRAMBaseDevice::Write16(uint32 addr, uint32 data)
 {
 	putlog(3, "$%08x.W <- $%04x", addr, data);
@@ -104,7 +104,7 @@ SubRAMBaseDevice::Write16(uint32 addr, u
 	return 0;
 }
 
-uint64
+busdata
 SubRAMBaseDevice::Write32(uint32 addr, uint32 data)
 {
 	putlog(3, "$%08x.L <- $%08x", addr, data);
@@ -117,21 +117,21 @@ SubRAMBaseDevice::Write32(uint32 addr, u
 	return 0;
 }
 
-uint64
+busdata
 SubRAMBaseDevice::Peek8(uint32 addr)
 {
 	uint32 offset = Decoder(addr);
 	return ram[offset];
 }
 
-uint64
+bool
 SubRAMBaseDevice::Poke8(uint32 addr, uint32 data)
 {
 	if ((int32)data >= 0) {
 		uint32 offset = Decoder(addr);
 		ram[offset] = data;
 	}
-	return 0;
+	return true;
 }