--- nono/vm/crtc.cpp	2026/04/29 17:04:41	1.1.1.5
+++ nono/vm/crtc.cpp	2026/04/29 17:04:50	1.1.1.6
@@ -48,31 +48,31 @@ CRTCDevice::ResetHard()
 }
 
 uint64
-CRTCDevice::Read(uint32 addr)
+CRTCDevice::Read(uint32 offset)
 {
 	uint64 data;
 
 	gMPU->AddCycle(9);	// InsideOut p.135
 
-	if (addr < 0x400 / 2) {		// CRTC レジスタ
+	if (offset < 0x400 / 2) {		// CRTC レジスタ
 		// 0x40 バイトでミラー
-		addr &= (0x40 / 2) - 1;
+		offset &= (0x40 / 2) - 1;
 		// R20, R21 のみ読み出し可能
-		switch (addr) {
+		switch (offset) {
 		 case 20:
-			data = crtc.r[addr];
-			putlog(2, "R%02d -> $%04x", addr, (uint32)data);
+			data = crtc.r[offset];
+			putlog(2, "R%02d -> $%04x", offset, (uint32)data);
 			break;
 		 case 21:
 			// R21 へのアクセスは多いのでログレベルを上げておく
-			data = crtc.r[addr];
-			putlog(3, "R%02d -> $%04x", addr, (uint32)data);
+			data = crtc.r[offset];
+			putlog(3, "R%02d -> $%04x", offset, (uint32)data);
 			break;
 		 default:
 			// それ以外は読み出し不可 ($00 が読める)
 			data = 0;
-			if (addr < countof(crtc.r)) {
-				putlog(3, "R%02d -> $%04x", addr, (uint32)data);
+			if (offset < countof(crtc.r)) {
+				putlog(3, "R%02d -> $%04x", offset, (uint32)data);
 			} else {
 				putlog(3, "$%06x -> $%04x", gMPU->GetPaddr(), (uint32)data);
 			}
@@ -80,9 +80,9 @@ CRTCDevice::Read(uint32 addr)
 		}
 
 	} else {					// 動作ポート
-		if ((addr & (0x80 / 2)) == 0) {	// +$00..+$7f
+		if ((offset & (0x80 / 2)) == 0) {	// +$00..+$7f
 			data = (uint64)-1;
-		} else {						// +$80..+$ff
+		} else {							// +$80..+$ff
 			data = crtc.op;
 		}
 	}
@@ -91,22 +91,22 @@ CRTCDevice::Read(uint32 addr)
 }
 
 uint64
-CRTCDevice::Write(uint32 addr, uint32 data)
+CRTCDevice::Write(uint32 offset, uint32 data)
 {
 	gMPU->AddCycle(9);	// InsideOut p.135
 
-	if (addr < 0x400 / 2) {		// CRTC レジスタ
+	if (offset < 0x400 / 2) {		// CRTC レジスタ
 		// 0x40 バイトでミラー
-		addr &= (0x40 / 2) - 1;
-		if (addr < countof(crtc.r)) {
-			SetReg(addr, data);
+		offset &= (0x40 / 2) - 1;
+		if (offset < countof(crtc.r)) {
+			SetReg(offset, data);
 		} else {
 			// ここ何がいるんだ?
 			putlog(2, "$%06x <- $%04x", gMPU->GetPaddr(), data);
 		}
 
 	} else {					// 動作ポート
-		if ((addr & (0x80 / 2)) == 0) {	// +$00..+$7f
+		if ((offset & (0x80 / 2)) == 0) {	// +$00..+$7f
 			return (uint64)-1;
 		} else {
 			crtc.op = data & 0x0b;
@@ -118,22 +118,22 @@ CRTCDevice::Write(uint32 addr, uint32 da
 }
 
 uint64
-CRTCDevice::Peek(uint32 addr)
+CRTCDevice::Peek(uint32 offset)
 {
 	uint64 data;
 
-	if (addr < 0x400 / 2) {		// CRTC レジスタ
+	if (offset < 0x400 / 2) {		// CRTC レジスタ
 		// 0x40 バイトでミラー
-		addr &= (0x40 / 2) - 1;
-		if (addr == 20 || addr == 21) {
+		offset &= (0x40 / 2) - 1;
+		if (offset == 20 || offset == 21) {
 			// R20, R21 のみ読み出し可能
-			data = crtc.r[addr];
+			data = crtc.r[offset];
 		} else {
 			data = 0;
 		}
 
 	} else {					// 動作ポート
-		if ((addr & (0x80 / 2)) == 0) {
+		if ((offset & (0x80 / 2)) == 0) {
 			data = (uint64)-1;
 		} else {
 			data = crtc.op;