--- nono/m88xx0/m88100subr.cpp	2026/04/29 17:04:58	1.1.1.8
+++ nono/m88xx0/m88100subr.cpp	2026/04/29 17:05:05	1.1.1.9
@@ -20,9 +20,10 @@ m88kcpu::m88kcpu()
 	for (int i = 1; i < 32; i++) {
 		r[i] = Undefined;
 	}
-	for (int i = 1; i < 9; i++) {
-		fcr[i] = Undefined;
+	for (int i = 0; i < countof(fcr); i++) {
+		fcr[i] = Undefined & fcr_mask[i];
 	}
+
 	epsr = Undefined;
 	ssbr = Undefined;
 	sfip = Undefined;
@@ -35,7 +36,6 @@ m88kcpu::m88kcpu()
 	dmd0 = Undefined;
 	dmd1 = Undefined;
 	dmd2 = Undefined;
-
 }
 
 // デストラクタ
@@ -84,6 +84,21 @@ m88kcpu::SetVersion(uint32 version)
 	pid |= version << 1;
 }
 
+// fcr のマスク
+/*static*/ const uint32 m88100reg::fcr_mask[11] = {
+	FPECR_MASK,
+	0xffffffff,	// fphs1
+	0xffffffff,	// fpls1
+	0xffffffff,	// fphs2
+	0xffffffff,	// fpls2
+	FPPT_MASK,
+	FPRH_MASK,
+	0xffffffff,	// fprl
+	FPIT_MASK,
+	FPSR_MASK,
+	FPCR_MASK,
+};
+
 /*static*/ const char * const m88100reg::sipname[3] = {
 	"sxip", "snip", "sfip",
 };