--- z80pack-1.17/z80sim/sim4.c	2008-10-20 22:02:11.000000000 +0200
+++ z80pack-1.18/z80sim/sim4.c	2010-03-31 13:45:51.000000000 +0200
@@ -1329,7 +1329,7 @@
 	fp_sampleLightGroup(0, 0);
 #endif
 	i = *(ram + ((H << 8) + L));
-	((i & 0xf) > (A & 0xF)) ? (F |= H_FLAG) : (F &= ~H_FLAG);
+	((i & 0xf) > (A & 0xf)) ? (F |= H_FLAG) : (F &= ~H_FLAG);
 	i = A -	i;
 	L++;
 	if (!L)
@@ -1345,12 +1345,12 @@
 }
 
 static int op_cpir(void)	/* CPIR */
-				/* H Flag not set!!! */
 {
 	register int t	= -21;
 	register BYTE *s;
 	register BYTE d;
 	register WORD i;
+	register BYTE tmp;
 
 	i = (B << 8) + C;
 	s = ram	+ (H <<	8) + L;
@@ -1361,7 +1361,9 @@
 #ifdef FRONTPANEL
 		fp_sampleLightGroup(0, 0);
 #endif
-		d = A -	*s++;
+		tmp = *s++;
+		((tmp & 0xf) > (A & 0xf)) ? (F |= H_FLAG) : (F &= ~H_FLAG);
+		d = A -	tmp;
 		t += 21;
 	} while	(--i &&	d);
 	F |= N_FLAG;
@@ -1386,7 +1388,7 @@
 	fp_sampleLightGroup(0, 0);
 #endif
 	i = *(ram + ((H << 8) + L));
-	((i & 0xf) > (A & 0xF)) ? (F |= H_FLAG) : (F &= ~H_FLAG);
+	((i & 0xf) > (A & 0xf)) ? (F |= H_FLAG) : (F &= ~H_FLAG);
 	i = A -	i;
 	L--;
 	if (L == 0xff)
@@ -1402,12 +1404,12 @@
 }
 
 static int op_cpdr(void)	/* CPDR */
-				/* H Flag not set!!! */
 {
 	register int t	= -21;
 	register BYTE *s;
 	register BYTE d;
 	register WORD i;
+	register BYTE tmp;
 
 	i = (B << 8) + C;
 	s = ram	+ (H <<	8) + L;
@@ -1418,7 +1420,9 @@
 #ifdef FRONTPANEL
 		fp_sampleLightGroup(0, 0);
 #endif
-		d = A -	*s--;
+		tmp = *s--;
+		((tmp & 0xf) > (A & 0xf)) ? (F |= H_FLAG) : (F &= ~H_FLAG);
+		d = A -	tmp;
 		t += 21;
 	} while	(--i &&	d);
 	F |= N_FLAG;