From 851a4f7ad71756046c5c37781b67a1c95fd90891 Mon Sep 17 00:00:00 2001
From: qeed <qeed@users.sf.net>
Date: Sat, 13 Jun 2009 17:40:42 +0000
Subject: [PATCH] Fix ATX opcode in the CPU, no timing changes, just a small
 behavior change (unofficial opcode 0xAB)

---
 src/ops.inc | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/ops.inc b/src/ops.inc
index 0d66b632..1524d615 100644
--- a/src/ops.inc
+++ b/src/ops.inc
@@ -343,8 +343,9 @@ case 0x6B: {
 /* ASR */
 case 0x4B: LD_IM(AND;LSRA);
 
-/* ATX(OAL) Is this(OR with $EE) correct? */
-case 0xAB: LD_IM(_A|=0xEE;AND;_X=_A);
+/* ATX(OAL) Is this(OR with $EE) correct? Blargg did some test
+   and found the constant to be OR with is $FF for NES */
+case 0xAB: LD_IM(_A|=0xFF;AND;_X=_A);
 
 /* AXS */ 
 case 0xCB: LD_IM(AXS);